WO2016067738A1 - 無線送信装置、無線受信装置、通信方法および通信システム - Google Patents
無線送信装置、無線受信装置、通信方法および通信システム Download PDFInfo
- Publication number
- WO2016067738A1 WO2016067738A1 PCT/JP2015/074383 JP2015074383W WO2016067738A1 WO 2016067738 A1 WO2016067738 A1 WO 2016067738A1 JP 2015074383 W JP2015074383 W JP 2015074383W WO 2016067738 A1 WO2016067738 A1 WO 2016067738A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- cca
- frame
- wireless
- carrier sense
- level
- Prior art date
Links
- 238000004891 communication Methods 0.000 title claims abstract description 102
- 238000000034 method Methods 0.000 title claims abstract description 30
- 230000011664 signaling Effects 0.000 claims abstract description 8
- 230000005540 biological transmission Effects 0.000 claims description 161
- 101100172132 Mus musculus Eif3a gene Proteins 0.000 abstract description 11
- OVGWMUWIRHGGJP-WVDJAODQSA-N (z)-7-[(1s,3r,4r,5s)-3-[(e,3r)-3-hydroxyoct-1-enyl]-6-thiabicyclo[3.1.1]heptan-4-yl]hept-5-enoic acid Chemical compound OC(=O)CCC\C=C/C[C@@H]1[C@@H](/C=C/[C@H](O)CCCCC)C[C@@H]2S[C@H]1C2 OVGWMUWIRHGGJP-WVDJAODQSA-N 0.000 description 84
- 101000988961 Escherichia coli Heat-stable enterotoxin A2 Proteins 0.000 description 83
- 101000752249 Homo sapiens Rho guanine nucleotide exchange factor 3 Proteins 0.000 description 44
- 102100021689 Rho guanine nucleotide exchange factor 3 Human genes 0.000 description 44
- 238000012545 processing Methods 0.000 description 20
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 13
- OVGWMUWIRHGGJP-WTODYLRWSA-N (z)-7-[(1r,3s,4s,5r)-3-[(e,3r)-3-hydroxyoct-1-enyl]-6-thiabicyclo[3.1.1]heptan-4-yl]hept-5-enoic acid Chemical compound OC(=O)CCC\C=C/C[C@H]1[C@H](/C=C/[C@H](O)CCCCC)C[C@H]2S[C@@H]1C2 OVGWMUWIRHGGJP-WTODYLRWSA-N 0.000 description 11
- 101100366889 Caenorhabditis elegans sta-2 gene Proteins 0.000 description 11
- 230000008859 change Effects 0.000 description 9
- 238000010586 diagram Methods 0.000 description 9
- 238000006243 chemical reaction Methods 0.000 description 8
- 230000004044 response Effects 0.000 description 8
- 239000000523 sample Substances 0.000 description 7
- 238000012549 training Methods 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 4
- 238000001914 filtration Methods 0.000 description 4
- 230000007246 mechanism Effects 0.000 description 4
- 238000012544 monitoring process Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 239000013256 coordination polymer Substances 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 238000000060 site-specific infrared dichroism spectroscopy Methods 0.000 description 2
- 101000829958 Homo sapiens N-acetyllactosaminide beta-1,6-N-acetylglucosaminyl-transferase Proteins 0.000 description 1
- 108700026140 MAC combination Proteins 0.000 description 1
- 102100023315 N-acetyllactosaminide beta-1,6-N-acetylglucosaminyl-transferase Human genes 0.000 description 1
- 230000003044 adaptive effect Effects 0.000 description 1
- 238000004378 air conditioning Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000013467 fragmentation Methods 0.000 description 1
- 238000006062 fragmentation reaction Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000007562 laser obscuration time method Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W74/00—Wireless channel access
- H04W74/002—Transmission of channel access control information
- H04W74/006—Transmission of channel access control information in the downlink, i.e. towards the terminal
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W74/00—Wireless channel access
- H04W74/08—Non-scheduled access, e.g. ALOHA
- H04W74/0808—Non-scheduled access, e.g. ALOHA using carrier sensing, e.g. carrier sense multiple access [CSMA]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/04—Wireless resource allocation
- H04W72/044—Wireless resource allocation based on the type of the allocated resource
- H04W72/0446—Resources in time domain, e.g. slots or frames
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W74/00—Wireless channel access
- H04W74/08—Non-scheduled access, e.g. ALOHA
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W84/00—Network topologies
- H04W84/02—Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
- H04W84/10—Small scale networks; Flat hierarchical networks
- H04W84/12—WLAN [Wireless Local Area Networks]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W48/00—Access restriction; Network selection; Access point selection
- H04W48/08—Access restriction or access information delivery, e.g. discovery data delivery
- H04W48/12—Access restriction or access information delivery, e.g. discovery data delivery using downlink control channel
Definitions
- the present invention relates to a wireless transmission device, a wireless reception device, a communication method, and a communication system.
- IEEE 802.11ac was developed by IEEE (The Institute of Electrical and Electronics Electronics, Inc.) as an evolutionary standard of IEEE 802.11n, which is a widely used wireless LAN (Local area network) standard.
- IEEE 802.11ax standardization activities are being carried out as a successor to IEEE 802.11n / ac.
- interference due to an increase in the number of terminals per area is becoming a big problem, and the IEEE 802.11ax standard needs to consider such an overcrowded environment.
- the IEEE802.11ax standard unlike the conventional wireless LAN standard, not only improvement of peak throughput but also improvement of user throughput are listed as main requirements. In order to improve user throughput, introduction of a highly efficient simultaneous multiplex transmission system (access system) is indispensable.
- CSMA / CA CarrierCarsense multiple access with collision avoidance
- SDMA Space-division-multiple-access: SDMA
- MU-MIMO multi-user multiple-input multiple-output
- the IEEE802.11ax standard requires backward compatibility with the existing IEEE802.11 standard. This suggests that it is necessary to support an access scheme based on CSMA / CA even in the IEEE802.11ax standard.
- CSMA / CA that requires carrier sense prior to transmission
- the terminal device Since the terminal device stops communication when measuring interference above the CCA level by carrier sense, the terminal device is less likely to lose a communication opportunity even in an overcrowded environment by increasing the CCA level. Needless to say, raising the CCA level causes a decrease in reception quality due to interference, but it is expected that communication quality is maintained by a packet capture effect specific to packet transmission and adaptive modulation transmission.
- the new terminal device corresponding to the IEEE802.11ax standard can obtain many communication opportunities by transmitting based on the newly defined CCA level, while the existing terminal device that performs communication based on the existing CCA level. (Conventional terminal devices and legacy terminal devices) have a problem that communication opportunities are hardly obtained.
- the present invention has been made in view of such circumstances, and an object of the present invention is to provide a terminal device that can use a new CCA level and an existing terminal device that uses an existing CCA level on the premise of CSMA / CA.
- An object of the present invention is to provide a wireless transmission device, a wireless reception device, a communication system, and a communication method capable of improving a communication opportunity of a new terminal device while ensuring a communication opportunity of an existing terminal device in a coexisting communication system.
- the radio transmitter, radio receiver, communication system, and communication method according to the present invention for solving the above-described problems are as follows.
- the wireless transmission device of the present invention is a wireless transmission device that communicates with a wireless reception device in a communication system that requires carrier sense, and receives information indicating a first CCA interval from the wireless reception device. Signaling to a device.
- the wireless transmission device is the wireless transmission device according to (1) above, characterized in that information indicating a second CCA interval is further signaled to the wireless reception device. It is characterized by.
- the wireless transmission device of the present invention signals the information indicating the end of the first CCA interval to the wireless reception device in the first CCA interval.
- the wireless transmission device of the present invention includes information indicating the first CCA section in a beacon frame notified to the wireless reception device. It is the wireless transmission device described.
- the wireless transmission device of the present invention transmits a second resource reservation frame before the first CCA interval, and transmits a first resource reservation frame before the second CCA interval.
- the wireless transmission device according to (1) or (3) is characterized in that
- the wireless reception device includes a first wireless reception device and a second wireless reception device, and the first resource securing frame is The wireless transmission device according to (5) above, wherein the second wireless reception device is a frame that cannot be recognized as a resource securing frame.
- wireless transmitter of this invention performs carrier sense based on the 1st CCA level in the said 1st CCA area, and based on the 2nd CCA level in the said 2nd CCA area.
- wireless receiver of this invention is a radio
- the radio reception apparatus of the present invention further performs the carrier sense based on the second CCA level in the second CCA interval based on information indicating the second CCA interval.
- the wireless reception device of the present invention includes a transmission unit that transmits a frame, and determines a CCA level in the first CCA interval based on a type of a frame transmitted by the transmission unit.
- the wireless receiver according to (8) or (9) above.
- the wireless reception device of the present invention performs the carrier sense based on the second CCA level.
- the wireless receiver according to (8) or (9) above is characterized by the above.
- a second resource reservation frame is transmitted from the wireless transmission device, and the section described in the second resource reservation frame is based on the first CCA level. Then, the wireless sensing device according to (8) above, wherein the carrier sensing is performed.
- the wireless reception device of the present invention is characterized in that a first resource reservation frame is transmitted from the wireless transmission device, and communication is stopped in a section described in the first resource reservation frame.
- a first resource reservation frame is transmitted from the wireless transmission device, and a section described in the first resource reservation frame is at the second CCA level.
- the communication method of the present invention is a communication method of a wireless transmission device that communicates with a wireless reception device in a communication system that requires carrier sense, and includes information indicating a first CCA interval, It is a communication method characterized by including the step of signaling to a wireless receiver.
- the communication method of the present invention is a communication method of a radio reception apparatus that communicates with a radio transmission apparatus in a communication system that requires carrier sense, and includes a first CCA level and a second CCA. Performing the carrier sense based on a level, and performing the carrier sense based on a first CCA level in the first CCA interval based on information indicating a first CCA interval. It is characterized by providing.
- the communication system of the present invention includes a wireless transmission device and a wireless reception device, and is a communication system that requires carrier sense.
- the wireless transmission device transmits information indicating a first CCA interval to the wireless communication device.
- the wireless receiving device includes a receiving unit that performs the carrier sense based on a first CCA level and a second CCA level, and based on information indicating the first CCA interval, In the first CCA section, the carrier sense is performed based on the first CCA level.
- the present invention it is possible to realize a wireless LAN system capable of improving the communication opportunity of a new terminal device while securing the communication opportunity of an existing terminal device, so that the user throughput can be greatly improved.
- the communication system in the present embodiment includes a wireless transmission device (access point, Access point (AP)) and a plurality of wireless reception devices (station, Station (STA)).
- a network composed of APs and STAs is called a basic service set (BSS).
- BSS basic service set
- the AP and STA in the BSS communicate with each other based on CSMA / CA (Carrier sense multiple access with collisions avoidance).
- CSMA / CA Carrier sense multiple access with collisions avoidance
- an infrastructure mode in which an AP communicates with a plurality of STAs is targeted.
- the method of this embodiment can also be implemented in an ad hoc mode in which STAs directly communicate with each other.
- each device can transmit transmission frames of a plurality of frame types having a common frame format.
- the transmission frame is defined in a physical (Physical: PHY) layer, a medium access control (Medium access control: MAC) layer, and a logical link control (Logical Link control: LLC) layer.
- PHY Physical
- MAC medium access control
- LLC logical link control
- the transmission frame of the PHY layer is called a physical protocol data unit (PHY protocol data unit: PPDU).
- the PPDU includes a physical layer header (PHY header) including header information for performing signal processing in the physical layer, and a physical service data unit (PHY service data unit: PSDU) that is a data unit processed in the physical layer.
- PHY header physical layer header
- PSDU physical service data unit
- the PSDU can be composed of an aggregated MPDU (Aggregated MPDU: A-MPDU) in which a plurality of MAC protocol data units (MAC-protocol-data unit: MPDU) as a retransmission unit in a radio section are aggregated.
- MPDU aggregated MPDU
- the PHY header includes a short training field (Short training field: STF) used for signal detection and synchronization, a long training field (Long training field: LTF) used to acquire channel information for data demodulation, etc. And a control signal such as a signal (Signal: SIG) including control information for data demodulation.
- STF is a legacy STF (Legacy-STF: L-STF), a high-throughput STF (High-throughput-STF: HT-STF), a very high-throughput STF (Very-high-throughput-STF), depending on the corresponding standard.
- VHT-STF VHT-STF
- LTF and SIG are similarly classified into L-LTF, HT-LTF, VHT-LTF, L-SIG, HT-SIG, and VHT-SIG.
- VHT-SIG is further classified into VHT-SIG-A and VHT-SIG-B.
- the PPDU is modulated according to the corresponding standard.
- the signal is modulated into an orthogonal frequency division multiplexing (OFDM) signal.
- OFDM orthogonal frequency division multiplexing
- the MPDU includes a MAC layer header (MAC header) that includes header information for performing signal processing in the MAC layer, and a MAC service data unit (MAC service data unit: MSDU) that is a data unit processed in the MAC layer. It consists of a frame body and a frame check section (FCS) that checks whether there is an error in the frame.
- a plurality of MSDUs may be aggregated as an aggregated MSDU (AggregatedgregMSDU: A-MSDU).
- the frame type of the transmission frame in the MAC layer is roughly classified into three types: a management frame that manages the connection state between devices, a control frame that manages the communication state between devices, and a data frame that includes actual transmission data. Each is further classified into a plurality of types of subframes.
- the control frame includes a reception completion notification (Acknowledge: ACK) frame, a transmission request (Request-to-send: RTS) frame, a reception preparation-completed (Clear-to-send: CTS) frame, and the like.
- Management frames include beacon frames, probe request frames, probe response frames, authentication frames, authentication frames, connection request frames, connection response frames, etc. included.
- the data frame includes a data frame, a polling (CF-poll) frame, and the like. Each device can grasp the frame type and subframe type of the received frame by reading the contents of the frame control field included in the MAC header.
- the beacon frame includes a field (Field) in which a beacon transmission period (Beacon interval) and information for identifying an AP (Service set identifier (SSID), etc.) are described.
- the AP can periodically notify the beacon frame in the BSS, and the STA can recognize the AP around the STA by receiving the beacon frame. It is called passive scanning that the STA grasps the AP based on a signal broadcast from the AP. On the other hand, when the STA reports the probe request frame in the BSS and searches for the AP, it is called active scanning.
- the AP can transmit a probe response frame as a response to the probe request frame, and the description content of the probe response frame is equivalent to the beacon frame.
- the STA After the STA recognizes the AP, the STA performs connection processing for the AP.
- the connection process is classified into an authentication procedure and an association procedure.
- the STA transmits an authentication frame to the AP that desires connection.
- the AP receives the authentication frame, the AP transmits an authentication frame including a status code indicating whether or not the STA can be authenticated to the STA.
- the STA can determine whether or not the own device has been authorized by the AP. Note that the AP and the STA can exchange authentication frames multiple times.
- the STA transmits a connection request frame to perform a connection procedure to the AP following the authentication procedure.
- the AP determines whether or not to permit the connection of the STA, and transmits a connection response frame to notify that effect.
- an association identification number (Association identifier: AID) for identifying the STA is described.
- the AP can manage a plurality of STAs by setting different AIDs for the STAs that have given connection permission.
- the AP and the STA perform actual data transmission.
- a distributed control mechanism distributed Coordination Function: DCF
- a centralized control mechanism Point Coordination Function: PCF
- an extended mechanism hybrid control mechanism (Hybrid Coordination function: HCF), etc.
- HCF hybrid Coordination function
- AP and STA perform carrier sense (Carrier sense: CS) to confirm the usage status of radio channels around the own device prior to communication.
- Carrier sense Carrier sense: CS
- the AP defers transmission of a transmission frame on the radio channel.
- CCA level clear channel evaluation level
- a state in which a signal above the CCA level is detected in the radio channel is referred to as a busy state, and a state in which a signal above the CCA level is not detected is referred to as an idle state.
- CS performed based on the power of the signal actually received by each device is called physical carrier sense (physical CS).
- the CCA level is also called a carrier sense level (CS (level) or a CCA threshold (CCA threshold: CCAT).
- CS carrier sense level
- CCA threshold CCAT
- the AP performs carrier sense only for the frame interval (Inter frame space: IFS) corresponding to the type of transmission frame to be transmitted, and determines whether the radio channel is busy or idle.
- the period during which the AP performs carrier sense varies depending on the frame type and subframe type of a transmission frame transmitted from the AP.
- a plurality of IFSs having different periods are defined, and a short frame interval (Short IFS: SIFS) used for a transmission frame having the highest priority is assigned to a transmission frame having a relatively high priority.
- PCF IFS PIFS
- DCF IFS distributed control frame interval
- the AP uses DIFS.
- AP waits for DIFS and then waits for a random backoff time to prevent frame collision.
- a random back-off time called a contention window (CW) is used.
- CW contention window
- CSMA / CA it is assumed that a transmission frame transmitted by a certain transmitting station is received by a receiving station without interference from other transmitting stations. For this reason, if transmitting stations transmit transmission frames at the same timing, the frames collide with each other, and the receiving station cannot receive them correctly. Thus, frame collisions are avoided by waiting for a randomly set time before each transmitting station starts transmission.
- the AP determines that the radio channel is in an idle state by carrier sense, the AP starts counting down the CW, acquires the transmission right only when the CW becomes 0, and can transmit a data frame to the STA.
- the AP determines that the wireless channel is busy by carrier sense during the CW countdown, the CW countdown is stopped.
- the radio channel is in an idle state, the AP resumes counting down the remaining CW following the previous IFS.
- the STA that is the receiving station receives the transmission frame, reads the PHY header of the transmission frame, and demodulates the received transmission frame. Then, the STA can recognize whether or not the transmission frame is addressed to its own device by reading the MAC header of the demodulated signal. The STA can also determine the destination of the transmission frame based on information described in the PHY header (for example, a group identification number (Group ID: Group ID) described in VHT-SIG-A). is there.
- the STA determines that the received transmission frame is addressed to its own device and can demodulate the transmission frame without error, the STA must transmit an ACK frame indicating that the frame has been correctly received to the AP that is the transmission station. Don't be.
- the ACK frame is one of the transmission frames with the highest priority that is transmitted only during the SIFS period (no random backoff time is taken).
- the AP ends a series of communications. Note that if the STA cannot correctly receive the frame, the STA does not transmit an ACK. Therefore, if the AP does not receive an ACK frame from the receiving station for a certain period (SIFS + ACK frame length) after frame transmission, the communication is deemed to have failed and communication is terminated.
- the end of one communication (also called a burst) of the IEEE 802.11 system is a special case such as the transmission of a notification signal such as a beacon frame or the case where fragmentation for dividing transmission data is used. Except for this, the determination is always made based on whether or not an ACK frame is received.
- the STA determines a network allocation vector (NAV) based on the length of the transmission frame described in the PHY header or the like (Length). ) Is set.
- NAV network allocation vector
- the STA does not attempt communication during the period set in the NAV. That is, since the STA performs the same operation as when the radio channel is determined to be busy by the physical CS for the period set in the NAV, the communication control by the NAV is also called virtual carrier sense (virtual CS).
- a transmission request (Request to send: RTS) frame introduced to solve the hidden terminal problem or reception preparation completion (Clear to send) : CTS) frame.
- a control station called a point coordinator (PC) controls the transmission right of each device in the BSS.
- the AP becomes a PC and acquires the transmission right of the STA in the BSS.
- the communication period by the PCF includes a non-contention period (Contention-free period: CFP) and a contention period (Contention-period: CP).
- CFP Contention-free period
- CP contention period
- the AP that is a PC broadcasts a beacon frame in which a CFP period (CFP Max duration) and the like are described in the BSS prior to PCF communication.
- CFP Max duration CFP period
- PIFS is used to transmit a beacon frame that is notified when PCF transmission starts, and is transmitted without waiting for CW.
- the STA that has received the beacon frame sets the CFP period described in the beacon frame to NAV.
- the STA signals transmission right acquisition transmitted from the PC. Only when a signal (for example, a data frame including CF-poll) is received, the transmission right can be acquired. Note that, within the CFP period, packet collisions do not occur within the same BSS, so each STA does not take the random backoff time used in DCF.
- the AP and STA provided in the communication system according to the present embodiment have a function of performing a series of communications based on the CSMA / CA described above, but do not necessarily have to have all the functions. .
- FIG. 1 is a schematic diagram showing an example of a downlink (downlink) of a communication system according to the first embodiment of the present invention.
- AP1 exists and 1a indicates a range that can be managed by AP1 (coverage range, Basic service set (BSS)).
- the BSS 1a includes STAs 2-1 to 4 connected to the AP 1 and STAs 3-1 to 4 that are existing terminal devices (conventional terminal devices and legacy terminal devices).
- the STAs 2-1 to -4 are also simply referred to as STA2 or the first wireless reception device.
- STAs 3-1 to -4 are also simply referred to as STA3 or a second wireless reception device.
- AP1, STA2, and STA3 have different standards that can be supported.
- AP1 and STA2 are apparatuses to which the present invention can be applied
- STA3 is an apparatus to which the present invention is not applied.
- AP1, STA2, and STA3 each perform communication based on CSMA / CA.
- the infrastructure mode in which each STA2 and STA3 communicate with AP1 is targeted.
- the method of the present embodiment can also be implemented in an ad hoc mode in which STAs directly communicate with each other.
- FIG. 2 is a block diagram showing an example of the configuration of the AP 1 according to the first embodiment of the present invention.
- the AP 1 includes an upper layer unit 101, a control unit 102, a transmission unit 103, a reception unit 104, and an antenna 105.
- the upper layer unit 101 performs processing such as a medium access control (MAC: Medium Access Control) layer.
- the upper layer unit 101 generates information for controlling the transmission unit 103 and the reception unit 104 and outputs the information to the control unit 102.
- the control unit 102 controls the upper layer unit 101, the transmission unit 103, and the reception unit 104.
- MAC Medium Access Control
- the transmission unit 103 further includes a physical channel signal generation unit 1031, a frame configuration unit 1032, a control signal generation unit 1033, and a wireless transmission unit 1034.
- the physical channel signal generation unit 1031 generates a baseband signal that the AP1 transmits to each STA.
- the signal generated by the physical channel signal generation unit 1031 includes TF (Training field) used by each STA for channel estimation and data transmitted by MSDU (MAC service data unit).
- TF Traffic field
- MSDU MAC service data unit
- the frame configuration unit 1032 multiplexes the signal generated by the physical channel signal generation unit 1031 and the signal generated by the control signal generation unit 1033, and configures the transmission frame of the baseband signal that is actually transmitted by the AP1.
- FIG. 3 is a schematic diagram illustrating an example of a transmission frame generated by the frame configuration unit 1032 according to the present embodiment.
- the transmission frame includes reference signals such as L-STF, L-LTF, VHT-STF, and VHT-LTF. Further, the transmission frame includes control information such as L-SIG, VHT-SIG-A, and VHT-SIG-B.
- the transmission frame includes a Data portion.
- the configuration of the transmission frame generated by the frame configuration unit 1032 is not limited to FIG. 4, and may include other control information (for example, HT-SIG), a reference signal (for example, HT-LTF), and the like. Further, the transmission frame generated by the frame configuration unit 1032 need not include all signals such as L-STF and VHT-SIG-A. Note that since the control information included in the L-SIG is information necessary for demodulating the Data portion, the control information included in the L-SIG is also referred to as a physical layer header (PHY header) below.
- PHY header
- the transmission frame generated by the frame configuration unit 1032 is classified into several frame types.
- the frame configuration unit 1032 generates transmission frames of three frame types: a management frame that manages the connection status between devices, a control frame that manages the communication status between devices, and a data frame that includes actual transmission data. can do.
- the frame configuration unit 1032 can include information indicating the frame type to which the generated transmission frame belongs in a medium access control layer header (MAC header) transmitted in the Data portion.
- MAC header medium access control layer header
- the radio transmission unit 1034 performs a process of converting the baseband signal generated by the frame configuration unit 1032 into a radio frequency (RF) band signal.
- the processing performed by the wireless transmission unit 1034 includes digital / analog conversion, filtering, frequency conversion from the baseband to the RF band, and the like.
- the antenna 105 transmits the signal generated by the transmission unit 103 to each STA.
- the AP1 also has a function of receiving a signal transmitted from each STA.
- the antenna 105 receives a signal transmitted from each STA and outputs it to the receiving unit 104.
- the receiving unit 104 includes a physical channel signal demodulating unit 1041 and a wireless receiving unit 1042.
- the wireless reception unit 1042 converts the RF band signal input from the antenna 105 into a baseband signal.
- the processing performed by the wireless reception unit 1042 includes frequency conversion from RF band to baseband, filtering, analog / digital conversion, and the like.
- the processing performed by the receiving unit 104 may include a function of measuring peripheral interference in a specific frequency band and securing the frequency band (carrier sense).
- the physical channel signal demodulator 1041 demodulates the baseband signal output from the wireless receiver 1042.
- the signal demodulated by the physical channel signal demodulator 1041 is a signal transmitted by the STA2 and STA3 on the uplink (uplink), and the frame configuration is the same as the data frame generated by the frame configuration unit 1032. Therefore, the physical channel signal demodulator 1041 can demodulate the uplink data from the data channel based on the control information transmitted on the control channel of the data frame.
- the physical channel signal demodulator 1041 may include a carrier sense function.
- the reception unit 104 may input signal power in the frequency band to the upper layer unit 101 via the control unit 102, and the upper layer unit 101 may perform processing related to carrier sense.
- AP1 Since AP1 performs communication based on the above-described CSMA / CA, it can transmit a transmission frame only to a frequency band that can be secured by carrier sense by the receiving unit 104.
- the AP1 according to the present embodiment and the STA2 described later can change the CCA level. For example, a CCA level higher than the CCA level used by the STA3 that is a legacy terminal device can be used.
- the AP 1 can instruct the STA 2 to perform carrier sense at a CCA level different from that of the STA 3 that is the legacy terminal device.
- AP1 can directly describe the value of the CCA level in the CCA field of the beacon frame.
- the STA2 receives the beacon frame and reads the CCA level described in the CCA field, so that the STA2 can grasp the CCA level that can be used by the STA2 in the BSS managed by the AP1 that transmitted the beacon frame. It becomes possible.
- the STA3 since the STA3 which is a legacy terminal device cannot read the CCA field, it performs communication based on the existing CCA level.
- the CCA level used by STA3 is referred to as a legacy CCA level.
- CCA level when it is simply described as a CCA level or when it is described as a variable CCA level, it indicates a CCA level that can be used by the STA2 or AP1 to which the present invention is applied.
- a CCA level that can be used only by STA2 is described as a first CCA level
- a legacy CCA level is described as a second CCA level.
- AP1 can also describe the difference (CCA offset) between the legacy CCA level and the variable CCA level in the CCA field.
- STA2 grasps at least one CCA level different from the legacy CCA level in advance as a variable CCA level, and AP1 uses a variable CCA level different from the legacy CCA level in the beacon frame. Can be signaled.
- 1-bit information indicating whether or not to use the variable CCA level is described in the CCA field.
- the AP 1 can also signal the above information using a management frame other than a beacon frame.
- AP1 can include the information (for example, the CCA level and the CCA offset) in the PHY header of the transmission frame, for example, instead of signaling information on the CCA level with a specific type of transmission frame.
- AP1 does not necessarily need to signal STA2 a usage instruction of a CCA level different from the legacy CCA level.
- the device connected to AP1 is almost STA2, or the type (type) of the signal transmitted by AP1 is a signal addressed to STA2 to which the present invention is applied, or the signal received by AP1. If most of the types of signals are signals received from the STA2 to which the present invention is applied, the AP1 may signal the legacy CCA level to the STA2 or may stop the notification of the CCA level itself. good.
- the AP1 sets the section in which AP1 and STA2 can change the CCA level and the section in which AP1 and STA2 cannot change the CCA level by dividing in time. To do.
- FIG. 4 is a diagram illustrating an example of communication according to the present embodiment.
- a transmission frame addressed to AP1 is generated in STA2 and STA3.
- the interference level around STA2 and STA3 is also shown.
- AP1 periodically transmits a beacon frame in the BSS.
- AP1 includes, in the beacon frame, a section in which the CCA level can be changed (also referred to as a dynamic CCA section or a first CCA section) and a section in which the CCA level cannot be changed (also referred to as a legacy CCA section or a second CCA section).
- Information indicating the length and period of the can be included.
- FIG. 5 is a schematic diagram illustrating an example of a beacon frame transmitted by the AP 1 according to the present embodiment.
- a beacon frame includes a MAC header including a frame type and a source address, a frame body (Frame body) including actual data, and a frame check unit (Frame check sequence: FCS) that checks whether the frame has an error. ).
- a field (Field) describing information Service set identifier (SSID) etc.
- a field describing information on clear channel evaluation (Clear channel assessment: CCA) used when the STA2 performs carrier sense
- a field that describes the length of the first CCA period (Dynamic CCA period field) is included.
- STA2 can read the values of the CCA field and the Dynamic CCA period field, it can grasp the length of the first CCA period and the CCA level within the first CCA period.
- the STA 3 cannot read the values of the CCA field and the Dynamic CCA period field, the carrier sense is always performed at the second CCA level during the period between the beacon frames.
- AP1 and STA2 determine that the first CCA period starts after transmitting the beacon frame, and the period indicated by the value described in the Dynamic CCA period field. Only when the carrier sense is performed based on the first CCA level and the period ends, it can be determined that the second CCA period starts.
- AP1 can include a field (Legacy ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ CCA period field) describing the length of the second CCA period in the beacon frame.
- AP1 and STA2 determine that the second CCA interval starts after transmission of the beacon frame, and based on the second CCA level only during the period indicated by the value described in the Legacy CCA period field, It is possible to determine that the first CCA section is started after the carrier sense is performed and the period ends.
- the method in which AP1 signals the lengths of the first CCA interval and the second CCA interval to STA2 is not limited to anything, and STA2 is not limited to the first CCA interval and the second CCA interval. It is only necessary that signaling from AP1 that makes it possible to grasp the length of the CCA interval and a prior agreement between AP1 and STA2 (for example, the first CCA interval is started after the beacon frame). .
- FIG. 4 there is one first CCA section and one second CCA section between the beacon intervals, but AP1 has a plurality of first CCA sections and second CCA sections between the beacon intervals.
- the CCA section may be set.
- AP1 also includes a beacon frame (first beacon frame) including information related to the first CCA interval and the second CCA interval, and a beacon frame not including information related to the first CCA interval and the second CCA interval. (Second beacon frame) may be transmitted at different periods. In this case, AP1 can include information indicating whether the beacon frame is the first beacon frame or the second beacon frame in the frame body of the beacon frame to be transmitted.
- first beacon frame including information related to the first CCA interval and the second CCA interval
- beacon frame not including information related to the first CCA interval and the second CCA interval may be transmitted at different periods.
- AP1 can include information indicating whether the beacon frame is the first beacon frame or the second beacon frame in the frame body of the beacon frame to be transmitted.
- AP1 can transmit a signal (CCA End frame: CCA-End frame) indicating the end of the first CCA interval during the first CCA interval.
- CCA End frame CCA-End frame
- the STA2 receives the CCA-End frame, it communicates with the DCF based on the second CCA level at least until the next beacon frame is received.
- the AP1 can notify the STA2 of the length and cycle of the first CCA section shown above based on a frame other than the beacon frame (for example, a probe response frame).
- the AP1 can also notify the STA2 by including the information related to the length and period of the first CCA section described above in the PHY header.
- the receiving unit 104 of AP1 can perform carrier sense based on the first CCA level during the first CCA interval, but performs carrier sense based on the second CCA level. Also good.
- the reception unit 104 of AP1 may switch between the first CCA level and the second CCA level in the first CCA period according to the type (type) of the received frame. For example, if the received frame is a frame of a standard to which the present invention is applicable, the receiving unit 104 of AP1 performs carrier sense at the first CCA level, while the received frame is When the frame is a standard frame to which the present invention is not applicable, carrier sense may be performed at the second CCA level.
- the receiving unit 104 of the AP 1 performs carrier sense at the first CCA level when the frame scheduled to be transmitted by the transmitting unit 103 is a frame of a standard to which the present invention is applicable,
- the reception unit 104 may perform carrier sense at the second CCA level.
- AP1 may change the priority of a frame to be transmitted based on the CCA level used by the receiving unit 104 for carrier sense.
- the transmission unit 103 may May be controlled so as to preferentially transmit a frame of an applicable standard.
- the interference level is lower than the first CCA level, so STA2 can try to acquire a transmission opportunity.
- STA2 can transmit a transmission frame if the interference level does not exceed the first CCA level during DIFS and CW.
- STA3 since STA3 performs carrier sense based on the second CCA level, it does not attempt to acquire a transmission opportunity at time t1.
- STA2 also becomes a legacy CCA section, and starts carrier sense at the second CCA level. At time t2, there is still interference above the second CCA level, so STA2 does not attempt to acquire a transmission opportunity.
- both STA2 and STA3 try to acquire a transmission opportunity. Then, a terminal (STA3 in FIG. 4) having a small total period of DIFS and CW can acquire a transmission opportunity. Therefore, since transmission opportunities of STA2 and STA3 can be equalized in the legacy CCA section, even in a communication system capable of changing the CCA level, a decrease in transmission opportunities of STA3, which is a legacy terminal device using the legacy CCA level. Can be minimized.
- FIG. 6 is a block diagram showing a configuration example of the STA 2 according to the present embodiment.
- the STA 2 includes an upper layer unit 201, a control unit 202, a transmission unit 203, a reception unit 204, and an antenna 205.
- the upper layer unit 201 performs processing such as a MAC layer.
- upper layer section 201 generates information for controlling transmission section 203 and reception section 204 and outputs the information to control section 202.
- the antenna 205 receives the signal transmitted by the AP 1 and outputs it to the receiving unit 204.
- the receiving unit 204 includes a physical channel signal demodulating unit 2041, a control information monitoring unit 2042, and a wireless receiving unit 2043.
- the wireless reception unit 2043 converts the RF band signal input from the antenna 205 into a baseband signal.
- the processing performed by the wireless reception unit 2043 includes frequency conversion from RF band to baseband, filtering, analog / digital conversion, and the like.
- the control information monitoring unit 2042 reads information described in a PHY header (for example, L-SIG or VHT-SIG-A) of a transmission frame transmitted by the AP 1 from a baseband signal output from the wireless reception unit 2043. , Input to the physical channel signal demodulator 2041.
- a PHY header for example, L-SIG or VHT-SIG-A
- the physical channel signal demodulation unit 2041 demodulates the transmission frame transmitted by the AP 1 based on the control information acquired by the control information monitoring unit 2042, and inputs the demodulation result to the upper layer unit 201 via the control unit 202. .
- the upper layer unit 201 interprets the data demodulated by the physical channel signal demodulation unit 2041 in the MAC layer, the LLC (Logical Link Control) layer, and the transport layer, respectively.
- information on the CCA level can be acquired from the transmission frame transmitted by the AP1.
- the CCA level and the first CCA period described in the CCA field and the Dynamic CCA period field of the beacon frame are included. Each length can be obtained. Further, the acquired CCA level and the length of the first CCA interval may be input to the reception unit 2043 via the control unit 202.
- the processing performed by the receiving unit 204 may include a function of measuring surrounding interference (carrier sense) in a specific frequency band and securing the frequency band.
- the STA2 also has a function of transmitting signals.
- the antenna 205 transmits the RF band signal generated by the transmission unit 203 to the AP1.
- the transmission unit 203 includes a physical channel signal generation unit 2031 and a wireless transmission unit 2032.
- the physical channel signal generation unit 2031 generates a baseband signal that the STA2 transmits to the AP1.
- the signal generated by the physical channel signal generation unit 2031 has the same configuration as the transmission frame generated by the frame configuration unit 1032 of AP1.
- the wireless transmission unit 2032 converts the baseband signal generated by the physical channel signal generation unit 2031 into an RF band signal.
- the processing performed by the wireless transmission unit 2032 includes digital / analog conversion, filtering, frequency conversion from the baseband to the RF band, and the like.
- the reception unit 204 performs carrier sense prior to the transmission processing of the transmission unit 203.
- the receiving unit 204 receives a signal having power higher than a specified CCA level in a certain frequency band, the receiving unit 204 can enter at least a signal demodulation operation of the PHY layer. Therefore, when the reception unit 204 does not enter the signal demodulation operation of the PHY layer in the frequency band, it is determined that the frequency band can be secured, and thus the transmission unit 203 can start transmission processing.
- the receiving unit 204 may determine whether or not to start a reception operation and whether or not transmission processing can be started by carrier sense. On the other hand, the receiving unit 204 only notifies the upper layer unit 201 via the control unit 202 of the power of the signal measured in the frequency band, and the upper layer unit 201 receives the signal in the frequency band. It may be determined whether or not to enter a reception operation and whether or not the transmission unit 203 can start transmission processing (whether or not the frequency band can be secured). In the following description, for the sake of simplicity, it is assumed that the determination related to carrier sense is performed by the reception unit 204.
- the receiving unit 204 can grasp a section for changing the CCA level and a section using the legacy CCA level based on the length of the first CCA section notified from the higher layer section 201.
- the receiving unit 204 can perform carrier sense based on the CCA level notified from the higher layer unit 201 in the section in which the CCA level is changed. For example, when the power of the signal received by the wireless reception unit 2043 of the reception unit 204 is greater than the CCA level, the reception unit 204 determines that the frequency band cannot be secured. On the other hand, when the power of the signal received by the wireless reception unit 2043 of the reception unit 204 is smaller than the CCA level, the reception unit 204 can determine that the frequency band can be secured. Therefore, the higher the CCA level used by the receiving unit 204, the greater the communication opportunity of the STA2.
- the physical channel signal generation units 1031 and 2031 of the AP1 and the STA2 can use a data modulation scheme with a low modulation level or an error correction code with a low coding rate in anticipation of a decrease in reception quality in advance.
- the receiving unit 204 may change the CCA level in the first CCA section according to the type (kind) of the received signal. For example, carrier sense can be performed at the CCA level notified from AP1 only when the signal received by the receiving unit 204 is determined to be a transmission frame transmitted from another STA2 to which the present invention is applied. On the other hand, if the receiving unit 204 determines that the received signal is a transmission frame transmitted from another STA 3 that is a legacy terminal device, the receiving unit 204 can perform carrier sense at the legacy CCA level. The receiving unit 204 may also change the CCA level in the first CCA interval depending on whether or not the received signal is a signal based on the IEEE 802.11 system.
- the receiving unit 204 may determine that the signal is not an IEEE 802.11 system signal and perform carrier sense at a CCA level higher than the first CCA level. The same applies when the upper layer unit 201 determines whether or not the frequency band can be secured.
- the receiving unit 204 may change the CCA level in the first CCA section according to the frequency (histogram) of the received signal. For example, when most of the signals received by the reception unit 204 during a certain period are transmission frames transmitted from other STAs 2 to which the present invention is applied, the reception unit 204 is notified from the AP 1. Carrier sense can be performed at the CCA level. On the other hand, when most of the signals received by the reception unit 204 during a certain period are transmission frames transmitted from the STA 3 to which the present invention is not applied, the reception unit 204 performs carrier sense at the legacy CCA level. It is possible to do. Note that the STA2 can also be signaled by the AP1 with respect to the above-described histogram information. The same applies when the upper layer unit 201 determines whether or not the frequency band can be secured.
- the receiving unit 104 of AP1 can perform carrier sense based on the first CCA level during the first CCA interval, but performs carrier sense based on the second CCA level. Also good.
- the reception unit 104 of AP1 may switch between the first CCA level and the second CCA level in the first CCA period according to the type (type) of the received frame. For example, if the received frame is a frame of a standard to which the present invention is applicable, the receiving unit 104 of AP1 performs carrier sense at the first CCA level, while the received frame is When the frame is a standard frame to which the present invention is not applicable, carrier sense may be performed at the second CCA level.
- the receiving unit 204 of the STA2 performs carrier sense at the first CCA level when the frame scheduled to be transmitted by the transmitting unit 203 is a frame of a standard to which the present invention is applicable.
- the reception unit 204 may perform carrier sense at the second CCA level.
- the STA2 may change the priority of the frame to be transmitted based on the CCA level used by the reception unit 204 for carrier sense.
- the transmission unit 203 may May be controlled so as to preferentially transmit a frame of an applicable standard.
- the receiving unit 204 may shift to the second CCA interval while performing carrier sense based on the first CCA level in the first CCA interval.
- the reception unit 204 can complete carrier sense based on the first CCA level (reset CW) and perform carrier sense again based on the second CCA level.
- the receiving unit 204 continues carrier sensing based on the first CCA level even when shifting to the second CCA interval during carrier sensing based on the first CCA level.
- the carrier sense may be continued by setting the CCA level to the second CCA level after a predetermined time has elapsed from the time of transition to the second CCA interval.
- the STA 2 in the second CCA interval, can perform carrier sense at a CCA level (third CCA level) lower than the legacy CCA level.
- AP1 can notify STA2 of the third CCA level using a beacon frame or the like.
- AP1 and STA2 basically distinguish between the first CCA interval and the second CCA interval based on information described in the beacon frame transmitted by AP1, but AP1
- the first CCA interval and the second CCA interval may be divided in time by transmission frames other than beacon frames.
- AP1 transmits to STA2 a frame indicating the start of the first CCA interval (CCA start frame: CCA-Start frame) and a CCA-End frame. It is also possible to divide the CCA section.
- the AP1 may broadcast the CCA-Start frame and the CCA-End frame to all the STA2, may send it to a specific STA2, or may transmit it to a specific STA2 group.
- the STA 2 that has received the CCA-Start frame can communicate with the DCF based on the first CCA level until the next CCA-End frame is received.
- AP1 and STA2 perform communication based on a CCA level higher than that of the existing STA3, while enabling a communication system that can secure a communication opportunity for the existing STA3.
- the system throughput of the communication system can be greatly improved.
- the outline of the communication system targeted by the present embodiment and the configurations of the AP1 and the STA2 are the same as those in the first embodiment, and thus description thereof is omitted. Further, it is assumed that AP1 notifies the STA2 of the first CCA level by a beacon frame or the like, as in the first embodiment.
- AP1 has a CTS-to-self frame (hereinafter referred to as a Legacy CTS-to-self frame or a second resource reservation frame) that can be grasped by STA3 before the first CCA interval. Send). Since the CTS-to-self frame is a CTS frame in which the address of the transmitting station is described in the destination address, the receiving station that has received the CTS-to-self frame receives the duration described in the CTS-to-self frame. NAV is set accordingly, and no attempt is made to acquire a communication opportunity.
- a CTS-to-self frame hereinafter referred to as a Legacy CTS-to-self frame or a second resource reservation frame
- AP1 transmits a CTS-to-self frame in which the length of the first CCA interval is described as a duration, so that STA3, which is a legacy terminal device, has a communication opportunity during the first CCA interval. Do not try to win.
- the STA 2 according to the present embodiment does not set the NAV even when receiving the Legacy CTS-to-self frame, and performs communication with the DCF based on the first CCA level.
- the STA3 that is a legacy terminal device can reduce the burden on carrier sense because it does not attempt to acquire a transmission opportunity in the first CCA interval in which it is relatively difficult to acquire a transmission opportunity.
- the STA2 capable of carrier sense at the first CCA level tries to acquire a transmission opportunity, so the frequency utilization efficiency of the communication system can be improved.
- CCA CTS-to-self frame (hereinafter referred to as CCA CTS-to-self frame or first resource).
- CCA CTS-to-self frame (Referred to as a reserved frame)
- the length of the second CCA interval is described as a duration and transmitted.
- the frame configuration of the CCA CTS-to-self frame is not limited to anything. For example, it may be configured to have a PHY header that cannot be grasped by the STA3. Since STA3 cannot recognize the CCA CTS-to-self frame as a CTS-to-self frame, after receiving the CCA CTS-to-self frame, it communicates with the DCF based on the second CCA level. It is possible.
- the STA 2 when the STA 2 receives the CCA CTS-to-self frame, the STA 2 sets the NAV based on the duration described in the CCA CTS-to-self frame. Don't try to win Therefore, in the second CCA interval, only STA3 tries to acquire a transmission opportunity, so it is possible to secure a transmission opportunity for STA3 even in a communication system in which STA2 and STA3 are mixed.
- FIG. 7 is a diagram illustrating an example of communication according to the present embodiment.
- AP1 first adds a Legacy CTS-to-self frame describing the length of the first CCA section (the length of t1 to t2 in FIG. 7) as the duration before the first CCA section (dynamic CCA section).
- the STA3 sets the NAV for the duration described in the Legacy CTS-to-self frame.
- the STA2 receives the Legacy CTS-to-self frame, it does not set the NAV and performs communication using the DCF based on the first CCA level.
- AP1 transmits a CCA CTS-to-self frame in which the length of the second CCA section (the length of t3 to t4 in FIG. 7) is described as the duration before the second CCA section.
- STA2 sets NAV for the duration described in the CCA CTS-to-self signal.
- STA3 since STA3 cannot recognize the CCA CTS-to-self frame as a CTS-to-self frame, after receiving the CCA CTS-to-self frame, the STA3 performs DCF based on the second CCA level. Can communicate.
- the operation of STA2 in a section other than the duration described in Legacy CTS-to-self and CCA CTS-to-self is not limited to anything.
- the STA2 can communicate with the DCF based on the first CCA level during the period between t2 and t3 in FIG.
- the duration of the duration described in the CCA CTS-to-self signal is communicated by the DCF based on the second CCA level. It doesn't matter.
- AP1 when transmitting a Legacy CTS-to-self frame, AP1 describes the first address decided in advance with STA2 instead of its own address (second address) as the destination address of the frame. May be. For example, AP1 can describe the broadcast address as the first address in the destination address of the frame.
- the STA2 receives the Legacy CTS-to-self frame in which the first address is described, the STA2 communicates with the DCF based on the first CCA level, and the Legacy in which the second address is described. Communication can be stopped when a CTS-to-self frame is received.
- the STA 2 receives the first The problem of starting communication with DCF can be avoided based on the CCA level.
- the resource securing frame transmitted by AP1 is not limited to the CTS-to-self frame described above.
- AP1 and STA2 according to the present embodiment can divide the first CCA period and the second CCA period in time by exchanging an RTS frame and a CTS frame.
- AP1 sets the length of the first CCA interval to a specific STA2 in the BSS, an RTS frame that can also be recognized by STA3 (referred to as a Legacy RTS frame), and a duration.
- a Legacy RTS frame an RTS frame that can also be recognized by STA3
- a duration Send as described.
- the STA2 that has received the Legacy RTS frame makes the Legacy CTS frame (referred to as LegacyTSCTS frame) recognizable to the STA3 from the duration indicating the first CCA section described in the Legacy RTS frame.
- a period obtained by subtracting a period required for transmission / reception of the CTS frame is described as a duration and transmitted.
- the STA 3 that has received the Legacy RTS frame or the Legacy CTS frame sets the NAV for the duration described in each frame, and therefore does not attempt to acquire a communication opportunity during the first CCA interval.
- AP1 and STA2 that have received (or transmitted) a Legacy RTS frame or a Legacy CTS frame communicate with each other on the basis of the first CCA level during the duration described in each frame. .
- AP1 describes the length of the second CCA interval as a duration in a specific STA2 in the BSS, in an RTS frame (referred to as CCA3RTS frame) that STA3 cannot recognize. Then send.
- the STA2 Upon receiving the CCA RTS frame, the STA2 receives the CCA CTS from the duration indicating the second CCA interval described in the CCA RTS frame in the CTS frame (referred to as CCA CTS frame) that the STA3 cannot recognize to the AP1.
- a period obtained by subtracting a period required for frame transmission / reception is described as a duration and transmitted.
- the STA2 that receives (or transmits) the CCA RTS frame or the CCA CTS frame sets the NAV for the duration described in each frame, it does not attempt to acquire a communication opportunity during the second CCA interval.
- STA3 cannot recognize CCA RTS or CCA CTS, communication is performed by DCF based on the second CCA level during the second CCA interval.
- AP1 can divide the first CCA interval and the second CCA interval in time.
- STA2 receives CCA RTS or CCA CTS it does not set NAV, but communicates with DCF based on the second CCA level during the duration period described in each frame. You may do.
- AP1 and STA2 perform communication based on a CCA level higher than that of the existing STA3, while enabling a communication system that can secure a communication opportunity for the existing STA3.
- the system throughput of the communication system can be greatly improved.
- the program that operates in the AP1, STA2, and STA3 according to the present invention is a program that controls a CPU or the like (a program that causes a computer to function) so as to realize the functions of the above-described embodiments related to the present invention.
- Information handled by these devices is temporarily stored in the RAM at the time of processing, then stored in various ROMs and HDDs, read out by the CPU, and corrected and written as necessary.
- a recording medium for storing the program a semiconductor medium (for example, ROM, nonvolatile memory card, etc.), an optical recording medium (for example, DVD, MO, MD, CD, BD, etc.), a magnetic recording medium (for example, magnetic tape, Any of a flexible disk etc. may be sufficient.
- the processing is performed in cooperation with the operating system or other application programs.
- the functions of the invention may be realized.
- the program when distributing to the market, can be stored in a portable recording medium for distribution, or transferred to a server computer connected via a network such as the Internet.
- the storage device of the server computer is also included in the present invention.
- a part or all of AP1, STA2, and STA3 in the above-described embodiment may be realized as an LSI that is typically an integrated circuit.
- Each functional block of AP1, STA2, and STA3 may be individually chipped, or a part or all of them may be integrated into a chip.
- an integrated circuit controller for controlling them is added.
- the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor.
- an integrated circuit based on the technology can also be used.
- AP1, STA2 and STA3 of the present invention are not limited to application to mobile station apparatuses, but are stationary or non-movable electronic devices installed indoors and outdoors, such as AV devices, kitchen devices, cleaning devices, etc. -Needless to say, it can be applied to laundry equipment, air conditioning equipment, office equipment, vending machines, and other daily life equipment.
- the present invention is suitable for use in a wireless transmission device, a wireless reception device, a communication system, and a communication method.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
Description
本実施形態における通信システムは、無線送信装置(アクセスポイント、Access point(AP))、および複数の無線受信装置(ステーション、Station(STA))を備える。また、APとSTAとで構成されるネットワークを基本サービスセット(Basic service set:BSS)と呼ぶ。
本実施形態が対象とする通信システムは、仮想キャリアセンスによって、第1のCCA区間と第2のCCA区間を切り替える。
本発明に係るAP1、STA2およびSTA3で動作するプログラムは、本発明に関わる上記実施形態の機能を実現するように、CPU等を制御するプログラム(コンピュータを機能させるプログラム)である。そして、これら装置で取り扱われる情報は、その処理時に一時的にRAMに蓄積され、その後、各種ROMやHDDに格納され、必要に応じてCPUによって読み出し、修正・書き込みが行なわれる。プログラムを格納する記録媒体としては、半導体媒体(例えば、ROM、不揮発性メモリカード等)、光記録媒体(例えば、DVD、MO、MD、CD、BD等)、磁気記録媒体(例えば、磁気テープ、フレキシブルディスク等)等のいずれであっても良い。また、ロードしたプログラムを実行することにより、上述した実施形態の機能が実現されるだけでなく、そのプログラムの指示に基づき、オペレーティングシステムあるいは他のアプリケーションプログラム等と共同して処理することにより、本発明の機能が実現される場合もある。
2、2-1、2-2、2-3、2-4、3、3-1、3-2、3-3、3-4 STA
101、201 上位層部
102、202 制御部
103、203 送信部
104、204 受信部
105、205 アンテナ
1031、2031 物理チャネル信号生成部
1032 フレーム構成部
1033 制御信号生成部
1034、2032 無線送信部
1041、2041 物理チャネル信号復調部
1042、2043 無線受信部
2042 制御情報モニタリング部
Claims (17)
- キャリアセンスを必要とする通信システムにおいて、無線受信装置と通信を行なう無線送信装置であって、
第1のCCA区間を示す情報を、前記無線受信装置にシグナリングすることを特徴とする無線送信装置。 - さらに第2のCCA区間を示す情報を、前記無線受信装置にシグナリングすることを特徴とする、請求項1に記載の無線送信装置。
- 前記第1のCCA区間内において、前記第1のCCA区間の終了を示す情報を、前記無線受信装置にシグナリングすることを特徴とする、請求項1に記載の無線送信装置。
- 前記第1のCCA区間を示す情報を、前記無線受信装置に報知するビーコンフレームに含めることを特徴とする請求項1または請求項3に記載の無線送信装置。
- 前記第1のCCA区間の前に、第2のリソース確保フレームを送信し、
第2のCCA区間の前に、第1のリソース確保フレームを送信することを特徴とする、請求項1または請求項3に記載の無線送信装置。 - 前記無線受信装置には、第1の無線受信装置と、第2の無線受信装置が含まれており、
前記第1のリソース確保フレームは、前記第2の無線受信装置がリソース確保フレームと認識できないフレームであることを特徴とする、請求項5に記載の無線送信装置。 - 前記第1のCCA区間において、第1のCCAレベルに基づいてキャリアセンスを行ない、
前記第2のCCA区間において、第2のCCAレベルに基づいてキャリアセンスを行ない、
前記第1のCCAレベルは、前記第2のCCAレベルよりも高いことを特徴とする、請求項6に記載の無線送信装置。 - キャリアセンスを必要とする通信システムにおいて、無線送信装置と通信を行なう無線受信装置であって、
第1のCCAレベルと、第2のCCAレベルに基づいて、前記キャリアセンスを行なう受信部を備え、
第1のCCA区間を示す情報に基づいて、前記第1のCCA区間において、前記第1のCCAレベルに基づいて前記キャリアセンスを行なうことを特徴とする無線受信装置。 - さらに第2のCCA区間を示す情報に基づいて、前記第2のCCA区間において、前記第2のCCAレベルに基づいて前記キャリアセンスを行なうことを特徴とする、請求項8に記載の無線受信装置。
- フレームを送信する送信部を備え、
前記送信部が送信するフレームのタイプに基づいて、前記第1のCCA区間におけるCCAレベルを決定することを特徴とする、請求項8または請求項9に記載の無線受信装置。 - 前記第1のCCA区間の終了を示す情報が前記無線送信装置よりシグナリングされた場合、前記第2のCCAレベルに基づいて、前記キャリアセンスを行なうことを特徴とする、請求項8または請求項9に記載の無線受信装置。
- 前記無線送信装置より、第2のリソース確保フレームが送信され、
前記第2のリソース確保フレームに記載の区間は、前記第1のCCAレベルに基づいて、前記キャリアセンスを行なうことを特徴とする、請求項8に記載の無線受信装置。 - 前記無線送信装置より、第1のリソース確保フレームが送信され、
前記第1のリソース確保フレームに記載の区間は、通信を停止することを特徴とする請求項12に記載の無線受信装置。 - 前記無線送信装置より、第1のリソース確保フレームが送信され、
前記第1のリソース確保フレームに記載の区間は、前記第2のCCAレベルに基づいて、前記キャリアセンスを行なうことを特徴とする、請求項12に記載の無線受信装置。 - キャリアセンスを必要とする通信システムにおいて、無線受信装置と通信を行なう無線送信装置の通信方法であって、
第1のCCA区間を示す情報を、前記無線受信装置にシグナリングするステップを備えることを特徴とする通信方法。 - キャリアセンスを必要とする通信システムにおいて、無線送信装置と通信を行なう無線受信装置の通信方法であって、
第1のCCAレベルと、第2のCCAレベルに基づいて、前記キャリアセンスを行なうステップと、
第1のCCA区間を示す情報に基づいて、前記第1のCCA区間において、第1のCCAレベルに基づいて前記キャリアセンスを行なうステップと、を備えることを特徴とする通信方法。 - 無線送信装置と無線受信装置を備え、キャリアセンスを必要とする通信システムであって、
前記無線送信装置は第1のCCA区間を示す情報を、前記無線受信装置にシグナリングし、
前記無線受信装置は第1のCCAレベルと、第2のCCAレベルに基づいて、前記キャリアセンスを行なう受信部を備え、前記第1のCCA区間を示す情報に基づいて、前記第1のCCA区間において、前記第1のCCAレベルに基づいて前記キャリアセンスを行なうこと、を特徴とする通信システム。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2016556415A JP6744219B2 (ja) | 2014-10-31 | 2015-08-28 | 無線送信装置、無線受信装置、通信方法および通信システム |
CN201580045668.0A CN106664724B (zh) | 2014-10-31 | 2015-08-28 | 无线发送装置、无线接收装置、通信方法以及通信系统 |
EP15854268.8A EP3214890B1 (en) | 2014-10-31 | 2015-08-28 | Wireless transmitting device, wireless receiving device, communication method and communication system |
US15/522,866 US10575328B2 (en) | 2014-10-31 | 2015-08-28 | Radio transmission device, radio reception device, communication method, and communication system |
US16/784,288 US11388749B2 (en) | 2014-10-31 | 2020-02-07 | Radio transmission device, radio reception device, communication method, and communication system |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2014222235 | 2014-10-31 | ||
JP2014-222235 | 2014-10-31 |
Related Child Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US15/522,866 A-371-Of-International US10575328B2 (en) | 2014-10-31 | 2015-08-28 | Radio transmission device, radio reception device, communication method, and communication system |
US16/784,288 Continuation US11388749B2 (en) | 2014-10-31 | 2020-02-07 | Radio transmission device, radio reception device, communication method, and communication system |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2016067738A1 true WO2016067738A1 (ja) | 2016-05-06 |
Family
ID=55857084
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2015/074383 WO2016067738A1 (ja) | 2014-10-31 | 2015-08-28 | 無線送信装置、無線受信装置、通信方法および通信システム |
Country Status (5)
Country | Link |
---|---|
US (2) | US10575328B2 (ja) |
EP (1) | EP3214890B1 (ja) |
JP (2) | JP6744219B2 (ja) |
CN (1) | CN106664724B (ja) |
WO (1) | WO2016067738A1 (ja) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2019537902A (ja) * | 2016-11-10 | 2019-12-26 | ソニーモバイルコミュニケーションズ株式会社 | 可変閾値によるリッスンビフォアトーク方式 |
JP2021141620A (ja) * | 2017-06-14 | 2021-09-16 | ホーチキ株式会社 | 無線装置 |
US11186691B2 (en) | 2015-06-25 | 2021-11-30 | Toray Industries, Inc. | Epoxy resin composition, fiber reinforced composite material, molded article and pressure vessel |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10362150B2 (en) * | 2015-09-09 | 2019-07-23 | Sony Corporation | Communication device and communication method |
US10708279B2 (en) * | 2015-12-24 | 2020-07-07 | Electronics And Telecommunications Research Institute | Method and apparatus for transmitting data |
US10397024B2 (en) * | 2016-03-04 | 2019-08-27 | Intel IP Corporation | Signaling for uplink sounding |
EP3697134B1 (en) * | 2017-10-30 | 2022-10-26 | LG Electronics Inc. | Method for transmitting or receiving frame in wireless lan system and apparatus therefor |
WO2019102041A1 (en) | 2017-11-27 | 2019-05-31 | Telefonaktiebolaget Lm Ericsson (Publ) | Methods, devices and communications systems for resource allocation for carrier aggregation |
MX2020006038A (es) * | 2018-01-12 | 2020-08-17 | Ericsson Telefon Ab L M | Transmision programada mejorada. |
US11057932B2 (en) * | 2018-12-31 | 2021-07-06 | Fortinet, Inc. | Increasing downstream network throughput from access points in data communication systems using transmit opportunities from RTS (request to send)frame errors |
CN112423318B (zh) * | 2020-07-21 | 2022-06-17 | 上海移远通信技术股份有限公司 | 一种被用于无线通信的节点中的方法和装置 |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003124878A (ja) * | 2001-08-07 | 2003-04-25 | Toshiba Corp | 無線通信システム及び無線端末装置 |
JP2009500945A (ja) * | 2005-07-05 | 2009-01-08 | クゥアルコム・インコーポレイテッド | 無線ネットワークにおけるネットワーキング拡張範囲およびレガシーデバイスのためのmacレベル保護 |
JP2012169796A (ja) * | 2011-02-11 | 2012-09-06 | Denso Corp | 無線通信システム |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE60206715T2 (de) | 2001-08-07 | 2006-07-13 | Kabushiki Kaisha Toshiba | Drahtloses Kommunikationssystem und drahtlose Station |
US7720440B2 (en) | 2006-05-18 | 2010-05-18 | Intel Corporation | Distributed coordination of a clear channel assessment (CCA) threshold |
JP4631956B2 (ja) | 2008-10-14 | 2011-02-16 | ソニー株式会社 | 無線通信装置及び無線通信方法 |
CN101873710B (zh) * | 2009-04-23 | 2013-08-14 | 厦门星网锐捷软件有限公司 | 基于ieee802.15.4标准的非槽道方式csma-ca算法的优化方法 |
US8666319B2 (en) * | 2011-07-15 | 2014-03-04 | Cisco Technology, Inc. | Mitigating effects of identified interference with adaptive CCA threshold |
CN103220065B (zh) * | 2012-01-18 | 2018-02-06 | 中兴通讯股份有限公司 | 空闲信道评估阈值的调整方法及装置 |
US10516457B2 (en) * | 2013-06-28 | 2019-12-24 | Mediatek Singapore Pte. Ltd. | Beamforming enhancements for spatial reuse in wireless networks |
US10104620B2 (en) * | 2014-06-02 | 2018-10-16 | Lg Electronics Inc. | Method and device for operation based on power save mode in WLAN |
US9473284B2 (en) * | 2014-07-14 | 2016-10-18 | Nokia Corporation | Contention for channel access in wireless network |
-
2015
- 2015-08-28 EP EP15854268.8A patent/EP3214890B1/en active Active
- 2015-08-28 WO PCT/JP2015/074383 patent/WO2016067738A1/ja active Application Filing
- 2015-08-28 JP JP2016556415A patent/JP6744219B2/ja active Active
- 2015-08-28 CN CN201580045668.0A patent/CN106664724B/zh active Active
- 2015-08-28 US US15/522,866 patent/US10575328B2/en active Active
-
2020
- 2020-02-07 US US16/784,288 patent/US11388749B2/en active Active
- 2020-07-30 JP JP2020129584A patent/JP7216465B2/ja active Active
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003124878A (ja) * | 2001-08-07 | 2003-04-25 | Toshiba Corp | 無線通信システム及び無線端末装置 |
JP2009500945A (ja) * | 2005-07-05 | 2009-01-08 | クゥアルコム・インコーポレイテッド | 無線ネットワークにおけるネットワーキング拡張範囲およびレガシーデバイスのためのmacレベル保護 |
JP2012169796A (ja) * | 2011-02-11 | 2012-09-06 | Denso Corp | 無線通信システム |
Non-Patent Citations (2)
Title |
---|
REZA HEDAYAT ET AL.: "Adaptive CCA for llax, IEEE 802.11-14/1233r2", 14 September 2014 (2014-09-14), Retrieved from the Internet <URL:https://mentor.ieee.org/802.11/dcn/14/11-14-1233-02-00ax-adaptive-cca-for-llax.pptx> * |
See also references of EP3214890A4 * |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11186691B2 (en) | 2015-06-25 | 2021-11-30 | Toray Industries, Inc. | Epoxy resin composition, fiber reinforced composite material, molded article and pressure vessel |
JP2019537902A (ja) * | 2016-11-10 | 2019-12-26 | ソニーモバイルコミュニケーションズ株式会社 | 可変閾値によるリッスンビフォアトーク方式 |
US11546939B2 (en) | 2016-11-10 | 2023-01-03 | Sony Group Corporation | Listen before talk operation with variable threshold |
JP2021141620A (ja) * | 2017-06-14 | 2021-09-16 | ホーチキ株式会社 | 無線装置 |
Also Published As
Publication number | Publication date |
---|---|
JP7216465B2 (ja) | 2023-02-01 |
JP2020178375A (ja) | 2020-10-29 |
JP6744219B2 (ja) | 2020-08-19 |
EP3214890A1 (en) | 2017-09-06 |
US10575328B2 (en) | 2020-02-25 |
CN106664724A (zh) | 2017-05-10 |
JPWO2016067738A1 (ja) | 2017-09-14 |
US20170325262A1 (en) | 2017-11-09 |
US11388749B2 (en) | 2022-07-12 |
EP3214890B1 (en) | 2021-12-08 |
CN106664724B (zh) | 2021-08-20 |
EP3214890A4 (en) | 2018-06-13 |
US20200178300A1 (en) | 2020-06-04 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP7216465B2 (ja) | 無線送信装置、無線受信装置、通信方法および通信システム | |
US11297631B2 (en) | Radio receiving apparatus radio transmission apparatus communication method and communication system using multi-user transmission | |
JP6689209B2 (ja) | 端末装置および基地局装置 | |
JP7128861B2 (ja) | 端末装置および通信方法 | |
WO2017119470A1 (ja) | 無線通信装置および端末装置 | |
WO2016195012A1 (ja) | 無線通信装置、通信方法および通信システム | |
JP7079060B2 (ja) | 端末装置、基地局装置、通信方法及び通信システム | |
WO2017030162A1 (ja) | 端末装置、通信方法及び集積回路 | |
WO2017082094A1 (ja) | 端末装置および通信方法 | |
JP6992134B2 (ja) | 移動通信システム、移動局装置および通信方法 | |
WO2016140179A1 (ja) | 基地局装置および端末装置 | |
WO2017086009A1 (ja) | 無線通信システムおよび基地局装置 | |
WO2016143839A1 (ja) | 無線受信装置、無線送信装置、および通信方法 | |
WO2023054153A1 (ja) | アクセスポイント装置、及び通信方法 | |
JP2023114921A (ja) | 通信装置および通信方法 | |
WO2016039180A1 (ja) | 無線受信装置、無線送信装置、通信システムおよび通信方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 15854268 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2016556415 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 15522866 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
REEP | Request for entry into the european phase |
Ref document number: 2015854268 Country of ref document: EP |