Communication control device, control method, and non-transitory computer product

Abstract

To provide a communication device for performing data communication by bundling a plurality of bands.SOLUTION: The communication device includes a communication unit that transmits and receives a radio signal using a plurality of bands, and a control unit that controls a communication operation in the communication unit, in which the control unit performs control to transmit a first signal in a first band during a period from acquisition of a transmission right in the first band to acquisition of a transmission right in a second band, and to perform data transmission using the first band and the second band at the same time when the transmission right is acquired in both the first band and the second band. As the first signal, an RTS frame, a CTS frame, a data frame, a busy tone, or the like is transmitted.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a communication device and a communication method for transmitting and receiving wireless signals. [Background technology]

[0002] In recent years, there has been an expectation that wireless LANs (Local Area Networks) will be used in applications such as virtual reality (VR), and improvements in peak throughput are required to support these applications. One technology that has attracted attention as a means of improving peak throughput is carrier aggregation, which secures broadband by simultaneously using multiple frequency bands in the next-generation wireless LAN standard.

[0003] For example, when communicating simultaneously in multiple separate frequency bands, a wireless communication device has been proposed that maps transmission data to multiple frequency bands, allocates power to each frequency band, and determines the modulation method, channel coding rate, and transmission bandwidth (see Patent Document 1).

[0004] A wireless communication device has also been proposed that observes channel conditions, performs carrier sensing on channels and periods predicted to be idle, and transmits simultaneously on multiple bands based on the results (see Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-157535 [Patent Document 2] Japanese Patent Application Publication No. 2018-78447 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the technology disclosed in this specification is to provide a communication device and a communication method for performing data communication by bundling multiple bands. [Means for solving the problem]

[0007] A first aspect of the technology disclosed in this specification is: a communication unit that transmits and receives wireless signals using multiple bands; a control unit that controls a communication operation in the communication unit; Equipped with the control unit controls to transmit a first signal in the first band during a period from when a transmission right in a first band is acquired until when a transmission right in a second band is acquired; It is a communication device.

[0008] The control unit controls the first signal so that information regarding acquisition of a transmission right in another band is included in the first signal.

[0009] Then, when the control unit acquires the transmission right in both the first band and the second band, the control unit performs control so that data transmission is performed using the first band and the second band simultaneously.

[0010] As the first signal, an RTS frame, a CTS frame, a data frame, a busy tone, or the like is transmitted.

[0011] A second aspect of the technology disclosed in this specification is: A communication method for a communication device that transmits and receives wireless signals using multiple bands, comprising: acquiring a transmission right in a first band; transmitting a first signal in the first band until a transmission right in the second band is acquired; transmitting data simultaneously using the first band and the second band when the transmission rights are acquired in both the first band and the second band; It is a communication method having the above.

[0012] A third aspect of the technology disclosed in this specification is: a communication unit that transmits and receives wireless signals using multiple bands; a control unit that controls a communication operation in the communication unit; Equipped with the control unit controls to receive data transmitted using the first band and the second band simultaneously after receiving a first signal in the first band; It is a communication device.

[0013] A fourth aspect of the technology disclosed in this specification is a communication method in a communication device that transmits and receives wireless signals using a plurality of bands, comprising: receiving a first signal in a first band; receiving data transmitted using the first band and the second band simultaneously; It is a communication method having the above. [Effects of the Invention]

[0014] According to the technology disclosed in this specification, it is possible to provide a communication device and a communication method that can acquire transmission rights in other bands while maintaining transmission rights in the band in which the transmission rights were previously acquired, thereby bundling multiple bands to perform data communication.

[0015] It should be noted that the effects described in this specification are merely examples, and the effects brought about by the technology disclosed in this specification are not limited to these. Furthermore, the technology disclosed in this specification may also bring about additional effects in addition to the effects described above.

[0016] Further objects, features, and advantages of the technology disclosed in this specification will become apparent from the following detailed description based on the embodiments and accompanying drawings. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a diagram showing a schematic configuration example of a communication system 100. As shown in FIG. [Figure 2]FIG. 2 is a diagram showing an example of the functional configuration of the communication device 200. As shown in FIG. [Figure 3] FIG. 3 is a diagram showing an example of a communication sequence (first embodiment) when a base station and a slave unit communicate using two channels, band A and band B. In FIG. [Figure 4] FIG. 4 is a diagram showing an example of the format of an RTS frame. [Figure 5] FIG. 5 is a diagram showing an example of the format of a CTS frame. [Figure 6] FIG. 6 is a flowchart showing the processing procedure executed by the AP (first embodiment). [Figure 7] FIG. 7 is a diagram showing an example of a communication sequence (second embodiment) when a base station and a slave unit communicate using two channels, band A and band B. In FIG. [Figure 8] FIG. 8 is a flowchart showing a processing procedure executed by the AP (second embodiment). [Figure 9] FIG. 9 is a diagram showing an example of a communication sequence (third embodiment) when a base station and a slave unit communicate using two channels, band A and band B. In FIG. [Figure 10] FIG. 10 is a flowchart showing a processing procedure executed by the AP (third embodiment). [Figure 11] FIG. 11 is a diagram showing an example of a communication sequence (fourth embodiment) when a base station and a mobile station communicate using two channels, band A and band B. In FIG. [Figure 12] FIG. 12 is a flowchart showing a processing procedure executed by the AP (fourth embodiment). [Figure 13] FIG. 13 is a diagram showing an example of a communication sequence (fifth embodiment) when a base station and a slave unit communicate using two channels, band A and band B. In FIG. [Figure 14] FIG. 14 is a flowchart showing a processing procedure executed by the AP (fifth embodiment). [Figure 15] FIG. 15 is a flowchart showing the processing procedure executed by the STA (sixth embodiment). DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the technology disclosed in this specification will be described in detail with reference to the drawings.

[0019] The applicant believes that there are two major problems with transmitting data simultaneously on multiple bands. One is that after a terminal acquires the transmission right on one band, another terminal may start transmitting before acquiring the transmission right on another band, making it impossible to transmit on the band that previously acquired the transmission right. The other is that the waiting time between acquiring the transmission right on one band and acquiring the transmission right on another band is wasted.

[0020] Therefore, this specification proposes a technology that enables a terminal to maintain the transmission right until it acquires the transmission right in another band by transmitting a signal in the band that has acquired the transmission right first.The signal to be transmitted in the band that has acquired the transmission right first may be a frame that includes information to make other terminals suspend transmission, such as RTS (Request To Send) or CTS (Clear To Send), or may be a signal that makes other terminals suspend transmission by detecting power, such as a busy tone.

[0021] 1 shows a schematic configuration example of a communication system 100 to which the technology proposed in this specification is applied. The illustrated communication system 100 is configured with one base station (AP) 101 and one mobile station (STA) 102. It is also assumed that two channels, band A and band B, are available in the communication system 100. Bands A and B are, for example, the 5 GHz band and the 6 GHz band. The mobile station 102 is connected to the base station 101 and communicates by bundling a channel in band A and a channel in band B.

[0022] 1 are merely examples, and are not limited to those described here. Furthermore, communication may be performed by bundling multiple different channels within each of bands A and B.

[0023] FIG. 2 shows an example of the functional configuration of a communication device 200 that can operate as either a base station or a mobile station in the communication system 100 according to this embodiment.

[0024] The illustrated communication device 200 is made up of a control unit 210, a power supply unit 220, a plurality of (three in the illustrated example) communication units 230-1, 230-2, 230-3, and an antenna unit 240-1, ... for each communication unit 230-1, .... Note that each communication unit 230-1 and the antenna unit 240-1 for each communication unit 230-1, ... have the same configuration, and therefore will be referred to as a communication unit 230 and an antenna unit 240 below for simplicity.

[0025] Communication unit 230 is composed of a processor or circuit such as a microprocessor, and includes radio control unit 231, data processing unit 232, modulation / demodulation unit 233, signal processing unit 234, channel estimation unit 235, a plurality of wireless interface (IF) units 236-1, ..., 236-N arranged in parallel, and amplifier units 237-1, ..., 237-N connected in series to each of the wireless interface units 236-1, ..., 236-N (where N is an integer of 2 or more). Each of amplifier units 237-1, ..., 237-N is connected to each of antenna elements constituting antenna unit 240 corresponding to that communication unit 230.

[0026] One or more sets of serially connected wireless interface unit 236, amplifier unit 237, and antenna element in antenna unit 240 may be components of communication unit 230. Furthermore, each of wireless interface units 236-1, ..., 236-N may include the function of the corresponding amplifier unit 237-1, ..., 237-N.

[0027] When data is input from an upper layer of its own communication protocol during transmission, the data processing unit 232 generates a packet for wireless transmission from the data, and further performs processing such as adding a header for Media Access Control (MAC) and adding an error detection code, and provides the processed data to the modulation / demodulation unit 233. When data is received from the modulation / demodulation unit 233 during reception, the data processing unit 232 analyzes the MAC header, detects packet errors, and reorders packets, and provides the processed data to the upper layer of its own protocol.

[0028] Wireless control unit 231 controls the exchange of information between the various units within communication device 200. Wireless control unit 231 also performs parameter setting in modulation / demodulation unit 233 and signal processing unit 234, packet scheduling in data processing unit 232, and parameter setting and transmission power control in wireless interface unit 236 and amplifier unit 237.

[0029] During transmission, modem unit 233 performs encoding, interleaving, and modulation processing on input data from data processing unit 232 based on the encoding method and modulation method set by radio control unit 231, generates a data symbol stream, and provides it to signal processing unit 234. During reception, modem unit 233 performs demodulation processing, deinterleaving, and decoding processing on the input symbol stream from signal processing unit 234, which are the opposite of those during transmission, and provides the data to data processing unit 232 or radio control unit 231.

[0030] During transmission, signal processing unit 234 performs signal processing for spatial separation on input from modem unit 233 as necessary, and provides the obtained one or more transmission symbol streams to each of radio interface units 236-1, .... During reception, signal processing unit 234 performs signal processing on reception symbol streams input from each of radio interface units 236-1, ..., performs spatial decomposition of the stream as necessary, and provides the resultant streams to modem unit 233.

[0031] The channel estimation unit 235 calculates complex channel gain information of the propagation path from the preamble portion and the training signal portion of the input signal from each of the radio interface units 236-1, .... The calculated complex channel gain information is used for demodulation processing in the modem unit 233 and spatial processing in the signal processing unit 234 via the radio control unit 231.

[0032] During transmission, the wireless interface unit 236 converts the input from the signal processing unit 234 into an analog signal, performs filtering, up-conversion to a carrier frequency, and phase control, and sends the signal to the corresponding amplifier unit 237 or antenna unit 240. During reception, the wireless interface unit 236 performs processing on the input from the corresponding amplifier unit 237 or antenna unit 240, such as down-conversion, filtering, and conversion to a digital signal, which is the opposite of that during transmission, and provides the data to the signal processing unit 234 and the channel estimation unit 235.

[0033] During transmission, amplifier unit 237 amplifies an analog signal input from wireless interface unit 236 to a predetermined power level and sends it to a corresponding antenna element in antenna unit 240. During reception, amplifier unit 237 low-noise amplifies a signal input from a corresponding antenna element in antenna unit 240 to a predetermined power level and outputs it to wireless interface unit 236.

[0034] At least one of the transmission function and the reception function of the amplifier unit 237 may be included in the wireless interface unit 236. Furthermore, at least one of the transmission function and the reception function of the amplifier unit 237 may be a component other than the communication unit 230.

[0035] A set of wireless interface unit 236 and amplifier unit 237 constitutes one RF (Radio Frequency) branch. One RF branch is capable of transmitting and receiving signals in one band. In the device configuration example shown in Fig. 2, communication unit 230 has N RF branches.

[0036] Control unit 210 is composed of a processor such as a microprocessor and circuits, and controls wireless control unit 231 and power supply unit 220. Control unit 210 may also perform at least a part of the above-described operations of wireless control unit 231 in place of wireless control unit 231. In particular, in this embodiment, control unit 210 and wireless control unit 231 control the operations of each unit to realize operations according to each example described below.

[0037] The power supply unit 220 is configured by a battery power supply or a fixed power supply, and supplies power to the communication device 200 for driving it.

[0038] While communication device 200 is in standby, communication unit 230 may be configured to transition to a standby state or a sleep state (or a state in which at least some functions are stopped) to reduce power consumption. In the example of the device configuration shown in FIG. 2, communication unit 230 includes N RF branches, but may be configured to transition to a standby state or a sleep state for each RF branch. However, when transmitting and receiving data using carrier aggregation, at least the RF branches corresponding to the number of bands to be aggregated must have returned to their normal operating states.

[0039] The control unit 210 and the communication unit 230 can be configured together as one or more LSIs (Large Scale Integration). [Example]

[0040] In the first embodiment, an example will be described in which a base station (AP) transmits a frame requesting transmission and then transmits a data frame in the communication system 100 shown in FIG.

[0041] 3 shows an example of a communication sequence in which a base station (AP) and a station (STA) communicate using two channels, band A and band B. The STA is assumed to be connected to the AP. The AP and the STA may confirm in advance whether they are compatible with the operation according to this embodiment. The AP and the STA can acquire the right to transmit according to a channel access method such as CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance).

[0042] First, the AP acquires the transmission right in band B. The AP intends to transmit data by bundling bands A and B, but the backoff has not yet expired in band A. Therefore, until the AP acquires the transmission right in band A, it transmits an RTS frame requesting transmission in band B in order to maintain the transmission right in band B as well (or to prevent other communication terminals from acquiring the transmission right).

[0043] After receiving the RTS frame from the AP on band B, the STA returns a CTS frame, which allows transmission, also on band B. As a result, other communication terminals (not shown) using band B set their NAV (Network Allocation Vector) upon receiving at least one of the RTS and CTS frames, and therefore wait for transmission on band B.

[0044] The RTS and CTS frames contain information about acquiring transmission rights in other bands (described later). Specifically, the information about acquiring transmission rights in other bands includes information indicating whether the AP is waiting to acquire transmission rights in other bands, and information about bands for which it has not yet acquired transmission rights. Specifically, the RTS and CTS frames contain information indicating that the AP is waiting to acquire transmission rights in band A.

[0045] Therefore, the STA can recognize from the received RTS frame that the AP is attempting to transmit data to itself by bundling Band A and Band B. For example, when the RF branch for Band A is in standby or sleep mode, the STA also restores the RF branch for Band A to its normal operating state to prepare for data transmission from the AP bundling Band A and Band B.

[0046] By having other communication terminals set NAV, the AP can maintain the right to transmit in Band B. After that, if the AP also acquires the right to transmit in Band A, it will start transmitting data to the STA by bundling Band A and Band B. The STA can then receive the data transmitted by bundling Band A and Band B.

[0047] Fig. 4 shows an example of the format of an RTS frame used in the communication sequence shown in Fig. 3. Fig. 5 shows an example of the format of a CTS frame used in the communication sequence shown in Fig. 3.

[0048] The Frame Control fields denoted by reference numbers 401 and 501 contain information about the type of each RTS and CTS frame.

[0049] The Duration fields indicated by reference numerals 402 and 502 contain information about the time until the subsequent data communication is completed. Surrounding terminals that are not communicating read the value of this field and set their NAV. If the time it takes for the AP to acquire the right to transmit in band A is known, the Duration field contains the period from transmitting data until receiving an ACK frame in response. If the time it takes for the AP to acquire the right to transmit in band A is unknown, the Duration field contains the maximum permissible value.

[0050] RA (Receiver Address) indicated by reference numbers 403 and 503 is a field containing the MAC address of the destination of each frame. TA (Transmitter Address) indicated by reference number 404 is a field containing the MAC address of the source of each frame.

[0051] Information regarding acquisition of transmission rights in other bands is written in the CA (Carrier Aggregation) Indiction fields indicated by reference numerals 405 and 504. Specifically, the CA Indication field contains information indicating that acquisition of transmission rights in other bands is on standby, or information indicating that there are bands for which transmission rights have not yet been acquired.

[0052] The FCS (Frame Check Sequence) indicated by reference numbers 406 and 505 is a field that indicates the error correction code for the entire frame.

[0053] For example, if band A becomes busy during the exchange of RTS / CTS frames in band B or after the frame exchange is completed, the AP or STA may suspend the reservation of transmission rights in band B.

[0054] 6 is a flowchart showing a processing procedure executed by an AP in the first embodiment. This processing procedure is executed when the communication device 200 shown in FIG. 2 functions as an AP in the communication system 100 that can use two channels, band A and band B.

[0055] When the AP acquires the transmission right in band B (step S601), it checks whether it has yet acquired the transmission right in band A (step S602).

[0056] If the AP has already acquired the transmission right for band A (No in step S602), the AP can transmit data by bundling bands A and B, and this process ends.

[0057] On the other hand, if the AP has not yet acquired the transmission right in band A (Yes in step S602), the AP transmits an RTS frame in band B (step S603), receives a CTS frame in band B (step S604), and maintains the transmission right in band B during the period until it acquires the transmission right in band A.

[0058] Then, when the AP acquires the transmission right in band A as well (step S605), the AP can transmit data by bundling bands A and B, and therefore this process ends.

[0059] Although not shown in the flowchart, if band A becomes busy during the exchange of RTS / CTS frames in band B or after the frame exchange is completed, the AP may suspend the reservation of transmission rights in band B.

[0060] According to the processing procedure shown in Figure 6, NAV is set not only for the peripheral terminals of the AP but also for the peripheral terminals of the STA, so that even terminals (hidden terminals) that are in locations where signals from the transmitting side (AP) cannot reach can be made to wait for transmission. [Example]

[0061] In the second embodiment, an example will be described in which the base station (AP) maintains the transmission right by transmitting a CTS frame in a band in which the base station (AP) has acquired the transmission right in the communication system 100 shown in FIG.

[0062] 7 shows an example of a communication sequence in which a base station (AP) transmits a CTS frame to a mobile station (STA). The STA is assumed to be connected to the AP. The AP and the STA may confirm in advance whether they are compatible with the operation according to this embodiment. The AP and the STA can acquire the right to transmit according to a channel access method such as CSMA / CA.

[0063] First, the AP acquires the transmission right in band B. The AP intends to transmit data by bundling bands A and B, but the backoff has not yet expired in band A. Therefore, the AP transmits a CTS frame in band B to maintain the transmission right in band B (or to prevent other communication terminals from acquiring the transmission right) until it acquires the transmission right in band A.

[0064] Here, the CTS frame sent by the AP has the frame format shown in Figure 5, and like CTS-to-Self, the RA is the MAC address of the AP that sent it. However, CTS-to-Self is a function defined in IEEE802.11g, and by deliberately sending a CTS to itself, the AP notifies STAs connected to that AP that communication will soon take place.

[0065] As a result, other terminals using band B set their NAVs according to the contents of the Duration in this CTS frame and wait for transmission on band B.

[0066] The CTS frame transmitted by the AP contains information regarding the acquisition of transmission rights in another band (as mentioned above). Specifically, the CTS frame contains information indicating that the AP is waiting to acquire transmission rights in Band A. Therefore, the STA can recognize from the received CTS frame that the AP is attempting to transmit data to itself by bundling Band A and Band B. For example, if the RF branch for Band A is in standby or sleep mode, the STA will also return the RF branch for Band A to its normal operating state to prepare for the AP's data transmission on the combined Band A and Band B.

[0067] By having other communication terminals set NAV, the AP can maintain the right to transmit in Band B. After that, if the AP also acquires the right to transmit in Band A, it will start transmitting data to the STA by bundling Band A and Band B. The STA can then receive the data transmitted by bundling Band A and Band B.

[0068] If band A becomes busy while transmitting a CTS frame in band B or after completing transmission of a CTS frame, the AP or STA may suspend the reservation of the transmission right in band B.

[0069] 8 is a flowchart showing a processing procedure executed by an AP in the second embodiment. This processing procedure is executed when the communication device 200 shown in FIG. 2 functions as an AP in the communication system 100 that can use two channels, band A and band B.

[0070] When the AP acquires the transmission right in band B (step S801), it checks whether it has yet acquired the transmission right in band A (step S802).

[0071] If the AP has already acquired the transmission right for band A (No in step S802), the AP can transmit data by bundling bands A and B, and this process ends.

[0072] On the other hand, if the AP has not yet acquired the transmission right in band A (Yes in step S802), the AP transmits a CTS frame in band B (step S803) and maintains the transmission right in band B until it acquires the transmission right in band A.

[0073] Then, when the AP acquires the transmission right for band A as well (step S804), the AP can transmit data by bundling bands A and B, and the process ends.

[0074] Although not shown in the flowchart, if band A becomes busy while transmitting a CTS frame on band B or after completing transmission of the CTS frame, the AP may suspend the reservation of transmission rights on band B.

[0075] According to the processing procedure shown in FIG. 8, the terminals around the AP can be made to wait for transmission, and the transmission right can be held until data is transmitted using a plurality of bands. [Example]

[0076] In the third embodiment, an example will be described in which, in the communication system 100 shown in FIG. 1, a base station (AP) maintains the transmission right by transmitting a data frame instead of an RTS frame or a CTS frame in the band in which it has acquired the transmission right.

[0077] 9 shows an example of a communication sequence in which a base station (AP) transmits a data frame to a slave station (STA). The STA is assumed to be connected to the AP. The AP and the STA may confirm in advance whether they are compatible with the operation according to this embodiment. The AP and the STA can acquire the right to transmit according to a channel access method such as CSMA / CA.

[0078] First, the AP acquires the transmission right in band B. The AP intends to transmit data by bundling bands A and B, but the backoff has not yet expired in band A. Therefore, the AP transmits a data frame addressed to the STA in band B. As a result, the AP maintains the transmission right in band B during the period until it acquires the transmission right in band A (or prevents other communication terminals from acquiring the transmission right). The data frame transmission period may be determined based on the period from when it acquires the transmission right in band B until it acquires the transmission right in band A.

[0079] Other terminals using band B set their NAV according to the contents of the Duration field in the data frame sent from the AP, and wait to transmit on band B. By having other communication terminals set their NAV, the AP can maintain the right to transmit on band B.

[0080] The data frame transmitted by the AP contains information regarding the acquisition of transmission rights in another band (as mentioned above). Specifically, the data frame contains information indicating that the AP is waiting to acquire transmission rights in Band A. Therefore, the STA can recognize from the received data frame that the AP is attempting to transmit data to itself by combining Band A and Band B. For example, when the RF branch for Band A is in standby or sleep mode, the STA also returns the RF branch for Band A to its normal operating state to prepare for the AP's data transmission combining Band A and Band B.

[0081] After that, if the AP also acquires the right to transmit on Band A, it will suspend the transmission of data on Band B and start transmitting data to the STA on Bands A and B combined together. The STA can then receive the data transmitted on Bands A and B combined together.

[0082] After acquiring the transmission right in band A, the AP may immediately suspend data transmission in band B, or may transmit data only in band B for a certain period during which the STA can decode the data, and then switch to data transmission using carrier aggregation that aggregates bands A and B. The certain period here refers to, for example, the end of a certain A-MPDU subframe in an A-MPDU (Aggregate MAC Protocol Data Unit) or a block unit of an LDPC (Low Density Parity Check) code.

[0083] If band A becomes busy during transmission of a data frame in band B or after transmission of a data frame is completed, the AP or STA may suspend the reservation of the transmission right in band B.

[0084] 10 is a flowchart showing a processing procedure executed by an AP in the third embodiment. This processing procedure is executed when the communication device 200 shown in FIG. 2 functions as an AP in the communication system 100 that can use two channels, band A and band B.

[0085] When the AP acquires the transmission right in band B (step S1001), it checks whether it has yet acquired the transmission right in band A (step S1002).

[0086] If the AP has already acquired the transmission right for band A (No in step S1002), the AP can transmit data by bundling bands A and B, and this process ends.

[0087] On the other hand, if the AP has not yet acquired the transmission right in band A (Yes in step S1002), the AP transmits a data frame in band B (step S1003) and maintains the transmission right in band B until it acquires the transmission right in band A.

[0088] Then, when the AP acquires the transmission right in band A as well (step S1004), the process ends.

[0089] After that, when the AP acquires the transmission right in band A as well, it suspends the data transmission in band B and starts transmitting data to the STA using carrier aggregation that aggregates bands A and B.

[0090] Although not shown in the flowchart, if band A becomes busy while transmitting a data frame on band B or after completing transmission of the data frame, the AP may suspend the reservation of transmission rights on band B.

[0091] According to the processing procedure shown in FIG. 10, the AP can transmit data efficiently using the time it takes to acquire the right to transmit in all bands used for carrier aggregation. [Example]

[0092] In the fourth embodiment, an example will be described in which, in the communication system 100 shown in FIG. 1, the base station (AP) maintains the transmission right by transmitting a busy tone in the band in which the transmission right has been acquired.

[0093] 11 shows an example of a communication sequence in which a base station (AP) transmits a busy tone to a mobile station (STA). The STA is assumed to be connected to the AP. The AP and the STA may confirm in advance whether they are compatible with the operation according to this embodiment. The AP and the STA can acquire the right to transmit according to a channel access method such as CSMA / CA.

[0094] First, the AP acquires the transmission right in band B. The AP intends to transmit data by bundling bands A and B, but the backoff has not yet expired in band A. Therefore, the AP transmits a busy tone in band B. As a result, the AP maintains the transmission right in band B during the period until it acquires the transmission right in band A (or prevents other communication terminals from acquiring the transmission right). The period for transmitting the busy tone may be determined based on the period from when it acquires the transmission right in band B until it acquires the transmission right in band A.

[0095] If other terminals using band B detect the busy tone transmitted from the AP during the backoff period, they will wait to transmit on band B. In this way, the AP can maintain the right to transmit on band B by preventing other communication terminals from obtaining the right to transmit.

[0096] In addition, the busy tone transmitted by the AP contains information regarding the acquisition of transmission rights in another band (as described above). Specifically, the busy tone (e.g., preamble signal) contains information indicating that the AP is waiting to acquire transmission rights in Band A. Therefore, the STA can recognize from the received busy tone that the AP is attempting to transmit data to itself by combining Band A and Band B. For example, when the RF branch for Band A is in standby or sleep mode, the STA also returns the RF branch for Band A to its normal operating state to prepare for the AP's data transmission combining Band A and Band B.

[0097] After that, when the AP acquires the right to transmit in Band A as well, it stops transmitting the busy tone in Band B and starts transmitting data to the STA using carrier aggregation that aggregates Band A and Band B. The STA can then receive the data transmitted by aggregating Band A and Band B.

[0098] The busy tone used in this embodiment may have any format. The busy tone may include information regarding the time when the AP transmits a data signal, so that a communication terminal conforming to the IEEE 802.11 standard can set a NAV. The busy tone may also include network identification information such as BSS (Basic Service Set) identification information, so that a communication terminal conforming to the IEEE 802.11 standard can determine whether to terminate signal reception. A signal pattern common to other systems (e.g., cellular systems) may be superimposed on the busy tone. This can also prevent interruptions from other systems.

[0099] If band A becomes busy while a busy tone is being transmitted in band B or after the transmission of the busy tone has been completed, the AP or STA may suspend the reservation of the transmission right in band B.

[0100] 12 is a flowchart showing a processing procedure executed by an AP in the fourth embodiment. This processing procedure is executed when the communication device 200 shown in FIG. 2 functions as an AP in the communication system 100 that can use two channels, band A and band B.

[0101] When the AP acquires the transmission right in band B (step S1201), it checks whether it has yet acquired the transmission right in band A (step S1202).

[0102] If the AP has already acquired the transmission right for band A (No in step S1202), the AP can transmit data by bundling bands A and B, and this process ends.

[0103] On the other hand, if the AP has not yet acquired the transmission right in band A (Yes in step S1202), the AP transmits a busy tone in band B (step S1203) to prevent other terminals from acquiring the transmission right in band B during the period until the AP acquires the transmission right in band A, thereby maintaining the transmission right in band B.

[0104] Then, when the AP acquires the transmission right in band A as well (step S1204), it ends this process.

[0105] After that, when the AP acquires the right to transmit in band A as well, it stops transmitting the busy tone in band B and starts transmitting data to the STA using carrier aggregation that aggregates bands A and B.

[0106] Although not shown in the flowchart, if band A becomes busy while transmitting a busy tone on band B or after completing transmission of the busy tone, the AP may suspend the reservation of transmission rights on band B.

[0107] According to the processing procedure shown in Fig. 12, the AP can prevent other communications from interrupting even if it takes a short time to acquire the right to transmit across all bands used for carrier aggregation. Also, the AP can suspend transmissions from terminals of other wireless communication systems that cannot decode frames conforming to the IEEE 802.11 standard by detecting the power of the busy tone. [Example]

[0108] In the fifth embodiment, an example will be described in which, in the communication system 100 shown in FIG. 1, a base station (AP) changes the signal to be transmitted depending on the time from when it acquires the transmission right in one band to when it acquires the transmission right in another band, thereby maintaining the transmission right in the band that it first acquired.

[0109] 13 shows an example of a communication sequence in which a base station (AP) transmits a signal according to time to a mobile station (STA). The STA is assumed to be connected to the AP. The AP and the STA may confirm in advance whether they are compatible with the operation according to this embodiment. The AP and the STA can acquire the right to transmit according to a channel access method such as CSMA / CA.

[0110] First, the AP acquires the transmission right in band B. The AP intends to transmit data by bundling bands A and B, but the backoff has not yet expired in band A. Therefore, the AP transmits a frame addressed to the STA in band B. As a result, the AP maintains the transmission right in band B as well (or prevents other communication terminals from acquiring the transmission right) until it acquires the transmission right in band A.

[0111] Here, the AP changes the frame to be transmitted depending on the first time period until the AP acquires the transmission right in band A.

[0112] If the first time is equal to or greater than the time required for a STA to transmit the smallest unit of data that can be decoded, such as at least one subframe of an A-MPDU (in other words, the minimum transmission time of a data frame), the AP transmits the data frame on band B and performs the same operation as in the third embodiment.

[0113] Also, if the first time is longer than the time required to exchange RTS / CTS frames between the AP and the STA, the AP transmits an RTS frame on band B and performs the same operation as in the first embodiment.

[0114] Also, if the first time is less than the time required to exchange RTS / CTS frames between the AP and the STA, but is greater than or equal to the time required to transmit a CTS frame, the AP transmits a CTS frame on band B and performs the same operation as in the second embodiment.

[0115] Also, if the first time is less than the time required to transmit the CTS frame, the AP transmits a busy tone in band B and performs the same operation as in the fourth embodiment.

[0116] In this way, by transmitting a signal in band B according to the first length of time, the AP maintains the transmission right in band B (or prevents other communication terminals from obtaining the transmission right) during the period until it obtains the transmission right in band A.

[0117] When the AP transmits a data frame, an RTS frame, or a CTS frame, other terminals using band B set their NAVs according to the contents of the Duration field in the frame transmitted from the AP and wait for transmission in band B. By other communication terminals setting their NAVs, the AP can maintain the right to transmit in band B.

[0118] Furthermore, when the AP transmits a busy tone, other terminals using band B will wait to transmit on band B if they detect the busy tone transmitted from the AP during the backoff period. In this way, the AP can maintain the right to transmit on band B by preventing other communication terminals from obtaining the right to transmit.

[0119] After that, when the AP acquires the right to transmit in band A as well, it stops transmitting the busy tone in band B and starts transmitting data to the STA using carrier aggregation that aggregates bands A and B.

[0120] 14 is a flowchart showing a processing procedure executed by an AP in the fifth embodiment. This processing procedure is executed when the communication device 200 shown in FIG. 2 functions as an AP in the communication system 100 that can use two channels, band A and band B.

[0121] When the AP acquires the transmission right in band B (step S1401), it checks whether it has yet acquired the transmission right in band A (step S1402).

[0122] If the AP has already acquired the transmission right for band A (No in step S1402), the AP can transmit data by bundling bands A and B, and this process ends.

[0123] On the other hand, if the AP has not yet acquired the transmission right in band A (Yes in step S1402), the AP checks the length of the first time until it acquires the transmission right in band A.

[0124] If the first time is equal to or greater than the time required for the STA to transmit the smallest unit of data that can be decoded, such as at least one subframe of an A-MPDU (in other words, the minimum transmission time of a data frame) (No in step S1403), the AP transmits the data frame on band B (step S1408), as in the third embodiment.

[0125] Also, if the first time is less than the minimum transmission time of a data frame (Yes in step S1403) but is greater than or equal to the time required to exchange RTS / CTS frames between the AP and the STA (Yes in step S1404), the AP transmits an RTS frame to the STA on band B (step S1409), as in the first embodiment, and then receives a CTS frame from the STA (step S1410).

[0126] Furthermore, if the first time is less than the time required to exchange RTS / CTS frames between the AP and the STA (Yes in step S1404) but is greater than or equal to the time required to transmit a CTS frame (No in step S1405), the AP transmits a CTS frame addressed to itself in band B (step S1411), as in the second embodiment.

[0127] Also, if the first time is less than the time required to transmit the CTS frame (Yes in step S1405), the AP transmits a busy tone in band B (step S1406), as in the fourth embodiment.

[0128] Then, while transmitting a signal according to the length of the first time required to acquire the transmission right in band A, the AP acquires the transmission right in band A as well (step S1407), and then ends this process.

[0129] Thereafter, when the AP also acquires the transmission right in band A, it starts transmitting data to the STA using carrier aggregation that aggregates band A and band B. If the AP is transmitting a data frame here (step S1408), it suspends the transmission of data in band B and performs carrier aggregation using band A and band B. If the AP is transmitting a busy tone (step S1406), it suspends the transmission of the busy tone in band B and performs carrier aggregation using band A and band B.

[0130] According to the processing procedure shown in FIG. 14, the AP can select the optimal processing without wasting time until it acquires the right to transmit in all bands used for carrier aggregation. [Example]

[0131] In the sixth embodiment, an example will be described in which a slave station (STA) receives a data frame transmitted from a base station (AP) in the communication system 100 shown in Fig. 1. However, in this case, it is assumed that the AP transmits the data frame by any of the methods of the first to fifth embodiments described above.

[0132] 15 is a flowchart showing a processing procedure executed by an STA in the sixth embodiment. This processing procedure is executed when the communication device 200 shown in FIG. 2 functions as an STA in the communication system 100 that can use two channels, band A and band B.

[0133] For example, when a STA detects a signal in band B while waiting for reception in band B (step S1501), the STA checks whether the signal is addressed to itself (step S1502).

[0134] Here, if the signal detected on band B is not addressed to the STA (No in step S1502), the STA sets the NAV based on information such as the Duration contained in the signal (step S1507), skips all subsequent processing, and terminates this processing.

[0135] On the other hand, if the signal detected in band B is addressed to the STA (Yes in step S1502), the STA performs reception processing of the signal (step S1503). For example, if the received signal is an RTS frame transmitted from the AP, the STA performs processing to return a CTS frame. Also, if the received signal is a data frame transmitted from the AP, the STA performs reception processing of the data frame.

[0136] Next, the STA checks whether the received signal contains a CA Indication (or information indicating whether or not the STA is waiting to acquire the transmission right in band A) (step S1504).

[0137] If the received signal does not contain a CA Indication (No in step S1504), the STA ends this process upon completing the processing of the received signal.

[0138] Furthermore, if the received signal includes a CA Indication (Yes in step S1504), the STA prepares for carrier aggregation using band A and band B (step S1505). For example, if the RF branch for band A is in a standby state or a sleep state while the STA is waiting for reception in band B, the STA returns the RF branch for band A to a normal operating state to prepare for the start of carrier aggregation using band A and band B.

[0139] Thereafter, the STA performs a receiving process for the data transmitted by the AP through carrier aggregation that aggregates bands A and B (step S1506).

[0140] Up to now, the technology disclosed in this specification has been described in detail using Examples 1 to 6. Finally, the effects of the technology disclosed in this specification will be mentioned.

[0141] According to the technology disclosed in this specification, when a communication device transmits data using multiple bands, even if the timing for acquiring the transmission right differs for each band, it is possible to transmit without being interrupted by other terminals and without wasting time until the transmission right is acquired across all bands. [Industrial Applicability]

[0142] Although the technology disclosed in this specification has been described in detail with reference to specific embodiments, it is obvious that those skilled in the art can modify or substitute the embodiments without departing from the spirit of the technology disclosed in this specification.

[0143] The technology disclosed in this specification can be applied to, for example, an IEEE802.11 wireless LAN system, and can realize data communication by efficiently bundling multiple bands to broaden the bandwidth while following the channel access method using CSMA / CA. Of course, the technology disclosed in this specification can also be suitably applied to wireless LAN systems other than the IEEE802.11 system.

[0144] Although the present specification has mainly described an embodiment in which carrier aggregation is performed during downlink communication from an access point to a subordinate device, the gist of the technology disclosed in this specification is not limited to this. For example, the technology disclosed in this specification can also be applied to cases in which carrier aggregation is performed during uplink communication from a device to a connected access point, or when carrier aggregation is performed during sidelink communication between terminals.

[0145] In short, the technology disclosed in this specification has been described in the form of examples, but the contents of this specification should not be interpreted in a limiting manner. To determine the gist of the technology disclosed in this specification, the claims should be taken into consideration.

[0146] The technology disclosed in this specification can also be configured as follows.

[0147] (1) a communication unit that transmits and receives wireless signals using multiple bands; a control unit that controls a communication operation in the communication unit; Equipped with the control unit controls to transmit a first signal in the first band during a period from when a transmission right in a first band is acquired until when a transmission right in a second band is acquired; Communication equipment.

[0148] (2) the control unit controls the first signal to include information regarding acquisition of a transmission right in another band; The communication device according to (1) above.

[0149] (3) The information regarding the acquisition of transmission rights in another band includes information indicating whether or not the transmission right is being waited for in another band, or information regarding bands for which the transmission right has not yet been acquired. The communication device according to (2) above.

[0150] (4) when the control unit acquires transmission rights in both the first band and the second band, the control unit performs control so as to simultaneously use the first band and the second band for data transmission; The communication device according to (1) above.

[0151] (5) the control unit controls to transmit an RTS frame requesting transmission as the first signal; A communication device according to any one of (1) to (4) above.

[0152] (5-1) After receiving a CTS frame that authorizes transmission of the RTS frame in the first band, the control unit controls to start data transmission using the first band and the second band simultaneously. The communication device according to (5) above.

[0153] (6) When the second band becomes busy during the exchange of the RTS frame and the CTS frame in the first band or after the frame exchange is completed, the control unit controls to suspend the reservation of the transmission right in the first band. The communication device according to (5) above.

[0154] (7) the control unit controls to transmit a CTS frame that allows transmission as the first signal; A communication device according to any one of (1) to (3) above.

[0155] (7-1) the control unit transmits a CTS-to-self frame as a first signal; The communication device according to (7) above.

[0156] (8) the control unit controls to transmit a data frame as the first signal; A communication device according to any one of (1) to (3) above.

[0157] (9) After acquiring the transmission right in the second band, the control unit controls to suspend the data transmission in the first band. The communication device according to (8) above.

[0158] (9-1) the control unit controls the data transmission in the first band to be suspended immediately after acquiring the transmission right in the second band; The communication device according to (9) above.

[0159] (9-2) After acquiring the transmission right in the second band, the control unit controls the data transmission to be completed only in the first band until a certain period during which the destination terminal can decode the data. The communication device according to (9) above.

[0160] (9-3) The certain period is the end of a certain A-MPDU subframe of the A-MPDU or a block unit of an LDPC code. The communication device according to (9-2) above.

[0161] (10) The control unit controls to transmit a busy tone as the first signal. A communication device according to any one of (1) to (3) above.

[0162] (11) The busy tone includes information about the time when the data signal is to be transmitted. The communication device according to (10) above.

[0163] (12) The busy tone includes network identification information. The communication device according to any one of (10) and (11) above.

[0164] (12-1) The busy tone includes a signal pattern common to other systems. A communication device according to any one of (10) to (12) above.

[0165] (13) The control unit transmits the first signal according to a time period required to acquire a transmission right in the second band. A communication device according to any one of (1) to (3) above.

[0166] (14) When the time required to acquire the transmission right in the second band is equal to or longer than the time required to transmit the minimum unit of decodable data, the control unit controls to transmit a data frame as the first signal. The communication device according to (13) above.

[0167] (15) If the time required to acquire the transmission right in the second band is equal to or longer than the time required to exchange the RTS frame and the CTS frame, the control unit controls to transmit an RTS frame as the first signal. The communication device according to (13) above.

[0168] (16) When the time required to acquire the transmission right in the second band is less than the time required to exchange the RTS frame and the CTS frame but is equal to or greater than the time required to transmit the CTS frame, the control unit controls to transmit the CTS frame as the first signal. The communication device according to (13) above.

[0169] (17) When the time required to acquire the transmission right in the second band is shorter than the time required to transmit the CTS frame, the control unit controls to transmit a busy tone as the first signal. The communication device according to (13) above.

[0170] (18) A communication method for a communication device that transmits and receives wireless signals using multiple bands, acquiring a transmission right in a first band; transmitting a first signal in the first band until a transmission right in the second band is acquired; transmitting data simultaneously using the first band and the second band when the transmission rights are acquired in both the first band and the second band; A communication method comprising:

[0171] (19) A communication unit that transmits and receives wireless signals using multiple bands; a control unit that controls a communication operation in the communication unit; Equipped with the control unit controls to receive data transmitted using the first band and the second band simultaneously after receiving a first signal in the first band; Communication equipment.

[0172] (20) A communication method in a communication device that transmits and receives wireless signals using multiple bands, receiving a first signal in a first band; receiving data transmitted using the first band and the second band simultaneously; A communication method comprising: [Explanation of symbols]

[0173] 200...communication device, 210...control unit, 220...power supply unit 230...communication unit, 231...wireless control unit, 232...data processing unit 233...modulation / demodulation unit, 234...signal processing unit, 235...channel estimation unit 236...wireless interface unit, 237...amplifier unit 240...Antenna section

Claims

1. a communication unit that transmits and receives wireless signals using multiple bands; a control unit that controls a communication operation in the communication unit; Equipped with the control unit controls the transmission of a first signal in the first band during a period from when a transmission right in the first band is acquired until when a transmission right in the second band is acquired; Communication equipment.

2. the control unit controls the first signal to include information regarding acquisition of a transmission right in another band. The communication device according to claim 1 .

3. The information regarding acquisition of a transmission right in another band includes information indicating whether or not acquisition of a transmission right in another band is being waited for, or information regarding a band for which a transmission right has not yet been acquired. The communication device according to claim 2 .

4. the control unit, when acquiring transmission rights in both the first band and the second band, performs control so as to transmit data using the first band and the second band simultaneously. The communication device according to claim 1 .

5. the control unit controls to transmit an RTS frame requesting transmission as the first signal; The communication device according to claim 1 .

6. When the second band becomes busy during the exchange of the RTS frame and the CTS frame in the first band or after the frame exchange is completed, the control unit performs control to suspend the reservation of the transmission right in the first band. The communication device according to claim 5 .

7. the control unit controls to transmit a CTS frame indicating permission to transmit as the first signal; The communication device according to claim 1 .

8. the control unit controls to transmit a data frame as the first signal; The communication device according to claim 1 .

9. the control unit performs control to suspend data transmission in the first band after acquiring the transmission right in the second band; The communication device according to claim 8.

10. the control unit controls to transmit a busy tone as the first signal; The communication device according to claim 1 .

11. The busy tone includes information about the time when the data signal is to be transmitted. The communication device according to claim 10.

12. the busy tone includes network identification information; The communication device according to claim 10.

13. the control unit transmits the first signal according to a time period required to acquire a transmission right in the second band. The communication device according to claim 1 .

14. When the time required to acquire the transmission right in the second band is equal to or longer than the time required to transmit the minimum unit of decodable data, the control unit controls to transmit a data frame as the first signal.

14. The communication device of claim 13.

15. If the time required to acquire the transmission right in the second band is equal to or longer than the time required to exchange an RTS frame and a CTS frame, the control unit controls to transmit an RTS frame as the first signal.

14. The communication device of claim 13.

16. When the time required to acquire the transmission right in the second band is less than the time required to exchange the RTS frame and the CTS frame but is equal to or greater than the time required to transmit the CTS frame, the control unit performs control to transmit the CTS frame as the first signal.

14. The communication device of claim 13.

17. When the time required to acquire the transmission right in the second band is shorter than the time required to transmit a CTS frame, the control unit controls to transmit a busy tone as the first signal.

14. The communication device of claim 13.

18. A communication method for a communication device that transmits and receives wireless signals using multiple bands, comprising: acquiring a transmission right in a first band; transmitting a first signal in the first band until a transmission right in the second band is acquired; transmitting data simultaneously using the first band and the second band when the transmission rights are acquired in both the first band and the second band; A communication method comprising:

19. a communication unit that transmits and receives wireless signals using multiple bands; a control unit that controls a communication operation in the communication unit; Equipped with the control unit controls to receive data transmitted using the first band and the second band simultaneously after receiving a first signal in the first band; Communication equipment.

20. A communication method for a communication device that transmits and receives wireless signals using multiple bands, comprising: receiving a first signal in a first band; receiving data transmitted using the first band and the second band simultaneously; A communication method comprising:

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