Description
Title of Invention
DEVICE
5
Technical Field
[0001]
The present disclosure relates to a device.
10 Background Art
[0002]
In the 3rd Generation Partnership Project (3GPP), various technologies for
improving system throughput have been discussed. It may be said that a first
shortcut for improving the system throughput is increasing a frequency to be used.
15 In the 3GPP, the technology of carrier aggregation (CA) has been considered in
Release 10 and Release 11. CA is a technology for improving the system
throughput and a maximum data rate by aggregating component carriers (CCs)
having a bandwidth of 20 MHz for use. A frequency band available as a CC must
adopt the technology of such CA. Thus, a frequency band available for wireless
20 communication of a cellular system is required.
[0003]
For example, in Patent Literature 1, technology which enables a registered
frequency band available for a registered provider and an unlicensed band available
when a predetermined condition is satisfied to be used in addition to a dedicated
25 frequency band allocated to each provider for exclusive use is disclosed.
Citation List
Patent Literature
[0004]
30 Patent Literature 1: JP 2006-094001A
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Summary of Invention
Technical Problem
[0005]
However, for example, even when a frequency band to be used in wireless
5 communication of a wireless local area network (LAN) is also used in wireless
communication of a cellular system, the above-mentioned frequency band is not
likely to be appropriately used in wireless communication of the above-mentioned
cellular system.
[0006]
10 An example in which the cellular system uses the above-mentioned
frequency band on the basis of carrier sense multiple access with collision avoidance
(CSMA/CA) is considered. However, because the CSMA/CA is a mechanism for
simultaneously enabling only one-to-one communication, undesirable results can be
caused when the CSMA/CA is applied as is to a cellular system in which a frequency
15 band is used simultaneously by one base station and a plurality of terminal devices.
For example, the wireless communication of the cellular system is performed in a
state in which no hidden terminal problem is solved.
[0007]
Therefore, it is desirable to provide a mechanism which enables a frequency
20 band shared between wireless communication of a cellular system and wireless
communication conforming to a wireless LAN standard to be more appropriately
used in the cellular system.
Solution to Problem
25 [0008]
According to the present disclosure, there is provided a device including: an
acquisition unit configured to acquire information indicating a terminal device which
is a device candidate for performing wireless communication of a cellular system
using a frequency band shared between the wireless communication of the cellular
30 system and wireless communication conforming to a wireless local area network
(LAN) standard; and a control unit configured to notify the terminal device that the
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terminal device is the device candidate.
[0009]
According to the present disclosure, there is provided a device including: a
recognition unit configured to recognize that a terminal device is a device candidate
5 for performing wireless communication of a cellular system using a frequency band
shared between the wireless communication of the cellular system and wireless
communication conforming to a wireless local area network (LAN) standard through
a notification by a base station of the cellular system; and a control unit configured to
perform control for using the frequency band in the wireless communication of the
10 cellular system when the terminal device is the device candidate.
Advantageous Effects of Invention
[0010]
According to the above-described present disclosure, a frequency band
15 shared between wireless communication of a cellular system and wireless
communication conforming to a wireless LAN standard can be more appropriately
used in the cellular system. Note that the effects described above are not
necessarily limited, and along with or instead of the effects, any effect that is desired
to be introduced in the present specification or other effects that can be expected
20 from the present specification may be exhibited.
Brief Description of Drawings
[0011]
[FIG. 1] FIG. 1 is an explanatory diagram illustrating a frame format of Institute of
25 Electrical and Electronics Engineers (IEEE) 802.11.
[FIG. 2] FIG. 2 is an explanatory diagram illustrating a frame format of long-term
evolution (LTE).
[FIG. 3] FIG. 3 is an explanatory diagram illustrating an example of a schematic
configuration of a cellular system according to an embodiment of the present
30 disclosure.
[FIG. 4] FIG. 4 is an explanatory diagram illustrating an example of a communication
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area of a wireless local area network (LAN) overlapping a small cell.
[FIG. 5] FIG. 5 is an explanatory diagram illustrating an example of a communication
area of a wireless LAN overlapping a macro cell.
[FIG. 6] FIG. 6 is a block diagram illustrating an example of a configuration of a base
5 station according to the embodiment.
[FIG. 7] FIG. 7 is a block diagram illustrating a first example of a configuration of
cellular communication according to the embodiment.
[FIG. 8] FIG. 8 is a block diagram illustrating a second example of a configuration of
cellular communication according to the embodiment.
10 [FIG. 9] FIG. 9 is a block diagram illustrating a third example of a configuration of
cellular communication according to the embodiment.
[FIG. 10] FIG. 10 is a block diagram illustrating a fourth example of a configuration
of cellular communication according to the embodiment.
[FIG. 11] FIG. 11 is an explanatory diagram illustrating an example of cellular
15 communication when time division duplex (TDD) is adopted.
[FIG. 12] FIG. 12 is an explanatory diagram illustrating an example of cellular
communication when frequency division duplex (FDD) is adopted.
[FIG. 13] FIG. 13 is an explanatory diagram illustrating another example of cellular
communication when FDD is adopted.
20 [FIG. 14] FIG. 14 is a block diagram illustrating an example of a configuration of a
terminal device according to the embodiment.
[FIG. 15] FIG, 15 is a sequence diagram illustrating a first example of a schematic
flow of a process according to the embodiment.
[FIG. 16] FIG. 16 is a sequence diagram illustrating a second example of a schematic
25 flow of a process according to the embodiment.
[FIG. 17] FIG. 17 is a sequence diagram illustrating a third example of a schematic
flow of a process according to the embodiment.
[FIG. 18] FIG. 18 is an explanatory diagram illustrating an example of acquisition of
synchronization for a shared band.
30 [FIG. 19] FIG. 19 is a flowchart illustrating an example of a schematic flow of a
process according to a first modified example of the embodiment.
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[FIG. 20] FIG. 20 is a sequence diagram illustrating an example of a schematic flow
of a process according to a second modified example of the embodiment.
[FIG. 21] FIG. 21 is a block diagram illustrating a first example of a schematic
configuration of an eNB.
5 [FIG. 22] FIG. 22 is a block diagram illustrating a second example of a schematic
configuration of an eNB.
[FIG. 23] FIG. 23 is a block diagram illustrating an example of a schematic
configuration of a smartphone.
[FIG. 24] FIG. 24 is a block diagram illustrating an example of a schematic
10 configuration of a car navigation device.
Description of Embodiment(s)
[0012]
Hereinafter, preferred embodiments of the present disclosure will be
15 described in detail and with reference to the attached drawings. Note that, in this
specification and the appended drawings, structural elements that have substantially
the same function and structure are denoted with the same reference numerals, and
repeated explanation of these structural elements is omitted.
[0013]
20 Also, the description will be given in the following order.
1. Introduction
2. Schematic configuration of system
3. Configuration of each device
3.1. Configuration of base station
25 3.2. Configuration of terminal device
4. Flow of process
5. First modified example
6. Second modified example
7. Application example
30 7.1. Application example related to base station
7.2. Application example related to terminal device
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8. Conclusion
[0014]
« 1 . Introduction»
First, sharing of a frequency band, technology of wireless communication
5 conforming to a wireless local area network (LAN) standard, and technology of
wireless communication of a cellular system will be described with reference to
FIGS. 1 and 2.
[0015]
(Sharing of frequency band)
10 A frequency band available for the wireless communication of the cellular
system is required. For example, a band of 5 GHz is considered as a frequency
band for use in wireless communication of the cellular system (hereinafter referred to
as "cellular communication").
[0016]
15 However, the band of 5 GHz is used in wireless communication conforming
to the wireless LAN standard (hereinafter referred to as "wireless LAN
communication"). Thus, when the cellular system uses the band of 5 GHz, for
example, the band of 5 GHz is shared between cellular communication and wireless
LAN communication. Specifically, for example, a frequency band of 5GHz (for
20 example, a channel of a wireless LAN) is used in the wireless LAN communication
at a certain time and used in the cellular communication at another time. Thereby,
frequency utilization efficiency of the band of 5 GHz is improved. Also, the
wireless LAN standard includes Institute of Electrical and Electronics Engineers
(IEEE) 802.11a, lib, llg, I In, llac, and Had, etc. and these standards are
25 characterized in that IEEE 802.11 is adopted for a media access control (MAC) layer.
[0017]
Devices for performing wireless LAN communication are already
widespread in the world. Thus, from the viewpoint of backward compatibility, a
mechanism for sharing a frequency band between cellular communication and
30 wireless LAN communication without changing an operation of the device for
performing the wireless LAN communication is considered as the technology of
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Long Term Evolution (LTE) and is desired to be defined as a new standard of LTE.
Also, a terminal device conforming to the above-mentioned new standard uses the
shared frequency band, but a terminal device which does not conform to the abovementioned
new standard is considered as a terminal device not using the shared
5 frequency band.
[0018]
In LTE, LTE-Advanced, or a cellular system conforming to a
communication standard equivalent thereto, the shared frequency band will be used
as, for example, a component carrier (CC). Further, it is assumed that the frequency
10 band of the cellular system is used as a primary component carrier (PCC) and the
shared frequency band is used as a secondary component carrier (SCC). Also, a
control signal and a data signal can be transmitted and received using a frequency
band of the cellular system and the data signal can be transmitted and received using
the shared frequency band.
15 [0019]
(Technology of wireless communication conforming to wireless LAN
standard)
A frame format of IEEE 802.11 will be described as the technology of
wireless communication conforming to the wireless LAN standard with reference to
20 FIG. 1. FIG. 1 is an explanatory diagram illustrating a frame format of IEEE 802.11.
[0020]
In IEEE 802.11, a DATA frame and an acknowledgement (ACK) frame are
basic frames. When the DATA frame is correctly received, the ACK frame is a
frame which causes a transmitting side to know the success of reception of the DATA
25 frame. Although wireless LAN communication can be performed only by the
DATA frame and the ACK frame, two frames such as a request to send (RTS) frame
and a clear to send (CTS) frame are generally further used.
[0021]
Before the RTS frame is transmitted, each terminal device which performs
30 the wireless LAN communication confirms that no signal is transmitted during a
period referred to as a distributed coordination function (DCF) inter-frame space
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(DIFS). This is referred to as carrier sense. When terminal devices
simultaneously start to transmit signals at a point in time at which the DIFS has
elapsed, the signals may collide with each other. Thus, each terminal device waits
for a backoff time randomly set for each terminal device and transmits a signal if no
5 signal is transmitted for the backoff time.
[0022]
Basically, the terminal device cannot transmit the signal while any signal is
detected. However, because there is a hidden terminal problem, an RTS frame and
a CTS frame including a duration field for setting a value referred to as a network
10 allocation vector (NAV) are added. The NAV is set on the basis of a value included
in the duration field. The terminal device setting the NAV avoids transmitting a
signal during a period of the NAV.
[0023]
First, a first terminal device for transmitting the DATA frame transmits the
15 RTS frame. Then, another terminal device located around the first terminal device
receives the RTS frame and acquires a value included in the duration field in the RTS
frame. The other terminal device sets, for example, its own NAV to the abovementioned
acquired value and avoids transmitting a signal during the period of the
NAV. For example, the period of the NAV is a period from the end of the RTS
20 frame to the end of the ACK frame.
[0024]
Also, a second terminal device for receiving the DATA frame transmits the
CTS frame after only a short inter-frame space (SIFS) from the end of the RTS frame
according to the reception of the RTS frame. Then, another terminal device located
25 around the above-mentioned second terminal device receives the CTS frame and
acquires a value included in the duration field in the CTS frame. The other terminal
device sets, for example, its own NAV to the above-mentioned acquired value and
avoids transmitting a signal during the period of the NAV. The period of the NAV is
a period from the end of the CTS frame to the end of the ACK frame. Thereby, for
30 example, it is possible to prevent the other terminal device (that is, a hidden terminal
for the above-mentioned first terminal device) close to the above-mentioned second
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terminal device without being close to the above-mentioned first terminal device
.from transmitting a signal during communication of the above-mentioned first
terminal device and the above-mentioned second terminal device.
[0025]
5 Also, the RTS frame includes a frame control field, a reception address field,
a transmission address field, and a frame check sequence (FCS) in addition to the
duration field. Also, the CTS frame includes a frame control field, a reception
address field, and an FCS in addition to the duration field.
[0026]
10 Also, the DIFS and the SIFS in the standard of the IEEE 802.11 series have,
for example, the following lengths.
[0027]
[Table 1]
SIFS
DIFS
802. lib
10 us
50 us
802. llg
10 us
28 us
802. 11a
16 us
34 us
802.lln
16 us
34 us
802. llac
16 us
34 us
[0028]
(Technology of wireless communication of cellular system)
(a) Frame format
The frame format of LTE will be described with reference to FIG. 2. FIG.
2 is an explanatory diagram illustrating the frame format of LTE.
[0029]
First, a unit of time such as a radio frame is used in LTE. One radio frame
is 10 ms. Each radio frame is identified by a system frame number (SFN) which is
any one of 0 to 1023.
[0030]
The radio frame includes 10 sub-frames identified by #0 to #9. Each subframe
is 1 ms. Further, each sub-frame includes two slots and each slot incudes, for
example, seven orthogonal frequency division multiplexing (OFDM) symbols.
That is, each sub-frame includes 14 OFDM symbols. Also, the frame format
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illustrated in FIG. 2 is a frame format of a downlink and the frame format of an
uplink includes a single carrier frequency division multiple access (SC-FDMA)
symbol in place of an OFDM symbol.
[0031]
5 (b) Carrier aggregation
- Component carriers
With carrier aggregation in Release 10, up to a maximum of five CCs are
aggregated for use by user equipment (UE). Each CC is a band with a maximum
width of 20 MHz. Carrier aggregation includes a case in which successive CCs in
10 the frequency direction are used, and a case in which separated CCs in the frequency
direction are used. With carrier aggregation, the CCs to be used may be set for each
UE.
[0032]
- PCC and SCC
15 In carrier aggregation, one of the multiple CCs used by a UE is a special CC.
This special CC is called the primary component carrier (PCC). Also, the
remaining CCs among the multiple CCs are called secondary component carriers
(SCCs). The PCC may be different depending on the UE.
[0033]
20 Since the PCC is the most important CC among the multiple CCs, it is
desirable for the PCC to be the CC with the most stable communication quality.
Note that in actual practice, which CC to treat as the PCC depends on the
implementation.
[0034]
25 The SCC is added to the PCC. In addition, an existing SCC that has been
added may also be removed. Note that changing an SCC is conducted by removing
an existing SCC and adding a new SCC.
[0035]
- PCC determination method and changing method
30 When a UE connection is initially established and the status of the UE goes
from Radio Resource Control (RRC) Idle to RRC Connected, the CC that the UE
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used during the establishment of the connection becomes the PCC for that UE.
More specifically, a connection is established through a connection establishment
procedure. At this point, the status of the UE goes from RRC Idle to RRC
Connected. Also, the CC used in the procedure becomes the PCC for the above UE.
5 Note that the above procedure is a procedure initiated from the UE side.
[0036]
Additionally, PCC . changing is conducted by a handover between
frequencies. More specifically, if a handover is specified in a connection
reconfiguration procedure, a PCC handover is conducted, and the PCC is changed.
10 Note that the above procedure is a procedure initiated from the network side.
[0037]
-Adding SCC
As discussed above, the SCC is added to the PCC. As a result, the SCC is
associated with the PCC. In other words, the SCC is subordinate to the PCC. SSC
15 addition may be conducted through a connection reconfiguration procedure. Note
that this procedure is a procedure initiated from the network side.
[0038]
- Removing SSC
As discussed above, an SCC may be removed. SSC removal may be
20 conducted through a connection reconfiguration procedure. Specifically, a specific
SCC specified in a message is removed. Note that the above procedure is a
procedure initiated from the network side.
[0039]
In addition, the removal of all SCCs may be conducted through a connection
25 re-establishment procedure.
[0040]
-Special role of PCC
The connection establishment procedure, the transmitting and receiving of
non-access stratum (NAS) signaling, and the transmitting and receiving of uplink
30 control signals on the physical uplink control channel (PUCCH) are conducted only
by the PCC, and not by the SCCs.
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[0041]
In addition, the detection of a radio link failure (RLF) and a subsequent
connection re-cstablishment procedure are also conducted only by the PCC, and not
by the SCCs.
5 [0042]
(Conditions of backhauling for carrier aggregation)
For example, an ACK of a downlink signal on an SCC is transmitted by the
PUCCH of the PCC. Since the ACK is used for the retransmission of data by the
evolved Node B (eNB), a delay of the ACK is not acceptable. Consequently, when
10 a first eNB using a CC that acts as the PCC for a UE is different from a second eNB
using a CC that acts as an SCC for the UE, a backhaul delay of approximately 10 ms
between the first eNB and the second eNB is desirable.
[0043]
« 2 . Schematic configuration of cellular system»
15 Next, a schematic configuration of a cellular system 1 according to an
embodiment of the present disclosure will be described with reference to FIGS. 3 to
5. FIG. 3 is an explanatory diagram illustrating an example of the schematic
configuration of the cellular system I according to the embodiment of the present
disclosure. Referring to FIG. 3, the system 1 includes a base station 100 and a
20 terminal device 200. The cellular system 1 is, for example, LTE, LTE-Advanced, or
a system conforming to a communication standard equivalent thereto.
[0044]
(Base station 100)
The base station 100 performs wireless communication (cellular
25 communication) of the cellular system 1. That is, the base station 100 performs
wireless communication with the terminal device 200. For example, the base
station 100 performs wireless communication with the terminal device 200 located
within a cell 10 which is a communication area of the base station 100. Specifically,
for example, the base station 100 transmits a downlink signal to the terminal device
30 200 and receives an uplink signal from the terminal device 200.
[0045]
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As an example, the base station 100 is a small base station and the cell 10 is
a small cell. As another example, the base station 100 may be a macro base station
and the cell 10 may be a macro cell.
[0046]
5 (Terminal device 200)
The terminal device 200 performs wireless communication (cellular
communication) of the cellular system.
[0047]
For example, the terminal device 200 performs wireless communication
10 with the base station 100. For example, when the terminal device 200 is located
within the cell 10 of the base station 100, the terminal device 200 performs wireless
communication with the base station 100. Specifically, for example, the terminal
device 200 receives the downlink signal from the base station 100 and transmits the
uplink signal to the base station 100.
15 [0048]
Also, the terminal device 200 can perform wireless communication with
another terminal device (for example, another terminal device 200 or the like). For
example, the terminal device 200 can perform device-to-device (D2D)
communication. Also, the terminal device 200 can perform wireless
20 communication within a localized network (LN) formed by the terminal device.
[0049]
Also, the terminal device 200 may perform other wireless communication.
For example, the terminal device 200 may perform wireless communication (wireless
LAN communication) conforming to the wireless LAN standard.
25 [0050]
(Frequency band to be used)
In wireless communication (that is, cellular communication) of the cellular
system 1} the frequency band of the cellular system I (hereinafter referred to as a
"cellular band") is used. The cellular band is, for example, a band allocated to a
30 provider of the cellular system I, and can be referred to as a licensed band.
[0051]
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Particularly, in the embodiment of the present disclosure, a frequency band
to be used in wireless communication (that is, wireless LAN communication)
conforming to a wireless LAN standard is also used in cellular communication.
That is, a frequency band shared between the cellular communication and the wire
5 LAN communication (hereinafter referred to as a "shared band"). The abovementioned
shared band is, for example, a channel of a wireless LAN. As an
example, the shared band is the channel of 20 MHz.
[0052]
(Wireless LAN)
10 A communication area of the wireless LAN can be located within the ceil 10.
That is, the cell 10 can overlap the communication area of the wireless LAN.
Hereinafter, in this regard, a specific example will be described with reference to
FIGS. 4 and 5.
[0053]
15 FIG. 4 is an explanatory diagram illustrating an example of a
communication area of a wireless LAN overlapping a small cell. Referring to FIG.
4, the base station 100 which is a small base station and the terminal device 200 are
illustrated. Further, an access point 30 of a wireless LAN and a terminal device 50
for performing wireless LAN communication are located around the base station 100
20 and the terminal device 200. A communication area 40 of the access point 30
overlaps the cell 10 which is a small cell.
[0054]
FIG. 5 is an explanatory diagram illustrating an example of a
communication area of a wireless LAN overlapping a macro cell. Referring to FIG.
25 5, the base station 100 which is a macro base station and the terminal device 200 are
illustrated. Further, the access point 30 of a wireless LAN and the terminal device
50 for performing wireless LAN communication are located around the base station
100 and the terminal device 200. The communication area 40 of the access point 30
overlaps the cell 10 which is a macro cell.
30 [0055]
Also, the wireless LAN communication (that is, the wireless communication
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conforming to the wireless LAN standard) can include wireless communication
conforming to a wireless LAN standard between terminal devices which perform the
wireless LAN communication in addition to wireless communication between the
wireless LAN access point and the terminal device (which perform wireless LAN
5 communication). As an example, the wireless LAN communication can also
include wireless communication according to Wi-Fi Direct.
[0056] . ,
The cellular system 1 according to the embodiment of the present disclosure
has been described above. Also, the cellular system 1 can include a plurality of
10 base stations 100 as well as one base station 100. Also, the cellular system 1 can
include another device in addition to the base station 100 and the terminal device 200.
For example, the cellular system 1 can include core network nodes (for example, a
mobility management entity (MME), a serving gateway (S-GW), and a packet data
network gateway (P-GW), etc.).
15 [0057]
« 3 . Configuration of each device»
Next, a configuration of each device according to the present embodiment
will be described with reference to FIGS. 6 to 14.
[0058]
20 <3.1. Configuration of base station>
Next, an example of the configuration of a base station 100-1 according to
the first embodiment will be described with reference to FIGS. 6 to 10. FIG. 6 is a
block diagram illustrating an example of the configuration of the base station 100-1
according to the first embodiment. Referring to FIG. 6, the base station 100-1 is
25 equipped with an antenna unit 110, a wireless communication unit 120, a network
communication unit 130, a storage unit 140, and a processing unit 150.
[0059]
(Antenna unit 110)
The antenna unit 110 emits a signal output by the wireless communication
30 unit 120 into space as a radio wave. Additionally, the antenna unit 110 converts a
radio wave from space into a signal, and outputs the signal to the wireless
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communication unit 120.
[0060]
(Wireless communication unit 120)
The wireless communication unit 120 transmits and receives signals. For
5 example, the wireless communication unit 120 transmits a downlink signal to a
terminal device 200 positioned within the cell 10, and receives an uplink signal from
the terminal device 200 positioned within the cell 10.
[0061]
For example, the wireless communication unit 120 transmits and receives a
10 signal using the frequency band of the cellular system 1 (that is, a cellular band).
Also, particularly, in the embodiment of the present disclosure, the wireless
communication unit 120 transmits and receives a signal using the frequency band
shared between the cellular communication and the other wireless communication
(for example, wireless LAN communication) (that is, a shared band).
15 [0062]
(Network communication unit 130)
The network communication unit 130 communicates with other nodes. For
example, the network communication unit 130 communicates with core network
nodes (for example, MME, S-GA, P-GW, etc.). Also, the network communication
20 unit 130 communicates with another base station 100.
[0063]
(Storage unit 140)
The storage unit 140 temporarily or permanently stores programs and data
for the operation of the base station 100.
25 [0064]
(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
communication control unit 153. Also, the processing unit 150 can further include
30 another constituent element other than these constituent elements.
[0065]
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(Information acquisition unit 151)
The information acquisition unit 151 acquires information indicating the
terminal device 200 which is a device candidate for performing cellular
communication (hereinafter, "device candidate information") using a frequency band
5 shared between the cellular communication and the wireless LAN communication
(that is, a shared band).
[0066]
For example, the processing unit 150 (for example, the information
acquisition unit 151, the communication control unit 153, or another constituent
10 element) determines a device candidate for performing cellular communication using
the above-mentioned shared band from among a plurality of terminal devices 200
communicable with the base station 100. Information indicating the terminal
device 200 which is the device candidate (that is, device candidate information) is
stored in the storage unit 140. Thereafter, the information acquisition unit 151
15 acquires the above-mentioned device candidate information at any timing.
[0067]
As an example, the above-mentioned device candidate information is a list
including identification information of each terminal device 200 which is the abovementioned
device candidate.
20 [0068]
(Communication control unit 153)
(a) Notification of device candidate
The communication control unit 153 notifies the terminal device 200 that
the terminal device 200 is the above-mention device candidate.
25 [0069]
- Timing of notification
For example, the communication control unit 153 notifies the terminal
device 200 that the terminal device 200 is the above-mentioned device candidate
before the above-mentioned shared band is used in the cellular communication.
30 Thereby, for example, the communication control unit 153 can cause the terminal
device 200 which is the above-mentioned candidate to perform a preparatory
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operation for using the above-mentioned shared band in cellular communication.
[0070]
- Frequency band to be used
For example, the communication control unit 153 notifies the terminal
5 device 200 that the terminal device 200 is the above-mentioned device candidate
using the cellular band.
[0071]
Specifically, for example, the communication control unit 153 notifies the
above-mentioned terminal device 200 that the above-mentioned terminal device 200
10 is the above-mentioned device candidate using a cellular band to be used in cellular
communication by the base station 100 and the terminal device 200 (for example, a
CC).
[0072]
- Technique of notification
15 For example, the communication control unit 153 notifies the terminal
device 200 which is the above-mentioned device candidate that the terminal device
200 is the above-mentioned device candidate on the basis of device candidate
information acquired by the information acquisition unit 151. More specifically, for
example, the communication control unit 153 notifies the terminal device 200 for
20 which identification information is included in the above-mentioned device candidate
information that the terminal device 200 is the above-mentioned device candidate.
[0073]
- First example: notification in system information block (SIB)
As an example, the communication control unit 153 notifies the terminal
25 device that the terminal device 200 is the above-mentioned device candidate in the
SIB.
[0074]
For example, the above-mentioned SIB includes the above-mentioned
device candidate information. As described above, as an example, the device
30 candidate information is a list including identification information of each terminal
device 200 which is the above-mentioned device candidate. Through control by the
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communication control unit 153, the base station 100 transmits the SIB including the
above-described device candidate information. For example, the communication
control unit 153 generates the above-mentioned SIB. Also, for example, the
communication control unit 153 allocates radio resources including the above-
5 mentioned device candidate information to the above-mentioned STB.
[0075]
Thereby, for example, a notification of a large number of terminal devices
200 by less radio resources is possible.
[0076]
10 — Second example: notification by signaling
As another example, the communication control unit 153 may notify the
terminal device 200 that the terminal device 200 is the above-mentioned device
candidate by individual signaling for the terminal device 200.
[0077]
15 For example, the above-mentioned individual signaling may be radio
resource control (RRC) signaling. Through control by the communication control
unit 153, the base station 100 may transmit a message indicating that the terminal
device 200 is the above-described device candidate by the RRC signaling for the
terminal device 200 which is the above-mentioned device candidate. For example,
20 the communication control unit 153 may generate the message. Also, for example,
the communication control unit 153 may allocate radio resources to the message.
[0078]
Thereby, for example, a fast notification of the terminal device 200 which is
the above-mentioned device candidate is possible.
25 [0079]
As mentioned above, the communication control unit 153 notifies the
terminal device 200 that the terminal device 200 is the above-mentioned device
candidate. Thereby, for example, the above-mentioned shared band can be more
appropriately used in the cellular system 1. Specifically, for example, it is possible
30 to cause the terminal device 200 which is the above-mentioned device candidate to
perform an operation for using the above-mentioned shared band in cellular
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communication. Also, because it is unnecessary for a terminal device 200 which is
not the above-described device candidate to perform any special operation, it is
possible to suppress an increase in the number of operations of the terminal device
200 which is not the above-described device candidate.
5 [0080]
(b) Determination of use of shared band
For example, the communication control unit 153 determines whether to use
the above-mentioned shared band in the cellular communication before the base
station 100 uses the above-mentioned shared band in the cellular communication.
10 [0081]
For example, the communication control unit 153 determines whether to use
the above-mentioned shared band in the cellular communication on the basis of a
result of carrier sensing for the above-mentioned shared band by the terminal device
200 which is the above-mentioned device candidate.
15 [0082]
Specifically, for example, one or more terminal devices 200 which are the
above-mentioned device candidates perform carrier sensing for the above-mentioned
shared band and provide results of the carrier sensing to the base station 100. The
communication control unit 153 determines whether to use the above-mentioned
20 shared band in cellular communication on the basis of the results of the abovementioned
carrier sensing by the above-mentioned one or more terminal devices 200.
As an example, the communication control unit 153 determines to use the abovementioned
shared band in the cellular communication when results of carrier sensing
of a predetermined number of terminal devices 200 or terminal devices 200 of a
25 predetermined ratio among the above-mentioned one or more terminal devices 200
indicate that no signal is transmitted using the above-mentioned shared band. As
another example, when all the results of the carrier sensing of the above-mentioned
one or more terminal devices 200 indicate that no signal is transmitted using the
above-mentioned shared band, the communication control unit 153 may determine to
30 use the above-mentioned shared band in the cellular communication.
[0083]
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Thereby, for example, when the above-mentioned shared band for the
cellular communication is used, a usage state of the above-mentioned shared band in
the periphery of the terminal device 200 is considered. Thus, the occurrence of
interference between cellular communication by the terminal device 200 and wireless
5 LAN communication is suppressed.
[0084]
(c) Transmission of frame
For example, the communication control unit 153 controls the transmission
of the frame by the base station 100 so that the frame including duration information
10 for setting an NAV is transmitted using the above-mentioned shared band before the
above-mentioned shared band is used in the cellular communication.
[0085]
Thereby, for example, it is possible to cause the terminal device for
performing wireless LAN communication (hereinafter, referred to as a "wireless
15 LAN device") in which the above-mentioned frame is received to set the abovementioned
NAV. That is, it is possible to cause the wireless LAN device positioned
in the periphery of the base station 100 to set the above-mentioned NAV.
Consequently, when the cellular communication is performed using the abovementioned
shared band, the use of the above-mentioned shared band by the wireless
20 LAN device positioned in the periphery of the base station 100 can be prevented.
[0086]
- Frame
For example, the above-mentioned frame has a duration field and includes
the above-mentioned duration information in the duration field.
25 [0087]
As an example, the above-mentioned frame is an RTS frame. As another
example, the above-mentioned frame may be a CTS frame. As still another
example, the above-mentioned frame may be another type of frame similar to the
RTS frame and the CTS frame.
30 [0088]
- Duration information
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As described above, the above-mentioned duration information is
information for setting the NAV. For example, the above-mentioned duration
information indicates the duration. Aiso, the duration is a period after the
transmission of the above-mentioned frame and covers a period in which the cellular
5 communication is performed using the above-mentioned shared band. For example,
the duration is determined by the communication control unit 153.
[0089]
According to the transmission of the frame including such duration
information, for example, it is possible to cause the wireless LAN device (that is, the
10 wireless LAN device positioned in the periphery of the base station 100) for
receiving the frame to set the NAV for covering a period in which the cellular
communication is performed using the above-mentioned shared band.
Consequently, the use of the above-mentioned shared band by the wireless LAN
device positioned in the periphery of the base station 100 can be prevented during the
15 period in which the cellular communication is performed using the above-mentioned
shared band.
[0090]
Also, the duration indicated by the above-mentioned duration information
may cover a part of the period in which the cellular communication is performed
20 using the above-mentioned shared band. An additional frame including the
duration information for setting the NAV may be transmitted through control by the
communication control unit 153 at any timing after the transmission of the abovedescribed
frame. Also, another additional frame may be transmitted at any timing
after the transmission of the additional frame. One or more additional frames may
25 be transmitted at different timings as described above through control by the
communication control unit 153. Every time an additional frame is transmitted, the
wireless LAN device can receive the additional frame and update the NAV on the
basis of duration information included in the additional frame. As a result, the
above-mentioned time in which the cellular communication is performed using the
30 above-mentioned shared band can be covered according to the duration information
included in the above-mentioned frame and the above-mentioned one or more
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additional frames. Also, according to this technique, for example, it is possible to
further lengthen a period in which the above-mentioned shared band is used in the
cellular communication.
[0091]
5 - Timing of transmission
The above-mentioned frame is transmitted, for example, at a timing at
which a period in which no signal is transmitted using the above-mentioned shared
band becomes a sum of a DIFS and a backoff time. For example, the
communication control unit 153 controls the above-mentioned frame to start to be
10 transmitted as described above.
[0092]
Also, the above-mentioned frame may start to be transmitted before the
period in which no signal is transmitted using the above-mentioned shared band
becomes the DIFS. Thereby, for example, it is possible to more reliably transmit
15 the above-mentioned frame using the above-mentioned shared band. Further, the
above-mentioned frame may start to be transmitted after the period in which no
signal is transmitted using the above-mentioned shared band is longer than the SIFS
(and before the period becomes the DIFS). Thereby, for example, a collision of a
signal of the above-mentioned frame with a signal of wireless LAN communication
20 can be avoided.
[0093]
- Specific content of control
For example, the processing unit 150 (the communication control unit 153
or another constituent element) performs carrier sensing for the above-mentioned
25 shared band. When the period in which no signal is transmitted using the abovementioned
shared band becomes a sum of the DIFD and the backoff time, the
communication control unit 153 triggers the transmission of a frame including
duration information for setting the NAV. Then, the processing unit 150 (the
communication control unit 153 or another constituent element) generates a frame
30 including duration information for setting the NAV. Also, for example, the
processing unit 150 (the communication control unit 153 or another constituent
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element) generates a signal of a physical layer of the above-mentioned frame by
scrambling, encoding, interleaving, symbol mapping, modulation, etc. and causes the
wireless communication unit 120 to transmit the signal.
[0094]
5 (d) Instruction of transmission of frame
For example, the communication control unit 153 instructs the terminal
device 200 which is the above-described device candidate to transmit a frame
including duration information for setting the NAV using the above-mentioned
shared band before the above-mentioned shared band is used in the cellular
10 communication.
[0095]
Thereby, for example, it is possible to cause the terminal device 200 which
is the above-mentioned device candidate to transmit the above-mentioned frame
before the cellular communication is performed using the above-mentioned shared
15 band. As a result, the wireless LAN device for receiving the above-described frame
can set the above-mentioned NAV. That is, it is possible to cause the wireless LAN
device positioned in the periphery of the terminal device 200 which is the abovementioned
device candidate to set the above-mentioned NAV. Consequently, when
the cellular communication is performed using the above-mentioned shared band, the
20 use of the above-mentioned shared band by the wireless LAN device positioned in
the periphery of the above-mentioned terminal device 200 can be prevented. That
is, a hidden terminal problem can be solved.
[0096]
- Frame
25 For example, the above-mentioned frame has a duration field and includes
the above-mentioned duration information in the duration field.
[0097]
As an example, the above-mentioned frame is a CTS frame. As another
example, the above-mentioned frame may be an RTS frame. As still another
30 example, the above-mentioned frame may be another type of frame similar to the
RTS frame and the CTS frame.
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[0098]
- Technique of instruction
— First example: instruction using cellular band
As the first example, the communication control unit 153 uses a cellular
5 band to instruct the above-mentioned terminal device 200 to transmit the abovementioned
frame using the above-mentioned shared band.
[0099]
For example, using the cellular band used in the cellular communication by
the base station 100 and the terminal device 200 (for example, a CC), the
10 communication control unit 153 instructs the above-mentioned terminal device 200
to transmit the above-mentioned frame using the above-mentioned shared band.
[0100]
As an example, the communication control unit 153 instructs the abovementioned
terminal device 200 to transmit the above-mentioned frame using the
15 above-mentioned shared band by individual signaling for the above-mentioned
terminal device 200 which is the above-mentioned device candidate. For example,
through control by the communication control unit 153, the base station 100
transmits a frame transmission instruction message for performing an instruction for
the transmission of the above-mentioned frame using the above-mentioned shared
20 band by RRC signaling for the terminal device 200 which is the above-mentioned
device candidate. For example, the communication control unit 153 generates the
message. Also, for example, the communication control unit 153 allocates radio
resources to the message.
[0101]
25 By performing the instruction using the cellular band, for example, the
terminal device 200 can transmit a frame such as a CTS frame without decrypting the
RTS frame. That is, a burden on the terminal device 200 can be reduced. Also, by
individual signaling for the terminal device 200, for example, a fast notification of
the terminal device 200 which is the above-mentioned device candidate is possible.
30 [0102]
Also, the communication control unit 153 instructs the above-mentioned
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terminal device 200 to transmit the above-mentioned frame using the abovementioned
shared band, for example, after the base station 100 transmits a frame
including duration information for setting the NAV (for example, an RTS frame).
[0103]
5 Also, the communication control unit 153 may instruct the above-mentioned
terminal device 200 to transmit the above-mentioned frame using the abovementioned
shared band in an SIB in place of individual signaling.
[0104]
— Provision of timing information
10 For example, the communication control unit 153 provides the abovementioned
terminal device 200 with information which specifies the timing at which
the above-mentioned frame is transmitted (hereinafter referred to as "timing
information).
[0105]
15 Specifically, for example, through control by the communication control
unit 153, the base station 100 transmits a frame transmission instruction message
including the above-mentioned timing information to the terminal device 200 using
the cellular band.
[0106]
20 For example, the above-described timing is any timing after the base station
100 transmits a frame including duration information for setting the NAV (for
example, an RTS frame).
[0107]
According to provision of the above-mentioned timing information, for
25 example, the base station 100 can control the timing of frame transmission by the
terminal device 200. Also, according to the provision of the above-mentioned
timing information, for example, it is possible to cause a plurality of terminal devices
200 to simultaneously transmit frames.
[0108]
30 — Provision of duration information
Also, for example, the communication control unit 153 provides the
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terminal device 200 with the above-mentioned duration information included in the
above-mentioned frame. Alternatively, the communication control unit 153
provides the above-mentioned terininal device 200 with information which specifies
the duration information.
5 [0109]
Specifically, for example, through control by the communication control
unit 153, the base station 100 transmits a fame transmission instruction message
including the above-mentioned duration information (or information which specifies
the above-mentioned duration information) included in the above-mentioned frame
10 using the cellular band to the terminal device 200.
[0110]
For example, the duration indicated by the above-mentioned duration
information is a duration from a point in time at which an SIFS has elapsed from an
end time-point of transmission of the above-mentioned frame transmitted by the
15 terminal device 200 to a point in time at which the duration indicated by the duration
information included in the frame transmitted by the base station 100 ends.
[0111]
According to provision of the above-mentioned duration information, for
example, the base station 100 can control a period in which the wireless LAN device
20 for receiving a frame transmitted by the terminal device 200 avoids transmitting a
signal.
[0112]
- Second example: instruction by other frame for triggering transmission of
frame
25 As the second example, the communication control unit 153 may instruct
the above-mentioned terminal device 200 to transmit the above-mentioned frame
using the above-mentioned shared band by another frame for triggering the
transmission of the above-mentioned frame by the above-mentioned terminal device
200.
30 [0113]
As described above, for example, the communication control unit 153
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controls the transmission of the frame so that a frame including duration information
for setting the NAV is transmitted using the above-mentioned shared band (by the
base station 100). For example, the frame is the above-mentioned other frame (that
is, another frame for triggering the transmission of the above-mentioned frame by the
5 above-described terminal device 200).
[0114]
For example, the above-mentioned frame has a reception address field and
includes a predetermined value in the reception address field. The terminal device
200 which is the above-mentioned device candidate transmits a frame including
10 duration information for setting the NAV using the above-mentioned shared band
when the above-mentioned other frame including the above-mentioned
predetermined value in the reception address field is received using the abovementioned
shared band. Also, a predetermined value may be included in another
field (for example, a transmission address field) in place of the reception address
15 field, and the terminal device 200 may transmit the above-described other frame
using the above-mentioned shared band when the frame including the abovementioned
value is received using the above-mentioned shared band.
[0115]
As an example, the above-mentioned other frame is an RTS frame and
20 triggers the transmission of a CTS frame by the terminal device 200 which is the
above-mentioned device candidate.
[0116]
According to the instruction by the above-mentioned other frame, for
example, it is possible to cause the above-mentioned terminal device 200 which is
25 the above-mentioned device candidate to more quickly transmit the above-mentioned
frame.
[0117]
(e) Cellular communication
For example, the communication control unit 153 controls wireless
30 communication (that is, the cellular communication) of the cellular system 1.
[0118]
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For example, the communication control unit 153 controls wireless
communication using the above-mentioned shared band. Also, for example, the
communication control unit 153 controls wireless communication using a cellular
band.
5 [0119]
- Example of cellular communication using shared band
Hereinafter, an example of cellular communication using the abovementioned
shared band will be described with reference to FIGS. 7 to 13.
[0120]
10 - First example
FIG. 7 is an explanatory diagram illustrating the first example of the cellular
communication according to an embodiment of the present disclosure. Referring to
FIG. 7, first, the base station 100 transmits an RTS frame using the shared band.
Also, the base station 100 transmits a frame transmission instruction message
15 including timing information and duration information to the terminal device 200
using the cellular band. The terminal device 200 transmits a CTS frame including
the above-mentioned duration information using the above-mentioned shared band at
a timing indicated by the above-mentioned timing information. At a point in time at
which an SIFS has elapsed from an end time-point of the transmission (or the
20 reception) of the CTS frame, the base station 100 starts the cellular communication
with the terminal device 200 using the above-mentioned shared band. Also, the
base station 100 ends the cellular communication before the passage of the period of
an NAV set according to the RTS frame (or a period of the NAV set according to the
CTS frame). •
25 [0121]
— Second example
FIG. 8 is an explanatory diagram illustrating the second example of cellular
communication according to an embodiment of the present disclosure. Referring to
FIG. 8, first, the base station 100 transmits an RTS frame using a shared band. Then,
30 the terminal device 200 transmits a CTS frame using the above-mentioned shared
band according to the reception of the RTS frame. At a point in time at which the
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SIFS has elapsed from an end time-point of the transmission (or the reception) of the
CTS frame, the base station 100 starts cellular communication with the terminal
device 200 using the above-mentioned shared band. Also, the base station 100 ends
the cellular communication before the passage of the period of an NAV set according
5 to the RTS frame (or the period of the NAV set according to the CTS frame).
[0122]
-Thirdexample -
FIG. 9 is an explanatory diagram illustrating the third example of cellular
communication according to an embodiment of the present disclosure. Referring to
10 FIG. 9, the base station 100 transmits a frame transmission instruction message
including timing information and duration information to the terminal device 200
using a cellular band, and the terminal device 200 transmits a CTS frame including
the above-mentioned duration information using the above-mentioned shared band at
a timing indicated by the timing information. At a point in time at which the SIFS
15 has elapsed from the end time-point of the transmission (or the reception) of the CTS
frame, the base station 100 starts the cellular communication with the terminal device
200 using the above-mentioned shared band. Also, the base station 100 ends the
cellular communication before the passage of the period of an NAV set according to
the CTS frame.
20 [0123]
- Fourth example
FIG. 10 is an explanatory diagram illustrating the fourth example of cellular
communication according to an embodiment of the present disclosure. Referring to
FIG. 10, the-base station 100 transmits an RTS frame using a shared band. At a
25 point in time at which the SIFS has elapsed from an end time-point of the
transmission (or the reception) of the RTS frame, the base station 100 starts cellular
communication with the terminal device 200 using the above-mentioned shared band.
Also, the base station 100 ends the cellular communication before the passage of the
period of an NAV set according to the RTS frame.
30 [0124]
- Duplex operation
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In the cellular system 1, time division duplex (TDD) or frequency division
duplex (FDD) are adopted as the duplex operation. That is, the duplex operation of
the cellular system 1 is the TDD or FDD.
[0125]
5 -- TDD
As the first example, the TDD is adopted as the duplex operation in the
cellular system 1. That is, the duplex operation of the cellular system 1 is the TDD.
In this case, the above-mentioned shared band is used as a band for both downlink
and uplink in the cellular system I. Hereinafter, an example of the cellular
10 communication when the TDD is adopted will be described with reference to FIG. i I.
[0126]
FIG. II is an explanatory diagram illustrating an example of cellular
communication when the TDD is adopted. Referring to FIG. 11, for example,
within a period in which the cellular communication is performed using a shared
15 band, the base station 100 transmits a signal to the terminal device 200 using the
shared band in a downlink frame, and the terminal device 200 receives the signal.
Also, in an uplink sub-frame within the above-mentioned period, the terminal device
200 transmits a signal to the base station 100 using the above-mentioned shared band,
and the base station 100 receives the signal.
20 [0127]
Also, cellular communication of only one radio frame is illustrated in the
example of FIG. II, but, of course, cellular communication of two or more frames
may be performed. This is applied to FIGS. 12 and 13 which will be described
below as well as FIG. 11.
25 [0128]
- FDD
As the second example, the FDD is adopted as the duplex operation in the
cellular system 1. That is, the duplex operation of the cellular system 1 is the FDD.
[0129]
30 For example, a partial band included in the above-mentioned shared band in
the cellular system 1 is used as a downlink band and another partial band included in
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the above-mentioned shared band is used as an uplink band. Hereinafter, an
example of cellular communication when the FDD is adopted will be described with
reference to FIG. 12.
[0130]
5 FIG. 12 is an explanatory diagram illustrating an example of cellular
communication when the FDD is adopted. Referring to FIG. 12, for example,
within a period in which the cellular communication is performed using a shared
band, the base station 100 transmits a signal to the terminal device 200 using a partial
band of the shared band as a downlink band, and the terminal device 200 receives the
10 signal. Also, within the above-mentioned period, the terminal device 200 transmits
a signal to the base station 100 using another partial band of the above-mentioned
shared band as an uplink band, and the base station 100 receives the signal.
[0131]
Also, two shared bands may be used in place of using the partial band of the
15 shared band as the downlink band and using the other partial band of the shared band
as the uplink band. In this case, in the cellular system I, one of the two shared
bands may be used as the downlink band and the other of the two shared bands may
be used as the uplink band.
[0132]
20 Also, the shared band may be used as one of the downlink band and the
uplink band. For example, the shared band may be used as the downlink band in
the cellular system 1. The cellular band may be used as the uplink band
corresponding to the above-mentioned shared band. That is, an uplink control
signal associated with the shared band may be transmitted to the base station 100 by
25 the terminal device 200 using the cellular band. Hereinafter, in this regard, a
specific example will be described with reference to FIG. 13.
[0133]
FIG. 13 is an explanatory diagram illustrating another example of cellular
communication when the FDD is adopted. Referring to FIG. 13, within a period in
30 which the cellular communication is performed using the shared band, the base
station 100 may transmit a signal to the terminal device 200 using the shared band as
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a downlink band, and the terminal device 200 may receive the signal. Also, an
uplink control signal associated with the shared band may be transmitted to the base
station 100 by the terminal device 200 using the cellular band.
[0134]
5 By using the shared band as the downlink band, for example, a hidden
terminal problem can be reduced. Specifically, for example, because the terminal
device 200 does not transmit an uplink signal using the above-mentioned shared
band, the interference to wireless LAN commimication of the wireless LAN device
positioned in the periphery of the terminal device 200 is suppressed.
10 [0135]
<3.2. Configuration of terminal device>
Next, an example of a configuration of the terminal device 200-1 according
to an embodiment of the present disclosure will be described with reference to FIG.
14. FIG. 14 is a block diagram illustrating the example of the configuration of the
15 terminal device 200 according to an embodiment of the present disclosure.
Referring to FIG. 14, the terminal device 200 includes an antenna unit 210, a wireless
communication unit 220, a storage unit 230, and a processing unit 240.
[0136]
(Antenna unit 210)
20 The antenna unit 210 emits a signal output by the wireless communication
unit 220 into space as a radio wave. Additionally, the antenna unit 210 converts a
radio wave from space into a signal, and outputs the signal to the wireless
communication unit 220.
[0137]
25 (Wireless communication unit 220)
The wireless communication unit 220 transmits and receives a signal. For
example, the wireless communication unit 220 receives a downlink signal from the
base station 100 and transmits an uplink signal to the base station 100 when the
terminal device 200 is located within the cell 10.
30 [0138]
For example, the wireless communication unit 220 transmits and receives a
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signal using a cellular band. Also, particularly, in the embodiment of the present
disclosure, the wireless communication unit 220 transmits and receives a signal using
a frequency band shared between cellular communication and other wireless
communication (for example, wireless LAN communication) (that is, a shared band).
5 [0139]
(Storage unit 230)
The storage unit 230 temporarily or permanently stores programs and data
for the operation of the terminal device 200.
[0140]
10 (Processing unit 240)
The processing unit 240 provides various functions of the terminal device
200. The processing unit 240 includes a recognition unit 241 and a communication
control unit 243. Also, the processing unit 240 can further include another
constituent element other than these constituent elements.
15 [0141]
(Recognition unit 241)
The recognition unit 241 recognizes that the terminal device 200 is a device
candidate for performing cellular communication using the shared band shared
between the cellular communication and the wireless LAN communication through a
20 notification by the base station 100.
[0142]
For example, when the terminal device 200 is a device candidate for
performing the cellular communication using the above-mentioned shared band, the
base station 100 (the communication control unit 153) notifies the terminal device
25 200 that the terminal device 200 is the above-mentioned device candidate as
described above. Thus, the recognition unit 241 recognizes that the terminal device
200 is the above-mentioned device candidate according to the notification by the
base station 100.
[0143]
30 (Communication control unit 243)
The communication control unit 243 performs control for using the aboveSP357001WO00
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mentioned shared band in the cellular communication when the terminal device 200
is the above-mentioned device candidate.
[0144]
(a) Report of result of carrier sensing
5 For example, the above-mentioned control for using the above-mentioned
shared band in the cellular communication includes reporting the result of carrier
sensing by_ the terminal device 200 to the base station 100. That is, the
communication control unit 243 reports the result of the carrier sensing by the
terminal device 200 to the base station 100 when the terminal device 200 is the
10 above-mentioned device candidate.
[0145]
Specifically, for example, when the recognition unit 241 recognizes that the
terminal device 200 is the above-mentioned device candidate, the processing unit
240 (the communication control unit 243 or another constituent element) performs
15 the carrier sensing for the above-mentioned shared band. That is, the processing
unit 240 confirms whether a signal is transmitted using the above-mentioned shared
band. The communication control unit 243 reports the result of the abovementioned
carrier sensing to the base station 100 using the cellular band. As an
example, the above-mentioned result of the above-mentioned carrier sensing is
20 information indicating whether the signal is transmitted using the above-mentioned
shared band.
[0146]
According to the report of the result of the carrier sensing described above,
for example, the base station 100 can know a usage state of the above-mentioned
25 shared band in the periphery of the terminal device 200. Thus, when the abovementioned
shared band for the cellular communication is used, the usage state of the
above-mentioned shared band in the periphery of the terminal device 200 is
considered. Thus, the occurrence of interference between the cellular
communication and the wireless LAN communication by the terminal device 200 can
30 be suppressed.
[0147]
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(b) Transmission of frame
For example, the above-mentioned control for using the above-mentioned
band in the cellular communication includes controlling the transmission of the
frame by the terminal device 200 so that the frame including the duration information
5 for setting the NAV is transmitted using the above-mentioned shared band. That is,
the communication control unit 243 controls the transmission of the frame by the
terminal device 200 so that the frame including the duration information for setting
the NAV is transmitted using the above-mentioned shared band.
[0148]
10 - Frame
For example, the above-mentioned frame has a duration field and includes
the above-mentioned duration information in the duration field.
[0149]
As an example, the above-mentioned frame is a CTS frame. As another
15 example, the above-mentioned frame may be an RTS frame. As still another
example, the above-mentioned frame may be another type of frame similar to the
RTS frame and the CTS frame.
[0150]
- Transmission according to instruction by base station
20 For example, the communication control unit 243 controls the transmission
of the frame by the terminal device 200 so that the above-mentioned frame is
transmitted using the above-mentioned shared band according to the instruction by
the base station 100.
[0151]
25 — First example: instruction using cellular band
As the first example, using the cellular band, the base station 100 instructs
the terminal device 200 to transmit the above-mentioned frame using the abovementioned
shared band. According to this instruction, the communication control
unit 243 controls the transmission of the frame by the terminal device 200 so that the
30 above-mentioned frame is transmitted using the above-mentioned shared band.
[0152]
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For example, timing information which specifies a timing at which the
above-mentioned frame is transmitted is provided to the terminal device 200 by the
base station 100. The communication control unit 243 controls the transmission of
the above-mentioned frame by the terminal device 200 so that the above-mentioned
5 frame (for example, the CTS frame) is transmitted at the timing specified from the
timing information.
[0153]
Also, for example, the duration information (or information which specifies
the duration information) included in the above-mentioned frame is provided to the
10 terminal device 200 by the base station 100. The communication control unit 243
controls the transmission of the above-mentioned frame by the terminal device 200
so that the frame (for example, the CTS frame) including the above-mentioned
duration information provided by the base station 100 is transmitted.
[0154]
15 — Second example: instruction by other frame for triggering transmission of
frame
As the second example, the base station 100 instructs the terminal device
200 to transmit the above-mentioned frame using the above-mentioned shared band
by the other frame for triggering the transmission of the above-mentioned frame by
20 the terminal device 200. The communication control unit 243 controls the
transmission of the frame by the terminal device 200 so that the above-mentioned
frame is transmitted using the above-mentioned shared band according to the
reception of the above-mentioned other frame.
[0155]
25 For example, the above-mentioned other frame has a reception address field
(or another field) and includes a predetermined value in the reception address field
(or the other field). Thus, the communication control unit 243 controls the
transmission of the frame by the terminal device 200 so that the above-mentioned
frame is transmitted using the above-mentioned shared band according to the
30 reception of another frame including the above-mentioned predetermine value in the
reception address field (or the other field).
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[0156]
As an example, the above-mentioned other frame is an RTS frame and
triggers the transmission of a CTS frame by the above-mentioned terminal device
200. That is, the base station 100 transmits the RTS frame using the above-
5 mentioned shared band and the terminal device 200 transmits CTS using the abovementioned
shared band according to the reception of the RTS frame.
[0157]
As mentioned above, the above-mentioned frame is transmitted by the
terminal device 200. Thereby, for example, the wireless LAN device which
10 receives the above-mentioned frame transmitted by the terminal device 200 can set
the above-mentioned NAV. That is, it is possible to cause the wireless LAN device
positioned in the peripheiy of the terminal device 200 which is the above-mentioned
device candidate to set the NAV. Consequently, when the cellular communication is
performed using the above-mentioned shared band, the use of the above-mentioned
15 shared band by the wireless LAN device positioned in the peripheiy of the abovementioned
terminal device 200 can be prevented. That is, a hidden terminal
problem can be solved.
[0158]
(c) Cellular communication
20 For example, the communication control unit 243 controls the cellular
communication by the terminal device 200.
[0159]
For example, the communication control unit 243 controls the cellular
communication by the terminal device 200 using the above-mentioned shared band.
25 Also, for example, the communication control unit 243 controls the cellular
communication by the terminal device 200 using the cellular band.
[0160]
« 4 . Flow of process»
Next, examples of the process according to the embodiment of the present
30 disclosure will be described with reference to FIGS. 15 to 17.
[0161]
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(First example)
FIG. 15 is a sequence diagram illustrating the first example of a schematic
flow of the process according to the embodiment of the present disclosure.
[0162]
5 The base station 100 acquires device candidate information indicating the
terminal device 200 which is the device candidate for performing cellular
communication using a shared band and notifies the terminal device 200 that the
terminal device 200 is the above-mentioned device candidate using a cellular band
(S301).
10 [0163]
Thereafter, the terminal device 200 performs carrier sensing for the abovementioned
shared band (S303). The terminal device 200 reports a result of the
above-mentioned carrier sensing to the base station 100 using the cellular band
(S305).
15 [0164]
Further, the base station 100 determines whether to use the abovementioned
shared band in the cellular communication on the basis of the result of the
above-mentioned carrier sensing (S307). For example, the base station 100
determines to use the above-mentioned shared band in the cellular communication.
20 [0165]
The base station 100 performs the carrier sensing for the above-mentioned
shared band (S309) and transmits an RTS frame when a period in which no signal is
transmitted using the above-mentioned shared band becomes a sum of a DIFS and a
backoff time (S311).
25 [0166]
Also, the base station 100 transmits a frame transmission instruction
message including timing information and duration information using the cellular
band (S313).
[0167]
30 Then, the terminal device 200 transmits a CTS frame including the abovementioned
duration information using the above-mentioned shared band at a timing
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specified from the above-mentioned timing information (S315).
[0168]
The base station 100 and the terminal device 200 perform the cellular
communication using the above-mentioned shared band in a period after the
5 transmission of the CTS frame (S317). That is, the base station 100 and the
terminal device 200 transmit signals of the cellular communication in the period.
[0169]
Also, no frame transmission instruction message is transmitted and the
terminal device 200 may transmit the CTS frame using the above-mentioned shared
10 band according to the reception of the RTS frame transmitted using the abovementioned
shared band by the base station 100.
[0170]
Also, as described above, the base station 100 may transmit another type of
frame in place of the RTS frame. Also, the terminal device 200 may transmit
15 another type of frame in place of the CTS frame.
[0171]
(Second example)
FIG. 16 is a sequence diagram illustrating the second example of a
schematic flow of the process according to the embodiment of the present disclosure.
20 The second example is an example in which a result of carrier sensing is not reported
by the terminal device 200.
[0172]
Steps S331 to S341 of the above-mentioned second example illustrated in
FIG. 16 are the same as steps S301 and S309 to S317 of the above-mentioned first
25 example illustrated in FIG. 15. Consequently, redundant description will be omitted
here.
[0173]
(Third example)
FIG. 17 is a sequence diagram illustrating the third example of a schematic
30 flow of the process according to the embodiment of the present disclosure. The
third example is an example in which no frame (for example, a CTS frame) is
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transmitted by the terminal device 200.
[0174]
Steps S361 to S371 of the above-mentioned third example illustrated in FIG.
17 are the same as steps S301 to S311 of the above-mentioned first example
5 illustrated in FIG. 15. Consequently, redundant description will be omitted here and
only step S373 will be described.
[0175]
The base station 100 and the terminal device 200 perform the abovementioned
cellular communication using the above-mentioned shared band in a
10 period after the transmission of the RTS frame (S373). That is, the base station 100
and the terminal device 200 transmit a signal of the cellular communication in the
period.
[0176]
« 5 . First modified example»
15 Next, the first modified example of the embodiment of the present
disclosure will be described with reference to FIGS. 18 and 19.
[0177]
(Summary)
In the first modified example, the base station 100 synchronizes wireless
20 communication using a shared band with wireless communication using a cellular
band. Also, the terminal device 200 achieves the synchronization (achieve) for the
above-mentioned shared band on the basis of a result of achieving the
synchronization for the cellular band.
[0178] •
25 Thereby, for example, when the above-mentioned shared band is used in the
cellular communication, the terminal device 200 can more quickly start the cellular
communication using the above-mentioned shared band.
[0179]
(Base station 100: communication control unit 153)
30 (e) Cellular communication
In the first modified example, the communication control unit 153
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synchronizes the wireless communication using the cellular band with the wireless
communication using the above-mentioned shared band.
[0180]
For example, the communication control unit 153 synchronizes the wireless
5 communication using the cellular band with the wireless communication using the
above-mentioned shared band in a time direction. More specifically, for example,
the communication control unit 153 synchronizes a radio frame for the cellular band
with a radio frame for the above-mentioned shared band.
[0181]
10 Also, for example, the same transceiver is used for the above cellular band
and the above-mentioned shared band, and the wireless communication of the abovementioned
cellular band and the above-mentioned shared band are synchronized in a
frequency direction. Here, the synchronization in the frequency direction means
that a deviation in the frequency direction is a predetermined degree (for example,
15 such as 500 Hz) or less.
[0182]
(Terminal device 200: communication control unit 243)
(c) Cellular communication
In the first modified example, the communication control unit 243 achieves
20 the synchronization for the above-mentioned shared band on the basis of a result of
achieving the synchronization for the cellular band.
[0183]
For example, the communication control unit 243 achieves the
synchronization for the above-mentioned cellular band. When the above-mentioned
25 shared band is configured to be used in the cellular communication, the
communication control unit 243 achieves the synchronization for the abovementioned
shared band on the basis of a result of achieving synchronization for the
above-mentioned cellular band. Hereinafter, a specific example will be described
with reference to FIG. 18.
30 [0184]
FIG. 18 is an explanatory diagram illustrating the achievement of
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synchronization for the shared band. Referring to FIG. 18, the cellular band and the
shared band are illustrated. The base station 100 synchronizes the wireless
communication using the cellular band with the wireless communication using the
shared band in the time direction and the frequency direction. First, the
5 communication control unit 243 achieves synchronization in the time direction and
the frequency direction for the cellular band before the shared band is used in the
cellular communication. Thereafter, when the use of the shared band for the
cellular communication starts, the communication control unit 243 achieves the
synchronization in the time direction and the frequency direction for the above-
10 mentioned shared band on the basis of the synchronization result in the time direction
and the frequency direction for the above-mentioned cellular band. For example,
the communication control unit 243 achieves the synchronization in the time
direction for the above-mentioned shared band by matching the radio frame for the
above-mentioned shared band to the radio frame for the above-mentioned cellular
15 band. Also, for example, the communication control unit 243 achieves the
synchronization of the frequency direction for the above-mentioned shared band by
correcting deviation in the frequency direction for the above-mentioned shared band
as in the correction of the deviation in the frequency direction for the abovementioned
cellular band.
20 [0185]
For example, when the above-mentioned shared band is used in the cellular
communication according to the achievement of the synchronization for the abovementioned
shared band as described above, the terminal device 200 can more quickly
start the cellular communication using the above-mentioned shared band.
25 [0186]
More specifically, when the terminal device 200 achieves the
synchronization for the above-mentioned shared band, for example, after the abovementioned
shared band starts to be used in the cellular communication, starting the
cellular communication (for example, the transmission/reception of data) using the
30 above-mentioned shared band by the terminal device 200 can be delayed. Also,
because no synchronization signal for the above-mentioned shared band is
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transmitted before the above-mentioned shared band is used in the cellular
communication, the terminal device 200 cannot acquire the synchronization for the
above-mentioned shared band. Therefore, as described above, for example, by
achieving the synchronization for the shared band on the basis of a result of
5 achieving the synchronization for the cellular band, the terminal device 200 can more
quickly start the cellular communication using the above-mentioned shared band.
[0187]
(Flow of process)
FIG. 19 is a flowchart illustrating an example of a schematic flow of the
10 process according to the first modified example of the present embodiment. This
process is a process of the terminal device 200.
[0188]
The communication control unit 243 achieves synchronization for a cellular
band(S401).
15 [0189]
The communication control unit 243 determines whether the terminal device
200 uses a shared band (S403). When the terminal device 200 does not use the
shared band (S403: NO), the process returns to step S401.
[0190]
20 When the terminal device 200 uses the shared band (S403: YES), the
communication control unit 243 achieves synchronization for the above-mentioned
shared band on the basis of a result of achieving the synchronization for the cellular
band (S405). The process ends.
[0191]
25 «6. Second modified example»
Next, the first modified example of the embodiment of the present
disclosure will.be described with reference to FIG. 20.
[0192]
(Summary)
30 In the first modified example, the base station 100 notifies one or more
terminal devices 200 of a period in which cellular communication is performed using
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a shared band. The one or more terminal devices 200 are not limited to the device
candidate for performing the cellular communication using the above-mentioned
shared band. Thereby, for example, the terminal device 200 can perform
measurement for the above-mentioned shared band.
5 [0193]
Also, the terminal device 200 recognizes the above-mentioned period
through a notification by the base station 100 and performs measurement for the
above-mentioned shared band in the period. Thereby, for example, the base station
100 can more appropriately determine the device candidate for performing the
10 cellular communication using the above-mentioned shared band.
[0194]
(Base station 100: communication control unit 153)
(f) Notification of period in which cellular communication is performed
using shared band
15 In the second modified example, the communication control unit 153
notifies the one or more terminal devices 200 of the period in which the cellular
communication is performed using the above-mentioned shared band. The one or
more terminal devices 200 are not limited to the device candidate for performing the
cellular communication using the above-mentioned shared band.
20 [0195]
- Period in which cellular communication is performed using shared band
For example, the base station 100 transmits a frame (for example, an RTS
frame) including duration information for setting an NAV using the above-mentioned
shared band after the carrier sensing for the above-mentioned shared band. Then,
25 the period in which the cellular communication is performed using the abovementioned
shared band is determined. The communication control unit 153 notifies
the one or more terminal devices 200 of the period.
[0196]
- Timing of notification
30 For example, the communication control unit 153 notifies one or more
terminal devices 200 of the above-mentioned period after the above-mentioned
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shared band is available in the cellular communication.
[0197]
Specifically, for example, the communication control unit 153 notifies the
one or more terminal devices 200 of the above-mentioned period after a frame
5 including duration information for setting the NAV is transmitted by the base station
100 and/or the terminal device 200.
[0198]
- Specific content of notification
As an example, the communication control unit 153 notifies the one or more
10 terminal devices 200 of the above-mentioned period through the notification of an
end time-point of the above-mentioned period. As another example, the
communication control unit 153 may notify the one or more terminal devices 200 of
the above-mentioned period through a notification of a length of the abovementioned
period.
15 [0199]
- Technique of notification
As an example, the communication control unit 153 notifies the one or more
terminal devices 200 of the above-mentioned period by individual signaling (for
example, RRC signaling) for each of the one or more terminal devices 200. In this
20 case, for example, the communication control unit 153 notifies the one or more
terminal devices 200 of the above-mentioned period by the above-mentioned
individual signaling using the cellular band used in the cellular communication
between the base station 100 and each of the above-mentioned one or more terminal
devices 200.
25 [0200]
As another example, the communication control unit 153 may notify the one
or more terminal devices 200 of the above-mentioned period in an SIB. In this case,
for example, the communication control unit 153 may notify the one or more
terminal devices 200 of the above-mentioned period in the SIB of each cellular band
30 (for example, each CC). That is, each cellular band (for example, each CC) may be
used in the notification of the above-mentioned period.
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[0201]
As described above, the one or more terminal devices 200 are notified of the
period in which the cellular communication is performed using the above-mentioned
shared band. Thereby, for example, the terminal device 200 can perform
5 measurement for the above-mentioned shared band. More specifically, because a
CRS or the like is not transmitted using the above-mentioned shared band, for
example, while the above-mentioned shared band is not used in the cellular
communication, the terminal device 200 cannot perforin the measurement for the
above-mentioned shared band. Therefore, for example, the terminal device 200 can
10 perform the measurement for the above-mentioned shared band by notifying the
terminal device 200 of the period in which the cellular communication is performed
using the above-mentioned shared band.
[0202]
(g) Determination of device candidate
15 For example, in the second modified example, the communication control
unit 153 determines the above-mentioned device candidate (that is, a device
candidate for performing the cellular communication using the shared band) on the
basis of a result of measurement for the above-mentioned shared band by at least
some of the above-mentioned one or more terminal devices.
20 [0203]
As described below, when the notification of the period in which the cellular
communication is performed using the above-mentioned shared band is provided, the
terminal device 200 performs measurement for the above-mentioned shared band in
the period and notifies the base station 100 of the result of the measurement for the
25 above-mentioned shared band. The communication control unit 153 determines the
above-mentioned device candidate on the basis of the above-mentioned measurement
result. As an example, a predetermined number of terminal devices 200 with better
communication quality in the above-mentioned shared band are determined as the
above-mentioned device candidate.
30 [0204]
Thereby, for example, the communication quality of cellular communication

CLAIMS
Claim 1
A device comprising:
an acquisition unit configured to acquire information indicating a terminal
device which is a device candidate for performing wireless communication of a
cellular system using a frequency band shared between the wireless communication
of the cellular system and wireless communication conforming to a wireless local
area network (LAN) standard; and
a control unit configured to notify the terminal device that the terminal
device is the device candidate.
Claim 2
The device according to claim 1, wherein the control unit notifies the
terminal device that the terminal device is the device candidate before the frequency
band is used in the wireless communication of the cellular system.
Claim 3
The device according to claim 1, wherein the control unit notifies the
terminal device that the terminal device is the device candidate using another
frequency band for the cellular system.
Claim 4
The device according to claim I, wherein the control unit notifies the
terminal device that the terminal device is the device candidate in a system
information block (SIB) or by individual signaling for the terminal device.
Claim 5
The device according to claim 1, wherein the control unit instructs the
terminal device to transmit a frame including duration information for setting a
network allocation vector (NAV) using the frequency band before the frequency band
is used in the wireless communication of the cellular system.
Claim 6
The device according to claim 5, wherein the control unit uses another
frequency band for the cellular system to instruct the terminal device to transmit the
frame using the frequency band.
Claim 7
The device according to claim 6, wherein the control unit provides the
terminal device with information which specifies a timing at which the frame is
transmitted.
Claim 8
The device according to claim 6, wherein the control unit provides the
terminal device with the duration information or information which specifies the
duration information.
Claim 9
The device according to claim 5, wherein the control unit instructs the
terminal device to transmit the frame using the frequency band by another frame for
triggering the transmission of the frame by the terminal device.
Claim 10
The device according to claim 1, wherein the control unit determines
whether to use the frequency band in the wireless communication of the cellular
system on the basis of a result of carrier sensing for the frequency band by the
terminal device.
Claim II
The device according to claim 1, wherein the control unit synchronizes
wireless communication using another frequency band for the cellular system with
wireless communication using the frequency band.
Claim 12
The device according to claim 1, wherein ihe control unit notifies one or
more terminal devices for performing wireless communication of the cellular system
of a period in which the wireless communication of the cellular system is performed
using the frequency band.
Claim 13
The device according to claim 12, wherein the control unit determines the
device candidate on the basis of a result of performing measurement for the
frequency band by at least some of the one or more terminal devices.
Claim 14
The device according to claim 1, wherein the device is a base station of the
cellular system, a base station device of the base station, or a module of the base
station device.
Claim 15
A device comprising:
a recognition unit configured to recognize that a terminal device is a device
candidate for performing wireless communication of a cellular system using a
frequency band shared between the wireless communication of the cellular system
and wireless communication conforming to a wireless local area network (LAN)
standard through a notification by a base station of the cellular system; and
a control unit configured to perform control for using the frequency band in
the wireless communication of the cellular system \vhen the terminal device is the
device candidate.
Claim 16
The device according to claim 15, wherein the control includes controlling
transmission of a frame by the terminal device so that the frame including duration
information for setting a NAV is transmitted using the1 frequency band.
Claim] 7
The device-according to claim 15, wherein the control includes notifying the
base station of a result of carrier sensing by the termit^' device.
Claim 18
The device according to claim 15, wherein the control unit achieves
synchronization for the frequency band on (he basis of a result of achieving
synchronization for another frequency band for the ce"l ,Iar system.
Claim 19
The device according to claim 15,
wherein the recognition unit recognizes a period in which the wireless
communication of the cellular system is performed u^ing me frequency band through
a notification by the base station, and
wherein the control unit performs measurement for the frequency band in
the period.
Claim 20
The device according to claim 15, wherein the device is the terminal device
or a module of the terminal device.
Claim 21
The device according to claim 1,
wherein a duplex operation of the cellular; system is frequency division
duplex (FDD), and
wherein the frequency band is used as a downlink band in the cellular
system.