Description
Title of Invention
COMMUNICATION CONTROL DEVICE, COMlvKJNICATION CONTROL
5 METHOD, TERMINAL DEVICE, AND INFORMATION PROCESSING DEVICE
Technical Field
[000 11
The present disclosure relates to a communication control device, a
10 cotnniunication control method, a tern~inal device, and an information processing
device.
Background Art
[0002]
15 Device-to-device comtnunication (D2D communication) is com~nunication
in which two or more teniiinal devices transmit atid receive signals directly, unlike
typical cellular communication in which a base station and a terminal device transmit
and receive signals. For this reason, it is anticipated that D2D cotnmunication will
be used to create new usage scenarios for terminal devices that differ from the typical
20 cellular con~niunicationa bove. For example, various applications are conceivable,
such as itifomlation sharing by data communication betweeti nearby terminal devices
or among a group of nearby terminal devices, distribution of information from an
installed terminal device, atid autotlomous con~municationb etween tnachines, called
machine-to-niachine (M2M) conin~unication.
25 [OO03]
Additionally, it is coriceivable that D2D communicatio~w~ ill be put to
effective use in data offloading in response to the significant increase in data traffic
due to the recent increase in smartphones. For example, in recent years, there has
been a sharp rise in the need to transmit and receive video image streaming data.
30 However, since video images typically have large data sizes, there is a problem of
consumit~g many resources on a radio access network (RAN). Consequently, if
terminal devices are in a state suitable for D2D comniunication with each other, such
as when the terminal devices are a short distance away from each other, video iniage
data may be offloaded to D2D comniunication, thereby tiloderating tlie resource
consumption and processing load on a RAN. In this way, D2D conimunication
5 provides value to both telecommunications carriers and users. For this reason, D2D
cotiltnut~icationi s currently recognized as one crucial technology area for Long Tern1
Evolution (LTE), and is receiving attention from tlie 3rd Generation Partnership
Project (3GPP) standards committee.
[0004]
10 For example, Non-Patent Literature 1 discloses use cases for D2D
communication.
Citation List
Non-Patent Literature
15 [0005]
Non-Patent Literature 1: 3GPP TR 22.803, "3rd Generation Partnership
Project; Teclinical Specification Group Services and System Aspects; Feasibility
study for Proximity Services (Prose)"
20 Sun~matyo f Invention
Technical Problem
[0006]
However, for exaniple, even if a discovery signal enabling another device to
discover a device conducting D2D communication is transmitted by a terminal
25 device conducting D2D con~tnunication, the other terminal device conducting D2D
con~inunication does not how the timing at which tlie discovery signal was
transmitted, or if the discovery signal is receivable. For this reason, for exaniple,
the terniinal device transtiiits the discovery sigtial at a high frequency of repetition,
and the other tennitial device conducts a detection process for detecting the
30 discovery signal at a high frequency of repetition. As a result, the load on that other
ternlitial device may increase.
[0007]
Accordingly, it is desirable to provide a nieclianism that enables a
tnoderation of the load for a device conducting device-to-device comniutiication
(D2D comn~unication).
5
Solution to Problem
[OOOS]
According to the presetit disclosure, tliere is provided a cotnniunicatio~~
cot~trol device including: an acquisition unit configured to acquire radio frame
10 i~iformatioti~n dicating a radio frame, the radio frame being a unit time of cellular
co~i~u~unicatiofno,r transmitting a discovely signal enabling another device to
discover a device conductil~g device-to-device commnunicatiot~; and a control unit
configured to control transmission of the radio fratlie information to a terminal
device.
15 [0009]
According to the present disclosure, there is provided a comniunication
control method including: acquiring radio frame information indicating a radio frame,
the radio frame being a unit time of cellular comt~~unicationfo, r transn~itting a
discovery signal enabling another device to discover a device cot~ducti~d~evgi ce-to-
20 device comniunication; and controlling, with a processor, transmission of the radio
frame information to a tenninal device.
[OOlO]
Accordi~ig to the present disclosure, there is provided a tertnit~al device
including: an acquisition unit cotlfigured to acquire radio frame information
26 indicati~iga radio frame, the radio frame being a unit titlie of cellular con~munication,
for transmitting a discovery signal enabling another device to discover a device
conducting device-to-device comniunicatioti; and a control unit configured to control
transtnission of the discovery signal based on the radio frame infortnation.
[OOll]
30 According to the present disclosure, there is provided an informatioti
processing device including: lnernory cot~figuredt o store a program; and one or more
processors able to execute the program. The progratn causes the execution of
acquiring radio fratne illformation indicating a radio frame, the radio fiame being a
unit time of cellular co~nmunicatiot~fo, r transmitting a discovery signal e~lablitlg
another device to discover a device co~lducti~dlgev ice-to-device commu~lication,a nd
5 controlling transtnission of the discovery signal based on the radio frame infor~nation.
[0012]
According to the present disclosure, there is provided a terminal device
including: an acquisition unit cotfigured to acquire radio frame information
indicating a radio frame, the radio frame being a unit time of cellular cotnmunication,
10 for transmitting a discovery signal enabling atlother device to discover a device
conducting device-to-device communication; and a cotltrol unit configured to cotltrol
a detection process for detecting the discovery signal based on the radio fratne
information.
[0013]
15 According to the present disclosure, there is provided at1 illfortnation
processing device including: memory cot~figuredto store a program; and one or Inore
processors able to execute the program. The program causes the execution of
acquiring radio frame information indicating a radio frame, the radio frame being a
unit time of cellular communication, for transmitting a discovery signal enabling
20 another device to discover a device conducting device-to-device comn~unicationa, nd
controlling a detection process for detecting the discovery signal based on the radio
fratne information
Advantageous Effects of lnvetltiotl
25 [0014]
According to the present disclosure as described above, it becon~esp ossible
to moderate the load for a device conducting device-to-device cornmu~lication (D2D
communication). Note that the above advantageous effect is not strictly limiting,
and that any advantageous effect indicated in the present disclosure or another
30 advantageous effect that may be reasoned from the present disclosure tnay also be
exhibited in addition to, or instead of, the above advantageous effect.
Brief Description of Drawi~~gs
[0015]
[FIG. 11 FIG 1 is an explanatory diagram for illustrating an exatnple of D2D
5 con~n~u~iication.
[FIG 21 FIG 2 is an explanatory diagram illustrating an example of a schematic
configuration of a co~nn~unicatiosny stem according to an embodiment of the preseut
disclosure.
[FIG 31 FIG 3 is a block diagram illustrating an example of a configuration of a base
10 statiot~a ccording to an enlbodinient of the disclosure.
[FIG 41 FIG. 4 is an explanatory diagram for illustrating at1 exanlple ofa radio frame
for transmitting a discovery signal.
[FIG. 51 FIG 5 is a block diagram illustrating an example of a configuration of a
termiual device according to the present disclosure.
15 FIG. 61 FIG. 6 is a flowchart illustrating an example of a schematic flow of a
communication control process on the base statiot~s ide according to an embodiment
of the present disclosure.
[FIG. 71 FIG 7 is a flowchart illustrating an example of a schematic flow of a first
communicatio~~c o~~troplr ocess on the terminal device side according to an
20 enlbodiment of the present disclosure.
[FIG 81 FIG. 8 is a flowchart illustrating an example of a schen~aticfl ow of a second
cotnn~unicatio~co~~ ~troplr ocess on the terminal device side accordiug to an
enlbodiment of the present disclosure.
[FIG 91 FIG 9 is an explanato~y diagram for illustrating an example of
25 correspondence relationships between radio frames and meanings.
[FIG 101 FIG 10 is a flowchart illustrating an example of a schenlatic flow of a first
comtnunication control process on the termiual device side accordit~g to a first
modification of an embodiment of the present disclosure.
[FIG 111 FIG 11 is a flowchart illustratir~g an exanlple of a schen~atic flow of a
30 second comnlunication control process on the terminal device side according to a
first niodification of an entbodime~o~ft the present disclosure.
[FIG 121 FIG. 12 is an explanato~yd iagram for illustrating an example of a cycle of
transniission of a discovery signal depending on the purpose of D2D communication.
[FIG 131 FIG 13 is a flowcliart illustratitig an exatiiple of a schematic flow of a first
cotnmunication control process on the terminal device side according to a second
~iiodificationo f an embodiment of the present disclosure.
[FIG 141 FIG 14 is a flowchart illustrating an example of a schematic flow of a
second coni~nunication control process on the terminal device side according to a
second modification of an etnboditilent of the present disclosure.
[FIG 151 FIG 15 is an explanatory diagrani for illustrating an example of
predetermined radio resources for transmitting information to be reported.
[FIG 161 FIG 16 is a flowcliart illustrating an example of a schematic flow of a
cotnmunication control process on the base station side according to a third
modification of an enlbodiment of the present disclosure.
[FIG 171 FIG. 17 is a flowchart illustrating an example of a schematic flow of a first
communication control process on the terminal device side according to a third
modification of an embodiment of tlie present disclosure.
[FIG 181 FIG 18 is a flowchart illustrating an example of a scheniatic flow of a
second comnlunication control process on the terminal device side according to a
third modification of an e~iibodimenot f the present disclosure.
[FIG 191 FIG 19 is a sequence diagram illustrating an example of a schematic flow
of a communication control process according to a fourth modification of an
enibodiment of the present disclosure.
[FIG 201 FIG 20 is at1 explanatory diagram for illustrating an example of the
frequency of repetition of a detection process in a co~uiectedm ode and an idle mode.
[FIG 211 FIG 21 is an expla~iato~dyia gram for illustrating an exatiiple of an incoverage
detection process and the frequency of repetition of the in-coverage
detection process.
[FIG 221 FIG. 22 is a flowchart illustrating an exaniple of a schematic flow of a
cot~imunication control process on tlie terniitial device side according to a fifth
nlodification of an enibodiment of the present disclosure.
[FIG 231 FIG. 23 is a block diagram illustrating a first exaniple of a schematic
configuration of an eNB to which technology according to an embodiment of the
present disclosure niay be applied.
[FIG 241 FIG 24 is a block diagram illustrating a second exanlple of a sclteniatic
configuration of an eNB to which technology according to an e;nbodiment of the
5 present disclosure may be applied.
[FIG 251 FIG 25 is a block diagram illustrating an exa~iiple of a schematic
configuration of a smartphone to which technology according to an ernbodinlent of
the present disclosure may be applied.
[FIG 261 FIG 26 is a block diagram illustrating an example of a schematic
10 configuration of a car navigation device to which technology according to an
enibodiment of the present disclosure may be applied
Description of En~bodiments
[0016]
15 Hereinafter, preferred embodiments of the present disclosure will be
described in detail and with reference to the attached drawings. Note that, in this
specification and the appended drawings, structural elements that have substantially
the same fbnction and structure are denoted with the same reference numerals, and
repeated explanation of these structural elements is omitted.
20 [0017]
Hereinafter, the description will proceed in the following order.
1. Introduction
2. Schematic configuration of communication system
3. Configuration of respective communication nodes
3.1. Base station configuration
3.2. Terminal device configuration
4. Process flow
5. Modifications
5.1. First ~nodification
5.2. Second modification
5.3. Third modification
5.4. Fourth modification
5.5. Fifth modification
6. Applications
6.1. Applications related to base station
5 6.2. Applications related to terniinal device
7. Conclusion
[00 181
<>
First, technology and considerations related to D2D communication will be
10 described with reference to FIG. 1.
[0019]
(D2D communication use cases)
Use cases for D2D comniunication have been argued in groups such as the
Service and System Aspects (SA) 1 of the 3GPP, and are described in TR 22.803.
15 Note that although TR 22.803 discloses use cases, specific configurations or methods
of realizing such use cases are not disclosed
[0020]
- Uses of D2D communication
hl an ordinary LTE system, a base station and a terminal device wirelessly
20 communicate, but terniinal devices do not wirelessly co~nmunicatew ith each other.
However, there is demand for techniques enabling terminal devices to wirelessly
comnlunicate with each other directly for public safety uses or other general uses.
[0021]
Public safety uses niay include anti-collision warnings and disaster warnings,
25 for example. Since nlost public safety uses are expected to relate to emergency
situations, response time in D2D comtnunicatiot~is considered to be itnportant.
roo221
Meanwhile, other general uses include data offloading, for example. With
data offloading by D2D comn~unication, it beconies possible to reduce the load on a
30 cellular connnunication network.
[0023]
- Coverage
D2D co~~imut~icatmioany be conducted inside the coverage of a base station,
atid tnay also be cor~ductedo utside the coverage of a base station. Alternatively, if
one terminal device is positioned inside the coverage of a base station while another
5 ter~ninald evice is positioned outside that coverage, D2D co~~~r~~ut~imcaayt iboen
conducted by these terminal devices. Hereinafter, a specific exatnple of a use case
will be described with reference to FIG 1.
[0024]
FIG 1 is an explanato~y diagram for illustratit~g an example of D2D
10 communication. Referring to FIG 1, a base station 11 and nlultiple terminal
devices 21 (that is, terminal devices 21A to 21F) are illustrated. As a first example
of D2D communication, a tern~inald evice 21A and a termitla1 device 21B positioned
inside a cell 10 formed by the base station 11 (that is, the coverage of the base station
11) conduct D2D comt~~unication.S uch D2D co~~~municatiiso cna lled in-coverage
15 D2D communication. As a second exatnple of D2D communication, a tertninal
device 21C and a tenninal device 21D positioned outside the cell 10 conduct D2D
communication. Such D2D con~munication is called out-of-coverage D2D
con~munication. As a third example of D2D con~municationa, terminal device 21E
positioned inside the cell 10 and a terminal device 21F positioned outside the cell 10
20 conduct D2D communication. Such D2D conltnunication is called partial-coverage
D2D communication. From the perspective of public safety, out-of-coverage D2D
con~municationa nd pa~tial-coverageD 2D con~municationa re also important
[0025]
(Flow up to D2D communicatiot~)
25 For example, syncl~onization,d iscovery, and co~ll~ectioens tablishtne~~arte
cor~ductedit 1 order, and after that, D2D con~municatioti~s conducted.
[0026]
- Sy~lchronization
When two ternlitla1 devices are positioned inside the coverage of a base
30 station (that is, a cell formed by a base station), the two terminal devices are able to
synchronize with other to a degree by acquiring syt~chronizatiow~it~h the base station
using dow~~linsikg nals from the base station.
[0027]
011 the other hand, if at least one of the two terminal devices attempting to
conduct D2D comt~lunication is positioned outside the coverage of the base station
5 (that is, a cell fortued by a base station), at least one of the two ten~litlal devices
trat~smits a synchronization signal for sytlchrotlization in D2D communication, for
example.
[0028]
- Discovery
10 Discovery is a process by which a terminal device identifies the presence of
another terminal device nearby. In other words, discovery may also called a process
by which a terminal device discovers another terminal device, or by which a terminal
device is discovered by another tern~inadl evice.
[0029]
15 Discovery is conducted by, for example, transmitting and receiving a
discovery signal that enables another device to discover a device conductit~gD 2D
cotntnut~icatio~~M. ore specifically, one of two terminal devices transmits a
discovery signal, and the other of the two termi~lal devices receives that discovery
signal, for example. The other tern~inal device then attempts to corumunicate with
20 the terminal device.
[0030]
Note that a discovery signal is appropriately detected by l~avit~thge two
terminal devices attempting to cot~ducDt 2D comn~unicatiosy~n~c hronize in advance
before transmitting or receiving the discovery signal.
25 [0031]
(Discovery signal)
When two terminal devices attempting to cottduct D2D comtl~unication are
positioned inside the coverage of a base station, it is demanded that the discovery
sigtlals trat~smitted by the above two terminal devices not collide with signals
30 transmitted and received between the base station and the terminal devices. For this
reason, for example, otle of the two devices atte~~~ptitnog conduct D2D
cotn~l~utlicatiomn ay transmit a discovery signal according to control by the base
station.
[0032]
On the other hand, when two terminal devices attempting to cotlduct D2D
6 commnu~licationa re positioned outside the coverage of a base station, it is desirable
that tl~ed iscovery signals are transmitted according to a contention-based method.
From the perspective of unified design, it is desirable that a contention-based method
is implemented in both the in-coverage D2D communicatio~an~d the out-of-coverage
D2D comtnunication. Obviously, however, separate methods may also be
10 implemented in each of in-coverage D2D communication and out-of-coverage D2D
communication.
[0033]
A contention-based method means a nlethod designed while presupposing
signal collisions, like in random access, for example. With a contention-based
15 method, each terminal device transmits a signal on its own judgment. A method in
which the transmission of a signal by a terminal device is controlled by any control
station is not a contention-based nlethod.
[0034]
(Radio resources for D2D comnlunication)
20 When D2D comn~unication is conducted inside the coverage of a base
station, interfering with the radio cotnnlunicatio~l between the base station and a
terminal device is not allowed. Accordingly, it is cot~ceivable to use the frame
format for radio communicatiotl between the base station and a tenninal device as the
frame format for D2D commu~~ication. For example, radio frames and subframes
25 are used as units of time in D2D con~munication. A radio fratne has a length of 10
Ins, while a subframe has a length of 1 Ins. As an example, a specific subframe
inside a radio frame is released as radio resources for D2D communication. If the
base station announces such radio resources for D2D comnlunication to the terminal
devices, the interference of D2D cotnmunication on the radio conlmunication
30 between the base statiotl and a terminal device may be avoided. Note that a
resource block is used as the unit of radio resources in D2D co~nmunication, for
example. Such a resource block is a radio resource extending over 12 subcarriers in
the frequency direction, and over 7 OFDM symbols in the time direction.
[0035]
011 the other hand, when D2D con~tnunication is conducted outside the
5 coverage of a base station, the likelihood of D2D colntnunicatiol~in terfering with the
radio con~tnunication between the base station and a tet-minal device may be
considered to be low. However, since different instances of D2D conlnlunicatiotl
may be cot~ductedw ithin a narrow region, it is desirable to accoutlt for interference
between different instances of D2D communication. For example, a contention-
10 based method may be used. Specifically, for example, signal retransmission may be
conducted when a signal is not transmitted or received appropriately due to collision.
[0036]
As discussed above, when the frame format for radio comtnunicatiotl
between the base station and a terminal device is also used for D2D cornnlunication,
15 it is conceivable that the radio resources in any of the subframes among the uplink
radio resources will be used for D2D communication. This is because on the uplink,
if no radio resources are allocated to a terminal device in a subframe, no signals are
transmitted in the subframe. On the other hand, on the downlink, even if no radio
resources are allocated to any termitla1 devices, a reference signal is still transmitted
20 on all of the subframes. For this reason, on the downlink, a D2D commnunication
signal and a reference signal may collide.
[0037]
(Discovery-related load)
The discovery-related load on a terminal device includes the load of
25 transmitting a discovely signal, and the load of a process for detecting a discovery
signal. Herein, the term load tnay encompass factors such as load from the
perspective of power consumption, and load from the perspective of processing
complexity.
[003 81
<<2. Schematic configuration of cornnlunication system>>
Next, a schematic configuration of a comtnunication system I according to
an embodiment of the present disclosure will be described with reference to FIG. 2.
FIG 2 is an explanatory diagram illustratil~ga n example of a schematic cot~figuration
of a con~tnut~icatsiyos~te~m 1 according to an embodiment of the present disclosure.
Referring to FIG 2, the co~l~tnunicatiosny stem 1 i~~cludeas base station 100 and
5 multiple terrni~lal devices 100. The communication systenl 1 is a system
confor~llingt o LTE, LTE-Advanced, or a compliant com~~lunicatiosnc heme, for
example.
[0039]
(Base station 100)
10 The base station 100 wirelessly communicates with the terminal devices 200.
For example, the base station 100 wirelessly com~~~unicatiwonitsh terminal devices
200 positioned inside a cell 10. '
[0040]
(Tetminal devices 200)
16 The tern~inadl evices 200 wirelessly cotnmunicate with the base station 100.
For example, the terminal devices 200 wirelessly comn~unicatew ith the base station
100 when positioned inside the cell 10.
[004 11
Particularly, in an embodime~lto f the present disclosure, a tenllit~ald evice
20 200 conducts D2D comtllunication with another terminal device 200. For example,
if a terminal device 200 is positioned inside the cell 10 (that is, the coverage of the
base station loo), the terminal device 200 conducts in-coverage D2D con~munication
with anotl~ert erminal device 200 positioned inside the cell 10. Furthermore, if a
terminal device 200 is positioned inside the cell 10, the ternlinal device 200 may also
25 conduct pattial-coverage D2D cot~~muuicatiowt~it h a~~otheterr tllinal device 200
positiot~ed outside the cell 10. Also, if a ternlinal device 200 is positioned outside
the cell 10, the terminal device 200 may conduct out-of-coverage D2D
con~municationw ith another ter~nit~adle vice 200 positioned outside the cell 10, or
conduct partial-coverage D2D co~~~municatiwointh another terminal device 200
30 positioned inside the cell 10.
[0042]
Note that, for tlie fiame format for D2D comnlu~iication, the fiatlie format
for radio co~llniunication between the base station and a terminal device is used, for
example. For example, radio frames and subfratiles are used as units of time in
D2D commnunication. Furthennore, even in D2D communication, orthogonal
5 freque~icy-division tnultiplexing (OFDM) is used, and resource blocks are used as
units of radio resources, for example. Such a resource block is a radio resource
extending over 12 subcarriers i11 the frequency direction, and over 7 OFDM symbols
in the titlie direction.
[0043]
10 <<3. Configuration of respective cotnmunicatioti nodes>>
Next, a configuratioti of the base station 100 and the ternli~ial device 200
according to an embodiment of the present disclosure will be described with
reference to FIGS. 3 to 5.
[0044]
<3.1. Base station configuration>
First, an example of a configuration of a base station 100 according to an
embodinlent of the present disclosure will be described with reference to FIGS. 3 and
4. FIG. 3 is a block diagram illustrating an exanlple of a configuration of a base
station 100 according to an embodiment of tlie present disclosure. Referring to FIG.
20 3, tlie base station 100 is equipped with an antenna unit 110, a radio co~nmunication
unit 120, a network communication unit 130, a storage unit 140, anda processing
unit 150.
[0045]
(Antenna unit 110)
25 The anitenna unit 110 emits a signal output by the radio comniunication unit
120 into space as a radio wave. Additionally, the antenna unit 110 converts a radio
wave fro111 space into a signal, and outputs tlie signal to tlie radio communication unit
120.
[0046]
(Radio coniniu~~icatiouni t 120)
The radio comtiiunication unit 120 cotiducts radio cotntn~uiication. For
exaniple, the radio coniniu~iicatiou~ni it 120 transniits a downlink signal to a terminal
device 200 positioned inside the cell 10, atid receives an uplink signal fro111 a
terniinal device 200 positioned inside tlie cell 10.
[0047]
6 (Network com~~iunicatioun it 130)
The network con~~ilunication unit 130 coni~nunicates with other
comniunication nodes. For example, the network conimunication unit 130
conimunicates with a core network and other base stations.
[0048]
10 (Storage unit 140)
The storage unit 140 temporarily or perrnanently stores programs and data
for the operation of the base station 100.
[0049]
(Processing unit 150)
15 The processing unit 150 provides various functions of the base station 100.
The processing unit 150 includes an information acquisition unit 151 and a
cotnn~unicationc ontrol unit 153.
[0050]
(Information acquisition unit 151)
20 The inforniation acquisition unit 151 acquires inforniation for the purpose of
control by the cotnniunication control unit 153.
[0051]
Particularly, in an etnbodiment of the present disclosure, the information
acquisition unit 151 acquires radio frame information indicating a radio fiame for
25 transn~itting a discovery signal. The radio frame is a unit time of cellular
cotnniunication. Also, tlie discovery signal is a signal is a signal that enables
anotlier device to discover a device conducting D2D conimu~~ication.
[0052]
The radio frame inforniation indicates, for example, the system frame
30 number (SFN) of the radio frame for trans~nittinga discovery signal. Hereinafter, a
specific exatnple of the radio fratne for transmitting a discovery signal will be
described with reference to FIG. 4
[0053]
FIG 4 is an explanato~y diagram for illustrati~lg an exatnple of the radio
franie for transmitting a discovery signal. Referring to FIG. 4, part of a series of
5 radio frames having an SFN from 0 to 1023 are illustrated. For example, the radio
franie for transmitting a discovery sigtial is a radio frame arriving each cycle 31. In
other words, in this example, the cycle 31 is 10 radio frames (that is, 100 ms), a~id
tlie radio frames for transmitting a discovery signal are the radio franies having an
SFN that is an integer ~llultipleo f 10 (the radio frames having an SFN of 0, 10, 20,
10 and so on). For example, if tlie response rate demanded for tlie purpose of public
safety is 0.1 s (that is, 100 ms), discovery signals tilay be transmitted 011 such a cycle
31.
[0054]
The radio frame for transmitting a discovery signal is predefined, for
15 example, and radio frame information indicating tlie radio frame is stored in the
storage unit 140. The iuformatio~i acquisition unit 151 acquires the radio frame
information from the storage unit 140. As an example, the radio frame i~iforniation
is included in system information, and the system information including the radio
frame information is stored in the storage unit 140. Subseque~ltly, the information
20 acquisition unit 151 acquires the system i~iformatioti~n cluding the radio frame
infor~~iatiofr~omi the storage unit 140. Note that if the radio frame infor~ilatio~isi
stored in another device without being stored in the storage unit 140, the information
acquisition unit 151 may acquire the radio frame informati011 from the other device
via the network comrnu~~icatiouni t 130, for example.
25 [0055]
TIle radio frame itifortnation may indicate the SF'N of the radio fratne 011
which a discovery sigtlal is tra~is~iiittebdy including the SEN itself, or indicate the
SFN by including infor~nation for identifying the SF'N (for example, the cycle of the
F'.
SFN, a condition of the SFN, or the like).
30 [0056]
(Conimunication cotltrol unit 153)
The cotnmunication colitrol unit 153 co~iducts colitrol related to radio
comlllunication.
[0057]
Particularly, in an enibodimetit of the present disclosure, the cotnn~uliicatioli
5 control unit 153 cotitrols the transmission of the radio frame information to the
ternii~iald evice 200.
[005S]
For example, the radio frame information is transmitted as part of tlie
system information. In other words, the cotnniunication cotitrol unit 153 controls
10 the transmission of the radio frame infortnation to the ter~nit~dael vice 200 so that the
radio frame information is tratistiiitted as part of the system information. As a
specific process, the communication control unit 153 may, for example, map systerii
information including the radio kame information onto a radio resource allocated to
that system information. As a result, the radio frame information is transmitted as
15 part of the system information. Note that the radio frame information may also be
transmitted by individual signaling to the terminal device 200, instead of being
transtnitted as part of the system information.
[0059]
Consequently, it becomes possible to moderate the load on a terminal device
20 200 cotiducting D2D commnunication, for example.
[0060]
Specifically, for example, the terminal device 200 may conduct a detection
process for detecting a discovery signal on a signal transmitted in a radio frame for
transmitting a discovery signal, and rapidly and reliably detect tlie discovery signal,
25 for example. For this reason, tlie terminal device 200 may also not coliduct the
detection process on a signal tral~sliiittedi n a radio franie other than the radio franie.
hi other words, the terminal device 200 does not have to conduct the detection
process at a high frequency of repetition in order to detect tlie discovery signal
rapidly and reliably. Consequently, the load imposed by the discovery signal
30 detection process may be moderated.
[0061]
As another example, the terminal device 200 may transmit a discovery
signal in a radio flame for transmitting a discovery signal, and not transmit a
discovery signal in 'a radio frame other than the radio frame. hi other words, the
terminal device 200 does not have to tratistiiit the discovery signal at a high
5 frequency of repetition so that the discovery signal will be detected rapidly and
reliably by another terminal device 200. Consequently, the load itnposed by the
transmission of the discovery signal may be moderated.
[0062]
Note that with typical paging, the radio frame in which a terminal device
10 receives a paging message differs depending on the terminal device, and thus the
base station transmits paging messages at a high frequency of repetition for all
terminal devices. On the other hand, since the radio frame in which a discovery
signal is received may be cotnlnon among the terminal devices 200, a terminal
device 200 does not have to tratistnit a discovery signal at a high frequency of
15 repetition. In other words, the radio frame for transinitting a discovery signal does
not have to appear at a high frequency of repetition like a paging frame. For this
reason, the load imposed by tlie trat~smission of the discovety signal may be
moderated.
[0063]
<3.2. Tertninal device configuratio~l>
Next, an example of a configuration of a terminal device 200 according to
an embodiment of the present disclosure will be described with reference to FIG. 5.
FIG. 5 is a block diagram illustrating an example of a configuration of a terminal
device 200 an embodi~iietit of tlie present disclosure. Referring to FIG 5, the
25 terminal device 200 is equipped with an antenna unit 210, a radio comtnunicatioti
unit 220, a storage unit 230, an input unit 240, a display unit 250, and a processing
unit 260.
[0064]
(Antentia unit 210)
30 The antenna unit 210 emits a signal output by the radio cotii~nunicatiotui nit
220 into space as a radio wave. Additionally, the antenna unit 210 converts a radio
wave from space into a signal, and outputs tlie signal to the radio coniniunication unit
220.
[0065]
(Radio cotntnunication unit 220)
5 The radio comni~unication unit 220 conducts radio comn~unication. For
example, if the ter~iiinal device 200 is positioned inside the cell 10, tlie radio
coniniunication unit 220 receives a dowrilink sig~ial frotn the base station 100, and
transmits an uplink signal to the base station 100. As another example, in D2D
communication, tlie radio communication unit 220 receives a sigual from anotller
10 terminal device 200, and transmits a sigtial to another ternii~iadl evice 200.
[0066]
(Storage unit 230)
The storage unit 230 tenlporarily or permanently stores programs and data
for the operatiori of the terminal device 200.
15 [0067]
(Input unit 240)
The input unit 240 receives input from a user of the termir~al device 200.
The input unit 240 then provides an input result to the processing nilit 260.
[0068]
(Display unit 250)
The display unit 250 displays an output screeti (that is, an output image)
from the termitla1 device 200. For example, the display unit 250 displays an output
screen according to control by the processing unit 260 (display control unit 265).
25 (Processing unit 260)
The processi~lgu nit 260 provides various futlctions of the terniinal device
200. The processing unit 260 illcludes an infortnation acquisition unit 261, a
cotnn~utiicationc ontrol unit 263, atid a display control unit 265.
[0070]
(Itiformation acquisition unit 261)
The informatiori acquisitiou unit 261 acquires information for tlie purpose of
control by the cotntnunication control unit 263.
[0071]
Patticularly, in at1 e~nbodi~nenotf the present disclosure, the infor~nation
acquisition unit 261 acquires radio frame illfortnation indicating a radio frame for
transmitting a discovery signal. The specific content of the radio frame information
is as discussed earlier.
[0072]
For example, the radio frame information is transmitted by the base station
100 as part of the system inforn~ation. In this case, the infortnation acquisition unit
261 acquires the radio frame information included in the system information.
[0073]
Note that the radio franie infortnation may also be transmitted by individual
signaling to the terminal device 200, instead of being transmitted as part of the
system information. Also, the radio frame information may also be stored in
advance in the terminal device 200 (storage unit 230), without being transmitted by
the base station 100. This point applies similarly to the respective modifications of
an embodiment of the present disclosure discussed later.
[0074]
(Communication control unit 263)
The comniunication control unit 263 conducts control related to radio
cotnmunication by the terminal device 200.
[0075]
- Control related to transtuission of discovery signal
For example, the terminal device 200 acts as the discovery signal
transtnittit~gs ide, atld transmits a discovery signal. In this case, the comtnunication
cotxtrol unit 263 controls the transn~ission of the discovery signal on the basis of the
radio frame information.
[0076]
Specifically, for example, when the terminal device 200 transmits the
discovery signal, the communication co~ltroul nit 263 controls the transn~issiono f the
discovery signal so that the discovery signal is transmitted in radio frames indicated
by the radio frame inforniatiotl, and so that the discovery signal is not transmitted in
other radio frames. As an example, referring again to FIG 4, the conitnunication
colitrol unit 263 controls the transmission of the discovery signal so tliat tlie
discovery signal is transniitted in radio frames having an SFN that is an integer
5 multiple of 10 (the radio frames liavi~~ang SFN of 0, 10, 20, and so on), and so that
the discovery signal is not tra~ismitted in other radio frames. Note that the
discovery signal is transmitted with, for example, predetermined radio resources
inside radio frames indicated by the radio frame inforination (for example,
predetermined resource blocks of predetermined subframes).
10 [0077]
As a specific process, the communicatior~c o~itroul nit 263 may, for example,
map a discovery signal onto predetermined radio resources inside radio frames
indicated by the radio frame information. Consequently, the discovery signal is
transmitted with predetermined radio resources inside radio fratnes indicated by the
15 radio frame infornlation.
[0078]
- Control related to detection of discovery signal
For example, the terminal device 200 acts as the discovery signal receiving
side, and conducts a detection process for detecting a discovery signal. In this case,
20 the cotiiniur~icatioti control unit 263 controls a detection process for detecting a
discovery signal on the basis of the radio frame information.
[0079]
Specifically, for example, when the terniitial device 200 co~~ductas
detection process for detecting a discovery signal, the con~munication control unit
25 263 controls the detection process so that the detection process is co~~ducteodn
signals transmitted in radio frames indicated by the radio frame information, and so
that tlie detection process is not conducted on signals transmitted in other radio
frames. As an example, referring again to FIG 4, the cotiirnunication control unit
263 controls the detection process so that tlie detection process is conducted on
30 signals transmitted in radio frames having an SFN that is an integer multiple of 10
(tlie radio frames having an SFN of 0, 10, 20, and so on), and so tliat the detectioti
process is not conducted on signals transmitted in other radio frames. Note that the
detection process is conducted on signals transmitted with, for example,
predetermined radio resources inside radio fra~iles indicated by the radio fiame
information (for example, predetermined resource blocks of predetermined
5 subfiames).
[0080]
As a specific process, for example, the conir~lu~~icatcioot~~it rolu nit 263
deternlines whether or not a sequence in a signal transmitted with predetermined
radio resources inside a radio frame indicated by the radio frarne information
10 matches a discovery signal sequence. When these sequences match, a discovery
signal is detected, whereas when these sequences do not match, a discovery signal is
not detected.
[008l]
- Control related to transmission of system information including SFN
15 Note that the c o ~ ~ ~ t ~ ~ u ~c~oinctraotl i ounti~t 263 may also control the
transmission of system illformation itlcluding a system frame number (SFN). 111
other words, according to control by the comnlutiication control unit 263, the
terminal device 200 may also trat~smits ystem infortnation including an SFN. As an
example, according to control by the con~~uunicatiocro~n trol unit 263, the terminal
20 device 200 may transmit a master inforn~ationb lock (MIB) including an SFN.
[0082]
Consequently, for example, even if two or lnore terrnitlal devices 200 are
positioned outside the coverage (cell 10) of the base station 100, the sharing of an
SFN between the two or more ternlinal devices 200 becotnes possible.
26 [0083]
(Display control unit 265)
The display co~~truonli t 265 controls the display of an output screen by the
display unit 250. For example, the display control unit 265 generates an output
screen to be displayed by the display unit 250, and causes the display unit 250 to
30 display that output screen.
[0084]
<<4. Process flow>>
Next, a com~~~ut~iccoanttirool~ p~r ocess accordit~gto an etnboditnent of the
present disclosure will be described with reference to FIGS. 6 to 8.
[OOSS]
5 (Conimnutiication cot~tropl rocess on base station side)
FIG 6 is a flowchart illustrating at1 example of a schen~atic flow of a
communicatio~c~o ntrol process on the base station side according to an eniboditnent
of the present disclosure.
[0086]
10 First, the information acquisition unit 151 acquires system it~fortnation
including radio frame information indicating a radio frame for transmitting a
discove~ys ignal (S401).
[0087]
Subsequently, the base station 100, accordins to cotitrol by the
15 conin~unicatiot~co ntrol unit 153, transmits the system information including the
radio frame information (S403). The process then ends.
[0088]
Note that the comtnunication control process discussed above is conducted
every time the system informatiot~is transmitted.
20 [0089]
(First comtnut~icationc ontrol process on terminal device side: transmission
of discovery sigt~al)
FIG. 7 is a flowchart illustrating an exatnple of a schematic flow of a first
communicatiot~ col~trol process on the termitla1 device side according to an
25 embodimet~t of the present disclosure. The first communication control process is
conducted when the tenninal device 200 transmits a discovery sigt~al.
[0090]
W11et1 the radio &ame is a radio frame for tratisn~ittinga discovery signal
(S501: Yes), the terminal device 200, accorditig to cot~trol by the con~n~unication
30 control unit 263, transtnits a discovery signal in the radio frame (S503).
Subsequently, the system fi.ame lumber is incremented (S505), and the process is
repeated.
[0091]
On the other hand, when the radio frame is not a radio frame for
transmitting a discovery signal (S501: No), a discovery signal is not transmitted.
5 Subsequently, the system frame number is incremented (SSOS), and the process is
repeated.
[0092]
(Second cot~imunicationc ontrol process on tertl~inald evice side: detectiot~
of discove~ys ignal)
10 FIG 8 is a flowchart illustrating an example of a schematic flow of a second
comniunication control process on the terminal device side according to an
etnbodituent of the present disclosure. The second communication control process
is conducted when the terminal device 200 co~~ducths e detection process for
detecting a discovery signal.
15 LO0931
When the radio fiame is a radio frame for transmitting a discovery signal
(S601: Yes), the terminal device 200, according to control by the cotnnlutlication
control unit 263, conducts the detection process for detecting a discovery signal on
the signal transmitted in the radio frame (S603). Subsequently, the systeni frame
20 number is incremented (S605), and the process is repeated
[0094]
When the radio frame is not a radio frame for transmitting a discovery
signal (S601: No), the detection process is not conducted on the signal transmitted in
the radio frame. Subsequently, the system frame number is incremented (S605),
25 and the process is repeated.
[0095]
<<5. Modifications>>
Next, first to fifth modifications of an embodiment of the present disclosure
will be described with reference to FIGS. 9 to 22.
30 [0096]
<5.1. First n~odificatioti>
First, a first ~nodificationo f an embodiment of tlie present disclosure will be
described with reference to FIGS. 9 to 11.
[0097]
(Summary)
In tlie first modification, each of multiple radio fratnes in which a discovery
signal is transmitted corresponds to any one meaning fro111 among two or more
meanings. Additionally, the terminal device 200 on the transmitting side trans~nits
a discovery signal in a radio frame corresponding to a meaning to be reported. The
terminal device 200 on tlie receiving side, upon detecting tlie discovery signal,
10 identifies tlie nieaning corresponding to the radio frame.
[0098]
Consequently, for example, by only transmitting and receiving a discovery
signal, it becomes possible for the terminal device 200 on tlie receiving side to
identify a meaning to be reported by the ter~ninadl evice 200 on the transriiitting side.
15 For this reason, the rapid conveyance of meaning beconies possible. More
specifically, for example, in D2D communication, when data indicating a meaning is
transmitted and received after a connection is established through niultiple
transactions, the time taken to convey the meaning becomes long. On tlie other
hand, when a discovery signal is transmitted and received in a radio frame
20 corresponding to a meaning, the time taken to convey the meaning beconies short.
For this reason, conveyance of the meaning beconies rapid. Note that wliet~ the
purpose of D2D conitnunication is for public safety, the urgency is high, and thus
such rapid conveyance of meaning is particularly effective.
[0099]
(Radio frame information)
Particularly, in tlie first modification, the radio frame infortnation indicates
multiple radio frames for transmitting a discovery signal. As an exatnple, like tlie
exaniple illustrated in FIG. 4, the radio kame information indicates radio frame
having an SFN that is an integer nlultiple of 20 (the radio frames having an SFN of 0,
30 10, 20, and so on).
[OlOO]
Furthermore, in the first modification in particular, each of nlultiple radio
frames corresponds to ally one meaning from anlong two or more n~eanings. The
two or more n~eani~~ingcslu de meanings related to public safety, for example.
Hereinafter, a specific example of correspondence relationships between radio
5 frames and lneanings will be described with reference to FIG. 9.
[OIOl]
FIG. 9 is an explanatory diagram for illustrating an example of
correspondence relationships between radio frames and meanings. Referring to FIG
9, co~respondeticer elationships between meanings and radio frames are illustrated.
10 For example, the radio flames having the SFN of 100, 200 and 300 correspond to the
meaning of a fire alert, while the radio fi.ames having the SFN of 500, 600, and 700
correspond to the nieatiitig of a burglar alarm.
[O 1021
The examples of meanings illustrated in FIG 9 (fire alert and burglar alarm)
15 may also be said to be purposes of D2D communication. In this way, each of the
above two or more meanings n~aym atch a purpose of D2D communication.
[0103]
Note that, for example, the radio fiame information additionally indicates
which meaning from aniong the two or more meanings each of the multiple radio
20 frames corresponds to. As an example, tlie radio frame information indicates
co~respondence relationships as illustrated in FIG. 9, for example. Consequently,
for example, it becomes possible for the terminal device 200 to know tlie
correspo~~dencreel ationships in advance. Obviously, the information itidicating the
~~lultiprlaed io franles and the information indicating which meaning among tlie two
25 or more meatlings each of the multiple radio frames corresponds to may be included
in the radio frame irifor~nationa s integrated infortnation, or as separate information.
[O 1041
(Base station 100: comtnunication co~~truonlit 153)
As discussed above, the communication control unit 153 controls the
30 transniissioti of the radio frame information to the terminal device 200.
[0105]
As discussed above, the infortnatio~i~nd icating the ~~~ultirpaldeio frames
and the inforn~ation indicatiug which meaning among the two or more meanings
each of the multiple radio frames correspot~dst o may be included in the radio frame
i~~formatioans separate information. In this way, the conit~~u~~icactoinotnro l unit
5 153 may control the transmission of the radio frame information so that the separate
information is transmitted separately, or control the trans~nission of tlle radio frame
information so that the separate it~formatioits~ t ransmitted collectively.
[0 1061
(Terminal device 200: commut~ication control unit 263)
- Control related to transmissiou of discovery sigtial
Particularly, in the first modification, the cotnmunication control unit 263
cot~trols the transmission of a discovery sigtlal so that the discovery signal is
transmitted in a radio frame corresponding to a meaning to be reposed from alllong
the multiple radio frames.
15 [0107]
As a specific example, referring again to FIG 9, when the meaoing to be
reported is a fire alert, a discovery signal is transmitted in the radio frames having an
SFN of 100, 200, and 300, according to cotltrol by the communication control unit
263. Also, whet1 the meatling to be reported is a burglar alarm, a discovery signal is
20 transmitted in the radio frames having an SFN of 500, 600, and 700, according to
control by the com~nunicatiotc~o ntrol unit 263.
[O 1 081
Note that the meaning to be reported (sucli as a fire alert or a burglar alarm,
for example) is decided according to tlie applicatiot~ that requests D2D
25 con~munication,a s one example.
[0 1091
- Control related to detection of discovery signal
Particularly, in the first modification, the co~~lmunicatiocno t~trolu nit 263,
upon detecting a discovery s.ignal, identifies the meaning correspouding to tlie radio
30 frame in which the detected discovery signal was transmitted from among the
tnultiple radio frames.
[OllO]
As a specific example, referring again to FIG 9, when a discovery signal is
detected in a radio frame liavitig an SFN of 100, 200, or 300, the comtnunication
control unit 263 identifies a fire alert as the meaning corresponding to the radio
5 frame. Also, wlien a discovery signal is detected in a radio franie having an SEN of
500, 600, or 700, tlie communication control unit 263 identifies a burglar alarrn as
tlie meanitis corresponding to the radio frame.
[Olll]
(Process flow: first coniniunication control process on ternlinal device side:
10 transmission of discovery signal)
FIG 10 is a flowchart illustrating an example of a schematic flow of a first
co~nnlu~iicatioc~oni trol process on the terminal device side according to a first
n~odificationo f an e~nboditilento f tlie present disclosure. The first con~mutlication
control process is conducted wlien tlie tertiiinal device 200 transmits a discovery
15 signal.
[0112]
When the radio frame is a radio frame for transmitting a discovery signal
(S511: Yes), and a radio frame corresponding to a nieaning to be reported (S513:
Yes), the terminal device 200, according to control by the conimunication control
20 unit 263, transmits a discovery signal in the radio frame (S515). Subsequently, the
system franie number is increniented (S517), and the process is repeated.
[0113]
011 the other hand, if tlie radio frame is not a radio franle for trans~nitting a
discovery signal (S511: No), or is not a radio fianie corresponding to a meaning to be
25 transmitted (S513: No), a discovery signal is not transmitted. Subsequetitly, the
system frame number is incretnented (S517), and the process is repeated.
[0114]
(Process flow: second comniutiicatioti control process on terminal device
side: identification of meaning)
30 FIG 11 is a flowchart illustrating an example of a schematic flow of a
second conlnlunication control process on tlie terminal device side according to a
first modification of an enlbodinlent of the present disclosure. The second
comn~utlicatiollc ontrol process is conducted after the terminal device 200 detects a
discovery signal.
[0115]
First, the comniunication cot~trol unit 263 acquires the SFN of the radio
fiatlle it1 which a discovery signal was detected (S611)
[0116]
Subsequently, the comt~~u~~icactoinotnro l unit 263 identifies the tneatiing
corresponding to tlie radio frati~eh aving the acquired SFN, fro111a nlotlg two or Inore
meanings (S613). The process then ends.
[0117]
<5.2. Second niodificatiot~>
Next, a second modification of an embodinient of the present disclosure will
be described with reference to FIGS. 12 to 14.
[0118]
(Summary)
In tlie second modification, the terminal device 200 on the transmitting side
transmits a discovery signal at a frequency of repetition that depends on the purpose
of the D2D communication. Also, the termitial device 200 on the receiving side
conducts the detection process for detecting a discovery signal at a frequency of
repetition that depends on the purpose of the D2D communication.
[0119]
Consequently, for example, it beco~iles possible to tiloderate power
consu~nptionf or discovery, while still satisfying the demand on the time required for
discovery.
[0120]
Specifically, for exatnple, tlie demand on the time required for discovery
may differ depending on tlie purpose of the D2D com~ilunication (such as collisioti
warning, fire alett, and burglar alartn, for example). As an example, when the
purpose of tlie D2D comt~lunicatioti is a collision warning, the time required for
discovery is demanded to be within a first time, whereas when the purpose of the
D2D corntnutiication is a fire alert, the tinie required for discovery is demanded to be
within a second time that is longer than the first time. In such cases, if the
frequency of repetition of the discovery signal is stipulated so that the titile required
for discovery is witliin the first tinie, for example, wlieti a terminal device conducts
D2D comniunication for a fire alert but does not conduct D2D conimunication for a
collision warning, the terniirial device will transmit or detect a discovery signal at a
Iiiglier frequency of repetition than is required. As a result, power niay be wasted in
the transmission or detection of a discovety signal. On the other hand, if the
frequency of repetition of the discovery signal is stipulated so that tlie time required
for discovery is witliin the second time, for example, when a terminal device
conducts D2D commutiication for a collision warning, the terniinal device will
transmit or detect a discovery signal at an insufficient frequency of repetition. As a
result, the demand on the time required for discovery is not satisfied. Accordingly,
by transmitting a discovery signal and conducting the detection process at a
frequency of repetition that depends on the purpose, it becomes possible to moderate
power consumption for discovery, while still satisfying the detnatid on the time
required for discovery.
[0121]
(Radio frame information)
Particularly, in the second modification, tlie radio frame information
indicates, for each purpose of D2D coni~nunication, niultiple radio frames for
transrnitting a discovery signal at a frequency of repetition depending oti the purpose.
[O 1221
For example, the radio frame information indicates, for each purpose of
D2D coniniu~iication, a cycle of transmission of a discovery signal depending on the
purpose. In other words, by indicating a cycle depending on the purpose, the radio
frame information indicates radio frames for transmitting at a frequency of repetition
depending on the purpose. Hereinafter, a specific example of a cycle of
transmission of a discovery signal depending on the purpose of D2D cotnmutiication
will be described with reference to FIG. 12.
[0 1231
FIG 12 is an explanatory diagratii for illustrating an exa~~ipolef a cycle of
transmission of a discovery signal depending 011 tlie purpose of D2D com~iiunication.
Referring to FIG. 12, a first cycle 33 of transniission of a discovery sigtial and a
secotid cycle 35 of transniissioti of a discovery signal are illustrated. For exaniple,
5 the first cycle 33 is the cycle when the purpose of D2D coniniunication is a collisioti
warning, and is 100 111s (10 radio frames). On tlie other hatid, the second cycle 35 is
the cycle when tlie purpose of D2D comtnunication is a fire alert, and is 300 Ins (30
radio frames). In this way, a discovery sigtial is transtilitted on a cycle depending
011 the purpose of D2D cotntnunication.
10 [0124]
Note that although an exatiiple of cyclically transmitting a discovery signal
is described, the secotid modification is not limited to such an exaniple. For
example, a discovery sigtial may also be tratismitted at non-periodic intervals,
without being tratismitted cyclically (that is, at fixed intervals).
15 [0125]
(Tertninal device 200: com~nunicationc ontrol unit 263)
- Control related to transmission of discovery signal
Pa~ticularly,i n the second modification, tlie con~municationc otitrol unit 263
cotitrols the transmissiot~ of a discovery signal so that the discovery sigtial is
20 transmitted at a frequency of repetition depending on the purpose of D2D
coniniunication.
[0126]
For exaniple, the communication control unit 263 controls tlie tratisulissioti
of a discovery signal so that the discovery signal is transmitted oti a cycle depending
25 on the purpose of D2D comniutiication. As a specific exatnple, referring to FIG 12,
whet1 the purpose of D2D conimunication by a ter~iii~iadle vice 200 is a collision
warning, the terminal device 200, according to cotitrol by the cotntiiunicatioti cotitrol
unit 263, transmits a discovery signal on the first cycle 33. hi other words, the
tertnitial device 200 transmits a discovery signal every 10 radio frames (every 100
30 ms). Also, when the purpose of D2D con~tnunicatiotib y a tertni~iald evice 200 is a
fire alert, the terminal device 200, according to cotitrol by tlie cotnmunicatioti control
unit 263, tratlsmits a discovery signal on the secolld cycle 35. In other words, the
ter~ili~iadle vice 200 transillits a discovery signal every 30 radio fiatnes (every 300
ms). Note that when the purpose of D2D con~municatioli by a ter~iliual device 200
i~lcludesb oth a collision warning and a fire ale~tt,h e terminal device 200 transmits
5 discovery signals on the first cycle 33 a~idth e second cycle 35.
[0127]
Note that tlie purpose of D2D comt~lu~~icat(isouct~h as a collisiorl warning, a
fire alert, or a burglar alarm, for example) is decided according to the application that
requests D2D con~niunication, as one example.
10 [0128]
- Cotltrol related to detection of discovery signal
Particularly, in the second modification, the cotntilu~~icatiocno ntrol unit 263
controls the detection process for detecting a discovery signal so that the detection
process is cot~ducteda t a frequency of repetition depending on the purpose of D2D
15 communication.
[0 1291
For example, tlie communication control unit 263 controls the detection
process so that tlie detection process is conducted on a cycle depending on the
purpose of D2D comnlunication. As a specific example, referring to FIG. 12, when
20 the purpose of D2D communication by a terminal device 200 is a collision warning,
the terminal device 200, according to control by the co~ilmunicatioiic ontrol unit 263,
conducts the detection process on the first cycle 33. In other words, the terminal
device 200 conducts the detection process every 10 radio franles (every 100 111s).
Also, when the purpose of D2D communication by a terminal device 200 is a fire
25 alert, the terminal device 200, according to control by the conit~iunication control
unit 263, conducts the detection process on the second cycle 35. I11 other words, the
terminal device 200 cor~ducttsh e detection process every 30 radio frames (every 300
ms). Note that when the purpose of D2D cotnnlunicatiot~b y a terminal device 200
includes both a collisio~iw arning and a fire alert, the tertllitial device 200 conducts
30 the detection process on the first cycle 33 and the second cycle 35.
[0130]
Note that, as discussed above, the purpose of D2D coni~iiunication (such as
a collisioti warning, a fire alert, or a burglar alarm, for example) is decided according
to tlie application that requests D2D co~ii~iiunicationas, one example.
[0131]
5 (Process flow: first cornniunication control process on terminal device side:
transmission of discovely signal)
FIG 13 is a flowchart illustrating an example of a schematic flow of a first
co~nmunication control process on the terminal device side according to a second
~nodificationo f an etnbodit~ietito f the present disclosure. The first communication
10 control process is conducted when the tertllitial device 200 transmits a discovery
signal.
[0132]
When the radio frame-is a radio flame for tratisniitting a discovery signal
(S521: Yes), and a cycle corresponding to the purpose of D2D con~munication for a
15 tertliinal device 200 arrives (S523: Yes), the terminal device 200, according to
control by the cot~itnunication control unit 263, transmits a discovery signal in the
radio frame (S525). Subsequently, the system frame number is incremented (S527),
and tlie process is repeated.
[0133]
20 On the other hand, if the radio fratlie is not a radio frame for transmitting a
discovery signal (S521: No), or if a cycle corresponding to the purpose of D2D
comnlunication for tlie terminal device 200 does not arrive (S523: No), a discovery .
signal is not transmitted. Subsequently, the system frame number is iticremented
(S527), and the process is repeated.
25 [0134]
(Process flow: second co~iiniu~~icaticootnit rol process on terminal device
side: detection of discovery signal)
FIG 14 is a flowchart illustrating an example of a schematic flow of a
second commonication control process on the terminal device side according to a
30 second tliodification of an enibodin~ent of the present disclosure. The second
contn~unicatioct~o ntrol process is conducted when the terminal device 200 conducts
the detection process for detecting a discovery signal.
[0135]
When the radio frame is a radio frame for transmitting a discovery signal
(S621: Yes), and a cycle corresponding to the purpose of D2D connnunication for a
5 ternlinal device 200 arrives (S623: Yes), the terminal device 200, according to
control by the connnunicatioti control unit 263, conducts the detection process for
detecting a discovery signal on the signal transmitted in the radio frame (S625).
Subsequently, the system frame number is incremented (S627), and tlie process is
repeated.
10 [0136]
On the other hand, if the radio frame is not a radio fratne for transmitting a
discovery signal (S621: No), or if a cycle corresponding to the purpose of D2D
communication for the terminal device 200 does not atlive (S623: No), the detection
process is not conducted on the signal transmitted in the radio frame. Subsequently,
15 tlie systeni hatne number is incremented (S627), and the process is repeated.
[0137]
G.3. Third modification>
Next, a third modification of an embodiment of the present disclosure will
be described with reference to FIGS. 15 to 18.
20 [0138]
(Summary)
Particularly, in tlie third modification, the terminal device 200 on the
transmitting side, after transmitting a discovery signal, transmits information to be
repotted in a predetermined radio resource. Also, the terminal device 200 on the
25 receiving side, after detecting a discovery signal, acquires infortnation received in the
predetermined radio resource.
[0139]
Consequently, for example, it beconles possible to convey detailed
infom~ationra pidly.
30 [0140]
Specifically, for example, when a radio frame corresponds to one nieatiing,
like in tbe first modification, rapid conveyance of the meaning through transniission
and reception of a discovery signal becomes possible, but the coilveyance of detailed
infor~nation is difficult. Also, if detailed informatioa is transmitted and received
after a coutlection is established through multiple transactions, the time taken to
convey the detailed information becotnes long. Accordingly, by transmitting atid
receiving information to be reported in a predetermined radio resource after a
discovery signal, it becomes possible to convey detailed iliforrnation rapidly.
[0141]
Note that in cases such as when the purpose of D2D commu~iicatio~isi data
offloading, a large anlount of data is transmitted and received by D2D
comniunicatioti, and thus the establishment of a connection is effective. However,
when the purpose of D2D comniunication is public safety, the urgency is often high,
and thus the technique according to the third tnodification is effective.
[0 1421
(Base station 100: information acquisition unit 151)
Particularly, in the third modification, the information acquisition unit 151
additionally acquires radio resource infor~nation indicating a predetermined radio
resource for transmitting information to be reported after the transniission of a
discovery signal.
[0143]
For example, the radio resource information indicates predeterniined radio
resources for transn~itting information to be reported after the trans~ilission of a
discovery signal. Hereinafter, a specific example of predetermined radio resources
for transmitting information to be reported will be described with reference to FIG.
15.
[0144]
FIG 15 is an explanatory diagram for illustrating an exan~ple of
predete~nlined radio resources for transmitting information to be reported.
Referring to FIG. 15, a radio resource 41 for transrnittitlg a discovery signal and
predetermined radio resources 43 for transniitting information to be reported (that is,
radio resources 43A to 43J) are illustrated. The predetermined radio resources 43
are positioned after tlie radio resource 41 in the titile direction. For example, the
radio resource 41 is positioned at a fixed titile among tlie radio fiames, and is also
positioned in a fixed band atiiotig the entire frequency band. Also, each of the
predeterniined radio resources 43 is positioned at a fixed time among the radio
5 frames, and is also positioned in a fixed band among tlie entire fkequency band.
Note that the radio resource 41 is a radio resource including one or more resource
elemetits or one or niore resource blocks, for example. Also, each of the radio
resources 43A to 435 is a radio resource including one or more resource blocks, for
exaniple. Note that although an example of arranging tlie predetermined radio
10 resources 43A to 435 it1 the time direction is described, an etiibodiment of the present
disclosure is not liniited to such an example. Tlie predetermined radio resources
43A to 43J may also be arranged in the frequency direction, or dispersively
positioned in the fkequency direction and/or the time direction.
[0145]
15 The predetermined radio resources are predefined, for example, and the
radio resource information indicating tlie predete~ninedra dio resources are stored in
tlie storage unit 140. Tlie information acquisition unit 151 acquires the above radio
resource information fkom the storage unit 140. As an example, the above radio
resource infor~ilationi s iticluded in system infor~i~ationa,n d tlie system infornlation
20 iticluditig the radio resource information is stored in the storage unit 140.
Subsequetitly, the inforniation acquisition unit 151 acquires the system infortilation
including the radio resource information from tlie storage unit 140. Note that if the
above radio resource informati011 is stored it1 another device without being stored in
the storage unit 140, the inforniatiot~ acquisition unit 151 may acquire the radio
25 resource incornlation from the other device via the network commutiication unit 130,
for example.
[0146]
(Base station 100: communication control unit 153)
Particularly, in tlie third modification, tlie cotnniunication co~itrolu nit 153
30 controls tlie transtnissiot~o f the radio resource infortnation to the terminal device 200
[0147]
For example, the radio resource inforlnation is transmitted as part of the
system information. In otlier words, the conin~unication control unit 153 controls
the transtsmission of the radio resource information to the ter~llitial device 200 so that
tlie radio resource information is transtnitted as part of the system infor~natioti. As
6 a specific process, the co~~ini~unicaticoonn trol unit 153 may, for example, map
s y ~ t e ~itinfo r~iiatiotii ncluding the radio resource information otito a radio resource
allocated to that system information. Consequently, the radio resource information
is transmitted as part of the system itiformation. Note that tlie radio resource
infortnation may also be transmitted by individual signaling to the terminal device
10 200, instead of being transn~itted as patt of tlie system infortnation.
[0148]
(Tertninal device 200: itiformation acquisition unit 261)
Particularly, in tlie third modification, the information acquisition unit 261
acquires radio resource informatioti indicating a predetertiiined radio resource for
15 transmitting informatiot~t o be reported after the transmission of a discovery signal.
The specific content of the radio frame itiformation is as discussed earlier.
[0 1491
For example, the radio resource inforn~atiotl is transmitted by the base
station 100 as part of the systetn informatioti. hi this case, the information
20 acquisition unit 261 acquires tlie radio resource illformation included in the above
system information.
[also]
Note that the radio resource may also be tratisniitted by individual signaling
to tlie tern~inal device 200, instead of being transmitted as part of tlie system
26 information. Also, the radio resource information tilay also be stored in advance it1
the ter~ninal device 200 (storage unit 230), without being transmitted by the base
station 100.
[0151]
(Terminal device 200: comniunication control unit 263)
- Control related to tratlstnission of discovery signal
Patticularly, in the third modificatioti, the comtiiut~ication control unit 263
controls the transmission of information to be reported so that the information to be
reported is transmitted in a predetemlined radio resource after the tratlsmission of a
discovery signal.
[0 1521
-- First provision accounting for collisions between terminal devices
For example, a discovely signal includes a signal sequence con~mona nlong
terminal devices 200. Additionally, the commut~ication control unit 263 controls
the transn~issiono f information to be reported so that the information to be reported
is transnlitted in one of the radio resources from among the predeternlitled radio
resources after the transn~issiono f a discovery signal.
[0153]
As a specific example, referring again to FIG 15, the texminal device 200,
according to control by the cotnmunicatiot~ control unit 263, transmits a discovery
signal in the radio resource 41, and after that, trnnslnits information to be repoited in
one of the radio resources 43A to 43.J. As one example, the terminal device 200
transmits the information to be reported in the radio resource 43A.
[0154]
Note that another terminal device 200 likewise may transmit a discovery
signal in the radio resource 41, and after that, transmit infornlation to be reported in
one of the radio resources 43A to 435. In this case, both the terminal device 200
and the other terminal device 200 transmit a discovery signal in the same radio
resource 41, but a discovery signal is detected appropriately by the terminal device
200 on the receiving side. The reason for this is because the sequence in the
discovery signal is common among the tert~~inadle vices 200, and thus even if
discovery signals collide, the correlator suitably detects a discovery signal sinlilarly
to the detection of a reflected wave. As another example, the other terminal device
200 transmits informati011 to be reported in a radio resource other than the radio
resource 43A kom among the radio resources 43A to 435. Thus, the informatiot~ to
be reported that is transnlitted by the terillinal device 200 and the information to be
reported that is transmitted by the other terminal device 200 are both received and
acquired appropriately by the terminal device 200 on the receiving side.
[0155]
For exatnple, in this way, the discovery signal it~cludesa signal sequence
common among the tern~inal devices 200, and infor~nation to be reported is
transmitted i11 one of the radio resources fi-om anlong the predetermit~ed radio
5 resources. Consequently, for ,example, even if multiple terminal devices 200
tratlsmit a discovery sig~laal nd infortnation to be repo~tedt,h e terminal device on the
receiving side beco~~~abeles to detect the discovery signals appropriately, and in
addition, there is a higher likelihood of the infor~nationt o be reported being received
and acquired appropriately by the terminal device on the receiving side.
10 [0156]
-- Second provisio~ac~c ounting for collisions between terminal devices
Even if a predeterrnir~edp lurality of radio resources is prepared as discussed
above, there is still a possibility of two or Illore terminal devices 200 transmitting
infor~~~atito nb e reported in the same radio resource (for example, in the radio
15 resource 43Aillustrated in FIG. 15).
[0157]
Accordingly, for example, the com~nu~~icatcionnt rol unit 263 controls the
transmission of i~~formattioo b~e~ r eported so that every titne a discovery signal is
transmitted, the radio resource in which the information to be reported is transmitted
20 changes from one radio resource among the predetermined radio resources to another
radio resource among the predetermined radio resources.
[0158]
As a specific example, referring again to FIG. 15, in a radio frarne for
transmitting a discovery signal, the ternlinal device 200, according to control by the
25 con~municationc ontrol uuit 263, transmits a discovery signal in the radio resource 41,
and after that, transmits information to be reported in the radio resource 43A.
Subsequently, in the next radio frame for transmitting a discovery signal, the terminal
device 200, according to cot~trobl y the comn~unicationc ot~troul nit 263, additionally
transmits a discovery signal in the radio resource 41, and after that, transmits
30 infor~~lattioo b~e~ r eported in one of the radio resources 43B to 435.
[0159]
Note that the co~iiniiu~iicatiocno ntrol unit 263 is able to change the radio
resource it1 which tlie information to be reported is tra~isniitted by selecting tlie itli
radio resource from among the predetermined radio resources as the radio resource
according to the followi~igfo r~iiula.
5 [0160] - .
[Math. 11
[0161]
Herein, x is the SFN of the radio frame in which tlie discove~y signal is
10 transmitted, and y is an ID of the terminal device 200 (such as a unique ID in the
subscriber identification tiiodule (SIM), or a cell-radio network temporary identifier
(C-RNTI), for example). Also, z is tlie nuuiber of radio resources ill tlie
predetermined radio resources. Note that the co~iimu~iicatiocno ntrol unit 263 may
also select the radio resource in which tlie inforniatio~to~ be reported is transmitted
15 by using a ra~~donnuim ber or the like instead ofthe above formula.
[O 1621
Consequently, for example, the possibility of two or more terminal devices
200 transmitting infor~iiatio~toi be reported in the same radio resource may be
reduced.
20 [0163]
- Control related to detection of discovery signal
Pa~ticularly,i n the third niodification, tlie corn~~iunicatiocroi ritrol unit 263,
after the detection of a discovery sigtial, acquires informati011 received in a
predetermined radio resource for trans~~iitti~inifgo rmation to be reported after tlie
25 transniission of a discove~ys ignal.
[0164]
For example, the con~n~unicaticoo~~i itroul nit 263, after the detection of a
discovery signal, acquires i~ifortiiatio~rei ceived in each of predeter~llined radio
resources for traus~iiitting inforulatio~i to be reported after the transtilission of a
discovely signal.
[O 1651
As a specific example, referring again to FIG 15, the terminal device 200,
5 accordi~igto control by the corntiiuuication control unit 263, co~lductsth e detection
process on a signal transmitted in the radio resource 41, and detects a discovery
signal. Subsequently, tlie co~ntnunicatioti control unit 263 acquires inforniation
received in each of the radio resources 43A to 43J. For example, the information
received in olie of the radio resources 43A to 43J is itiforrnatioti to be reported from
10 another terminal device 200 that transniitted a discovery signal. For this reason, the
comtiiunication cotitrol unit 263 acquires the information to be reported.
[O 1661
(Process flow: communicatioti control process on base station side)
FIG 16 is a flowchart illustrating an example of a schematic flow of a
15 communicatioti control process on tlie base station side according to a third
modification of an emboditnetit of the present disclosure.
[0167]
First, the inforniation acquisition unit 151 acquires systetn information
including radio resource infortnation indicating predetermined radio resources for
20 transmitting itifor~nationt o be reported after the transmission of a discovery signal
(S43 1).
[0168]
Subsequently, the base station 100, according to control by the
communication control unit 153, transmits the system informatioti includi~lg the
25' radio resource information (S433). The process then etids.
[0169]
Note that the conimunication control process discussed above is conducted
every time the system infor~nationis transmitted.
[O 1701
30 (First comniunication control process on terminal device side: transmission
of discovery signal and the like)
FIG. 17 is a flowchart illustrating an exanlple of a schematic flow of a first
connnunication control process on the terminal device side according to a third
~nodification of an embodiment of the present disclosure. The first co~nnlunication
control process is conducted when the terminal device 200 transmits a discovery
5 signal and infortnation to be reported.
[0171]
First, the comn~unicatioc~o~n trol unit 263 selects, from among the
predetermined radio resources, a radio frame in which information to be reported is
transmitted (S531).
10 [0172]
Subsequently, if the radio frame is not a radio frame for transmitting a
discovery signal (S533; No), a discovery signal is not transmitted. Subsequently,
the system fratne number is incrernented (S534), and the process returns to step S533.
[0173]
15 011 the other hand, if the radio frame is a radio fia~nef or transmitting a
discovery signal (S533; Yes), the terminal device 200, according to control by the
communication control unit 263, transmits a discovery signal in the radio frame
(S535). Furthermore, the terminal device 200, according to control by the
communication control unit 263, transn~itsi nformation to be reported in the selected
20 radio resource (S537). Subsequently, the system frame nunlber is incremented
(S539), and the process returns to step S531.
[0 1741
(Second conl~nunicationc ontrol process on terminal device side: acquisition
of infor~nationt o be reported)
25 FIG. 18 is a flowchart illustrating an example of a schematic flow of a
second cot~lmunication control process on the tern~inal device side according to a
third modification of an etnbodiment of the present disclosure. The second
co~nmunication control process is conducted after the terminal device 200 detects a
discovery signal.
30 [0175]
First, the ter~ninald evice 200 receives information in each of predeternlined
radio resources (S63 1).
[0 1761
Subsequently, the commutlication control unit 263 acquires the information
received in each of the predetern~ined radio resources (S633). The process then
5 ends.
[0177]
<5.4. Fourth modification>
Next, a fourth modification of an embodiment of the present disclosure will
be described with reference to FIG. 19.
10 [0178]
(Summary)
In the fourth modification, if individual transmission information related to
radio fratnes for transt~~ittinga discovery signal by a terminal device 200 is
transmitted by each of one or more terminal devices 200 positioned within an area,
15 the base station 100 acquires the individual transmission information. Subsequently,
the base station 100 transnlits aggregate transn~ission information related to radio
frames for transmitting a discove~ys ignal by the one or more terminal devices 200.
[0 1791
Consequently, for example, when a terniinal device 200 positioned within
20 an area conducts the detection process for detecting a discovery signal, it becomes
possible to conduct the detection process in the necessary and sufficient radio frames.
For this reason, it becomes possible to moderate the load on the terrninal device 200.
[0180]
Specifically, for example, when none of the terminal devices 200 positioned
25 within an area is transmitting a discovery signal for a collision warning, conducting
the detection process in a radio frame for transmitting a discovery signal for a
collision warning is wasteful for a terminal device 200 conducting the detection
process within that area. Accordingly, by transtnitting the aggregate transmission
infortnation to the terminal device 200, the ternlinal device 200 becomes able to
30 identify the necessary and sufficient radio frames in which the detection process is
conducted. For this reason, the load on the tern~inald evice 200 may be moderated.
[0181]
Also, in tlie fourth modification, if individual detection information related
to radio frames for cotiductitig a detection process for detecting a discovery signal by
a terminal device 200 is transmitted by each of one or more tenninal devices 200
5 positioned within an area, the base station 100 acquires the individual detection
information. Subsequently, the base station 100 transmits aggregate detection
information related to radio frames for conducting the detection process by the one or
more terniinal devices 200.
[0 1821
10 Consequently, for example, when a terminal device 200 positioned within
an area transmits a discovery signal, it becomes possible to transmit the discovery
signal in the necessary and sufficient radio frames. For this reason, it becomes
possible to moderate the load on the terminal device 200.
[0 1831
15 Specifically, for example, when none of the terminal devices 200 positioned
within an area is detecting a discovery signal for a collision warning, transmitting a
discovery signal in a radio frame for transn~ittinga discovety signal for a collision
warning is wasteful for a terniinal device 200 transniitting a discovery signal within
that area. Accordingly, by transmitting the aggregate detection information to tlie
20 terminal device 200, the terminal device 200 becomes able to identify tlie necessary
and sufficient radio frames in which a discovery signal is transmitted. For this
reason, the load on tlie terminal device 200 may be moderated.
[0 1 841
Q3ase station 100: information acquisition unit 151)
- Individual transmission infor~nation
Particularly, in the foutth modification, for example, if individual
transmission irifornlation related to radio frames for transmitting a discovery signal
by a terminal device 200 is transmitted by each of one or more tenninal devices 200
positioned withiti an area, the information acquisitioti unit 151 acquires the
30 individual transmission information.
[0185]
The area is the coverage (that is, the cell 10) of tlie base station 100, for
example. Note that the area may also be a smaller area included in the coverage
(sucli as one fro111 among multiple sectors included in the cell 10, or an area
corresponding to a beam formed by beamforming, for example).
5 [0186]
For example, the radio fiame in which a discovery signal is transmitted is
predefined for each purpose of D2D communication. In this case, for example, the
individual transmission inforniation is infortnation indicating the purpose of D2D
comtnunication for the terminal device 200. Consequently, which radio frames may
10 be used to transmit a discovery signal by the terminal device 200 that transmitted the
individual transmission information may be ascertained froln the individual
tratlsrnissioti infortnation.
[OI 871
Note that the individual transniissior~ information is not limited to
15 informatioti indicating the purpose of D2D comtnunication for the terminal device
200, aud may also be other information. For exaniple, the individual tratlsmission
information may also be informatioti indicating a cycle of transmission of a
discovery signal by the terminal device 200. Consequently, what kind of cycle on
which a discovery signal may be transmitted by the terminal device 200 that
20 transmitted the individual transmission information may he ascertained from the
individual transmission infortnation, and as a result, which radio fratnes may be used
to transmit a discovery signal by the terminal device 200 that transmitted the
individual tratismission inforniatiori may be ascertained.
[0188]
- Individual detection iuforn~ation
Also, particularly in the fourth modification, for example, if individual
detection information related to radio frames for conducting a detection process for
detecting a discovery signal by a terliiinal device 200 is transmitted by each of one or
more terniinal devices 200 positioned within an area, tlie information acquisition unit
30 15 1 acquires tlie individual detection information.
[0 1891
As discussed above in relation to the individual transmission information,
the area is the coverage (that is, tlie cell 10) of the base station 100, for example.
Note that the area may also be a smaller area included in the coverage.
[0 1901
5 For example, the radio fkame in which a discovery signal is transmitted is
predefined for each purpose of D2D con~munication. In this case, the individual
detection information is information indicating the purpose of D2D conimunication
for the terminal device 200, for example. Consequently, which radio frames may be
used to coliduct the detection process by the terminal device 200 tliat transmitted the
10 individual detection information may be ascertained from the individual detection
information.
[0191]
Note tliat the individual detection information is not litnited to information
indicating the purpose of D2D conimunicatioti for the terminal device 200, and may
15 also be other information. For example, the individual detection information may
also be information indicating a cycle of the detection process by the terminal device
200. Consequently, what kind of cycle on which the detection process may be
conducted by the terminal device 200 that transmitted the individual detection
information niay be ascertained from the individual detection information, and as a
20 result, which radio frames niay be used to conduct the detection process by the
terminal device 200 that tratisnlitted tlie individual detection itiformation may be
ascertained.
[0 1921
(Base station 100: cot~i~nut~icactioontt~ro l unit 153)
-. Control related to transmission of aggregate transmission informatiot~
Particularly, in the fourth niodificatioti, the comtnnnication control unit 153
controls the transmission of aggregate tratistiiission information related to radio
frames for transmitting a discovery signal by one or more terniinal devices 200 that
provide the it~dividuatlr anstnission infor~natiot~.
30 [0193]
The aggregate trat~slnission inforn~ation is fortned by aggregating
information indicated by individual transmission information provided by the one or
more terminal devices 200, for example. Subsequently, the generated aggregate
transn~ission information is transmitted to terminal devices 200 within the area,
according to control by the communication control unit 153.
5 [0194]
For example, the radio frame in which a discovery signal is transmitted is
predefined for each purpose of D2D comtnunication. In this case, for example, the
aggregate transmission information is information indicating the purpose of D2D
communication for the one or more terminal devices 200. Consequetitly, which
10 radio frames may be used to transmit a discovery signal by the one or more terminal
devices 200 positioned within the area may be asce~tained from the aggregate
transmission infonnation.
[0195]
Note that the aggregate transmission information is not lirnited to
15 information indicating the purpose of D2D co~nn~unicatiofnor the terminal device
200, and may also be other information. For example, the aggregate transtnission
infor~nation may also be information indicating a cycle of transmission of a
discovery signal by the one or more terminal devices 200 within the area.
Consequently, what kind of cycle on which a discovery signal may be transmitted by
20 the one or more terminal devices 200 positioned within the area may be ascertained
from the aggregate transmission inforn~ationa, nd as a result, which radio frames may
be used to transmit a discovery signal by the one or more ter~ninadl evices 200 within
the area may be ascertained.
[0196]
25 - Control related to trans~nissiono f aggregate detection information
Also, particularly in the fourth modification, the comniunicatiot~c ontrol unit
153 controls the trans~nission of aggregate detection information related to radio
frames for conducting the detection process by one or more ter~ninald evices 200 that
provide the individual detection infonnation.
30 [0197]
The aggregate detection infor~nation is generated by aggregating
infortnation indicated by individual detection infortnation provided by the one or
more ter~ninal devices 200, for example. Subsequently, the generated aggregate
detection informati011 is trans~iiitted to terminal devices 200 within the area,
according to control by the conin~unicationc ontrol unit 153.
6 [0198]
For example, the radio frame in which a discovely signal is transmitted is
predefined for each purpose of D2D com~nunication. 111 this case, for example, the
aggregate detection information is infor~nation indicating the purpose of D2D
com~nunication for the one or more terminal devices 200. Consequently, which
10 radio frames may be used to conduct the detection process by the one or more
terminal devices 200 positioned within the area Inay be ascertained fro111 the
aggregate detection information.
[0199]
Note that the aggregate detection infornlation is not limited to information
15 indicating the purpose of D2D comtnunication for the terminal device 200, and may
also be other information. For example, the aggregate detection information niay
also be information indicating a cycle of the detection process by the one or more
terminal devices 200 within tlie area. Consequently, what kind of cycle on which
the detection process nlay be conducted by the one or more terminal devices 200
20 positioned within the area may be ascertained from the aggregate detection
information, and as a result, which radio frames may be used to conduct the detection
process by the one or more terminal devices 200 within the area may he ascertained.
[0200]
(Terminal device 200: information acquisition unit 261)
25 - It~dividuatlr ansn~issioni nfornlation
Particularly, in the fourth embodiment, for example, the infortnation
acquisition unit 261 acquires individual transmission information related to radio
frames for transtiiitting a discovery signal by a terminal device 200. For example,
the individual transnlissioti inforniation is stored in advance in the storage unit 230.
30 Subsequently, tlie information acquisition unit 261 acquires the individual
trans~i~issioinnf ortnation fro111 the storage unit 230.
[0201]
- Individual detection informati011
Also, particularly in the fourth enlbodin~etlt, for example, the it~for~nation
acquisition unit 261 acquires individual detection inforn~ationre lated to radio frames
5 for co~lducting a detection process for detecting a discovery signal by a terminal
device 200. For example, the individual detection information is stored in advance
in the storage unit 230. Subsequently, the infornlation acquisition unit 261 acquires
the individual detection inforn~ationfr om the storage unit 230.
[0202]
10 - Aggregate transtnission information
Also, particularly in the fourth embodimel~t, for example, the information
acquisition ut~it 261 acquires aggregate transmission information related to radio
frames for transmitting a discovery signal by one or more terminal devices 200
positioned within an area. For example, the aggregate transmission inforn~ationi s
15 transmitted by the base station 100, and received by the terminal device 200.
Subsequently, the informatio~a~c quisitio~u~n it 261 acquires the received aggregate
transmission information.
[0203]
-Aggregate detection illfortnation
20 Also, particularly in the fourth embodiment, for example, the information
acquisition unit 261 acquires aggregate detection information related to radio frames
for co~~ductitrh~eg d etection process by one or more terminal devices 200 positioned
within an area. For example, the aggregate detectiot~in formation is transmitted by
the base station 100, and received by the terminal device 200. Subsequently, the
25 information acquisition unit 261 acquires the received aggregate detection
information.
[0204]
(Terminal device 200: con~t~lunicatiocnon trol unit 263)
- Control related to transmission of discovery
-- Transmission of individual transmission illformation
Particularly, in the fourth embodiment, for example, the comn~unication
co~itroul nit 263 controls the tratistilission of the individual transmission infoniiatioti
to tlie base station 100.
[0205]
For example, the coniniunication control unit 263 maps a signal of
5 infortiiation including tlie individual transtnission inforniatioti onto an uplink radio
resource allocated to the termi~ial device 200. Consequently, the individual
transmission infor~iiatiois~ t~ra nsmitted to tlie base station 100.
[0206]
-- Transmission of discovery signal based on aggregate detectio~i
10 information
Particularly, in the fourth embodiment, the cotnmutiication control unit 263
controls the trat~stnissiotoi f a discovery signal on the basis of the aggregate detection
inforn~ation.
[0207]
15 For example, from the aggregate detection information, the cot~nnunication
control unit 263 knows the radio frames for conducting the detection process by the
one or more terminal devices 200 positioned within the area. Additionally, the
communication control unit 263 sets a radio frame for conducting the detection
process by tlie one or more terminal devices 200 fiom among tlie radio frames for
20 tratismittitig a discovery signal by the terminal device 200 as the radio frame in
which the terminal device 200 will actually transmit the discovery signal. After that,
the terminal device 200 transmits the discove~y signal in the set radio frame, and
does not transmit a discovery signal in other radio fianies.
[0208]
25 As an example, the purposes of D2D communication for the terminal device
200 include a first purpose (for example, a collision warning) atid a second purpose
(for example, a fire alert). In addition, the aggregate detection information indicates
that tlie purpose of D2D co~n~nutiicatiofno r any one of the one or more terminal
devices 200 does not include tlie first purpose, whereas the purpose of D2D
30 conimunicatioti for any one of the one or more terminal devices 200 includes the
second purpose. In this case, the communication control unit 263 sets tlie radio
frame for tra~lsniittinga discovery signal for D2D co~iimunicationw ith the purpose
of the second purpose as tlie radio fratne in which the teniiinal device 200 will
actually tl.ansmit the discovery signal. After that, the terminal device 200 transmits
the discovery signal in the set radio frame. In other words, the terminal device 200
5 transniits a discovery signal in the radio frame corresponding to the second purpose,
and does not trarisniit a discovery signal in other radio frames (such as a radio frame
corresponding to tlie first purpose and not corresponding to the second purpose, for
example).
[0209]
10 - Control related to detection of discovery signal
-- Transmission of individual detection inforrnatioti
Particularly, in the fourth embodiment, for example, the cotiimunication
control unit 263 controls tlie transmission of tlie individual detection itifor~iiationto
the base station 100.
15 [0210]
For example, tlie com~nunication control unit 263 maps a signal of
itiformation including the individual detection information onto an uplink radio
resource allocated to the terminal device 200. Consequently, the individual
detection itifornlation is transmitted to tlie base station 100.
20 [0211]
-- Detection of discovery signal based on aggregate trat~smissiotl
information
Particularly, in tlie fourth embodinietit, tlie coriltiiu~iicationc ontrol unit 263
controls the detection process for detecting a discovery signal, on the basis of the
25 aggregate transmission information.
[0212]
For example, fro111 the aggregate transmission information, the
co~n~nutiicatiocno ntrol unit 263 knows the radio frames for transmitting a discovery
signal by the one or more terniinal devices 200 positioned within the area.
30 Additionally, the conimunication colitrol unit 263 sets a radio frame for transmitting
a discovery signal by the one or more terminal devices 200 from among the radio
frames for conducting the detection process by the termi~lal device 200 as the radio
frame in which the terminal device 200 will actually conduct the detection process.
After that, the terminal device 200 cotlducts the detection process in the set radio
frame, and does not conduct the detection process in other radio frames.
5 [0213]
As an example, the purposes of D2D cotntnunicatiot~fo r the terminal device
200 include a first purpose (for example, a collision warning) and a second purpose
(for example, a fire alert). In addition, the aggregate transmission it~formation
indicates that the purpose of D2D cotnmunication for any one of the one or more
10 terminal devices 200 does not iticlude the first purpose, whereas the purpose of D2D
comniunication for any one of the one or more terminal devices 200 includes the
second purpose. In this case, the cotnmunicatio~l control unit 263 sets the radio
frame for transmitting a discovery sigtial for D2D communication with the purpose
of the second purpose as the radio frame in which the terminal device 200 will
15 actually conduct the detection process. After that, the terminal device 200 conducts
the detection process in the set radio frame. It1 other words, the tenninal device 200
conducts the detection process in the radio frame corresponditig to the second
purpose, and does not conduct the detection process in other radio frames (such as a
radio frame correspondit~gt o the first purpose and not correspo~ldi~ltgo the second
20 purpose, for example).
[0214]
(Process flow)
FIG. 19 is a sequence diagram illustrating an example of a scl~ematicfl ow of
a communication control process according to a fourth modification of an
25 embodiment of the present disclosure.
[0215]
The terminal device 200 transmits, to the base station 100, individual
trans~nission information related to radio frames for tratlsmittitig a discovery sigtial
by the terminal device 200, atld individual detection infornlation related to radio
30 f?ames for conducting a detection process for detecting a discovery signal by the
terminal device 200 (S701). Subsequently, the base station 100 acquires the
individual detection information.
[02 161
Subseqnelitly, the base station 100, on the basis of tlie individual
transmission information transmitted by one or more ternlitla1 devices 200 positioned
5 within the area, generates aggregate tra~ismission information related to radio frames
for transmitting a discovery signal by the one or more ternii~ial devices 200 (S703).
Also, the base station 100, on the basis of tlte individual detection information
translnitted by one or more terminal devices 200 positioned witllill the area,
generates aggregate detection information related to radio frames for conducting the
10 detection process by the one or more termilia1 devices 200 (S705). Subsequetitly,
the base station 100 transmits the aggregate transmission informati011 atid the
aggregate detection inforniatioti to tlie terminal device 200 (S707).
[02 171
After that, the tertiiitial device 200, on the basis of the aggregate
15 transmission information, sets the radio frame in which the terminal device 200 will
actually conduct the detection process (S709). After that, the tenilinal device 200
coliducts the detection process it1 the set radio frame. Also, the terminal device 200,
on the basis of the aggregate detection information, sets the radio frame in which the
terminal device 200 will actually transmit a discovery signal (S711). After that, the
20 terminal device 200 tra~ismitsth e discovery signal in tlie set radio frame.
[02 181
6 . 5 . Fifth modification>
Next, a fifth modification of an embodiment of the present disclosure will
be described with reference to FIGS. 20 to 22.
25 [0219]
(Summary)
In the fifth modification, when the mode of the terminal device 200 is a
contiected mode, the teniiinal device 200 conducts a detection process for detecting a
discovery signal at a first frequency of repetition, whereas when the mode of the
30 terminal device 200 is an idle mode, tlie terminal device 200 conducts the detection
process at a second frequency of repetition lower than the first frequency of
repetition.
[0220]
Consequently, it becon~esp ossible to moderate the load on a termi~iadl evice
200 in idle mode, for exaniple. Specifically, for example, in idle mode, the
6 frequency of repetition of the detection process by the terminal device 200 becomes
lower, making it possible to moderate power consutnption in the ternlinal device 200.
[0221]
(Terminal device 200: co~iimunication control unit 263)
Particularly, in the fifth modification, the communication control unit 263
10 conitrols a detection process for detecting a discovery signal so that when the mode of
the tertninal device 200 is a connected mode, the detection process is conducted at a
first frequency of repetition. Also, the co~nmunicatioti control unit 263 controls the
detection process so that when the mode of the terminal device 200 is an idle mode,
the detection process is conducted at a second frequency of repetition lower than the
15 first frequency of repetition. For example, the connected mode is the Radio
Resource Control (RRC) mode, while the idle 111ode is the RRC idle mode.
Hereinafter, a specific example of the frequency of repetition of the detection process
in connected mode and idle mode will be described with reference to FIG 20.
[0222]
20 FIG 20 is an explanatoly diagram for illustratitig an example of the
frequency of repetition of a detection process in cotit~ected mode and idle mode.
Referring to FIG 20, when tlie mode of the terminal device 200 is connected mode,
the terminal device 200 conducts a detection process for detecting a discovery signal
on a conliected mode cycle 51. The connected mode cycle 51 is 100 nis, for
25 example. On tlie other hand, when tlie mode of the terniinal device 200 is idle
mode, tlie terminal device 200 conducts a detection process for detecting a discovery
signal on an idle mode cycle 53. The idle niode cycle 53 is longer than the cycle 51,
and is 300 ms, for example. In this way, in the case in which tlie mode of the
terminal device 200 is idle niode, the frequency of repetition of the detection process
30 is lower than in the case in which tlie mode of the terminal device 200 is connected
mode.
Note that the co~il~nunicatiocno ntrol unit 263 nlay also cotitrol the detection
process so that when the ntode is idle mode, the detection process is conducted at a
third frequency of repetition if the ter~ni~tadle vice 200 is positioned inside the
5 coverage of the base station 100, and the detection process is conducted at a fou~th
frequency of repetition lower than the third frequency of repetition if the terminal
device 200 is positioned outside the coverage. Hereinafter, a specific example
regarding this point will be described with reference to FIG 21.
[0224]
10 FIG. 21 is an expla~~atordyi agram for illustrating an example of an incoverage
detection process and the frequency of repetition of the in-coverage
detection process. Referring to FIG 21, when the mode of the terminal device 200
is connected mode, the terminal device 200 conducts a detection process for
detecting a discovery signal on a coru~ected.~nodcyec le 51. As discussed above,
16 the connected mode cycle 51 is 100 ms, for example. Also, when the mode of the
terminal device 200 is idle mode, the terminal device 200 conducts the detection
process on a first idle mode cycle 55 if the terminal device 200 is positioned inside
the coverage of the base station 100. The first idle mode cycle 55 is longer than the
connected mode cycle 51, and is 300 ms, for example. Also, wlleen the mode of the
20 terminal device 200 is idle mode, the terminal device 200 conducts the detection
process on a second idle mode cycle 57 if the terminal device 200 is positioned
outside the coverage of the base station 100. The second idle mode cycle 57 is
longer than the first idle mode cycle 55, and is 600 Ins, for example. When the
mode of the ter~lli~d~eavli ce 200 is idle mode, the frequency of repetition of the
25 detection process is lower in the case in which the terminal device 200 is positioned
outside the coverage of the base station 100 than in the case in which the tern~inal
device 200 is positio~iedi nside the coverage of the base station 100.
[0225]
Conseque~~tlfyo, r example, it becomes possible to further moderate the load
30 on a terminal device 200 positioned outside the coverage of the base station 100.
Specifically, for example, when the terminal device 200 is positioned outside the
coverage of tlie base station 100, the frequency of repetition of the detection process
by the tertilitial device 200 becotnes particularly lower, making it possible to
moderate power consumption it1 the terrllitlal device 200 positioned outside the
coverage of tlie base station 100. Since the nuniber of terminal devices 200 outside
5 the coverage of tlie basestation 100 is also low, the possibility of a discovery signal
being transmitted is lower For this reason, lowering tlie frequeacy of repetition of
tlie detection process outside ilie coverage as described above is effective.
[0226]
(Process flow)
10 FIG 22 is a flowchart illustratilig an example of a schematic flow of a
cotnmutlicatioti control process on the terniinal device side according to a fifth
modification of an embodiment of the present disclosure. The conimunication
control process is conducted when the terminal device 200 in idle mode conducts the
detection process for detecting a discovery signal.
15 [0227]
When the radio frarile is a radio frame for transmitting a discovery signal
(S651: Yes), atid a cycle for idle mode arrives (S653: Yes), the terminal device 200,
according to cotitrol by the comniunication cotitrol unit 263, conducts the detection
process for detecting a discovery signal on the signal transmitted in the radio kame
20 (S655). Subsequently, the systeni fiame tiulilber is incremetited (S657), and the
process is repeated.
[0228]
On the other hand, if the radio fian~eis not a radio frame for transmitting a
discovery signal (S651: No), or if a cycle for idle mode does not arrive (S653: No),
25 the detection process is not conducted on the signal transmitted in the radio frame.
Subsequently, the systeni frame number is increnlented (S657), and the process is
repeated.
[0229]
<<6. Applicatiotis>>
30 Technology according to the present disclosure is applicable to various
products. For example, the base station 100 may be realized as an evolved Node B
(em) of any type, sucli as a macro eNB or a small e m . A small eNB may be an
eNB that covers a cell smaller than a tliacro cell, such as a pico eNB, micro eNB, or
home (fenito) eNB. Cotlversely, tlie base station 100 may also be realized as
another type of base station, sucli as a NodeB or a base tratisceiver station (BTS).
5 Tlie base station 100 may also include a maill unit that controls radio co~nmunication
(also called a base station device), and one or lilore remote radio heads (RRHs)
placed it1 a location separate frotii the main unit. Additionally, various types of
terminals to be discussed later niay also operate as the base station 100 by
temporarily or semi-permanently executing a base station function.
10 [0230]
In addition, tlie terminal device 200 may be realized as, for example, a
mobile terminal such as a smattphone, a tablet personal conlputer (PC), a notebook
PC, a portable game cotisole, a portablddongle-style mobile router, or a digital
camera, or as an in-vehicle terminal sucli as a car navigation device. In addition,
15 the terminal device 200 may also be realized as a terminal that conducts machine-tomachine
machine (M2M) co~nmunication( also called a maclii~ie-typec omniunication (MTC)
terminal). Furthermore, the terminal device 200 may he a radio communicatio~~
module mounted onboard these terminals (for example, an integrated circuit module
configured on a single die).
20 [0231]
<6.1. Applications related to base station>
(First application)
FIG. 23 is a block diagram illustrating a first example of a schematic
configuration of an eNB to which technology according to an eniboditne~it of tlie
25 present disclosure may be applied. At1 eNB 800 includes one or more antennas 810,
and a base station device 820. The respective antennas 810 and the base station
device 820 may be connected to each other via an RF cable.
[0232]
Each antenna 810 includes a single or multiple antenna eletnetits (for
30 example, ninltiple antenna elemetits constituting a MIMO antenna), atid is used by
tlie base station device 820 to transmit and receive radio signals. The eNB 800 may
include multiple antennas 810 as illustrated in FIG. 23, arid the niultiple antennas 810
tilay respectively correspond to ~nultiple frequency batids used by the eNB 800, for
exan~ple. Note that although FIG 23 illustrates an example of the eNl3 800
including multiple antennas 810, the eNB 800 tnay also it~cludea single antenna 810.
5 [0233]
The base station device 820 is equipped with a controller 821, memory 822,
a network interface 823, and a radio coti~munication interface 825.
[0234]
The controller 821 may be a CPU or DSP, for exan~ple,a nd causes various
10 higher-layer htictions of the base station device 820 to operate. For example, the
colitroller 821 generates a data packet from data inside a signal processed by tlie
radio comtnunicatio~i interface 825, and forwards tlie generated packet via the
network interface 823. Tlie cotitroller 821 may also generate a bundled packet by
bundling data froni multiple baseband processors, and forward tlie generated bundled
15 packet. In addition, tlie controller 821 may also include logical functions that
execute controls such as Radio Resource Control (RRC), Radio Bearer control,
mobility management, admissioti control, or scheduling. Also, such controls tnay
also be executed in coordination with a nearby eNB or core tietwork node. Tlie
memory 822 includes RAM and ROM, and stores programs executed by the
20 controller 821 as well as various cot~trodl ata (such as a terminal list, transmit power
data, and scheduli~igd ata, for example).
[0235]
The network interface 823 is a commu~~icatioitnit erface for connecting tlie
base station device 820 to a core network 824. The controller 821 niay also
25 con~tuunicationw ith a core network node or another eNB via the network interface
823. In this case, the eNB 800 atid tlie core network tiode or other eNB may be
cotu~ectedt o each other by a logical interface (for example, the S1 interface or the
X2 interface). The tietwork interface 823 may also be a wired con~ti~unication
interface, or a wireless cominunication interface for wireless backhaul. In tlie case
30 in which the network interface 823 is a wireless conimunication interface, the
network interface 823 tilay use a higher frequency band for wireless comn~unication
than the frequency band used by the radio com~~~unicatiinotner face 825.
[0236]
The radio co~nt~lunicatioin terface 825 supports a cellular communication
scheme such as Long Term Evolution (LTE) or LTE-Advanced, and provides a radio
5 connection to a terminal positioned inside the cell of the eNB 800 via an antenna 810.
Typically, the radio comtnunication interface 825 may include a baseband (BB)
processor 826, an RF circuit 827, and the like. The BB processor 826 may coltduct
processes such as encoding/decoding, modulation/demodulation, and
~nultiplexing/demuItiplexing, for example, and executes various signal processing in
10 respective layers (for example, L1, Medium Access Corltrol (MAC), Radio Link
Control (RLC), and Packet Data Cotlverge~~ceP rotocol (PDCP)). The BB
processor 826 [nay also include some or all of the logical functio~~diss cussed earlier
instead of the controller 821. The BB processor 826 may be a module it~cluding
menlory that stores a con~mu~~icatcionnt rol program, a processor that executes such
15 a program, and related circuits. The hnctio~~ofs t he BB processor 826 may also be
modifiable by updating the program. Also, the module may be a card or a blade
irlse~tedin to a slot of the base station device 820, or a chip mounted onboard the card
or the blade. Meanwhile, the RF circuit 827 may include colnponents such as a
mixer, a filter, and an amp, and transmits or receives a radio signal via an antenna
20 810.
[0237]
The radio communication interface 825 may also include multiple BB
processors 826 as illustrated in FIG. 23, and the ~nultiple BB processors 826 may
respectively correspond to multiple frequency bands used by the eNB 800, for
25 example. I11 addition, the radio communicatio~i~n terface 825 may also i~lclude
tllultiple RF circuits 827 as illustrated in FIG. 23, and the multiple RF circuits 827
may respectively correspond to multiple antenna elements, for example. Note that
although FIG. 23 illustrates an example of the radio com~nur~icatioinn terface 825
including ~llultiple BB processors 826 and 111ultiple RF circuits 827, the radio
30 co~n~nunicatioint erface 825 may also include a single BB processor 826 or a single
RF circuit 827.
[023 81
(Second application)
FIG 24 is a block diagram illustrating a secotid exatnple of a schematic
configuration of an eNB to which tecl~tiology according to an embodiment of the
presetit disclosure may be applied. An eNB 830 i~lcludeso ne or more anteluias 840,
a base station device 850, and an RRH 860. Tlie respective antennas 840 and the
RRH 860 may be corinected to eacli otlier via at1 RF cable. Also, the base station
device 850 and the RRH 860 may be connected to eacli otlier by a high-speed link
such as an optical fiber cable.
[0239]
Each antelilia 840 includes a single or multiple antenna eletnents (for
example, n~ultiplea titetina elements constituti~~ag M IMO antenna), and is used by
the RRH 860 to transmit and receive radio signals. Tlie eNB 830 may iticlude
multiple antennas 840 as illustrated in FIG 24, and the multiple atitemas 840 may
respectively correspond to multiple frequency bands used by the eNB 830, for
example. Note that althougl~ FIG 24 illustrates an exaruple of the eNB 830
including multiple atitennas 840, the eNB 830 may also include a single antenna 840.
[0240]
The base station device 850 is equipped with a controller 851, nieniory 852,
a network interface 853, a radio cotnmunication interface 855, and a connection
interface 857. The controller 851, the nienioty 852, and the network interface 853
are similar to the co~~trolle8r2 1, tlie tilemoly 822, and the network interface 823
described with reference to FIG 23.
[0241]
Tlie radio communication interface 855 supports a cellular co~n~i~utiication
scheme such as LTE or LTE-Advanced, atid provides a radio connection to a terti~itial
positioned inside a sector correspotidi~igt o the RRH 860 via tlie RRH 860 and an
antenna 840. Typically, tlie radio communication interface 855 niay include a BB
processor 856 and the like. The BB processor 856 is similar to the BB processor
826 described with reference to FIG 23, except for being connected to an RF circuit
864 of the RRH 860 via tlie connectiot~ interface 857. Tlie radio commu~iication
interface 855 niay also include ~liultipleB B processors 856 as illustrated in FIG 24,
and the nlultiple BB processors 856 lilay respectively correspond to ii~ultiple
frequency bands used by the eNB 830, for example. Note that although FIG. 24
illustrates an example of the radio co~llmunicationi nterface 855 i~lcludi~tlngu ltiple
6 BB processors 856, the radio comniu~iicationin terface 855 may also i~lcludea single
BB processor 856.
[0242]
The connection interface 857 is an interface for con~lectingt he base station
device 850 (radio communication interface 855) to the RRH 860. The co~ulectio~l
10 interface 857 may also be a conitnutlication module for co~il~nunicatiootni the highspeed
link connecting the base station device 850 (radio corilmunicatio~l interface
855) and the RRH 860.
[0243]
In addition, the RRH 860 is equipped with a con~iectioni nterface 861 and a
15 radio communication interface 863.
[0244]
The connection interface 861 is an interface for co~lnecting the RRH 860
(radio com~nunicationin terface 863) to the base station device 850. The connection
interface 861 may also be a communicatio~~~l iodulef or co~nmunicatiotlo n the high-
20 speed link.
[0245]
The radio co~n~iiunicatiointlt erface 863 transmits and receives a radio signal
via an antenna 840. Typically, the radio communicatio~in terface 863 may include
an RF circuit 864. The RF circuit 864 niay include components such as a mixer, a
25 filter, and at1 amp, and transnlits or receives a radio signal via an ante1111a 840. The
radio com~iiunication interface 863 may also include multiple RF circuits 864 as
illustrated in FIG. 24, and the multiple RF circuits 864 may respectively correspo~id
to ~iiultiplea ntenna eletuents, for example. Note that although FIG 24 illustrates an
example of the radio communication interface 863 i~lcluditigm ultiple RF circuits 864,
30 the radio coniniunication interface 863 may also include a single RF circuit 864.
[0246]
I11 the eNB 800 and the eNB 830 illustrated in FIGS. 23 and 24, the
information acquisition unit 151 and con~municationc ontrol unit 153 described with
reference to FIG. 3 may be implemetited in the radio communication interface 825 as
well as the radio communication interface 855 atidlor the radio comn~unication
5 interface 863: Also, at least some of these functions may also be implemented in
the controller 821 and the controller 851.
[0247]
<6.2. Applications related to terminal device>
(First application)
10 FIG 25 is a block diagram illustrating an example of a sche~natic
configuratiot~ of a smartphone 900 to which technology according to an embodiment
of the present disclosure may be applied. The sn~artphone9 00 is equipped with a
processor 901, nletnory 902, storage 903, an external connectiot~i t~te~fac9e0 4, a
camera 906, a sensor 907, a microphone 908, at1 input device 909, a display device
15 910, a speaker 911, a radio communication interface 912, one or more antenna
switches 915, one or more atlterulas 916, a bus 917, a battery 918, and at1 auxiliary
co~ltroller9 19.
[0248]
The processor 901 may be a CPU or system-on-a-chip (SoC), for example,
20 and controls functions in the application layer and other layers of the sn~attphone9 00.
The memory 902 includes RAhI and ROM, and stores programs executed by the
brocessor 901 as well as data. The storage 903 may iticlude a storage medium such
as setnico~~ductomre mory or a hard disk. The external connection interface 904 is
an interface for co~lnectinga t1 externally attached device, such as a nletnory card or
25 Universal serial Bus (USB) device, to the smartphone 900.
[0249]
Tlie camera 906 includes at1 image sensor such as a charge-coupled device
(CCD) or co~nplementarym etal-oxide-semiconductor (CMOS) sensor, and generates
a captured image. The sensor 907 may include a seusor group such as a positioning
30 sensor, a gyro sensor, a geotnagrietic sensor, and an acceleratio~s~en sor, for example.
The micropl~one 908 converts audio input into the stnartphone 900 into an audio
signal. Tlie input device 909 includes devices such as a touch sensor that detects
touches on a screen of the display device 910, a keypad, a keyboard, buttons, or
switches, and receives operations or infornlation input fro111 a usec Tlie display
device 910 includes a screen such as a liquid crystal display (LCD) or an organic
5 light-emitting diode '(OLED) display, and displays an output image of the
sniartphone 900. The speaker 911 converts an audio signal output fro111 tlie
smartphone 900 into audio.
[0250]
The radio communication interface 912 supports a cellular comnlunication
10 scheme such as LTE or LTE-Advanced, and executes radio comniunication.
Typically, the radio communication interface 912 may include a BB processor 913,
an RF circuit 914, and the like. The BB processor 913 may conduct processes such
as encoding/decoding, n~odulationldemodulation, and niultiplexing/den~ultiplexit~g,
for example, and executes various signal processing for radio communication.
15 Meanwhile, the RF circuit 914 may include components such as a mixer, a filter, and
an amp, and transmits or receives a radio signal via an antenna 916. The radio
communication interface 912 Inay also be a one-chip module integrating the BB
processor 913 and tlie RF circuit 914. The radio comniunication interface 912 may
also include multiple BB processors 913 atid multiple RF circuits 914 as illustrated in
20 FIG. 25. Note that although FIG 25 illustrates an example of tlie radio
commuliicatio~i interface 912 including multiple BB processors 913 and multiple RF
circuits 914, the radio comnlunication interface 912 may also include a single BB
processor 913 or a single RF circuit 914.
[025 11
25 Furthermore, in addition to a cellular conimunication scheme, the radio
con~mutiication interface 912 may also support other types of radio cotnmunication
sclienies such as a short-range wireless cotnmu~iications cheme, a near field wireless
co~iitnutiication scheme, or a wireless local area network (LAN) scheme. In this
case, a BB processor 913 and an RF circuit 914 niay be included for each radio
30 comniunication scheme.
[0252]
Each antenna switch 915 switches tlie destination of an antenna 916 among
tnultiple circuits included in the radio con~municatioli interface 912 (for example,
circuits for different radio cot~~r~~u~~sicchaemtieosn).
[0253]
5 Each antenna 916 iticludes a single or ~nultiple antenna elements (for
example, multiple antenna elements constituting a MIMO antenna), and is used by
tlle radio con~niunication interface 912 to transmit and receive radio signals. The
sniartplione 900 may also include nlultiple antennas 916 as illustrated in FIG 25.
Note that although FIG. 25 illustrates an example of the sniattplione 900 including
10 multiple antennas 916, the smartphone 900 may also include a single antenna 916.
[0254]
Furthermore, the smartphone 900 may also he equipped with an antenna 916
for each radio con~ti~utiicatiosnc hen~e. In this case, the antenna switch 915 may be
omitted fro111 the cotifiguration of the snlartphorie 900
15 [0255]
The bus 917 interconnects the processor 901, the metilory 902, the storage
903, the external connection interface 904, the camera 906, the sensor 907, tlie
tnicrophone 908, the input device 909, the display device 910, the speaker 911, tlie
radio con~n~ut~icatinotne rface 912, and the auxiliary controller 919. The battery
20 918 supplies electric power to the respective blocks of the stnartphone 900 illustrated
in FIG. 25 via power supply lines partially illustrated with dashed lines in the
drawing. The auxilia~yc ontroller 919 causes minimal functions of tlie smartphone
900 to operate while in a sleep mode, for exanlple.
[0256]
25 In the smartphone 900 illustrated in FIG. 25, the information acquisition unit
261 and tlie conimunication control unit 263 described with reference to FIG 5 may
be implemented in tlie radio communication interface 912. Also, at least sonie of
these functions niay also be impletnented in the processor 901 or tlie auxiliary
controller 919.
30 [0257]
(Second application)
FIG. 26 is a block diagram illustratit~g an exati~ple of a schematic
co~~figuratioonf a car navigation device 920 to whic11 tecl~nologya ccording to at1
en~bodin~eo~f tth e present disclosure may be applied. The car navigation device
920 is equipped with a processor 921, memory 922, a Global Positionitlg System
5 (GPS) module 924, a sensor 925, a data inte~face9 26, a content player 927, a storage
medium interface 928, an input device 929, a display device 930, a speaker 931, a
radio comniunication interface 933, one or more antenna switches 936, one or more
antetltlas 937, atid a battery 938.
[0258]
10 The processor 921 nlay be a CPU or SoC, for example, and controls a car
navigation function and other functions of the car navigation device 920. The
memory 922 itlcludes RAM and ROM, and stores programs executed by the
processor 921 as well as data.
[0259]
15 The GPS module 924 measures the position of the car navigation device 920
(for example, the latitude, longitude, and altitude) by using GPS sigaals received
from GPS satellites. The sensor 925 may include a sensor group such as a gyro
sensor, a geomagnetic sensor, and a barometric pressure sensor, for example. The
data interface 926 is connected to an in-vehicle network 941 via a port not illustrated
20 in the drawing, and acquires data generated on the vehicle side, such as vehicle speed
data.
[0260]
The content player 927 plays content stored on a storage tlledium (for
example, a CD or DVD) inserted into the storage n~ediunin~t erface 928. The input
25 device 929 includes devices such as a touch sensor that detects touches on a screen of
the display device 930, buttons, or switches, and receives operatiot~so r information
input fro111 a user. The display device 930 itlcludes a screen such as an LCD or
OLED display, and displays a r~avigatiotf~u nction or an image of played-back
content. The speaker 931 outputs audio of a navigation function or played-back
30 content.
[026 11
The radio colntnunication interface 933 supports a cellular comn~unication
scheme such as LTE or LTE-Advanced, and executes radio communication.
Typically, the radio comnlunication interface 933 may include a BB processor 934,
an RF circuit 935, and the like. The RB processor 934 tnay conduct processes such
5 as encoding/decoding, modulation/deniodulation, and n~ultiplexitlg/demultiplexing,
for example, and executes various signal processing for radio comniunication.
Meanwhile, the RF circuit 935 may include components such as a mixer, a filter, and
an amp, and transnlits or receives a radio signal via an antenna 937. The radio
communication interface 933 may also be a one-chip nlodule integrating the BB
10 processor 934 and the RF circuit 935. The radio corntnunication interface 933 may
also include multiple BB processors 934 and tnultiple RF circuits 935 as illustrated in
FIG. 26. Note that although FIG. 26 illustrates an example of the radio
conlnlu~lication interface 933 including niultiple BB processors 934 and multiple RF
circuits 935, the radio con~n~unicatioint erface 933 may also include a single BB
15 processor 934 or a single RF circuit 935.
[0262]
Furthermore, in addition to a cellular con~munication scheme, the radio
communication interface 933 may also support other types of radio con~munication
schenles such as a short-range wireless comtnunication scheme, a near field wireless
20 communication scheme, or a wireless LAN scheme. In this case, a BB processor
934 and an RF circuit 935 may be included for each radio con~rnunications cheme.
[0263]
Each antenna switch 936 switches the destination of an antenna 937 atnong
lnultiple circuits included in the radio comr~lunication interface 933 (for example,
25 circuits for different radio con~munications chemes).
[0264]
Each antenna 937 includes a single or multiple antenna elements (for
example, multiple antenna elements constituting a MIMO antenna), and is used by
the radio con~t~~unicatinotne rface 933 to transtnit and receive radio signals. The
30 car navigation device 920 may also include tnultiple antennas 937 as illustrated in
FIG 28. Note that although FIG. 26 illustrates an example of the car navigation
device 920 including ~nultiplea ntennas 937, the car navigation device 920 tnay also
include a single antenna 937.
[0265]
Furthermore, the car navigation device 920 tnay also be equipped with an
6 antenna 937 for each radio con~nlunications cheme. In this case, the antenna switch
936 may be omitted from the configuration of the car navigation device 920.
[0266]
The batte~y9 38 supplies electric power to the respective blocks of the car
navigation device 920 illustrated in FIG 26 via power supply lines pattially
10 illustrated with dashed lines in the drawing. Also, the battety 938 stores electric
power supplied fiotn the vehicle.
[0267]
In the car navigation device 920 illustrated in FIG. 26, the informati011
acquisition unit 261 and the comn~unicatioti control unit 263 described with
15 reference to FIG. 5 may be implemented in the radio communication interface 933.
Also, at least some of these functions tilay also be itnpletnented in the processor 921.
[0268]
In addition, technology according to the present disclosure may also be
realized as an in-vehicle system (or vehicle) 940 that includes one or more blocks of
20 the car navigation device 920 discussed above, the in-vehicle network 941, and a
vehicle-side tnodule 942. The vehicle-side module 942 generates vehicle-side data
such as the vehicle speed, number of engine revolutions, or malfunction information,
and outputs the generated data to the in-vehicle network 941.
[0269]
<<6. Conclusion>>
The foregoing thus describes respective cotnmunication devices and
respective processes according to an enlbodiment of the present disclosure with
reference to FIGS. 2 to 26.
[0270]
30 According to an embodiment according to the present disclosure, it1 the
terminal device 200, the information acquisition unit 261, the information acquisition
unit 261 acquires radio frame information indicating a radio fiatlie for trat~sliiitting a
discovery signal, and the cot~itiiunication control unit 263 controls the trans~iiission
of a discovery sigtial on the basis of the radio frame infortnation. Also, in tlie
terminal device 200, the infortnation acquisition unit 261 acquires radio fianie
5 information indicating a radio fianie for transmitting a discovery signal, atid tlie
cotn~nutiication control unit 263 controls a detection process for detecting a
discovery signal on tlie basis of the radio frame information. As another example,
in tlie base station 100, the information acquisitioti unit 151 acquires radio frame
information indicating a radio frame for transtnitting a discovery signal.
10 Additionally, the comn~unication cotitrol unit 153 controls the tratisniission of the
radio frame i~iforniationto the terminal device 200.
[0271]
Consequently, it becomes possible to moderate the load on a terminal device
200 cot~ductirigD 2D communication, for example.
15 [0272]
Specifically, for example, with respect to a signal transmitted in a radio
frame for transmitting a discovery signal, the terminal device 200 may conduct a
detection process for detecting a discovery signal, and rapidly and reliably detect tlie
discovery signal, for example. For this reason, tlie terminal device 200 may also
20 not conduct the above detection process on a signal transmitted in a radio frame other
than the above radio kame. In other words, the terminal device 200 does not have
to conduct the above detection process at a high frequency of repetition in order to
detect the discovery signal rapidly and reliably. Consequently, the load imposed by
the discovery signal detection process may be moderated.
25 [0273]
As another example, tlie terminal device 200 may transmit a discovery
signal it1 a radio kame for tratistiiittitig a discovety signal, and not transtnit a
discove~y signal in a radio frame other than tlie radio frame. In other' words, the
tertnitial device 200 does not have to transmit the discovery signal at a high
30 frequency of repetition so that the discovery sigtial will be detected rapidly and
reliably by another tert~iinal device 200. Consequetitly, the load imposed by the
transmission of the discovery signal may be moderated.
[0274]
- First modification
In the first modification, the radio frame information indicates niultiple
5 radio frames for transmitting a discovery signal, and each of the niultiple radio
franles corresponds to any one n~eaningf rom among two or more meanings. Also,
in the terminal device 200, the commut~icatiotc~o ntrol unit 263 controls the
. .
transtnission of a discovery signal so tliat tlie discovery sigtial is transtnitted in a
radio frame corresponding to a meaning to be reported from among the multiple
10 radio frames. Also, in the terminal device 200, the communication control unit 263,
upon detecting a discovery signal, identifies tlie meaning corresponding to the radio
frame in which the detected discovery signal was transtnitted fro11 anlong the
multiple radio frames.
[0275]
15 Consequently, for example, by only transmitting and receivit1g.a discovery
signal, it beconies possible for the terminal device 200 on the receiving side to
identify a meaning to be repotted by the terminal device 200 on the transmitting side.
For tlus reason, the rapid conveyance of meaning becomes possible. More
specifically, for example, in D2D conimunication, wlien data indicating a meaning is
20 transmitted and received after a connection is established through multiple
transactions, the time taken to convey the tneaning becotnes long. On the other
hand, when a discovery signal is transmitted and received in a radio frame
corresponding to a meaning, the time taken to convey the meaning becotnes short.
For this reason, conveyance of tlie meaning becotnes rapid. Note that wlien the
25 purpose of D2D communication is for public safety, the urgency is high, and thus
such rapid conveyance of meaning is particularly effective.
[0276]
- Second modification
hi tlie second modification, in the terminal device 200, tlie cotnmutiication
30 control unit 263 controls tlie transmission of a discovery signal so tliat tlie discovery
signal is transmitted at a frequency of repetition depending on tlie purpose of D2D
con~~ilunication. Also, in the terminal device 200, the communication control unit
263 controls the detection process so that the detection process is conducted at a
frequency of repetition depending on the purpose of D2D communication.
[0277]
5 Consequently, - for example, it becomes possible to moderate power
consutnption for discovery, while still satisfying the demand on the time required for
discovery.
[0278]
Specifically, for exanlple, the time demand required for discovery Ellay
10 differ depending on the purpose of the D2D co~u~~~ut~ic(asutcioh na s collision
warning, fire alert, and burglar alarm, for example). As an example, when the
purpose of the D2D col~lmunication is a collisiot~ warning, the time required for
discovery is demanded to be within a first time, whereas when the purpose of tlie
D2D communication is a fire alert, the time required for discovery is demanded to be
15 within a second time that is longer than tlie first tinie. In such cases, if the
frequency of repetition of tlie discovery signal is stipulated so that the time required
for discovery is within the first time, for example, when a terminal device conducts
D2D con~tnunicationf or a fire alert but does not conduct D2D colntnut~icationf or a
collision warning, the terminal device will transmit or detect a discovery signal at a
20 higher frequency of repetition thau is required. As a result, power may be wasted it1
the transmission or detection of a discovery signal. On the other hand, if the
frequency of repetition of the discovery signal is stipulated so that the tinie required
for discovery is within the second time, for example, when a terminal device
conducts D2D colnnlunication for a collision warning, the terminal device will
25 transmit or detect a discovery signal at an irisufficiet~tf requency of repetition. As a
result, the demand on the time required for discovery is not satisfied. Accordingly,
by transmitting a discovely signal and conducting the detection process at a
frequency of repetition that depends on the purpose, it becomes possible to tnoderate
power consumption for discovery, while still satisfying the denland on the time
30 required for discovery.
[0279]
- Third niodificatioti
In the third modification, in the terminal device 200, the coniniunicatioli
control unit 263 controls tlie tratistiiission of itiformation to be reported so tliat the
information to be reported is transmitted in a predetermined radio resource after the
5 transmission of a discovery signal. Also, in tlie ternlitla1 device 200, tlie
connnutiication cotitrol utiit 263, after the detection of a discovery signal, acquires
information received in a predetermined radio resource for transmitting it~formatioti
to be reported after the transtnission of a discovery signal. As another example, in
the base station 100, the infortnatioti acquisition unit 151 acquires radio resource
10 inforliiatioti indicating a predetermined radio resource for transmitting information to
be reported after the tratistnission of a discovery signal, atid the communication
control unit 153 controls the tratismissioti of the radio resource infortnatioti to the
terminal device 200.
[0280]
15 Consequently, for example, it becomes possible to rapidly convey detailed
information.
[0281]
Specifically, for example, when a radio frame corresponds to one meaning,
like in the first modification, rapid conveyance of the meatling through transnlission
20 and reception of a discovery signal becoti~esp ossible, but the conveyance of detailed
infortnatioti is difficult. Also, if detailed information is transmitted and received
after a cotinection is established tluougli niultiple trat~sactiotis, tlie tinie taken to
convey the detailed information becomes long. Accordingly, by transmitting atid
receiving information to be reported in a predetertiiitied radio resource after a
25 discovery signal, it becomes possible to convey detailed itiforlnation rapidly.
[0282]
Note tliat in cases such as when tlie purpose of D2D cotntnunicatioti is data
offloading, a large amount of data is tralisn~itted atid received by D2D
comtnunication, atid tlius the establishment of a connection is effective. However,
30 whet1 the purpose of D2D cotnmunicatioti is public safety, the urgency is often high,
acid tlius the technique accorditig to the third modification is effective.
[0283]
- Fourth modification
[0284]
-- lndividual transniission infornlatiot~ and aggregate transmission
5 information
In the fourth modification, in the base station 100, for example, if individual
transmission information related to radio frames for transmitting a discovery signal
by a terminal device 200 is transmitted by each of one or more terminal devices 200
positioned within an area, the information acquisition unit 151 acquires the
10 individual transtnission information. Subsequently, the communication control unit
153 controls the transniission of aggregate transtnission information related to radio
fiames for transmitting a discovery signal by the one or more terminal devices 200.
[0285]
Also, in the terminal device 200, the information acquisition unit 261
15 acquires individual tralislnission information related to radio frames for transmitting
a discovery signal by the tetnii~ial device 200, and the communication control unit
263 controls the transmission of the individual transmission information to the base
station 100. Also, in the terminal device 200, the inforlnation acquisition unit 261
acquires aggregate transmissio~in~f ormation related to radio frames for transcuittiilg a
20 discovery signal by one or more ternlinal devices 200 positioned within an area, and
the cornl~~unicatioctoi ntrol unit 263 controls the detection process on the basis of the
aggregate transmission information.
[0286]
Consequently, for example, when a terminal device 200 positioned within
25 an area conducts the detection process for detecting a discovery signal, it becomes
possible to conduct the detection process in the necessary and sufficient radio frames.
For this reason, it becomes possible to moderate the load on the.terrninal device 200.
[0287]
Specifically, for example, when tione of the terminal devices 200 positioned
30 within an area is transmitting a discovery signal for a collisiot~w arning, conducting
the detection process in a radio fra~ne for transmitting a discovery signal for a
collisio~w~a rning is wasteful for a terminal device 200 co~iductingt he detection
process within that area. Accorditigly, by transmitting the aggregate transmission
information to the terminal device 200, the tenninal device 200 becot~ies able to
identify the necessary and sufficient radio franies in which the detection process is
5 conducted. For this reason, the load on the terminal device 200 niay be moderated.
[0288]
-- Individual detection infortnatio~a~nd aggregate detection infortnation
Also, in the fourth modification, in the base station 100, for example, if
individual detection it~formatiotr~el ated to radio frames for conducting a detection
10 process for detecting a discovery signal by a terminal device 200 is transmitted by
each of one or more terminal devices 200 positioned within an area, the information
acquisition unit 151 acquires the individual detection informatiotl. Subsequently,
the commutlication control unit 153 co~~trotlhse transmission of aggregate detection
informati011 related to radio frames for conducting the detection process by the one or
15 more terminal devices 200.
[0289]
Also, in the terminal device 200, the itlformation acquisition unit 261
acquires individual detection information related to radio frames for conducting the
detection process by the termitla1 device 200, and the commut~ication control unit
20 263 controls the trat~smission of the individual detection information to the base
station 100. Also, in the ternlitla1 device 200, the infortnation acquisition unit 261
acquires aggregate detection information related to radio frames for conducting a
detection process for detecting a discovery signal by one or more terniinal devices
200 positioned within an area, and the comtnunication control unit 263 controls the
25 transn~issiono f a discovery signal on the basis of the aggregate detection information.
[0290]
Conseque~~tlyfo, r example, when a terminal device 200 positioned within
an area transmits a discovery signal, it becotnes possible to tratls~nit the discovery
signal in the necessary and sufficient radio fratnes. For this reason, it becotnes
30 possible to moderate the load on the ter~nit~daelv ice 200.
[0291]
Specifically, for example, wlieti none of tlie terniitial devices 200 positioned
within an area is detecting a discovery signal for a collision warning, traustiiittiug a
discovery signal in a radio fiame for tratismitting a discove~y signal for a collision
warning is wasteful for a temiinal device 200 transmitting a discovery signal witlii~i
tliat area. Accordinigly, by transmitti~ig the aggregate detection information to tlie
terminal device 200, tlie terminal device 200 becomes able to identify tlie necessary
and suficie~it radio frames in wliich a discovely signal is transmitted. For this
reason, the load 011 the terminal device 200 may be moderated.
[0292]
- Fifth modification
[0293]
In tlie fifth modification, in the terminal device 200, the communicatio~l
cotitrol unit 263 cot~trolsa detection process for detecting a discovery signal so that
when tlie mode of the terminal device 200 is a connected mode, the detection process
is co~~ducteadt a first freque~icyo f repetition, whereas when the mode of the terniinal
device 200 is an idle mode, the detection process is conducted at a second kequeticy
of repetition lower than the first frequency of repetition
[0294]
Consequently, it becomes possible to moderate the load on a tertni~iald evice
200 in idle mode, for example. Specifically, for example, in idle mode, tlie
frequeticy of repetition of the detection process by the terminal device 200 becotlies
lower, making it possible to moderate power consu~iiptioni n the terminal device 200.
[0295]
The preferred embodiment(s) of the present disclosure lias/have bee11
described above with reference to tlie accompanying drawings, whilst the present
disclosure is not limited to the above examples, of course. A person skilled in the
art may find various alterations and modifications within tlie scope of the appended
claims, and it should be understood tliat they will naturally come under the technical
scope of the present disclosure.
[0296]
For example, although an example is described in which the comn~unication
system is a systeni confornii~~gto LTE, LTE-Advanced, or a compliant
communication scheme, tlie present disclosure is not limited to such an example.
For example, the cotntnut~icatioti system may be a system conforming to another
con~munication standard.
5 [0297]
Also, the processing steps in a comn~unication control process in this
specification are not strictly limited to being executed in a time series following the
sequence described in a flowchart. For example, the processing steps in a
conimunication control process may be executed in a sequence that differs from a
10 sequence described herein as a flowchart, and furtherniore may be executed in
parallel.
[0298]
h~ addition, it is possible to create a conlputer program for causing hardware
such as a CPU, ROM, and RAM built into a corntnunication control device (for
15 example, a device included in a base station) or a terminal device to exhibit fnnctiotis
sitliilar to each structural element of the foregoing communication control device or
tert~~inadle vice. Also, a storage n~ediulnh aving such a computer progratn stored
therein may also be provided. Also, an illformation processing device (for example,
a processing circuit or chip) equipped with memory storing such a computer program
20 (for example, ROM and RAM) and one or more processors capable of executing
such a computer progranl (such as a CPU or DSP, for example) may also be provided.
[0299]
111 addition, the advantageous effects described in this specification are
merely for the sake of explanation or illustration, and are not limiting. In other
25 words, instead of or in addition to the above advatitageous effects, technology
according to the present disclosure may exhibit other advantageous effects that are
clear to persons skilled in the art from the description of this specification.
[0300]
Additionally, the present technology may also be configured as below.
30 (1)
A con~niunicationc ontrol device including:
an acquisition unit co~lfiguredt o acquire radio 6ame information indicating
a radio fratne, the radio frame being a unit time of cellular communication, for
trarls~ilitting a discovery signal enabling another device to discover a device
conducting device-to-device co~nmunication;a nd
5 a control unit configured to control transmission of the radio frame
information to a terminal device.
(2)
The connnu~~icatiocno ntrol device according to (I), wherein
the radio frame information indicates a systetn frame number of the radio
10 frame.
(3)
The cotn~nu~~icatcionnt rol device according to (I), or (2) wherein
the radio frame information indicates a plurality of radio frames for
transmitting the discovery signal, and
15 each of the plurality of radio frames corresponds to any one meaning from
among two or more meanings.
(4)
The com~~~unicatcioo~nl tro'dl evice according to (3), wherein
the radio frame informati011 additionally indicates which meaning from
20 anlong the two or more meanings each of the plurality of radio frames corresponds to.
(5)
The cotnmut~icationc ontrol device according to any one of (1) to 4, wherein
the radio frame information indicates, for each purpose of device-to-device
communication, a plurality of radio frames for transmitting the discovery signal at a
25 frequency of repetition depending on the purpose.
(6)
The conlmunication control device according to (5), wherein
the radio fiame information indicates, for each purpose of device-to-device
con~munication, a cycle of transtnission of the discovery signal depending on the
30 purpose
(7)
The coln~nunication co~~trodel vice according to ally one of (1) to (6),
wherein
the acquisition unit acquires radio resource inforniation indicating a
predeten~iined radio resource for transmitting infor~~~attioo tb~e reported after
5 transmission of the discovery signal, and
the colltrol uuit cotitrols transmissioti of the radio resource infor~~~attioo na
tern~inadl evice.
(8)
The com~nul~icatiocno t~trodl evice according to (7), wherein
10 the discovery signal includes a sigt~al sequence conltnon among terminal
devices, and
the radio resource inforn~ationi ndicates predetermined radio resources for
transmitting the information to be reported after transmission of the discovery signal.
(9)
15 The communication control device according to any one of (1) to (9,
wherein
when individual transn~ission informatiot~ related to a radio frame for
tratls~~~itttihneg discovery signal by a terminal device is transmitted by each of one
or more terminal devices positioned within at1 area, the acquisition unit acquires the
20 individual tralismission information, and
the coritrol unit controls trat~s~~~isosfi aogng regate transtnissiot~i nformation
related to a radio frame for transmitting the discovery signal by the one or more
terminal devices
(10)
The cotnmunicatio~c~o t~trodl evice according to (9), wherein
the individual transmission information is information indicating a purpose
of device-to-device communicatio~f~or a terminal device, or is informatio~in~d icating
a cycle of transmission of the discovery signal by a terminal device.
(11)
30 The con~muuication control device according to any one of (1) to (lo),
when individual detection information related to a radio fratne for
coilducting a detection process for detecting the discovery signal by a terminal
device is transmitted by each of one or niore terniinal devices positioned within an
area, the acquisition unit acquires the itidividual detection information, and
5 the control unit controls trat~smission of aggregate detection infortnation
related to a radio fiame for conducting the detection process by the one or more
terminal devices.
(12)
The communication control device according to (ll), whereiti
10 the individual detection information is information indicating a purpose of
device-to-device con~niut~icatiofonr a terminal device, or is information indicating a
cycle of the detection process by a terniinal device.
(13)
A comniunication control method including:
15 acquiring radio frame information indicating a radio fratne, the radio frame
being a unit time of cellular communication, for transmitting a discove~y signal
et~ablil~ga nother device to discover a device conducting device-to-device
comnlunication; arid
controlling, with a processor, transn~ission of the radio frame information to
20 a terminal device.
(14)
A tenninal device including:
an acquisition unit co~~figuretod acquire radio fratne information indicating
a radio frame, the radio frame being a unit time of cellular communication, for
25 transmitting a discovely signal enabling another device to discover a device
cotlducting device-to-device commu~~icatioann; d
a control unit configured to control transmission of the discovery signal
based on the radio fratne infor~l~ation.
(15)
The ternii~iald evice according to (14), wherein
the radio frame information indicates a plurality of radio frames for
transmitting the discovery signal,
each of the plurality of radio frames corresponds to any one lneanit~gf rom
anlong two or more meanings, and
the control unit controls transmissiotl of the discovery signal so that the
discovery signal i s transmitted in a radio fratne corresponding to a lneatling to be
reported from among the plurality of radio frames.
(16)
The tenninal device according to (14) or (15), wherein
the control unit controls transtnissiot~ of the discovery signal so that the
discovery signal is transmitted at a frequency of repetition depending on a purpose of
device-to-device con~mut~ication.
(17)
The terminal device according to (16), wherein
the control unit controls tral~smissioto~f the discovery signal so that the
discovery signal is transmitted on a cycle depending on a purpose of device-todevice
communication.
(18)
The terminal device according to any one of (14) to (17), wherein
the control unit cot~trolst ransmissio~o~f information to be reported so that
the informatiot~t o be reported is transmitted in a predetemit~edr adio resource after
transmission of the discovery signal.
(19)
The terminal device according to (IS), wherein
the discovery signal includes a signal sequence common alnong terminal
devices, and
the control unit controls transmission of the infortnation to be reported so
that the it~formationt o be reported is transmitted in one radio resource from among
predetermined radio resources after tralistnissioll of the discovery signal
(20)
The terminal device according to (19), wherein
the control unit controls transmission of the infor~nationt o be reported so
that every tine the discovery signal is transmitted, a radio resource in which the
information to be reported is transmitted clianges from one radio resource anlong the
predetermined radio resources to another radio resource among the predeter~nined
radio resources.
5 (21)
The tern~inadl evice according to any one of (14) to (20), wherein
the acquisition unit acquires individual transn~issionin for~nationr elated to a
radio frame for transmitting the discovery signal by the te~lninadl evice, and
the co~~trouln it controls transmission of the individual transmission
10 information to a base station.
(22)
The terminal device according to any one of (14) to (21), wherein
the acquisition unit acquires aggregate detection infortnatioli related to a
radio frame for conducting a detection process for detecting the discovery signal by
15 one or more terminal devices positio~~ewdi thin an area, and
the control unit controls transmission of the discovery signal based on the
aggregate detection information.
(23)
The terminal device according to any one of (14) to (22), wherein
20 the control unit controls transmissiot~o f system i~~formatioitni cluding a
system frame number.
(24)
An information processir~gd evice including:
memory configured to store a program; and
one or more processors able to execute the program, wherein
the program causes the execution of
acquiring radio frame information indicating a radio frame, the
radio frame being a unit time of cellular comtnunication, for transn~ittinga discovery
signal enabling another device to discover a device conducting device-to-device
30 comn~ut~icatioann,d
controlli~~trga nsn~issiono f the discovery signal based on the radio
frame inforn~ation.
(25)
A terminal device including:
an acquisition unit configured to acquire radio franle information indicating
5 a radio frame, the radio frame being a unit time of cellular communication, for
transmitting a discovery signal enabling another device to discover a device
conducti~~dgev ice-to-device communication; and
a cot~trol unit configured to cot~trol a detection process for detecting the
discovery signal based on the radio frame information
10 (26)
The tennilla1 device according to (25), wherein
the radio frame information indicates a plurality of radio fratnes for
trat~smittit~thge discovery signal,
each of the plurality of radio frames corresponds to any one meatlit~g from
15 among two or Inore meanings, and
when the discovery signal is detected, the control unit identifies a meaning
co~respondi~t~og a radio frame in which the detected discovety signal was
transmitted from among the plurality of radio frames.
(27)
20 The terminal device according to (25) or (26), wherein
the co~~truonli t controls the detection process so that the detection process is
conducted at a frequency of repetition depending on a purpose of device-to-device
con~munication.
(28)
The terminal device accordit~gto (27), wherein
the cot~troul nit controls the detection process so that the detection process is
cot~ductedo n a cycle dependir~go n a purpose of device-to-device co~nmunication.
(29)
The terminal device accordit~gto any one of (25) to (28), wherein
30 the control unit, after detection of the discovery signal, acquires infortnation
received in a predetermined radio resource for tratlsmitting information to be
reported after transn~issiono f the discovery signal.
(30)
The termitla1 device accordi~~tog (29), wherein
the control unit, after detection of the discovery signal, acquires itlformation
5 received it1 each of predetermined radio resources for tratlsmitting the information to
be reported aAer transtnission of the discovery signal.
(31)
The terminal device according to any one of (25) to (30), wherein
the acquisition unit acquires aggregate trat~smissioni nformatio~re~la ted to a
10 radio frame for transmitting the discovery signal by one or more terminal devices
positioned within a11 area, and
the control unit controls the detection process based on the aggregate
transn~issionin formation.
(3 2)
15 The terniinal device according to any one of (25) to (31), wherein
the acquisition unit acquires i~~dividuadle tection information related to a
radio frame for cot~ductingth e detection process by the terminal device, and
the control unit controls transmissiotl of the individual detection information
to a base station.
20 (33)
The terminal device according to any one of (25) to (32), wherein
the control unit controls the detection process so that the detection process is
cotiducted at a first frequency of repetition when a mode of the terminal device is a
contiected mode, and the detection process is co~~ducteadt a secot~df requency of
26 repetition lower than the first frequency of repetition when the mode of the terminal
device is an idle mode.
(34)
The terminal device according to ally one of (25) to (33), whereiti
the control unit controls transniissiot~ of system informati011 itlcluding a
30 system frame number.
(35)
An i~ifornlationp rocessi~igd evice including:
menlory co~~figuretod store a program; and
one or more processors able to execute the program, wherein
tlie progratn causes tlie execution of
5 acquiring radio game informati011 indicating a radio flame, the
radio frame being a unit titne of cellular comtnunication, for transtnittitig a discovery
signal enabling another device to discover a device conducting device-to-device
communication, atid
controlling a detection process for detectitig tlie discovery signal
10 based on the radio frame information.
Reference Signs List
[0301]
1 comtnunication system
15 100 base station
15 1 information acquisition unit
153 communication co~itroul nit
200 ter~llitladl evice
261 information acquisitioti unit
20 263 co~nmunicationc otitrol unit
CLAIMS
Claim 1 (Ci~r~e~Alttltyle nded)
A communication control device colllprising:
an acquisition unit configured to acquireL-radio resource information
5 indicating a radio resource, the radio resource being a radio resource of cellular
comn~unicationa nd having a periodicity, for transmitting a discovery signal enabling
another device to discover a device conducting device-to-device communication; and
a control unit cotlfigured to control transmission of the radio resource
information to a terminal device.
10
Clai1il02 (New)
The comtllu~lication control device according to claitll 1, wherein
the radio resource infornlation includes infor~llationf or identifying a systenl
fiane number of the radio resource.
15
Claim 03 (New)
The conlmu~licatioc~oln trol device according to claim 02, ~vlierein
the information for identifying a system fiatne number of the radio resource
indicates a cycle of the system frame nuulber of the r a d' lo resource.
20
Clairn 04 (New)
The cotlln~unicationc ontrol device according to claim 1, wherein
the radio resource information indicates a plurality of radio resources for
transmitting the discovery signal, the plurality of radio resources having different
25 cycles.
Claitll 05 (New)
The co~n~llutlicatiocno ntrol device according to claim' 4,w herein
each of the plurality of radio resources corresponds to any one meaning
30 fiom among two or more meatiings.
Claim 06 (New)
The connnunication control device according to clainl05, wherein
the radio resource infornlation additionally indicates which nleaning anlong
the two or Inore meanings each of the plurality of raclio resources corresponds to.
5
Claim 07 (New)
The comnmoication control device according to claim 1, wherein
the radio resource inforlnation indicates, for each purpose of device-todevice
conltnunication, a radio resource for transmitting the discovery signal at a
10 frequency of repetition rate depending on the purpose.
Claim 08 (New)
The comnlunication control device according to claim 07, wherein
the radio resource information indicates, for each purpose of device-to-
16 device communication, a cycle of transn~issiono f the discovery signal depending on
the purpose.
Claini 09 (New)
A co~n~nunicatioconn trol method comprising:
20 acquiring radio resource infornlation indicating a radio resource, the radio
resource being a radio resource of cellular comnlunication and having a periodicity,
for transmitting a discovery signal enabling another device to discover a device
conducting device-to-device co~~~municatiaonnd;
controlling, with a processor, trans~nissiono f the radio resource information
25 to a terniinal device.
Claim 10 (New)
The communication control method according to claim 43, wherein
the radio resource inforlnation includes information for identifying a system
30 frame number of the radio resource.
Claim 11 (New)
The com~nnnicationc ontrol method according to clai~n1 0, wherein
the information for identifying a system frame number ofthe radio resource
indicates a cycle of the systeln frame number of the radio resource.
5
Claim 12 (New)
The cotntnunicatiorl control method according to clai~n0 9, wherein
the radio resource infornlation indicates a plurality of radio resources for
transmitting the discovery signal, the plurality of radio resources having different
10 cycles.
Clai~n1 3 (New)
A terminal device comprising:
an acquisition unit configured to acquire radio resource infonnation
15 indicating a radio resource, the radio resource being a radio resource of cellular
co~n~nunicatioand having a periodicity, for transmitting a discovery signal enabling
another device to discover a device conducting device-to-device communication; and
a control unit configured to control transmission of the discovery signal
based on the radio resource infonnation.
20
Claim 14 (New)
The comn~unicationc ontrol device according to claim 13, wherein
the radio resource infonnation includes inforlilation for identifying a system
frame number of the radio resource.
25
Claim 15 (New)
'She communication control device according to claim 14, wherein
the information for identifying a system frame number of the radio resource
indicates a cycle of the systetn frame number of the r a d' lo resource.
30
Clai~n1 6 (New)
The communication control device according to claim 15, wherein
the radio resource information indicates a plurality of radio resotlrces for
trans~nittirig tlie discovery signal, the plurality of radio resources having different
cycles.
5
Claim 17 (New)
The client device according to claini 16, wherein
the control unit controls transmission of tlie discovery signal so tliat the
discovery signal is transmitted on a set cycle.
10
Claim 18 (New)
An inrormation processing device comprising:
memory configured to store a program; and
one or more processors able to execute the program, wherein
15 the program causes the execution of
acquiring radio resonrce information iticlicating a radio resource,
tlie radio resource being a radio resource of cellular cotnmunicatiori and having a
periodicity, for transmitting a discovery signal enabling anotlier device to discover a
device conducting device-to-device comtnunication, and
20 controlling transmission of the discovery signal based on the radio
resource information.
Claim 19 (New)
A terminal device comprising:
25 an acquisition unit configured to acquire radio resonrce information
indicating a radio resource, the radio resource being a radio resource of cellular
comn~onicationa nd having a periodicity, for trans~nittinga discovery signal enabling
another device to discover a device conducting device-to-device comniunication; and
a control unit configureci to control a detection process for detecting the
30 discovery signal based on the radio resource inforination.
Claim 20 (New)
An infornlation processing device comprising:
memory configured to store a program; and
one or more processors able to execute the program, wherein
5 the program causes the execution of
acquiring radio resource infornlation indicating a radio resource,
the radio resource being a radio resource of cellular co~n~nunicatioann d having a
periodicity, for trans~nittinga discovery sigual enabling another device to discover a
device cotlducting device-to-device comnlunication, and
10 controlling a detection process for detecting the tliscovery signal
based on the radio resource information.