Title of Invention:
RESOURCE ALLOCATION FOR D2D IN DYNAMIC CHANGE OF
TDD CONFIGURATION
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Japanese Priority Patent Application JP
2014-153812 filed July 29, 2014, the entire contents of which are incorporated herein
by reference.
Technical Field
[0002] The present disclosure relates to a device and a method.
Background Art
[0003] Device-to-device communication (D2D communication) is communication in which
two or more terminal devices transmit and 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 communication will be used
to create new usage scenarios for terminal devices that differ from the typical cellular
communication above. For example, various applications are conceivable, such as in
formation sharing by data communication between nearby terminal devices or among a
group of nearby terminal devices, distribution of information from an installed terminal
device, and autonomous communication between machines, called machineto-
machine (M2M) communication.
[0004] Additionally, it is conceivable that D2D communication will 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
necessity to transmit and receive video image streaming data. However, since video
images typically have large data sizes, there is a problem of consuming many resources
on a radio access network (RAN). Consequently, if terminal devices are in a state
suitable for D2D communication with each other, such as when the terminal devices
are a short distance away from each other, video image data may be offloaded to D2D
communication, thereby moderating the resource consumption and processing load on
a RAN. In this way, D2D communication provides value to both telecommunications
carriers and users. For this reason, D2D communication is currently recognized as one
crucial technology area for Long Term Evolution (LTE), and is receiving attention
from the 3rd Generation Partnership Project (3GPP) standards committee.
[0005] For example, Non Patent Literature 1 discloses a case in which D2D communication
is performed in an uplink subframe within a network coverage area in the case of time
division duplex (TDD).
Citation List
Non Patent Literature
[0006] [NPL 1] 3GPP TR 36.843 V12.0.0 (March 2014)
Summary
Technical Problem
[0007] For example, as radio resources available for D2D communication, periodic radio
resources are allocated. For example, at periods of an integer multiple of a radio frame,
radio resources of a specific subframe are allocated as the radio resources available for
D2D communication. Therefore, D2D communication is performed in the specific
subframe.
[0008] For example, when D2D communication is performed in a TDD carrier, radio
resources of an uplink subframe of an uplink/downlink configuration (UL/DL con
figuration) of the TDD carrier are allocated as the radio resources available for D2D
communication within a network coverage area. Therefore, D2D communication is
performed in the uplink subframe.
[0009] However, when the UL/DL configuration of the TDD carrier is dynamically changed,
the uplink subframe in which D2D communication is performed may be changed to a
downlink subframe or a special subframe. As a result, D2D communication may be
performed in the downlink subframe or the special subframe. That is, D2D commu
nication that does not comply with cellular communication standards may be
performed.
[0010] Accordingly, it is preferable to provide a mechanism in which a terminal device can
appropriately perform D2D communication under a TDD environment.
Solution to Problem
[001 1] According to an embodiment of the present disclosure, there is provided a device
including: circuitry configured to dynamically change an uplink/downlink con
figuration of a time division duplex (TDD) carrier. The circuitry notifies a terminal
device of a radio resource for device-to-device communication for the uplink/downlink
configuration. The radio resource is a radio resource of at least one uplink subframe of
the uplink/downlink configuration.
[0012] According to another embodiment of the present disclosure, there is provided a
method including: dynamically changing, by a processor, an uplink/downlink con
figuration of a time division duplex (TDD) carrier; and notifying a terminal device of a
radio resource for device-to-device communication for the uplink/downlink con
figuration. The radio resource is a radio resource of at least one uplink subframe of the
uplink/downlink configuration.
[0013] According to another embodiment of the present disclosure, there is provided a
device including: circuitry configured to acquire information indicating a radio
resource for device-to-device communication for an uplink/downlink configuration of
a TDD carrier that is dynamically changed by a base station; and the circuitry is further
configured to control device-to-device communication using the radio resource. The
radio resource is a radio resource of at least one uplink subframe of the uplink/
downlink configuration.
[0014] According to another embodiment of the present disclosure, there is provided a
method including: acquiring information indicating a radio resource for deviceto-
device communication for an uplink/downlink configuration of a time division
duplex (TDD) carrier that is dynamically changed by a base station; and controlling, by
a processor, device-to-device communication using the radio resource. The radio
resource is a radio resource of at least one uplink subframe of the uplink/downlink con
figuration.
Advantageous Effects of Invention
[0015] According to one or more of embodiments of the present disclosure described above,
a terminal device can appropriately perform D2D communication under a TDD en
vironment, but the present disclosure is not necessarily limited to this effect. Along
with or instead of this effect, any effect shown in this specification or other effects that
may be understood from this specification may be achieved.
Brief Description of Drawings
[0016] [fig.l]FIG. 1 is a first explanatory diagram illustrating a specific example of a use case
of D2D communication.
[fig.2]FIG. 2 is a second explanatory diagram illustrating a specific example of a use
case of D2D communication.
[fig.3]FIG. 3 is an explanatory diagram illustrating exemplary timings of a PSS and an
SSS in FDD.
[fig.4]FIG. 4 is an explanatory diagram illustrating exemplary timings of a PSS and an
SSS in TDD.
[fig.5]FIG. 5 is an explanatory diagram illustrating a radio frame and subframes in a
cellular system.
[fig.6]FIG. 6 is an explanatory diagram illustrating an exemplary resource pool.
[fig.7]FIG. 7 is an explanatory diagram illustrating an example of a signal and in
formation transmitted in a resource pool.
[fig.8]FIG. 8 is an explanatory diagram illustrating a UL/DL configuration.
[fig.9]FIG. 9 is an explanatory diagram schematically illustrating an exemplary con
figuration of a communication system according to an embodiment of the present
disclosure.
[fig.l0]FIG. 10 is a block diagram illustrating an exemplary configuration of a base
station according to the embodiment.
[fig. 11]FIG. 11 is a block diagram illustrating an exemplary configuration of a terminal
device according to the embodiment.
[fig. 12]FIG. 12 is an explanatory diagram illustrating a first example of D2D
resources.
[fig.l3]FIG. 13 is an explanatory diagram illustrating a notification example of D2D
resources according to a change of a UL/DL configuration.
[fig. 14]FIG. 14 is an explanatory diagram illustrating a second example of D2D
resources.
[fig.l5]FIG. 15 is an explanatory diagram illustrating a third example of D2D
resources.
[fig. 16]FIG. 16 is an explanatory diagram illustrating a fourth example of D2D
resources.
[fig.l7]FIG. 17 is an explanatory diagram illustrating a fifth example of D2D
resources.
[fig.l8]FIG. 18 is an explanatory diagram illustrating a first example of a period for
each configuration.
[fig. 19]FIG. 19 is an explanatory diagram illustrating a second example of a period for
each configuration.
[fig.20]FIG. 20 is a sequence diagram schematically illustrating a first example of a
process flow according to the embodiment.
[fig.21]FIG. 2 1 is a sequence diagram schematically illustrating a second example of a
process flow according to the embodiment.
[fig.22]FIG. 22 is a sequence diagram schematically illustrating a third example of a
process flow according to the embodiment of the present disclosure.
[fig.23]FIG. 23 is a block diagram illustrating a first example of a schematic con
figuration of an eNB.
[fig.24]FIG. 24 is a block diagram illustrating a second example of a schematic con
figuration of an eNB.
[fig.25]FIG. 25 is a block diagram illustrating an example of a schematic configuration
of a smartphone.
[fig.26]FIG. 26 is a block diagram illustrating an example of a schematic configuration
of a car navigation device.
Description of Embodiments
Hereinafter, preferred embodiments of the present disclosure will be described in
detail with reference to the appended drawings. Note that, in this specification and the
appended drawings, structural elements that have substantially the same function and
structure are denoted with the same reference numerals, and repeated explanation of
these structural elements is omitted.
Also, in this specification and the appended drawings, elements having substantially
the same function and structure may in some cases be distinguished by different letters
appended to the same sign. For example, multiple elements having substantially the
same function and structure are distinguished as terminal devices 10A, 10B, IOC, and
so on as appropriate. On the other hand, when not particularly distinguishing each of
multiple elements having substantially the same function and structure, only the same
sign will be given. For example, the terminal devices 10A, 10B, IOC will be simply
designated the terminal device 10 when not being particularly distinguished.
Hereinafter, the description will proceed in the following order.
1. Introduction
2. Technical problems according to embodiments of present disclosure
3. Schematic configuration of communication system
4. Configuration of respective devices
4.1. Base station configuration
4.2. Terminal device configuration
5. Technical features according to embodiments of present disclosure
5.1. First technical features
5.2. Second technical features
5.3. Other technical features
6. Process flow
7. Applications
8. Conclusion
«1. Introduction»
First, technology related to D2D communication will be described with reference to
FIGS. 1 to 7.
(Use case of D2D communication)
In general LTE systems, an evolved Node B (eNB) and a user equipment (UE)
perform radio communication, but UEs do not perform radio communication to each
other. However, a method in which the UEs directly perform radio communication to
each other is necessary for an application for public safety (for example, an application
such as collision avoidance) or data offloading.
Use cases of D2D communication are discussed in 3GPP service and systems aspects
(SA) 1 and the like, and are described in TR 22.803. Also, in TR 22.803, use cases are
disclosed, but specific implementation methods are not disclosed. Hereinafter, specific
examples of the use case will be described with reference to FIGS. 1 and 2.
FIG. 1 is a first explanatory diagram illustrating a specific example of a use case of
D2D communication. Referring to FIG. 1, multiple UEs 10 and an eNB 20 are i l
lustrated. As a first use case, for example, an UE 10A and an UE 10B positioned
within a network coverage area (for example, inside a cell 2 1 of the eNB 20) perform
D2D communication. Such D2D communication is referred to as in-coverage D2D
communication. As a second use case, for example, an UE IOC and an UE 10D p o
sitioned outside of the network coverage area perform D2D communication. Such D2D
communication is referred to as out-of-coverage D2D communication. As a third use
case, for example, an UE 10E positioned within the network coverage area and an UE
10F positioned outside of the network coverage area perform D2D communication.
Such D2D communication is referred to as partial-coverage D2D communication.
From the viewpoint of public safety, out-of-coverage D2D communication and partialcoverage
D2D communication are also important. Also, the network coverage area
refers to a coverage area of a cellular network. That is, a set of cells builds the network
coverage area.
[0024] FIG. 2 is a second explanatory diagram illustrating a specific example of a use case
of D2D communication. Referring to FIG. 2, an UE 10A and an UE 10B, and an eNB
20A and an eNB 20B are illustrated. In this example, the eNB 20A is operated by a
first mobile network operator (MNO) and the eNB 20B is operated by a second MNO.
Then, the UE 10A positioned within a first network coverage area (for example, inside
a cell 2 1A of the eNB 20A) and the UE 10B positioned within a second network
coverage area (for example, inside a cell 2IB of the eNB 20B) perform D2D commu
nication. From the viewpoint of public safety, such D2D communication is also
important.
[0025] (Flow up to D2D communication)
For example, synchronization, discovery, and connection establishment are se
quentially performed, and then D2D communication is performed. Hereinafter, consid
erations of steps of synchronization, discovery, and connection establishment will be
described.
[0026] (a) Synchronization
When two UEs are positioned within the network coverage area, the two UEs obtain
synchronization with the eNB using a downlink signal from the eNB and thus are able
to be synchronized to each other to some extent.
[0027] On the other hand, when at least one of two UEs attempting to perform D2D commu
nication is positioned outside of the network coverage area, at least one of the two UEs
is necessary to transmit a synchronization signal for synchronization in D2D commu
nication.
[0028] (b) Discovery of other UEs
Discovery of other UEs is performed by, for example, transmitting and receiving a
discovery signal. More specifically, for example, one UE of the two UEs transmits the
discovery signal, and the other UE of the two UEs receives the discovery signal and
attempts to communicate with the one UE.
[0029] The discovery signal is preferably transmitted at a predetermined timing in a time
direction. Accordingly, it is possible to restrict a timing at which the UE of a reception
side attempts to receive the discovery signal. Also, as the assumption, two UEs at
tempting to perform D2D communication may obtain synchronization in advance
before the discovery signal is received.
[0030] (c) Connection establishment
The two UEs attempting to perform D2D communication may establish a connection,
for example, as follows. First, a first UE transmits a discovery signal and a second UE
receives the discovery signal. Then, the second UE transmits a request message r e
questing connection establishment to the first UE. Then, the first UE transmits a
completion message indicating completion of connection establishment to the second
UE in response to the request message.
[0031] (Synchronization signal transmitted by eNB)
In LTE, the eNB transmits a primary synchronization signal (PSS) and a secondary
synchronization signal (SSS) as a synchronization signal. The PSS and the SSS are
transmitted at a predetermined timing in a frame structure of a radio frame.
Hereinafter, a specific example of timings of the PSS and the SSS in frequency
division duplex (FDD) and time division duplex (TDD) will be described with
reference to FIGS. 3 and 4.
[0032] FIG. 3 is an explanatory diagram illustrating exemplary timings of a PSS and an SSS
in FDD. Referring to FIG. 3, 10 subframes included in the radio frame are illustrated.
In FDD, in subframes (that is, a first subframe and a sixth subframe) having subframe
numbers 0 and 5, the PSS and the SSS are transmitted. More specifically, the SSS is
transmitted in a sixth symbol of a first slot included in each of the subframes, and the
PSS is transmitted in a seventh symbol of the first slot.
[0033] FIG. 4 is an explanatory diagram illustrating exemplary timings of a PSS and an SSS
in TDD. Referring to FIG. 4, 10 subframes included in the radio frame are illustrated.
In TDD, in subframes (that is, a second subframe and a seventh subframe) of subframe
numbers 1 and 6, the PSS is transmitted. More specifically, in a third symbol of a first
slot included in each subframe, the PSS is transmitted. In addition, in TDD, in
subframes (that is, a first subframe and a sixth subframe) of subframe numbers 0 and 5,
the SSS is transmitted. More specifically, in a seventh symbol of a second slot included
in each subframe, the SSS is transmitted.
[0034] When the PSS is detected, the UE can recognize a timing of each subframe. In
addition, when the SSS is detected, the UE can recognize which subframe is a
subframe #0.
[0035] Furthermore, the UE can identify a cell group to which a cell formed by the eNB that
transmits the PSS belongs among three cell groups based on a sequence of the PSS. In
addition, the UE can identify a cell formed by the eNB that transmits the SSS among
168 cell candidates that belong to one cell group based on a sequence of the SSS. That
is, the UE can identify a cell formed by the eNB that transmits the PSS and the SSS
among 504 cell candidates based on the sequence of the PSS and the sequence of the
SSS.
[0036] (Synchronization signal of D2D communication)
For example, when the UE is positioned within the network coverage area, synchro
nization for D2D communication is performed based on the synchronization signal
transmitted by the eNB. For example, when the UE is positioned outside of the
network coverage area, synchronization for D2D communication is performed based
on the synchronization signal transmitted by another UE. Also, the synchronization
signal may be a relayed signal.
[0037] The synchronization signal used by a terminal device for D2D communication may
have various attributes. For example, the synchronization signal may have an attribute
of a transmission source. The transmission source may be the eNB or the UE. For
example, the synchronization signal may have an attribute of presence or absence of
relay.
[0038] When the synchronization signal is wirelessly relayed, deterioration of precision of a
center frequency is concerned. Accordingly, it is preferable that the number of relays
(the number of hops) be smaller.
[0039] The eNB is more preferable than the UE as the transmission source of the synchro
nization signal. This is because precision of an oscillator of the eNB is higher than
precision of an oscillator of the UE.
[0040] (Radio resources available for D2D communication)
(a) Resource pool
As radio resources available for D2D communication, radio resources called a
resource pool are prepared. As the resource pool, periodic radio resources are
considered. For example, the resource pool is represented by a period and an offset (in
a time direction).
[0041] As a method of using the resource pool, two methods may be provided. In the first
method, a management node (for example, the eNB or the UE) allocates radio
resources among the resource pool to the UE and notifies the UE of the radio
resources. The UE can perform D2D communication in the allocated radio resources.
In the second method, the UE selects radio resources from among the resource pool,
and performs D2D communication in the radio resources. The first method is a noncontention-
based method and there is no collision. On the other hand, the second
method is a contention-based method, and collision may occur.
[0042] (b) Multiple resource pools
It is considered natural that multiple resource pools are prepared. In this case, the
period and the offset of the resource pool may be different from periods and offsets of
other resource pools. Also, the period of the resource pool may be the same as periods
of other resource pools while the offset of the resource pool is different from offsets of
the other resource pools.
[0043] Hereinafter, the radio frame and the subframe serving as a unit of time in a cellular
system will be described with reference to FIG. 5. A specific example of the resource
pool will be described with reference to FIG. 6.
[0044] FIG. 5 is an explanatory diagram illustrating a radio frame and subframes in a
cellular system. Referring to FIG. 5, the radio frame and 10 subframes included in one
radio frame are illustrated. Each radio frame is 10 ms, and each subframe is 1 ms. Each
radio frame has a system frame number (SFN) of any of 0 to 1023, and 1024 radio
frames are repeatedly presented.
[0045] FIG. 6 is an explanatory diagram illustrating an exemplary resource pool. Referring
to FIG. 6, two resource pools (that is, a resource pool # 1 and a resource pool #2) are i l
lustrated. The radio resources available for D2D communication are considered to be
periodically arranged in the subframe. For example, the resource pool # 1 includes
radio resources of subframes 3 1 that are repeated at a period 33, and the resource pool
#2 includes radio resources of subframes 35 that are repeated at a period 37. For
example, the period 33 is 200 ms, and the period 37 is 400 ms. Also, in this example,
the resource pool # 1 and the resource pool #2 have different offsets.
[0046] (c) Signal/information transmitted in resource pool
For example, in the resource pool, a synchronization signal and synchronization in
formation (information of synchronization) are transmitted by a representative UE. In
addition, the UE performs D2D communication in radio resources other than the radio
resources in which the synchronization signal and the synchronization information are
transmitted among the resource pool. Hereinafter, a specific example thereof will be
described with reference to FIG. 7.
[0047] FIG. 7 is an explanatory diagram illustrating an example of a signal and information
transmitted in a resource pool. Referring to FIG. 7, N resource pools (that is, resource
pools # 1 to #N) are illustrated. In each of the N resource pools, the synchronization
signal and the synchronization information are transmitted. In addition, in each of the
N resource pools, D2D communication may be performed in radio resources other than
the radio resources in which the synchronization signal and the information are
transmitted. Also, one UE may transmit the synchronization signal and the synchronization
information in two or more resource pools.
[0048] «2. Technical problems according to embodiments of present disclosure »
First, technical problems according to embodiments of the present disclosure will be
described with reference to FIG. 8.
[0049] (Premises)
For example, as radio resources available for D2D communication, periodic radio
resources are allocated. For example, at periods of an integer multiple of a radio frame,
radio resources of a specific subframe are allocated as the radio resources available for
D2D communication. Therefore, D2D communication is performed in the specific
subframe.
[0050] For example, when D2D communication is performed in a TDD carrier, radio
resources of an uplink subframe of a UL/DL configuration of the TDD carrier are
allocated as the radio resources available for D2D communication within a network
coverage area. Therefore, D2D communication is performed in the uplink subframe. A
specific example thereof will be described below with reference to FIG. 8.
[0051] FIG. 8 is an explanatory diagram illustrating a UL/DL configuration. Referring to
FIG. 8, seven configurations (configurations 0 to 6) that may be selected as the UL/DL
configuration of the TDD carrier are illustrated. In each of the configurations, each of
10 subframes included in a radio frame is determined as a downlink subframe, an
uplink subframe or a special subframe. As an example, when the UL/DL configuration
of the TDD carrier is the configuration 2, radio resources of any of subframes having
subframe numbers 2 and 7 are allocated as the radio resources available for D2D com
munication. As another example, when the UL/DL configuration of the TDD carrier is
the configuration 3, radio resources of any of subframes having subframe numbers 2,
3, and 4 are allocated as the radio resources available for D2D communication.
[0052] (First technical problem)
In the case of in-coverage, the base station may notify the terminal device of the
radio resources available for D2D communication. However, when the base station
freely selects the radio resources available for D2D communication without con
straints, the base station may use many radio resources in order to notify the radio
resources available for D2D communication. As a result, from the viewpoint of the
radio resources, a load on the base station may become large.
[0053] Referring again to FIG. 8, for example, when the UL/DL configuration of the TDD
carrier is the configuration 2, radio resources of a subframe having a subframe number
7 are allocated as the radio resources available for D2D communication. Then, the UL/
DL configuration is changed from the configuration 2 to the configuration 3.
Therefore, the subframe having a subframe number 7 becomes the downlink subframe.
As a result, D2D communication may be performed in the downlink subframe.
[0054] Accordingly, it is preferable to provide a mechanism in which the terminal device
can appropriately perform D2D communication under a TDD environment. More
specifically, for example, it is preferable to provide a mechanism in which the terminal
device can continuously perform D2D communication in the uplink subframe under
the TDD environment.
[0055] (Second technical problem)
In addition, when radio resources of the uplink subframe of the UL/DL configuration
of the TDD carrier are freely allocated as the radio resources available for D2D com
munication, a negative influence may occur in TDD radio communication between the
base station and the terminal device.
[0056] For example, when the uplink subframe is allocated for D2D communication, the
terminal device transmits no uplink signal in the uplink subframe. Therefore, for
example, communication quality in an uplink of the terminal device may decrease. As
an example, when a user of the terminal device makes a call, a transmission interval of
audio data by the terminal device may be longer. Therefore, a delay may occur when
audio data is transmitted. As a result, communication quality may decrease. As another
example, transmission of ACK/NACK (that is, ACK/NACK of downlink data) by the
terminal device in an uplink at an appropriate timing is considered to be difficult.
Specifically, errors or delays are considered to occur when ACK/NACK is transmitted
in the uplink.
[0057] Accordingly, it is preferable to provide a mechanism in which the terminal device
can appropriately perform D2D communication under the TDD environment. More
specifically, for example, it is preferable to provide a mechanism in which a negative
influence occurring in TDD radio communication between the base station and the
terminal device due to D2D communication can be reduced.
[0058] «2. Schematic Configuration of Communication System»
Next, a schematic configuration of a communication system 1 according to an em
bodiment of the present disclosure will be described with reference to FIG. 9. FIG. 9 is
an explanatory diagram illustrating an example of a schematic configuration of the
communication system 1 according to the embodiment of the present disclosure.
Referring to FIG. 9, the communication system 1 includes a base station 100 and a
terminal device 200. The communication system 1 is, for example, a cellular system,
and is a system compliant with, for example, LTE, LTE-Advanced, or communication
standards conforming thereto.
[0059] (The base station 100)
The base station 100 performs radio communication with the terminal device. For
example, the base station 100 performs radio communication with the terminal device
200 which is positioned inside a cell 101 of the base station 100.
[0060] Especially, in the embodiment of the present disclosure, the base station 100
performs radio communication in TDD. Specifically, for example, the base station 100
uses the TDD carrier, transmits a downlink signal in the downlink subframe, and
receives an uplink signal in the uplink subframe. The TDD carrier is a carrier for TDD
radio communication, for example, a component carrier.
[0061] Also, in FIG. 9, only one base station (that is, the base station 100) included in the
communication system 1 is illustrated. It is needless to say that the communication
system 1 may include multiple base stations. Then, a set of multiple base stations
builds the network coverage area (that is, a coverage area of the cellular network).
[0062] (The terminal device 200)
The terminal device 200 performs radio communication with the base station. For
example, when the terminal device 200 is positioned inside the cell 101 of the base
station 100, the terminal device 200 performs radio communication with the base
station 100. For example, the terminal device 200 performs radio communication with
the base station in TDD. Specifically, for example, the terminal device 200 uses the
TDD carrier, receives a downlink signal in the downlink subframe, and transmits an
uplink signal in the uplink subframe.
[0063] Especially, in the embodiment of the present disclosure, the terminal device 200
performs D2D communication. For example, the terminal device 200 performs D2D
communication with another terminal device 200.
[0064] «4. Configuration of Respective Devices»
Next, exemplary configurations of the base station 100 and the terminal device 200
will be described with reference to FIGS. 10 to 11.
[0065] <4.1. Base Station Configuration»
FIG. 10 is a block diagram illustrating an exemplary configuration of the base station
100 according to the embodiment of the present disclosure. Referring to FIG. 10, the
base station 100 includes an antenna unit 110, a radio communication unit 120, a
network communication unit 130, a storage unit 140 and a processing unit 150.
[0066] (The antenna unit 110)
The antenna unit 110 receives a radio signal and outputs the received radio signal to
the radio communication unit 120. In addition, the antenna unit 110 transmits a
transmission signal output by the radio communication unit 120.
[0067] (The radio communication unit 120)
The radio communication unit 120 transmits and receives a signal. For example, the
radio communication unit 120 transmits a downlink signal to the terminal device and
receives an uplink signal from the terminal device.
[0068] (The network communication unit 130)
The network communication unit 130 transmits and receives information. For
example, the network communication unit 130 transmits information to other nodes
and receives information from other nodes. For example, the other nodes include other
base stations and a core network node.
[0069] (The storage unit 140)
The storage unit 140 stores a program and data for operating the base station 100.
[0070] (The processing unit 150)
The processing unit 150 provides various functions of the base station 100. The
processing unit 150 includes an information acquisition unit 151 and a control unit
153. Also, the processing unit 150 may further include a component other than these
components. That is, the processing unit 150 may also perform an operation other than
operations of these components.
[0071] Operations of the information acquisition unit 151 and the control unit 153 will be
described later in detail.
[0072] <4.2. Terminal Device Configuration »
FIG. 11 is a block diagram illustrating an exemplary configuration of the terminal
device 200 according to the embodiment of the present disclosure. Referring to FIG.
11, the terminal device 200 includes an antenna unit 210, a radio communication unit
220, a storage unit 230 and a processing unit 240.
[0073] (The antenna unit 210)
The antenna unit 210 receives a radio signal and outputs the received radio signal to
the radio communication unit 220. In addition, the antenna unit 210 transmits a
transmission signal output by the radio communication unit 220.
[0074] (The radio communication unit 220)
The radio communication unit 220 transmits and receives a signal. For example, the
radio communication unit 220 receives a downlink signal from the base station and
transmits an uplink signal to the base station. In addition, for example, the radio com
munication unit 220 receives a signal from another terminal device and transmits a
signal to another terminal device.
[0075] (The storage unit 230)
The storage unit 230 stores a program and data for operating the terminal device 200.
[0076] (The processing unit 240)
The processing unit 240 provides various functions of the terminal device 200. The
processing unit 240 includes an information acquisition unit 241 and a control unit
243. Also, the processing unit 240 may further include a component other than these
components. That is, the processing unit 240 may also perform an operation other than
operations of these components.
[0077] Operations of the information acquisition unit 241 and the control unit 243 will be
described later in detail.
[0078] «5. Technical features according to embodiments of present disclosure»
Next, technical features according to embodiments of the present disclosure will be
described with reference to FIGS. 12 to 19.
[0079] <5. 1. First technical features>
First, the first technical features according to the embodiment of the present
disclosure will be described with reference to FIGS. 12 to 15. The first technical
features are, for example, features that correspond to the first technical problem
according to the embodiment of the present disclosure described above.
[0080] (Dynamic change of UL/DL configuration)
The base station 100 (the control unit 153) dynamically changes the UL/DL con
figuration of the TDD carrier.
[0081] (a) Multiple configurations
For example, the base station 100 (the control unit 153) changes the UL/DL con
figuration from one configuration among multiple configurations to another con
figuration among the multiple configurations.
[0082] For example, the multiple configurations include seven configurations
(configurations 0 to 6) illustrated in FIG. 8. That is, the base station 100 (the control
unit 153) changes the UL/DL configuration from one configuration among the seven
configurations to another configuration.
[0083] As a specific process, for example, the control unit 153 changes the UL/DL con
figuration by changing an operation parameter designating the UL/DL configuration.
Also, this is only an example of a specific process, and it is needless to say that the
control unit 153 may perform another process according to mounting.
[0084] (b) Notification of UL/DL configuration
For example, the base station 100 (the control unit 153) notifies the terminal device
of the UL/DL configuration of the TDD carrier.
[0085] (b- 1) Notification method
- Reporting system information
For example, the base station 100 (the control unit 153) notifies the terminal device
of the UL/DL configuration by reporting system information indicating the UL/DL
configuration. For example, the system information is a system information block
(SIB) 1.
[0086] Accordingly, for example, not only the terminal device in a connection mode but also
the terminal device in an idle mode can recognize the UL/DL configuration.
[0087] - Separate signaling
The base station 100 (the control unit 153) may notify the terminal device in a
connection mode of the UL/DL configuration using separate signaling in addition to
reporting the system information. The separate signaling may be radio resource control
(RRC) signaling. The terminal device in a connection mode may be, for example, the
terminal device 200.
[0088] Accordingly, for example, it is possible to notify of a change in the UL/DL con
figuration quickly.
[0089] (b-2) Operation of the terminal device 200
For example, the terminal device 200 (the information acquisition unit 241) acquires
the UL/DL configuration. Therefore, the terminal device 200 (the control unit 243)
performs radio communication with the base station using the TDD carrier according
to the UL/DL configuration.
[0090] (Notification of radio resources for D2D communication)
The base station 100 (the control unit 153) notifies the terminal device of the radio
resources for D2D communication appropriate for the UL/DL configuration. The radio
resources are radio resources of the TDD carrier. Also, "radio resources for D2D com
munication" may be simply referred to as "D2D resources" below.
[0091] On the other hand, the terminal device 200 (the information acquisition unit 241)
acquires information indicating the D2D resources appropriate for the UL/DL con
figuration (that is, the UL/DL configuration of the TDD carrier that is dynamically
changed by the base station 100). Therefore, the terminal device 200 performs D2D
communication using the D2D resources. The control unit 243 of the terminal device
200 controls D2D communication using the D2D resources.
[0092] (a) D2D resources appropriate for UL/DL configuration
The D2D resources appropriate for the UL/DL configuration are radio resources of at
least one uplink subframe of the UL/DL configuration.
[0093] Referring again to FIG. 8, as an example, when the UL/DL configuration is the con
figuration 1, the D2D resources appropriate for the UL/DL configuration are radio
resources of at least one subframe among subframes having subframe numbers 2, 3, 7,
and 8. As another example, when the UL/DL configuration is the configuration 4, the
D2D resources appropriate for the UL/DL configuration are radio resources of at least
one subframe among subframes having subframe numbers 2 and 3.
[0094] Also, for example, the D2D resources are periodic radio resources. More specifically,
for example, the D2D resources are radio resources that are repeated at periods of an
integer multiple of a radio frame. In this case, as long as the period is not one radio
frame, the D2D resources are radio resources of a specific subframe of a limited radio
frame. The D2D resources may be referred to as a resource pool. Multiple resource
pools each having a period (and an offset) may be prepared. The D2D resources may
be indicated by a period (and an offset) of a radio frame and a subframe.
[0095] (b) Notification method
For example, the base station 100 (the control unit 153) notifies the terminal device
of the D2D resources by reporting system information indicating the D2D resources
appropriate for the UL/DL configuration. Accordingly, for example, not only the
terminal device in a connection mode but also the terminal device in an idle mode can
recognize the D2D resources.
[0096] Also, the base station 100 (the control unit 153) may notify the terminal device 200
of the D2D resources using separate signaling. The separate signaling may be RRC
signaling.
[0097] (c) Notification form
(c-1) Notification of D2D resources according to change of the UL/DL configuration
As described above, the base station 100 (the control unit 153) changes the UL/DL
configuration from one configuration among the multiple configurations to another
configuration among the multiple configurations.
[0098] As a first notification form, for example, the base station 100 (the control unit 153)
notifies the terminal device of the D2D resources appropriate for the other con
figuration according to a change of the UL/DL configuration. The D2D resources ap
propriate for the other configuration are radio resources of at least one uplink subframe
of the other configuration.
[0099] On the other hand, the terminal device 200 (the information acquisition unit 241)
acquires information indicating the D2D resources of which the base station 100 has
notified the terminal device 200. Therefore, the terminal device 200 uses the D2D
resources of which the base station 100 has notified the terminal device 200, and
performs D2D communication. That is, the control unit 243 of the terminal device 200
controls D2D communication using the D2D resources of which the base station 100
has notified the terminal device 200.
[0100] A specific example of the D2D resources of which the base station 100 has notified
the terminal device will be described below with reference to FIGS. 12 and 13.
[0101] FIG. 12 is an explanatory diagram illustrating a first example of D2D resources.
Referring to FIG. 12, configurations 0 to 6 are illustrated. In this example, one uplink
subframe is prepared as the D2D resources for each configuration. For example, the
D2D resources appropriate for each of the configurations 0, 1, 3, 4 and 6 are radio
resources of an uplink subframe having a subframe number 3. In addition, for example,
the D2D resources appropriate for each of the configurations 2 and 5 are radio
resources of an uplink subframe having a subframe number 2.
[0102] FIG. 13 is an explanatory diagram illustrating a notification example of the D2D
resources according to the change of the UL/DL configuration. Referring to FIG. 13,
for example, the UL/DL configuration of the TDD carrier is changed from the con
figuration 0 to the configuration 2. The D2D resources appropriate for the con
figuration 0 are radio resources of a subframe having a subframe number 3. The D2D
resources appropriate for the configuration 2 are radio resources of a subframe having
a subframe number 2. In this case, the base station 100 (the control unit 153) notifies
the terminal device of radio resources of an uplink subframe having a subframe
number 2 as the D2D resources according to the change of the UL/DL configuration.
As a result, the terminal device 200 does not perform D2D communication in a
subframe having a subframe number 3 after the change of the UL/DL configuration,
but performs D2D communication in a subframe having a subframe number 2.
[0103] In this manner, for example, when the UL/DL configuration is changed to any of the
configurations 0, 1, 3, 4 and 6, the base station 100 (the control unit 153) notifies the
terminal device of radio resources of an uplink subframe having a subframe number 3
as the D2D resources. In addition, for example, when the UL/DL configuration is
changed to any of the configurations 2 and 5, the base station 100 (the control unit
153) notifies the terminal device of radio resources of an uplink subframe having a
subframe number 2 as the D2D resources.
[0104] Also, in the example of FIG. 12, the D2D resources are radio resources of one
subframe within a radio frame. However, it is needless to say that the D2D resources
may be radio resources of two or more subframes within a radio frame.
[0105] In addition, for example, the D2D resources are periodic radio resources and have a
period (and an offset). In this case, for example, the base station 100 (the control unit
153) notifies of not only the subframe but also the period (and the offset) when the
D2D resources are notified of. For example, the period is a period of an integer
multiple of a radio frame.
[0106] As described above, for example, the base station 100 (the control unit 153) notifies
the terminal device of the D2D resources appropriate for the other configuration (that
is, the changed configuration) according to the change of the UL/DL configuration.
Accordingly, for example, the terminal device can continuously perform D2D commu
nication in the uplink subframe under the TDD environment. That is, even when a UL/
DL subframe of the TDD carrier is changed, the base station 100 notifies the terminal
device 200 of the D2D resources (the radio resources of the uplink subframe) ap
propriate for the changed configuration, and the terminal device 200 can perform D2D
communication in the uplink subframe.
[0107] Also, for example, the base station 100 reports system information indicating the
other configuration (that is, the changed configuration) from immediately before the
change of the UL/DL configuration to immediately before the following change of the
UL/DL configuration. The base station 100 may notify the terminal device 200 of the
other configuration (that is, the changed configuration) using separate signaling im
mediately before the change of the UL/DL configuration.
[0108] (c-2) Notification of D2D resources appropriate for each of the multiple configurations
As described above, the base station 100 (the control unit 153) changes the UL/DL
configuration from one configuration among the multiple configurations to another
configuration among the multiple configurations.
[0109] As a second notification form, for example, the base station 100 (the control unit
153) notifies the terminal device of the D2D resources appropriate for each of the
multiple configurations.
[01 10] - First example: D2D resources for each configuration
As a first example, the radio resources appropriate for each of the multiple config
urations include the D2D resources for each configuration. That is, the base station 100
(the control unit 153) notifies the terminal device of the D2D resources for each con
figuration included in the multiple configurations.
[0111] Referring again to FIG. 12, for example, the multiple configurations are the config
urations 0 to 6. The D2D resources for each configuration are illustrated. For example,
the base station 100 (the control unit 153) notifies the terminal device of the D2D
resources for each of these configurations.
[0112] On the other hand, the terminal device 200 (the information acquisition unit 241)
acquires information indicating the D2D resources appropriate for the UL/DL con
figuration among the D2D resources appropriate for each of the multiple config
urations based on the UL/DL configuration of which the base station 100 has notified
the terminal device. Therefore, the terminal device 200 performs D2D communication
using the D2D resources.
[01 13] Referring again to FIG. 13, for example, the UL/DL configuration of the TDD carrier
is changed from the configuration 0 to the configuration 2. In this case, the base station
100 notifies the terminal device of the configuration 2, and the terminal device 200
(the information acquisition unit 241) acquires information indicating the D2D
resources appropriate for the configuration 2 among the D2D resources appropriate for
each of the configurations 0 to 6. Therefore, the terminal device 200 performs D2D
communication in the D2D resources appropriate for the configuration 2.
[01 14] In addition, for example, the D2D resources are periodic radio resources and have a
period (and an offset). In this case, for example, the base station 100 (the control unit
153) notifies of not only the subframe but also the period (and the offset) when the
D2D resources are notified of. For example, the period is a period of an integer
multiple of a radio frame.
[01 15] As described above, the base station 100 (the control unit 153) notifies the terminal
device of the D2D resources for each configuration included in the multiple config
urations. Accordingly, for example, the terminal device can continuously perform D2D
communication in the uplink subframe under the TDD environment. That is, even
when the UL/DL subframe of the TDD carrier is changed, the terminal device 200 can
specify the D2D resources (the radio resources of the uplink subframe) appropriate for
the changed configuration, and perform D2D communication in the uplink subframe.
[0116] - Second example: D2D resources common among multiple configurations
As a second example, the radio resources appropriate for each of the multiple config
urations may be radio resources of at least one uplink subframe common among the
multiple configurations. That is, the base station 100 (the control unit 153) may notify
the terminal device of radio resources of at least one uplink subframe common among
the multiple configurations as the D2D resources.
[01 17] On the other hand, the terminal device 200 (the information acquisition unit 241)
may acquire information indicating the D2D resources (that is, radio resources of at
least one uplink subframe common among the multiple configurations) of which the
base station 100 has notified the terminal device. Therefore, the terminal device 200
may use the D2D resources of which the base station 100 has notified the terminal
device 200 and perform D2D communication. That is, the control unit 243 of the
terminal device 200 may control D2D communication using the D2D resources of
which the base station 100 has notified the terminal device 200.
[0118] A specific example of the D2D resources will be described below with reference to
FIG. 14.
[0119] FIG. 14 is an explanatory diagram illustrating a second example of the D2D
resources. Referring to FIG. 14, configurations 0 to 6 are illustrated. In this example,
radio resources of an uplink subframe (that is, a subframe having a subframe number
2) common among the configurations 0 to 6 are prepared as the D2D resources. In this
case, the base station 100 notifies the terminal device of radio resources of an uplink
subframe having a subframe number 2 as the D2D resources. Accordingly, either
before the change or after the change of the UL/DL subframe of the TDD carrier, the
terminal device 200 can perform D2D communication in the uplink subframe having
the subframe number 2.
[0120] While the example in which a subframe common among the multiple configurations
is a subframe having a subframe number 2 has been described, the subframe common
among the multiple configurations is not limited thereto. For example, the multiple
configurations may not be seven configurations (that is, the configurations 0 to 6), but
may be some of the seven configurations. Therefore, the subframe common among the
multiple configurations may be a subframe other than the subframe having a subframe
number 2. A specific example thereof will be described below with reference to FIG.
15.
[0121] FIG. 15 is an explanatory diagram illustrating a third example of the D2D resources.
Referring to FIG. 15, the configurations 0, 1, 3, 4 and 6 are illustrated. In this example,
the multiple configurations are the configurations 0, 1, 3, 4 and 6. Therefore, radio
resources of an uplink subframe (for example, a subframe having a subframe number
3) common among the configurations 0, 1, 3, 4 and 6 are prepared as the D2D
resources. In this case, the base station 100 notifies the terminal device of radio
resources of an uplink subframe having a subframe number 3 as the D2D resources.
Accordingly, either before the change or after the change of the UL/DL subframe of
the TDD carrier, the terminal device 200 can perform D2D communication in the
uplink subframe having the subframe number 3.
[0122] In addition, for example, the D2D resources are periodic radio resources and have a
period (and an offset). In this case, for example, the base station 100 (the control unit
153) notifies of not only the subframe but also the period (and the offset) when the
D2D resources are notified of. For example, the period is a period of an integer
multiple of a radio frame.
[0123] As described above, the base station 100 (the control unit 153) may notify the
terminal device of radio resources of at least one uplink subframe common among the
multiple configurations as the D2D resources. Accordingly, for example, the terminal
device can continuously perform D2D communication in the uplink subframe under
the TDD environment. That is, either before the change or after the change of the UL/
DL subframe of the TDD carrier, the terminal device 200 can perform D2D commu
nication in the uplink subframe.
[0124] Also, for example, a period (and an offset) of the D2D resources may be common
among the multiple configurations. That is, the D2D resources common among the
multiple configurations may also be prepared. Accordingly, for example, regardless of
the change of UL/DL configuration, the terminal device can perform D2D commu
nication in the D2D resources.
[0125] As described above, the base station 100 (the control unit 153) notifies the terminal
device of the D2D resources appropriate for the UL/DL configuration. Also, for
example, the D2D resources refer to a resource pool having a period (and an offset),
and the base station 100 (the control unit 153) may notify the terminal device of the
resource pool (the D2D resources) appropriate for the UL/DL configuration in each of
multiple resource pools.
[0126] <5.1. Second technical features>
Next, the second technical features according to the embodiment of the present
disclosure will be described with reference to FIGS. 16 to 19. The second technical
features are, for example, features that correspond to the second technical problem
according to the embodiment of the present disclosure described above.
[0127] (D2D resources appropriate for UL/DL configuration)
As described above, the base station 100 (the control unit 153) notifies the terminal
device of the radio resources for D2D communication appropriate for the UL/DL con
figuration (the D2D resources). In addition, the D2D resources appropriate for the UL/
DL configuration are the radio resources of at least one uplink subframe of the UL/DL
configuration.
[0128] (a) Features of subframe
(a-1) Some of two or more successive uplink subframes
For example, each of the at least one uplink subframe is included in two or more
successive uplink subframes of the UL/DL configuration. That is, the D2D resources
appropriate for the UL/DL configuration are radio resources of at least one uplink
subframe included in each of the two or more successive uplink subframes of the UL/
DL configuration. Also, one or more uplink subframes among the two or more
successive uplink subframes are not included in the at least one uplink subframe. A
specific example of the D2D resources will be described below with reference to FIG.
16.
[0129] FIG. 16 is an explanatory diagram illustrating a fourth example of the D2D
resources. Referring to FIG. 16, configurations 0 to 6 are illustrated. For example, the
D2D resources appropriate for the configuration 0 are radio resources of subframes
having subframe numbers 3 and 8. In the configuration 0, a subframe having a
subframe number 3 is included in three successive uplink subframes, and a subframe
having a subframe number 8 is also included in three successive uplink subframes. The
D2D resources appropriate for the configuration 1 are radio resources of subframes
having subframe numbers 3 and 8. The D2D resources appropriate for the config
urations 3 and 4 are radio resources of a subframe having a subframe number 3. The
D2D resources appropriate for the configuration 6 are radio resources of subframes
having subframe numbers 3 and 7.
[0130] Accordingly, for example, it is possible to decrease a negative influence occurring in
TDD radio communication between the base station and the terminal device due to
D2D communication. More specifically, for example, even when the uplink subframe
is unable to be used in TDD radio communication due to D2D communication, a
maximum interval between the uplink subframes used in TDD radio communication
hardly becomes longer. Therefore, a decrease in uplink communication quality due to
an increase in the interval of the uplink subframe is suppressed.
[0131] - Limitation of D2D communication
For example, when the UL/DL configuration includes two or more successive uplink
subframes, the base station 100 (the control unit 153) notifies the terminal device of
the D2D resources appropriate for the UL/DL configuration. On the other hand, when
the UL/DL configuration does not include two or more successive uplink subframes,
the base station 100 (the control unit 153) does not notify the terminal device of the
D2D resources appropriate for the UL/DL configuration.
[0132] That is, when the UL/DL configuration includes two or more successive uplink
subframes, D2D communication is performed, and when the UL/DL configuration
does not include two or more successive uplink subframes, no D2D communication is
performed.
[0133] Referring again to FIG. 16, for example, when the UL/DL configuration of the TDD
carrier is any of the configurations 0, 1, 3, 4 and 6, the base station 100 (the control
unit 153) notifies the terminal device of the D2D resources appropriate for the UL/DL
configuration. On the other hand, when the UL/DL configuration of the TDD carrier is
any of the configurations 2 and 5, the base station 100 (the control unit 153) does not
notify the terminal device of the D2D resources appropriate for the UL/DL con
figuration. That is, when the UL/DL configuration is any of the configurations 0, 1, 3,
4 and 6, D2D communication is performed, and when the UL/DL configuration is any
of the configurations 2 and 5, no D2D communication is performed.
[0134] Accordingly, for example, radio resources of at least one uplink subframe included in
each of the two or more successive uplink subframes may be used as the D2D
resources.
[0135] - Limitation of configuration
Alternatively, the UL/DL configuration of the TDD carrier may be a configuration
including two or more successive uplink subframes.
[0136] Referring again to FIG. 16, for example, the UL/DL configuration of the TDD carrier
may be any of the configurations 0, 1, 3, 4 and 6. That is, the configurations 2 and 5
that do not include two or more successive uplink subframes may be excluded.
[0137] Accordingly, for example, radio resources of at least one uplink subframe included in
each of the two or more successive uplink subframes may be used as the D2D
resources.
[0138] (a-2) Number of uplink subframes
As described above, the D2D resources appropriate for the UL/DL configuration are
radio resources of at least one uplink subframe of the UL/DL configuration.
[0139] The number of uplink subframes included in the at least one uplink subframe may be
different according to the number of uplink subframes of the UL/DL configuration.
[0140] For example, when the number of uplink subframes of the UL/DL configuration is
greater, the D2D resources appropriate for the UL/DL configuration may be radio
resources of a greater number of uplink subframes. A specific example of the D2D
resources will be described below with reference to FIG. 17.
[0141] FIG. 17 is an explanatory diagram illustrating a fifth example of the D2D resources.
Referring to FIG. 17, configurations 0 to 6 are illustrated. For example, the con
figuration 0 includes six uplink subframes. The configuration 1 includes four uplink
subframes. The configuration 2 includes two uplink subframes. The configuration 3
includes three uplink subframes. The configuration 4 includes two uplink subframes.
The configuration 5 includes one uplink subframe. The configuration 6 includes five
uplink subframes. Since the configurations 0, 1, and 6 include great numbers of uplink
subframes (for example, four or more uplink subframes), the D2D resources ap
propriate for each of the configurations 0, 1, and 6 are radio resources of two uplink
subframes. On the other hand, since the configurations 2, 3, 4, and 5 include small
numbers of uplink subframes (for example, three or fewer uplink subframes), the D2D
resources appropriate for each of the configurations 2, 3, 4, and 5 are radio resources of
one uplink subframe.
[0142] Accordingly, for example, it is possible to decrease a negative influence occurring in
TDD radio communication between the base station and the terminal device due to
D2D communication. More specifically, for example, even when the uplink subframe
is unable to be used in TDD radio communication due to D2D communication, the
uplink subframe used in TDD radio communication may be ensured to some extent in
any configuration. Therefore, according to the configuration, a situation in which the
uplink subframe is absent or the number of uplink subframes significantly decreases
may be avoided. Therefore, a decrease in uplink communication quality due to a
decrease of the number of uplink subframes may be suppressed.
[0143] - Limitation of D2D communication
When the number of uplink subframes of the UL/DL configuration is equal to or
greater than a predetermined number, the base station 100 (the control unit 153) may
notify the terminal device of the D2D resources appropriate for the UL/DL con
figuration. On the other hand, when the number of uplink subframes of the UL/DL
configuration is less than the predetermined number, the base station 100 (the control
unit 153) may not notify the terminal device of the D2D resources appropriate for the
UL/DL configuration.
[0144] That is, when the number of uplink subframes of the UL/DL configuration is equal to
or greater than the predetermined number, D2D communication may be performed,
and when the number of uplink subframes is less than the predetermined number, no
D2D communication may be performed.
[0145] As an example, the predetermined number may be 3. In this case, when the UL/DL
configuration is any of the configurations 0, 1, 3, and 6, the base station 100 (the
control unit 153) may notify the terminal device of the D2D resources appropriate for
the UL/DL configuration. On the other hand, when the UL/DL configuration is any of
the configurations 2, 4, and 5, the base station 100 (the control unit 153) may not
notify the terminal device of the D2D resources appropriate for the UL/DL con
figuration. That is, when the UL/DL configuration is any of the configurations 0, 1, 3,
and 6, D2D communication may be performed, and when the UL/DL configuration is
any of the configurations 2, 4, and 5, no D2D communication may be performed.
[0146] As another example, the predetermined number may be 2. In this case, when the UL/
DL configuration is any of the configurations 0, 1, 2, 3, 4, and 6, the base station 100
(the control unit 153) may notify the terminal device of the D2D resources appropriate
for the UL/DL configuration. On the other hand, when the UL/DL configuration is the
configuration 5, the base station 100 (the control unit 153) may not notify the terminal
device of the D2D resources appropriate for the UL/DL configuration. That is, when
the UL/DL configuration is any of the configurations 0, 1, 2, 3, 4, and 6, D2D commu
nication may be performed, and when the UL/DL configuration is the configuration 5,
no D2D communication may be performed.
[0147] Accordingly, for example, although the number of uplink subframes of the con
figuration is small, it is possible to prevent the uplink subframe from not being used in
TDD radio communication due to D2D communication.
[0148] - Limitation of configuration
Alternatively, the UL/DL configuration may also be a configuration including a pre
determined number or more of uplink subframes.
[0149] As an example, the predetermined number may be 3. In this case, the UL/DL con
figuration of the TDD carrier may be any of the configurations 0, 1, 3, and 6. That is,
the configurations 2, 4, and 5 in which the number of uplink subframes is less than 3
may be excluded.
[0150] As another example, the predetermined number may be 2. In this case, the UL/DL
configuration of the TDD carrier may be any of the configurations 0, 1, 2, 3, 4, and 6.
That is, the configuration 5 in which the number of uplink subframes is less than 2 may
be excluded.
[0151] Accordingly, for example, although the number of uplink subframes of the con
figuration is small, it is possible to prevent the uplink subframe from not being used in
TDD radio communication due to D2D communication.
[0152] (b) Features of period
The D2D resources appropriate for the UL/DL configuration may be periodic radio
resources that are repeated at periods corresponding to the number of uplink subframes
of the UL/DL configuration.
[0153] (b-1) First example
When the number of uplink subframes of the UL/DL configuration is greater, a
period of the D2D resources appropriate for the UL/DL configuration may be shorter.
A specific example of the period for each configuration will be described below with
reference to FIG. 18.
[0154] FIG. 18 is an explanatory diagram illustrating a first example of the period for each
configuration. Referring to FIG. 18, periods and subframes of seven configurations
(configurations 0 to 6) are illustrated. In this example, similar to the example i l
lustrated in FIG. 12, the D2D resources appropriate for each of the configurations are
radio resources of one uplink subframe. For example, the configurations 0, 1, and 6
include four or more uplink subframes, and a period of the D2D resources appropriate
for the configurations 0, 1, and 6 is 100 ms (that is, 10 radio frames). The config
urations 2, 3, and 4 include two or three uplink subframes, and a period of the D2D
resources appropriate for the configurations 0, 1, and 6 is 200 ms (that is, 20 radio
frames). The configuration 5 includes one uplink subframe, and a period of the D2D
resources appropriate for the configuration 5 is 400 ms (that is, 40 radio frames).
[0155] Accordingly, for example, as the number of uplink subframes of the configuration is
great, a greater number of D2D resources (the D2D resources having a shorter period)
are ensured. Therefore, an influence of TDD radio communication between the base
station and the terminal device may be suppressed and as many D2D resources as
possible may be ensured.
[0156] (b-2) Second example
When the UL/DL configuration is a first configuration, the D2D resources ap
propriate for the UL/DL configuration may be radio resources of an uplink subframe of
a first number and may be periodic radio resources that are repeated at a first period.
On the other hand, when the UL/DL configuration is a second configuration, the D2D
resources appropriate for the UL/DL configuration may be radio resources of an uplink
subframe of a second number that is less than the first number and may be periodic
radio resources that are repeated at a second period that is shorter than the first period.
[0157] That is, the D2D resources have a longer period when the radio resources have a
greater number of uplink subframes, and have a shorter period when the radio
resources have a smaller number of uplink subframes. A specific example of the period
for each configuration will be described below with reference to FIG. 19.
[0158] FIG. 19 is an explanatory diagram illustrating a second example of the period for
each configuration. Referring to FIG. 19, periods and subframes of seven config
urations (configurations 0 to 6) are illustrated. For example, the configurations 0, 1,
and 6 include four or more uplink subframes, and the D2D resources appropriate for
each of the configurations 0, 1, and 6 are radio resources of two uplink subframes and
have a period of 400 ms (that is, 40 radio frames). In addition, the configurations 2, 3,
4, and 5 include three or fewer uplink subframes, and the D2D resources appropriate
for each of the configurations 2, 3, 4, and 5 are radio resources of one uplink subframe
and have a period of 200 ms (that is, 20 radio frames).
[0159] Accordingly, for example, when the number of uplink subframes of the configuration
is small, the D2D resources are radio resources in which a small number of uplink
subframes are included in the radio frame and that have a shorter period. Therefore, in
an individual radio frame, an influence of TDD radio communication between the base
station and the terminal device may be suppressed and a difference of amounts of the
D2D resources between configurations may decrease.
[0160] «6. Process Flow»
Next, process examples of embodiments of the present disclosure will be described
with reference to FIGS. 20 to 22.
[0161] (First example)
FIG. 20 is a sequence diagram schematically illustrating a first example of a process
flow according to the embodiment of the present disclosure.
[0162] The base station 100 reports system information indicating the first configuration as
the UL/DL configuration of the TDD carrier (S401). In addition, the base station 100
reports system information indicating the D2D resources appropriate for the first con
figuration (S403).
[0163] The terminal device 200 uses the D2D resources (that is, the D2D resources ap
propriate for the first configuration) of which the base station 100 has notified the
terminal device 200, and performs D2D communication (S405).
[0164] Then, the base station 100 determines changing of the UL/DL configuration of the
TDD carrier from the first configuration to the second configuration, and reports
system information indicating the second configuration as the UL/DL configuration
(S407). In addition, the base station 100 reports system information indicating the D2D
resources appropriate for the second configuration (S409).
[0165] The terminal device 200 uses the D2D resources (that is, the D2D resources ap
propriate for the second configuration) of which the base station 100 has notified the
terminal device 200, and performs D2D communication (S411).
[0166] (Second example)
FIG. 2 1 is a sequence diagram schematically illustrating a second example of a
process flow according to the embodiment of the present disclosure.
[0167] The base station 100 reports system information indicating the first configuration as
the UL/DL configuration of the TDD carrier (S421). In addition, the base station 100
reports system information indicating the D2D resources appropriate for each of the
multiple configurations (S423). Especially, in this example, the base station 100
reports system information indicating the D2D resources for each configuration
included in the multiple configurations.
[0168] The terminal device 200 uses the D2D resources appropriate for the first con
figuration among the D2D resources appropriate for each of the multiple config
urations and performs D2D communication (S425).
[0169] Then, the base station 100 determines changing of the UL/DL configuration of the
TDD carrier from the first configuration to the second configuration, and reports
system information indicating the second configuration as the UL/DL configuration
(S427).
[0170] The terminal device 200 uses the D2D resources appropriate for the second con
figuration among the D2D resources appropriate for each of the multiple config
urations and performs D2D communication (S429).
[0171] (Third example)
FIG. 22 is a sequence diagram schematically illustrating a third example of a process
flow according to the embodiment of the present disclosure.
[0172] The base station 100 reports system information indicating the first configuration as
the UL/DL configuration of the TDD carrier (S441). In addition, the base station 100
reports system information indicating the D2D resources appropriate for each of the
multiple configurations (S443). Especially, in this example, the base station 100
reports system information indicating the radio resources of the uplink subframe
common among the multiple configurations. Further, for example, the radio resources
may be the D2D resources (that is, the D2D resources whose subframe, period and
offset are common among the multiple configurations) common among the multiple
configurations.
[0173] The terminal device 200 uses the D2D resources (that is, the D2D resources common
among the multiple configurations) of which the base station 100 has notified the
terminal device 200 and performs D2D communication (S445).
[0174] Also, for example, the base station 100 then changes the UL/DL configuration of the
TDD carrier from the first configuration to the second configuration. Regardless of this
change, the terminal device 200 continuously uses the D2D resources (that is, the D2D
resources common among the multiple configurations) and performs D2D commu
nication.
[0175] «7. Applications»
Technology according to one or more of the embodiments of the present disclosure is
applicable to various products. A base station 100 may be realized as any type of
evolved Node B (eNB) such as a macro eNB, and a small eNB. A small eNB may be
an eNB that covers a cell smaller than a macro cell, such as a pico eNB, micro eNB, or
home (femto) eNB. Instead, the base station 100 may be realized as any other types of
base stations such as a NodeB and a base transceiver station (BTS). The base station
100 may include a main body (that is also referred to as a base station device)
configured to control radio communication, and one or more remote radio heads
(RRH) disposed in a different place from the main body. Additionally, various types of
terminals to be discussed later may also operate as the base station 100 by temporarily
or semi-permanently executing a base station function. Further, at least some of
structural elements of the base station 100 may be realized in the base station device or
in a module for the base station device.
[0176] For example, the terminal device 200 may be realized as a mobile terminal such as a
smartphone, a tablet personal computer (PC), a notebook PC, a portable game terminal,
a portable/dongle type mobile router, and a digital camera, or an in-vehicle terminal
such as a car navigation device. The terminal device 200 may also be realized as a
terminal (that is also referred to as a machine type communication (MTC) terminal)
that performs machine-to-machine (M2M) communication. Furthermore, at least some
of structural elements of the terminal device 200 may be a module (such as an in
tegrated circuit module including a single die) mounted on each of the terminals.
[0177] <7. 1. Application 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 an embodiment of the technology of the present disclosure may be
applied. An eNB 800 includes one or more antennas 810 and a base station device 820.
Each antenna 810 and the base station device 820 may be connected to each other via
an RF cable.
[0178] Each of the antennas 810 includes a single or multiple antenna elements (such as
multiple antenna elements included in an MIMO antenna), and is used for the base
station device 820 to transmit and receive radio signals. The eNB 800 may include the
multiple antennas 810, as illustrated in FIG. 23. For example, the multiple antennas
810 may be compatible with multiple frequency bands used by the eNB 800. Although
FIG. 23 illustrates the example in which the eNB 800 includes the multiple antennas
810, the eNB 800 may also include a single antenna 810.
[0179] The base station device 820 includes a controller 821, a memory 822, a network
interface 823, and a radio communication interface 825.
[0180] The controller 821 may be, for example, a CPU or a DSP, and operates various
functions of a higher layer of the base station device 820. For example, the controller
821 generates a data packet from data in signals processed by the radio communication
interface 825, and transfers the generated packet via the network interface 823. The
controller 821 may bundle data from multiple base band processors to generate the
bundled packet, and transfer the generated bundled packet. The controller 821 may
have logical functions of performing control such as radio resource control, radio
bearer control, mobility management, admission control, and scheduling. The control
may be performed in corporation with an eNB or a core network node in the vicinity.
The memory 822 includes RAM and ROM, and stores a program that is executed by
the controller 821, and various types of control data (such as a terminal list,
transmission power data, and scheduling data).
[0181] The network interface 823 is a communication interface for connecting the base
station device 820 to a core network 824. The controller 821 may communicate with a
core network node or another eNB via the network interface 823. In that case, the eNB
800, and the core network node or the other eNB may be connected to each other
through a logical interface (such as an SI interface and an X2 interface). The network
interface 823 may also be a wired communication interface or a radio communication
interface for radio backhaul. If the network interface 823 is a radio communication
interface, the network interface 823 may use a higher frequency band for radio com
munication than a frequency band used by the radio communication interface 825.
[0182] The radio communication interface 825 supports any cellular communication scheme
such as Long Term Evolution (LTE) and LTE-Advanced, and provides radio
connection to a terminal positioned in a cell of the eNB 800 via the antenna 810. The
radio communication interface 825 may typically include, for example, a baseband
(BB) processor 826 and an RF circuit 827. The BB processor 826 may perform, for
example, encoding/decoding, modulating/demodulating, and multiplexing/demul
tiplexing, and performs various types of signal processing of layers (such as LI,
medium access control (MAC), radio link control (RLC), and a packet data con
vergence protocol (PDCP)). The BB processor 826 may have a part or all of the abovedescribed
logical functions instead of the controller 821. The BB processor 826 may be
a memory that stores a communication control program, or a module that includes a
processor and a related circuit configured to execute the program. Updating the
program may allow the functions of the BB processor 826 to be changed. The module
may be a card or a blade that is inserted into a slot of the base station device 820. Al
ternatively, the module may also be a chip that is mounted on the card or the blade.
Meanwhile, the RF circuit 827 may include, for example, a mixer, a filter, and an
amplifier, and transmits and receives radio signals via the antenna 810.
[0183] The radio communication interface 825 may include the multiple BB processors 826,
as illustrated in FIG. 23. For example, the multiple BB processors 826 may be
compatible with multiple frequency bands used by the eNB 800. The radio commu
nication interface 825 may include the multiple RF circuits 827, as illustrated in FIG.
23. For example, the multiple RF circuits 827 may be compatible with multiple
antenna elements. Although FIG. 23 illustrates the example in which the radio commu
nication interface 825 includes the multiple BB processors 826 and the multiple RF
circuits 827, the radio communication interface 825 may also include a single BB
processor 826 or a single RF circuit 827.
[0184] In the eNB 800 illustrated in FIG. 23, the control unit 153 (and the information ac
quisition unit 151) described with reference to FIG. 9 may be implemented in the radio
communication interface 825. Alternatively, at least some of these components may
also be implemented in the controller 821. As an example, the eNB 800 may mount a
module including a part (for example, the BB processor 826) or the entire radio com
munication interface 825 and/or the controller 821, and the control unit 153 (and the
information acquisition unit 151) may be implemented in the module. In this case, the
module may store a program (in other words, a program causing the processor to
execute operations of the control unit 153 (and the information acquisition unit 151))
causing the processor to function as the control unit 153 (and the information ac
quisition unit 151), and execute the program. As another example, a program causing
the processor to function as the control unit 153 (and the information acquisition unit
151) may be installed in the eNB 800, and the radio communication interface 825 (for
example, the BB processor 826) and/or the controller 821 may execute the program.
As described above, as a device including the control unit 153 (and the information ac
quisition unit 151), the eNB 800, the base station device 820 or the module may be
provided. A program causing the processor to function as the control unit 153(and the
information acquisition unit 151) may also be provided. In addition, a readable
recording medium in which the program is recorded may be provided.
[0185] In addition, in the eNB 800 illustrated in FIG. 23, the radio communication unit 120
described with reference to FIG. 10 may be implemented in the radio communication
interface 825 (for example, the RF circuit 827). In addition, the antenna unit 110 may
be implemented in the antenna 810. In addition, the network communication unit 130
may be implemented in the controller 821 and/or the network interface 823.
[0186] (Second Application)
FIG. 24 is a block diagram illustrating a second example of a schematic con
figuration of an eNB to which an embodiment of the technology of the present
disclosure may be applied. An eNB 830 includes one or more antennas 840, a base
station device 850, and an RRH 860. Each antenna 840 and the RRH 860 may be
connected to each other via an RF cable. The base station device 850 and the RRH 860
may be connected to each other via a high speed line such as an optical fiber cable.
[0187] Each of the antennas 840 includes a single or multiple antenna elements (such as
multiple antenna elements included in an MIMO antenna), and is used for the RRH
860 to transmit and receive radio signals. The eNB 830 may include the multiple
antennas 840, as illustrated in FIG. 24. For example, the multiple antennas 840 may be
compatible with multiple frequency bands used by the eNB 830. Although FIG. 24 i l
lustrates the example in which the eNB 830 includes the multiple antennas 840, the
eNB 830 may also include a single antenna 840.
[0188] The base station device 850 includes a controller 851, a memory 852, a network
interface 853, a radio communication interface 855, and a connection interface 857.
The controller 851, the memory 852, and the network interface 853 are the same as the
controller 821, the memory 822, and the network interface 823 described with
reference to FIG. 23.
[0189] The radio communication interface 855 supports any cellular communication scheme
such as LTE and LTE-Advanced, and provides radio communication to a terminal p o
sitioned in a sector corresponding to the RRH 860 via the RRH 860 and the antenna
840. The radio communication interface 855 may typically include, for example, a BB
processor 856. The BB processor 856 is the same as the BB processor 826 described
with reference to FIG. 23, except the BB processor 856 is connected to the RF circuit
864 of the RRH 860 via the connection interface 857. The radio communication
interface 855 may include the multiple BB processors 856, as illustrated in FIG. 24.
For example, the multiple BB processors 856 may be compatible with multiple
frequency bands used by the eNB 830. Although FIG. 24 illustrates the example in
which the radio communication interface 855 includes the multiple BB processors 856,
the radio communication interface 855 may also include a single BB processor 856.
[0190] The connection interface 857 is an interface for connecting the base station device
850 (radio communication interface 855) to the RRH 860. The connection interface
857 may also be a communication module for communication in the above-described
high speed line that connects the base station device 850 (radio communication
interface 855) to the RRH 860.
[0191] The RRH 860 includes a connection interface 861 and a radio communication
interface 863.
[0192] The connection interface 861 is an interface for connecting the RRH 860 (radio com
munication interface 863) to the base station device 850. The connection interface 861
may also be a communication module for communication in the above-described high
speed line.
[0193] The radio communication interface 863 transmits and receives radio signals via the
antenna 840. The radio communication interface 863 may typically include, for
example, the RF circuit 864. The RF circuit 864 may include, for example, a mixer, a
filter, and an amplifier, and transmits and receives radio signals via the antenna 840.
The radio communication interface 863 may include multiple RF circuits 864, as i l
lustrated in FIG. 24. For example, the multiple RF circuits 864 may support multiple
antenna elements. Although FIG. 24 illustrates the example in which the radio commu
nication interface 863 includes the multiple RF circuits 864, the radio communication
interface 863 may also include a single RF circuit 864.
[0194] In the eNB 830 illustrated in FIG. 24, the control unit 153 (and the information ac
quisition unit 151) described with reference to FIG. 10 may be implemented in the
radio communication interface 855 and/or the radio communication interface 863. Al
ternatively, at least some of these components may also be implemented in the
controller 851. As an example, the eNB 830 may mount a module including a part (for
example, the BB processor 856) or the entire radio communication interface 855 and/
or the controller 851, and the control unit 153 (and the information acquisition unit
151) may be implemented in the module. In this case, the module may store a program
(in other words, a program causing the processor to execute operations of the control
unit 153 (and the information acquisition unit 151)) causing the processor to function
as the control unit 153 (and the information acquisition unit 151), and execute the
program. As another example, a program causing the processor to function as the
control unit 153 (and the information acquisition unit 151) may be installed in the eNB
830, and the radio communication interface 855 (for example, the BB processor 856)
and/or the controller 851 may execute the program. As described above, as a device
including the control unit 153 (and the information acquisition unit 151), the eNB 830,
the base station device 850 or the module may be provided. A program causing the
processor to function as the control unit 153 (and the information acquisition unit 151)
may also be provided. In addition, a readable recording medium in which the program
is recorded may be provided.
[0195] In addition, in the eNB 830 illustrated in FIG. 24, for example, the radio commu
nication unit 120 described with reference to FIG. 10 may be implemented in the radio
communication interface 863 (for example, the RF circuit 864). In addition, the
antenna unit 110 may be implemented in the antenna 840. In addition, the network
communication unit 130 may be implemented in the controller 851 and/or the network
interface 853.
[0196] <7.2. Applications related to Terminal Device>
(First Application)
FIG. 25 is a block diagram illustrating an example of a schematic configuration of a
smartphone 900 to which an embodiment of the technology of the present disclosure
may be applied. The smartphone 900 includes a processor 901, a memory 902, a
storage 903, an external connection interface 904, a camera 906, a sensor 907, a mi
crophone 908, an input device 909, a display device 910, a speaker 9 11, a radio com
munication interface 912, one or more antenna switches 915, one or more antennas
916, a bus 917, a battery 918, and an auxiliary controller 919.
[0197] The processor 901 may be, for example, a CPU or a system on a chip (SoC), and
controls functions of an application layer and another layer of the smartphone 900. The
memory 902 includes RAM and ROM, and stores a program that is executed by the
processor 901, and data. The storage 903 may include a storage medium such as a
semiconductor memory and a hard disk. The external connection interface 904 is an
interface for connecting an external device such as a memory card and a universal
serial bus (USB) device to the smartphone 900.
[0198] The camera 906 includes an image sensor such as a charge coupled device (CCD)
and a complementary metal oxide semiconductor (CMOS), and generates a captured
image. The sensor 907 may include a group of sensors such as a measurement sensor, a
gyro sensor, a geomagnetic sensor, and an acceleration sensor. The microphone 908
converts sounds that are input to the smartphone 900 to audio signals. The input device
909 includes, for example, a touch sensor configured to detect touch onto a screen of
the display device 910, a keypad, a keyboard, a button, or a switch, and receives an
operation or an information input from a user. The display device 910 includes a
screen such as a liquid crystal display (LCD) and an organic light-emitting diode
(OLED) display, and displays an output image of the smartphone 900. The speaker 911
converts audio signals that are output from the smartphone 900 to sounds.
[0199] The radio communication interface 912 supports any cellular communication scheme
such as LTE and LTE-Advanced, and performs radio communication. The radio com
munication interface 912 may typically include, for example, a BB processor 913 and
an RF circuit 914. The BB processor 913 may perform, for example, encoding/
decoding, modulating/demodulating, and multiplexing/demultiplexing, and performs
various types of signal processing for radio communication. Meanwhile, the RF circuit
914 may include, for example, a mixer, a filter, and an amplifier, and transmits and
receives radio signals via the antenna 916. The radio communication interface 912 may
also be a one chip module that has the BB processor 913 and the RF circuit 914 in
tegrated thereon. The radio communication interface 912 may include the multiple BB
processors 913 and the multiple RF circuits 914, as illustrated in FIG. 25. Although
FIG. 25 illustrates the example in which the radio communication interface 912
includes the multiple BB processors 913 and the multiple RF circuits 914, the radio
communication interface 912 may also include a single BB processor 913 or a single
RF circuit 914.
[0200] Furthermore, in addition to a cellular communication scheme, the radio commu
nication interface 912 may support another type of radio communication scheme such
as a short-distance wireless communication scheme, a near field communication
scheme, and a radio local area network (LAN) scheme. In that case, the radio commu
nication interface 912 may include the BB processor 913 and the RF circuit 914 for
each radio communication scheme.
[0201] Each of the antenna switches 915 switches connection destinations of the antennas
916 among multiple circuits (such as circuits for different radio communication
schemes) included in the radio communication interface 912.
[0202] Each of the antennas 916 includes a single or multiple antenna elements (such as
multiple antenna elements included in an MIMO antenna), and is used for the radio
communication interface 912 to transmit and receive radio signals. The smartphone
900 may include the multiple antennas 916, as illustrated in FIG. 25. Although FIG. 25
illustrates the example in which the smartphone 900 includes the multiple antennas
916, the smartphone 900 may also include a single antenna 916.
[0203] Furthermore, the smartphone 900 may include the antenna 916 for each radio com
munication scheme. In that case, the antenna switches 915 may be omitted from the
configuration of the smartphone 900.
[0204] The bus 917 connects the processor 901, the memory 902, the storage 903, the
external connection interface 904, the camera 906, the sensor 907, the microphone 908,
the input device 909, the display device 910, the speaker 911, the radio communication
interface 912, and the auxiliary controller 919 to each other. The battery 918 supplies
power to blocks of the smartphone 900 illustrated in FIG. 25 via feeder lines, which
are partially shown as dashed lines in the figure. The auxiliary controller 919 operates
a minimum necessary function of the smartphone 900, for example, in a sleep mode.
[0205] In the smartphone 900 illustrated in FIG. 25, the information acquisition unit 241 and
the control unit 243 described with reference to FIG. 10 may be implemented in the
radio communication interface 912. Alternatively, at least some of these components
may also be implemented in the processor 901 or the auxiliary controller 919. As an
example, the smartphone 900 may mount a module including a part (for example, the
BB processor 913) or the entire radio communication interface 912, the processor 901
and/or the auxiliary controller 919, and the information acquisition unit 241 and the
control unit 243 may be implemented in the module. In this case, the module may store
a program (in other words, a program causing the processor to execute operations of
the information acquisition unit 241 and the control unit 243) causing the processor to
function as the information acquisition unit 241 and the control unit 243, and execute
the program. As another example, a program causing the processor to function as the
information acquisition unit 241 and the control unit 243 may be installed in the
smartphone 900, and the radio communication interface 912 (for example, the BB
processor 913), the processor 901 and/or the auxiliary controller 919 may execute the
program. As described above, as a device including the information acquisition unit
241 and the control unit 243, the smartphone 900 or the module may be provided. A
program causing the processor to function as the information acquisition unit 241 and
the control unit 243 may also be provided.
[0206] In addition, in the smartphone 900 illustrated in FIG. 25, for example, the radio com
munication unit 220 described with reference to FIG. 11 may be implemented in the
radio communication interface 912 (for example, the RF circuit 914). In addition, the
antenna unit 210 may be implemented in the antenna 916.
[0207] (Second Application)
FIG. 26 is a block diagram illustrating an example of a schematic configuration of a
car navigation device 920 to which an embodiment of the technology of the present
disclosure may be applied. The car navigation device 920 includes a processor 921, a
memory 922, a global positioning system (GPS) module 924, a sensor 925, a data
interface 926, a content player 927, a storage medium interface 928, an input device
929, a display device 930, a speaker 931, a radio communication interface 933, one or
more antenna switches 936, one or more antennas 937, and a battery 938.
[0208] The processor 921 may be, for example, a CPU or a SoC, and controls a navigation
function and another function of the car navigation device 920. The memory 922
includes RAM and ROM, and stores a program that is executed by the processor 921,
and data.
[0209] The GPS module 924 uses GPS signals received from a GPS satellite to measure a
position (such as latitude, longitude, and altitude) of the car navigation device 920. The
sensor 925 may include a group of sensors such as a gyro sensor, a geomagnetic
sensor, and an air pressure sensor. The data interface 926 is connected to, for example,
an in-vehicle network 941 via a terminal that is not shown, and acquires data generated
by the vehicle, such as vehicle speed data.
[0210] The content player 927 reproduces content stored in a storage medium (such as a CD
and a DVD) that is inserted into the storage medium interface 928. The input device
929 includes, for example, a touch sensor configured to detect touch onto a screen of
the display device 930, a button, or a switch, and receives an operation or an in
formation input from a user. The display device 930 includes a screen such as a LCD
or an OLED display, and displays an image of the navigation function or content that is
reproduced. The speaker 931 outputs sounds of the navigation function or the content
that is reproduced.
[021 1] The radio communication interface 933 supports any cellular communication scheme
such as LET and LTE-Advanced, and performs radio communication. The radio com
munication interface 933 may typically include, for example, a BB processor 934 and
an RF circuit 935. The BB processor 934 may perform, for example, encoding/
decoding, modulating/demodulating, and multiplexing/demultiplexing, and performs
various types of signal processing for radio communication. Meanwhile, the RF circuit
935 may include, for example, a mixer, a filter, and an amplifier, and transmits and
receives radio signals via the antenna 937. The radio communication interface 933 may
be a one chip module having the BB processor 934 and the RF circuit 935 integrated
thereon. The radio communication interface 933 may include the multiple BB
processors 934 and the multiple RF circuits 935, as illustrated in FIG. 26. Although
FIG. 26 illustrates the example in which the radio communication interface 933
includes the multiple BB processors 934 and the multiple RF circuits 935, the radio
communication interface 933 may also include a single BB processor 934 or a single
RF circuit 935.
[0212] Furthermore, in addition to a cellular communication scheme, the radio commu
nication interface 933 may support another type of radio communication scheme such
as a short-distance wireless communication scheme, a near field communication
scheme, and a radio LAN scheme. In that case, the radio communication interface 933
may include the BB processor 934 and the RF circuit 935 for each radio commu
nication scheme.
[0213] Each of the antenna switches 936 switches connection destinations of the antennas
937 among multiple circuits (such as circuits for different radio communication
schemes) included in the radio communication interface 933.
[0214] Each of the antennas 937 includes a single or multiple antenna elements (such as
multiple antenna elements included in an MIMO antenna), and is used for the radio
communication interface 933 to transmit and receive radio signals. The car navigation
device 920 may include the multiple antennas 937, as illustrated in FIG. 26. Although
FIG. 26 illustrates the example in which the car navigation device 920 includes the
multiple antennas 937, the car navigation device 920 may also include a single antenna
937.
[0215] Furthermore, the car navigation device 920 may include the antenna 937 for each
radio communication scheme. In that case, the antenna switches 936 may be omitted
from the configuration of the car navigation device 920.
[0216] The battery 938 supplies power to blocks of the car navigation device 920 illustrated
in FIG. 26 via feeder lines that are partially shown as dashed lines in the figure. The
battery 938 accumulates power supplied form the vehicle.
[0217] In the car navigation device 920 illustrated in FIG. 26, the information acquisition
unit 241 and the control unit 243 described with reference to FIG. 11 may be im
plemented in the radio communication interface 933. Alternatively, at least some of
these components may also be implemented in the processor 921. As an example, the
car navigation device 920 may mount a module including a part (for example, the BB
processor 934) or the entire radio communication interface 933 and/or the processor
921, and the information acquisition unit 241 and the control unit 243 may be im
plemented in the module. In this case, the module may store a program (in other words,
a program causing the processor to execute operations of the information acquisition
unit 241 and the control unit 243) causing the processor to function as the information
acquisition unit 241 and the control unit 243, and execute the program. As another
example, a program causing the processor to function as the information acquisition
unit 241 and the control unit 243 may be installed in the car navigation device 920, and
the radio communication interface 933 (for example, the BB processor 934) and/or the
processor 921 may execute the program. As described above, as a device including the
information acquisition unit 241 and the control unit 243, the car navigation device 920
or the module may be provided. A program causing the processor to function as the in
formation acquisition unit 241 and the control unit 243 may also be provided.
[0218] In addition, in the car navigation device 920 illustrated in FIG. 26, for example, the
radio communication unit 220 described with reference to FIG. 11 may be im
plemented in the radio communication interface 933 (for example, the RF circuit 935).
In addition, the antenna unit 210 may be implemented in the antenna 937.
[0219] Embodiments of the technology of the present disclosure may also be realized as an
in-vehicle system (or a vehicle) 940 including one or more blocks of the car navigation
device 920, the in-vehicle network 941, and a vehicle module 942. That is, as a device
including the information acquisition unit 241 and the control unit 243, the in-vehicle
system (or the vehicle) 940 may be provided. The vehicle module 942 generates
vehicle data such as vehicle speed, engine speed, and trouble information, and outputs
the generated data to the in-vehicle network 941.
[0220] «8. Conclusion»
Respective devices and respective processes according to the embodiments of the
present disclosure have been described above with reference to FIGS. 1 to 26.
[0221] According to the embodiment of the present disclosure, the base station 100 includes
the control unit 153 configured to dynamically change the UL/DL configuration of the
TDD carrier. The control unit 153 notifies the terminal device of the radio resources
for D2D communication appropriate for the UL/DL configuration. The radio resources
are the radio resources of at least one uplink subframe of the UL/DL configuration.
[0222] In addition, according to the embodiment of the present disclosure, the information
acquisition unit 241 configured to acquire information indicating the radio resources
for D2D communication appropriate for the UL/DL configuration of the TDD carrier
that is dynamically changed by the base station 100 and the control unit 243 configured
to control D2D communication using the radio resources are included. The radio
resources are radio resources of at least one uplink subframe of the UL/DL con
figuration.
[0223] Accordingly, for example, the terminal device can appropriately perform D2D com
munication under the TDD environment.
[0224] It should be understood by those skilled in the art that various modifications, com
binations, sub-combinations and alterations may occur depending on design re
quirements and other factors insofar as they are within the scope of the appended
claims or the equivalents thereof.
[0225] For example, while the first technical features and the second technical features have
been described, the first technical features and the second technical features not have to
be used in conjunction.
[0226] For example, the first technical features may be used without using the second
technical features.
[0227] For example, the second technical features may be used without using the first
technical features. In this case, the UL/DL configuration of the TDD carrier may not be
dynamically changed. As an example, the base station (the information acquisition
unit) may acquire information indicating the D2D resources appropriate for the UL/DL
configuration (it is not dynamically changed). Therefore, the base station (the control
unit) may notify the terminal device of the D2D resources. The D2D resources may be
the radio resources of at least one uplink subframe of the UL/DL configuration.
Therefore, the second technical features (that is, any of the second technical features)
may be applied to the D2D resources.
[0228] For example, the example in which the communication system is a system compliant
with LTE, LTE-Advanced, or communication standards conforming thereto has been
described, but the present disclosure is not limited to the example. For example, the
communication system may be a system compliant with other communication
standards.
[0229] Also, the processing steps in a 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 process may be executed in a sequence that differs
from a sequence described herein as a flowchart, and furthermore may be executed in
parallel.
[0230] In addition, a computer program (in other words, a computer program causing the
processor to execute operations of components of the device) causing the processor
(for example, the CPU and the DSP) included in devices (for example, the base station,
the base station device for the base station, or a module for the base station device, or
the terminal device or the module for the terminal device) of this specification to
function as components (for example, the information acquisition unit and/or the
control unit) of the device can be created. In addition, a recording medium in which the
computer program is recorded may be provided. In addition, a device (for example, a
finished product or a module (for example, a component, a processing circuit or a chip)
for the finished product) including a memory in which the computer program is stored
and one or more processors capable of executing the computer program may be
provided. In addition, a method including operations of components (for example, the
information acquisition unit and/or the control unit) of the device may be included in
the embodiments of the technology according to the present disclosure.
[0231] In addition, the effects described in the present specification are merely illustrative
and demonstrative, and not limitative. In other words, the technology according to the
present disclosure can exhibit other effects that are evident to those skilled in the art
along with or instead of the effects based on the present specification.
Additionally, the present technology may also be configured as below.
(1)
A device including:
circuitry configured to
dynamically change an uplink/downlink configuration of a time division duplex
(TDD) carrier, and
notify a terminal device of a radio resource for device-to-device communication for
the uplink/downlink configuration,
wherein the radio resource is a radio resource of at least one uplink subframe of the
uplink/downlink configuration.
(2)
The device according to (1), wherein the circuitry is further configured to change the
uplink/downlink configuration from one configuration among multiple configurations
to another configuration among the multiple configurations.
(3)
The device according to (2),
wherein the circuitry is further configured to notify the terminal device of the radio
resource for device-to-device communication for the other configuration in accordance
with the change of the uplink/downlink configuration, and
wherein the radio resource for the another configuration is a radio resource of at least
one uplink subframe of the another configuration.
(4)
The device according to (2), wherein the circuitry is further configured to notify the
terminal device of the radio resource for device-to-device communication for each of
the multiple configurations.
(5)
The device according to (4),
wherein the radio resource for each of the multiple configurations includes a radio
resource for device-to-device communication for each configuration, and
wherein the radio resource for each configuration is a radio resource of at least one
uplink subframe of the configuration.
(6)
The device according to (4), wherein the radio resource for each of the multiple con
figurations is a radio resource of at least one uplink subframe common among the
multiple configurations.
(7)
The device according to any one of (1) to (5), wherein a number of uplink subframes
included in the at least one uplink subframe differs according to a number of uplink
subframes of the uplink/downlink configuration.
(8)
The device according to any one of (1) to (7), wherein the radio resource is a periodic
radio resource that is repeated at a period corresponding to a number of uplink
subframes of the uplink/downlink configuration.
(9)
The device according to any one of (1) to (8), wherein the radio resource is a radio
resource of an uplink subframe of a first number and is a periodic radio resource that is
repeated at a first period when the uplink/downlink configuration is a first con
figuration, and the radio resource is a radio resource of an uplink subframe of a second
number that is less than the first number and is a periodic radio resource that is
repeated at a second period shorter than the first period when the uplink/downlink con
figuration is a second configuration.
(10)
The device according to any one of (1) to (9), wherein the circuitry is further
configured to notify the terminal device of the radio resource when a number of uplink
subframes of the uplink/downlink configuration is equal to or greater than a prede
termined number.
(ID
The device according to any one of (1) to (9), wherein the uplink/downlink con
figuration is a configuration including at least a predetermined number of uplink
subframes.
(12)
The device according to any one of (1) to (11),
wherein each of the at least one uplink subframe is included in two or more successive
uplink subframes of the uplink/downlink configuration, and
wherein one or more uplink subframes of the two or more successive uplink subframes
are not included in the at least one uplink subframe.
(13)
The device according to (12), wherein the circuitry is further configured to notify the
terminal device of the radio resource when the uplink/downlink configuration includes
two or more successive uplink subframes.
(14)
The device according to (12), wherein the uplink/downlink configuration is a con
figuration including two or more successive uplink subframes.
(15)
The device according to any one of (1) to (14), wherein the circuitry is further
configured to notify the terminal device of the radio resource by reporting system in
formation indicating the radio resource.
(16)
The device according to any one of (1) to (15), wherein the circuitry is further
configured to notify control unit notifies the terminal device of the uplink/downlink
configuration.
(17)
A method including:
dynamically changing, by a processor, an uplink/downlink configuration of a time
division duplex (TDD) carrier; and
notifying a terminal device of a radio resource for device-to-device communication for
the uplink/downlink configuration,
wherein the radio resource is a radio resource of at least one uplink subframe of the
uplink/downlink configuration.
(18)
A device including:
circuitry configured to
acquire information indicating a radio resource for device-to-device communication
for an uplink/downlink configuration of a time division duplex (TDD) carrier that is
dynamically changed by a base station; and
control device-to-device communication using the radio resource,
wherein the radio resource is a radio resource of at least one uplink subframe of the
uplink/downlink configuration.
(19)
The device according to (18),
wherein the uplink/downlink configuration is a configuration that is changed from one
configuration among multiple configurations to another configuration among the
multiple configurations, and
wherein the circuitry is further configured to acquire information indicating the radio
resource for the uplink/downlink configuration among radio resources for deviceto-
device communication appropriate for the respective multiple configurations on the
basis of the uplink/downlink configuration.
(20)
A method including:
acquiring information indicating a radio resource for device-to-device communication
for an uplink/downlink configuration of a time division duplex (TDD) carrier that is
dynamically changed by a base station; and
controlling, by a processor, device-to-device communication using the radio resource,
wherein the radio resource is a radio resource of at least one uplink subframe of the
uplink/downlink configuration.
(21)
A program causing a processor to execute:
dynamically changing an uplink/downlink configuration of a time division duplex
(TDD) carrier; and
notifying a terminal device of a radio resource for device-to-device communication for
the uplink/downlink configuration,
wherein the radio resource is a radio resource of at least one uplink subframe of the
uplink/downlink configuration.
(22)
A non-transitory computer-readable recording medium having a program stored
thereon, the program causing a processor to execute:
dynamically changing an uplink/downlink configuration of a time division duplex
(TDD) carrier; and
notifying a terminal device of a radio resource for device-to-device communication ap
propriate for the uplink/downlink configuration,
wherein the radio resource is a radio resource of at least one uplink subframe of the
uplink/downlink configuration.
(23)
A program causing a processor to execute:
acquiring information indicating a radio resource for device-to-device communication
for an uplink/downlink configuration of a time division duplex TDD carrier that is d y
namically changed by a base station; and
controlling device-to-device communication using the radio resource,
wherein the radio resource is a radio resource of at least one uplink subframe of the
uplink/downlink configuration.
(24)
A non-transitory computer-readable recording medium having a program stored
thereon, the program causing a processor to execute:
acquiring information indicating a radio resource for device-to-device communication
for an uplink/downlink configuration of a time division duplex TDD carrier that is d y
namically changed by a base station; and
controlling device-to-device communication using the radio resource,
wherein the radio resource is a radio resource of at least one uplink subframe of the
uplink/downlink configuration.
Reference Signs List
communication system
0 base station
1 cell
0 processing unit
1 information acquisition unit
3 control unit
0 terminal device
0 processing unit
1 information acquisition unit
3 control unit

Claims
A device comprising:
circuitry configured to
dynamically change an uplink/downlink configuration of a time
division duplex (TDD) carrier, and
notify a terminal device of a radio resource for device-to-device com
munication for the uplink/downlink configuration,
wherein the radio resource is a radio resource of at least one uplink
subframe of the uplink/downlink configuration.
The device according to claim 1, wherein the circuitry is further
configured to change the uplink/downlink configuration from one con
figuration among multiple configurations to another configuration
among the multiple configurations.
The device according to claim 2,
wherein the circuitry is further configured to notify the terminal device
of the radio resource for device-to-device communication for the other
configuration in accordance with the change of the uplink/downlink
configuration, and
the radio resource appropriate for the another configuration is a radio
resource of at least one uplink subframe of the other configuration.
The device according to claim 2, wherein the circuitry is further
configured to notify the terminal device of the radio resource for
device-to-device communication for each of the multiple config
urations.
The device according to claim 4,
wherein the radio resource for each of the multiple configurations
includes a radio resource for device-to-device communication for each
configuration, and
the radio resource for each configuration is a radio resource of at least
one uplink subframe of the configuration.
The device according to claim 4, wherein the radio resource for each of
the multiple configurations is a radio resource of at least one uplink
subframe common among the multiple configurations.
The device according to claim 1, wherein a number of uplink
subframes included in the at least one uplink subframe differs
according to a number of uplink subframes of the uplink/downlink con
figuration.
WO 2016/017100 PCT/JP2015/003567
[Claim 8] The device according to claim 1, wherein the radio resource is a
periodic radio resource that is repeated at a period corresponding to a
number of uplink subframes of the uplink/downlink configuration.
[Claim 9] The device according to claim 1, wherein the radio resource is a radio
resource of an uplink subframe of a first number and is a periodic radio
resource that is repeated at a first period when the uplink/downlink con
figuration is a first configuration, and the radio resource is a radio
resource of an uplink subframe of a second number that is less than the
first number and is a periodic radio resource that is repeated at a second
period shorter than the first period when the uplink/downlink con
figuration is a second configuration.
[Claim 10] The device according to claim 1, wherein the circuitry is further
configured to notify terminal device of the radio resource when a
number of uplink subframes of the uplink/downlink configuration is
equal to or greater than a predetermined number.
[Claim 11] The device according to claim 1, wherein the uplink/downlink con
figuration is a configuration including at least a predetermined number
of uplink subframes.
[Claim 12] The device according to claim 1,
wherein each of the at least one uplink subframe is included in two or
more successive uplink subframes of the uplink/downlink con
figuration, and
wherein one or more uplink subframes of the two or more successive
uplink subframes are not included in the at least one uplink subframe.
[Claim 13] The device according to claim 12, wherein the circuitry is further
configured to notify the terminal device of the radio resource when the
uplink/downlink configuration includes two or more successive uplink
subframes.
[Claim 14] The device according to claim 12, wherein the uplink/downlink con
figuration is a configuration including two or more successive uplink
subframes.
[Claim 15] The device according to claim 1, wherein the circuitry is further
configured to notify the terminal device of the radio resource by
reporting system information indicating the radio resource.
[Claim 16] The device according to claim 1, wherein the circuitry is further
configured to notify the terminal device of the uplink/downlink con
figuration.
[Claim 17] A method comprising:
WO 2016/017100 PCT/JP2015/003567
dynamically changing, by a processor, an uplink/downlink con
figuration of a time division duplex (TDD) carrier; and
notifying a terminal device of a radio resource for device-to-device
communication for the uplink/downlink configuration,
wherein the radio resource is a radio resource of at least one uplink
subframe of the uplink/downlink configuration.
[Claim 18] A device comprising:
circuitry configured to
acquire information indicating a radio resource for device-to-device
communication for an uplink/downlink configuration of a time division
duple (TDD) carrier that is dynamically changed by a base station; and
control device-to-device communication using the radio resource,
wherein the radio resource is a radio resource of at least one uplink
subframe of the uplink/downlink configuration.
[Claim 19] The device according to claim 18,
wherein the uplink/downlink configuration is a configuration that is
changed from one configuration among multiple configurations to
another configuration among the multiple configurations, and
wherein the circuitry is further configured to acquire information in
dicating the radio resource for the uplink/downlink configuration
among radio resources for device-to-device communication for the re
spective multiple configurations on the basis of the uplink/downlink
configuration.
[Claim 20] A method comprising:
acquiring information indicating a radio resource for device-to-device
communication for an uplink/downlink configuration of a time division
duple (TDD) carrier that is dynamically changed by a base station; and
controlling, by a processor, device-to-device communication using the
radio resource,
wherein the radio resource is a radio resource of at least one uplink
subframe of the uplink/downlink configuration.