Wireless communication device, wireless communication system, wireless communication method, and wireless communication program

Abstract

To provide a wireless communication device capable of improving the utilization efficiency of radio resources while guaranteeing transmission delay time in a wireless communication system adopting collision-type and non-collision type access methods.SOLUTION: A wireless communication device 100 includes: a storage unit 120 that stores terminal information including type information on a plurality of terminals forming a network; a DTI (Data Transmission Interval) configuration unit 114; a control information generation unit 115; and a control information transmission unit 116. The DTI configuration unit 114 configures DTI information indicating a data transmission period of data communicated over the network based on the terminal information. The control information generation unit 115 generates control information in the network, including the DTI information based on the DTI information generated by the DTI configuration unit. The control information transmission unit 116 transmits the control information to the terminals in the network.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a wireless communication device, a wireless communication system, a wireless communication method, and a wireless communication program.

Background Art

[0002] Conventionally, in a wireless communication system, in addition to a non-collision access method for controlling an access procedure for data transmission, a collision access method that shares wireless resources and allows collisions has been proposed. Patent Document 1 discloses a user device that can communicate using a non-collision access method and a collision access method. The user device disclosed in Patent Document 1 switches between and uses a non-collision access method and a collision access method.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the user device disclosed in Patent Document 1, when the traffic volume is equal to or greater than a predetermined threshold value, all user devices use the non-collision access method. As a result, a large amount of wireless resources are used during high traffic, and when there is a shortage of wireless resources, the transmission delay time increases regardless of the priority of the information to be transmitted.

[0005] The present invention has been made in view of such problems of the prior art. An object of the present invention is to provide a wireless communication device capable of improving the usage efficiency of wireless resources while guaranteeing the transmission delay time in a wireless communication system that employs collision and non-collision access methods.

Means for Solving the Problems

[0006] A wireless communication device according to an aspect of the present invention includes a storage unit that stores terminal information including type information of a plurality of terminals constituting a network, a DTI configuration unit that configures DTI information (Data Transmission Interval) indicating a data transmission period of data communicated in the network based on the terminal information, a control information generation unit that generates control information in the network including the DTI information based on the DTI information generated by the DTI configuration unit, and a control information transmission unit that transmits the control information to terminals in the network.

[0007] A wireless communication system according to an aspect of the present invention includes a plurality of the above-described wireless communication devices.

[0008] A wireless communication method according to an aspect of the present invention is a wireless communication method executed by a computer. Based on terminal information including type information of a plurality of terminals constituting a network stored in a storage unit, it configures DTI information (Data Transmission Interval) indicating a data transmission period of data communicated in the network, generates control information in the network including the DTI information based on the DTI information, and transmits the control information to terminals in the network.

[0009] A wireless communication program according to an aspect of the present invention causes a computer to execute steps of configuring DTI information (Data Transmission Interval) indicating a data transmission period of data communicated in the network based on terminal information including type information of a plurality of terminals constituting the network stored in a storage unit, generating control information in the network including the DTI information based on the DTI information, and transmitting the control information to terminals in the network.

Effects of the Invention

[0010] According to the present invention, in a wireless communication system adopting collision-type and non-collision-type access methods, it is possible to provide a wireless communication device capable of improving the usage efficiency of wireless resources while guaranteeing the transmission delay time.

Brief Description of the Drawings

[0011]

Figure 1

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Mode for Carrying Out the Invention

[0012] (First Embodiment) Hereinafter, the wireless communication system 10 according to this embodiment will be described in detail with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for convenience of explanation and may be different from the actual ratios. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

[0013] (Schematic Configuration of Wireless Communication System 10) FIG. 1 is a configuration diagram showing the outline of the wireless communication system 10 according to this embodiment. The wireless communication system 10 shown in FIG. 1 is an example of a network system in the millimeter-wave wireless LAN standard (IEEE802.11ad) corresponding to the non-collision access method and the collision access method (LAN: Local Area Network).

[0014] Conventionally, a BSS (Basic Service Set) mode for communication via an access point (AP) commonly used in a wireless LAN has been defined. In the IEEE802.11ad standard, in order to cope with the use of a directional antenna and the short communication distance, in addition to the BSS mode, a PBSS (Personal Basic Service Set) mode in which stations STAs communicate directly with each other is also defined. In this PBSS mode, one of the stations STA becomes a PCP (PBSS Central Point) and controls the communication. In the present embodiment, the station STA corresponds to a terminal.

[0015] In a conventional wireless LAN, DCF (Distributed Coordination Function), which is a collision type access method that transmits when each station STA wants to transmit by itself, is used. Also, in the IEEE802.11ad standard, in addition to this DCF, a non - collision type access method that allocates communication time to a specific station STA in advance is also defined. That is, the non - collision type access method is a transmission method in which communication time is allocated to a specific station STA in advance, while the collision type access method is a transmission method in which communication time is not allocated in advance. In the present embodiment, the non - collision type access method corresponds to the first access method. Also, in the present embodiment, the collision type access method corresponds to the second access method.

[0016] The wireless communication system 10 shown in FIG. 1 is configured to include a plurality of wireless communication devices 100. The wireless communication devices 100 of the wireless communication system 10 are divided into a master - side PCP / AP 100ab and a slave - side station 100c according to their roles, situations, etc.

[0017] FIGS. 2A and 2B show an example of the configuration of the wireless communication system 10. FIG. 2A is a schematic diagram of a network system when the wireless communication system 10 is in the BSS mode. In the case of the configuration shown in FIG. 2A, communication with each station 100c is performed via the access point AP100a.

[0018] FIG. 2B is a schematic diagram of a network system when the wireless communication system 10 is in the PBSS mode. In FIG. 2B, any one of the stations 100c serves as the PCP 100b (PBSS Central Point) to control communication.

[0019] That is, in the present embodiment, the station STA (wireless communication device 100) can be the AP 100a, the PCP 100b, the PCP / AP 100ab, or the station 100c according to its role. Note that in the present embodiment, the PCP / AP 100ab is a notation (including both) without distinguishing between the PCP 100b and the AP 100a. Hereinafter, when there is no need to distinguish between the AP 100a, the PCP 100b, the PCP / AP 100ab, and the station 100c respectively for explanation, it is simply denoted as the "wireless communication device 100".

[0020] In the IEEE802.11ad standard, access control is performed based on the beacon interval shown in FIG. 3. The beacon interval is composed of a BHI (Beacon Header Interval) and a DTI (Data Transmission Interval) as shown in FIG. 3. The wireless communication device 100 performs data transmission through this DTI.

[0021] In the present embodiment, the DTI is composed of including a CBAP (Contention Based Access Period) which is a collision type access period and / or an SP (Service Period) which is a non - collision type scheduled access period.

[0022] CBAP is an access period by DCF known as CSMA / CA (Carrier Sense Multiple Access / Collision Avoidance). For the station STA to transmit data, CBAP first senses the medium in advance to determine whether another station STA is transmitting. Then, if the medium is not determined to be busy, CBAP continues the transmission. On the other hand, if the medium is determined to be busy, CBAP defers the transmission until the medium becomes idle.

[0023] SP is an access period during which only specific stations STA scheduled in advance by PCP / AP100ab can transmit data. Note that in the IEEE802.11ad standard, the number and order of CBAP used in the collision access method during DTI and SP used in the non-collision access method are not specified and can be arbitrarily set by AP / PCP.

[0024] As described above, the wireless communication system 10 of this embodiment is composed of a plurality of wireless communication devices 100 (stations STA) as shown in FIG. 1. Each wireless communication device 100 is connected to external devices 300 (see FIG. 5) such as sensors and switches that generate information, and displays and actuators that are the objects of control based on control data obtained by wireless communication. In the wireless communication system 10, wireless communication of information is intermittently performed between the wireless communication devices 100 via the antennas 400 (see FIG. 5) of the wireless communication devices 100.

[0025] In the example shown in FIG. 1, one of the wireless communication devices 100 becomes PCP / AP100ab and generates the beacon interval shown in FIG. 3. Also, the DTI information regarding the configuration of the data transmission period (DTI) within the beacon interval is determined by PCP / AP100ab and notified to the wireless communication devices 100 within the wireless communication system 10 by a beacon frame including the configuration information of the beacon interval.

[0026] Figures 4A to 4C show an example of the allocation of the data transmission interval (DTI) and an example of the data transmission image when data transmission requests occur simultaneously at each station STA.

[0027] Figure 4A shows an example when only the contention-based access period (CBAP) of the DTI is allocated by the PCP / AP 100ab. Each station STA simultaneously checks the channel usage status by carrier sense indicated by the hatched blocks in Figure 4A at the start timing of the DTI (CBAP), and executes data transmission processing when it is confirmed that the channel is unused (Idle). The communication collision probability is reduced by individually changing the carrier sense time of each station STA (CSMA / CA). As a result of the carrier sense, when it is confirmed that the channel is being used (BUSY) by other station STAs or the like, the data transmission processing is not performed, and the station waits until the channel becomes unused and starts over from the carrier sense. In the contention-based access method, as the number of station STAs increases or the transmission data of each station STA increases, the channel utilization rate increases, and the data transmission delay and the data transmission failure probability also increase. The example shown in Figure 4A shows an example where the data transmission of STA2 could not be completed within the same DTI.

[0028] Figure 4B shows an example when only the non-contention-based access period (SP) of the DTI is allocated by the PCP / AP 100ab. Each station STA identifies the SP allocated to itself from the DTI allocation information notified within the BHI from the PCP / AP 100ab and performs data transmission. In non-contention-based access, if it is possible to allocate an SP to all station STAs, it is possible to ensure data transmission. However, as the number of station STAs increases or the transmission data of each station STA increases, the data transmission delay increases.

[0029] FIG. 4C shows an example in which a collision-based access period (CBAP) and a non-collision-based access period (SP) are allocated to DTI by PCP / AP100ab. Each STA performs data transmission using the corresponding SP when there is an SP assigned to the STA in the DTI notification information notified by the PCP / AP100ab within the BHI. When there is no assigned SP, the STA performs data transmission using the CBAP.

[0030] The wireless communication system 10 according to this embodiment determines the configuration of the collision-based access period (CBAP) and the non-collision-based access period (SP) allocated within the DTI based on the terminal information regarding each station STA in the wireless communication system 10.

[0031] (Configuration of Wireless Communication Device 100) FIG. 5 is a block diagram showing a schematic configuration of the wireless communication device 100. In this embodiment, the wireless communication device 100 includes a control unit 110, a storage unit 120, an external I / F 130 (Interface), and a PHY unit 140. The control unit 110 includes a MAC unit 110a as a function.

[0032] Further, the wireless communication device 100 can be a general computer including the above-described respective blocks. By executing a control program by the general computer, it is possible to realize the functions shown in FIG. 6 described later. Hereinafter, only the parts related to the features in this embodiment will be described. Therefore, the wireless communication device 100 naturally includes other functional blocks that are not directly related to the features in this embodiment. Details of the control unit 110 will be described later.

[0033] The storage unit 120 can be a ROM (Read Only Memory), a RAM (Random Access Memory), a hard disk, or the like. The storage unit 120 can also store various data such as input data, output data, and intermediate data for the wireless communication device 100 to execute processing. Note that the storage unit 120 for storing these various data may be one or plural. For example, a configuration may be adopted in which a single storage unit 120 stores data in divided areas. Alternatively, data may be distributed and stored in a plurality of storage devices installed at physically separate locations.

[0034] The external I / F 130 is a connection interface with an external device 300 that generates information to be wirelessly transmitted or uses information acquired by wireless transmission.

[0035] The PHY unit 140 executes processes such as modulation and demodulation for transmitting information over radio waves via the antenna 400, and executes processes such as generation and analysis of PHY frames. Parameters for executing processes such as modulation and demodulation can be stored in the storage unit 120. Note that the PHY unit 140 can execute functions corresponding to the physical layer in a model in which communication protocols (communication rules) are layered. In the antenna 400, conversion between the high-frequency signal actually transmitted and received and the electrical signal is performed.

[0036] The MAC unit 110a executes processes such as multiple access control for sharing radio waves serving as a transmission medium among a plurality of wireless communication devices 100. Parameters for executing processes such as multiple access control can be stored in the storage unit 120. Note that the MAC unit 110a can execute functions corresponding to the MAC layer in a model in which communication protocols are layered. In the present embodiment, the MAC unit 110a is configured as a part of the functions provided in the control unit 110.

[0037] FIG. 6 shows a part of the functions of the MAC unit 110a. The MAC unit 110a includes, as functions, a mode selection unit 111, a beacon interval configuration unit 112, and a wireless communication processing unit 113. The beacon interval configuration unit 112 includes, as functions, a DTI configuration unit 114, a control information generation unit 115, and a control information transmission unit 116. Further, the wireless communication processing unit 113 includes, as functions, a DTI configuration acquisition unit 117, an access period determination unit 118, and a data transmission / reception unit 119.

[0038] The mode selection unit 111 reads out the operation mode that determines whether the operation mode corresponding to the wireless communication device 100 is the PCP / AP 100ab or the station 100c. In the present embodiment, the operation mode is determined (set) in advance at the time of system construction and stored in the storage unit 120. The mode selection unit 111 also selects the operation mode. Specifically, the mode selection unit 111 selects whether the read operation mode is the PCP / AP 100ab or the station 100c.

[0039] (Functions and Configuration of the Beacon Interval Configuration Unit 112) When the operation mode corresponding to the wireless communication device 100 is the PCP / AP 100ab, the beacon interval configuration unit 112 configures the beacon interval and transmits (notifies) a beacon frame including the configuration information of the beacon interval to each station STA. Specifically, the DTI configuration unit 114 configures the DTI. The control information generation unit 115 generates control information. Further, the control information transmission unit 116 transmits the control information.

[0040] The DTI configuration unit 114 configures the beacon interval including the configuration information of the DTI. The DTI configuration unit 114 configures the beacon interval as shown in FIG. 8 based on the terminal information shown in FIG. 7.

[0041] The terminal information shown in FIG. 7 includes information regarding each station STA in the wireless communication system 10. The information regarding the station STA includes, for example, an ID (Identifier) for identifying the station STA. Further, the terminal information includes information regarding the data type indicating whether the data to be transmitted is control data or information data. Note that in the present embodiment, the control data is data that requires higher communication quality than the information data. That is, the control data is data with a higher priority in data transmission than the information data. Further, the terminal information includes the data size of the data to be transmitted and the allowable delay time in data transmission. Furthermore, the terminal information includes information regarding the DTI allocation configured by the DTI configuration unit 114. The information regarding the DTI allocation is information indicating whether the transmission method of the data transmitted from the station STA is CBAP of the collision access method or SP of the non-collision access method.

[0042] In the present embodiment, the DTI configuration unit 114 determines DTI allocation information based on the data type shown in FIG. 7 and stores it in the terminal information of the storage unit 120. Specifically, the DTI configuration unit 114 determines the DTI allocation information based on the data type included in the terminal information. The DTI configuration unit 114 allocates SP as the DTI allocation information to the station STA whose data type is control data. Further, the DTI configuration unit 114 allocates CBAP as the DTI allocation information to the station STA whose data type is information data. That is, the DTI configuration unit 114 allocates the period of the non-collision access method (SP) in the case of the control data with a higher priority.

[0043] Furthermore, the DTI component 114 determines the allocation order within the SP for the station STA that has been assigned the SP in the DTI allocation information, based on its allowable delay time. In the present embodiment, the DTI component 114 allocates the order of the SPs in ascending order of the allowable delay time. In the example shown in FIG. 7, since the STA2 assigned to the SP has a shorter allowable delay time than the STA0 also assigned to the SP, STA2 is allocated so that its order in the SP is earlier than that of STA0.

[0044] The control information generation unit 115 generates control information (beacon frame) such as a beacon frame including the access period allocation information in the DTI. Specifically, the control information generation unit 115 generates control information including the DTI allocation information in the BTI (Beacon Transmission Interval) included in the BHI of the beacon interval. Note that the BTI is included in the BHI as shown in the beacon interval of FIG. 3. In the present embodiment, the beacon frame corresponds to the control information.

[0045] That is, the DTI allocation information is notified (Extended Schedule Element) within the Body (not shown) of the beacon frame transmitted from the PCP / AP100ab in the BTI based on the IEEE802.11ad standard. This Body includes information such as the STA allocation identifier, allocation type, allocation time block length, and number of blocks necessary for configuring the DTI. The station 100c that has received the control information transmitted from the PCP / AP100ab can recognize its own data transmission timing and the like.

[0046] The control information transmission unit 116 performs transmission processing of the generated control information (beacon frame). Specifically, the generated control information is transmitted to each station STA.

[0047] (Function and Configuration of the Wireless Communication Processing Unit 113) The wireless communication processing unit 113 performs wireless communication processing based on the beacon frame (control information) transmitted from the PCP / AP 100ab.

[0048] The DTI configuration acquisition unit 117 acquires the configuration information of the DTI from the DTI allocation information transmitted from the PCP / AP 100ab in the BHI included in the beacon interval.

[0049] The access period determination unit 118 determines whether it corresponds to the access period in the allocated SP or CBAP based on the configuration information of the DTI acquired by the DTI configuration acquisition unit 117.

[0050] The data transmission / reception unit 119 performs data transmission / reception processing during the access period for its own station STA based on the result determined by the access period determination unit 118.

[0051] (Outline of the processing flow of the wireless communication device 100) Next, the processing flow in the wireless communication device 100 is shown using the flowcharts shown in FIGS. 9 to 12. A series of operations of the wireless communication device 100 shown in the flowcharts of FIGS. 9 to 12 start when the wireless communication device 100 is activated and end when the work is completed. Also, the flowcharts shown in FIGS. 9 to 12 also end the processing by power-off or an interrupt of the processing end. In the following description of the flowchart, the same content as that described in the description of the above-described wireless communication system 10 and wireless communication device 100 will be omitted or simplified in the description.

[0052] (Operation mode selection processing) First, the operation of the wireless communication system 10 will be described based on the flowchart shown in FIG. 9. In step S901, the mode selection unit 111 selects whether the wireless communication device 100 is the PCP / AP 100ab or the station 100c. Specifically, the mode selection is performed by the subroutine processing of "operation mode selection" shown in FIG. 10.

[0053] The subroutine processing related to "operation mode selection" in FIG. 10 will be described.

[0054] In step S1001, the mode selection unit 111 reads the operation mode. The operation mode is determined (set) in advance at the time of system construction and stored in the storage unit 120.

[0055] In step S1002, the mode selection unit 111 selects the operation mode. Specifically, the mode selection unit 111 selects whether the operation mode of the wireless communication device 100 is PCP / AP100ab or station 100c based on the read operation mode. In step S1002, when the mode selection unit 111 determines that the operation mode is PCP / AP100ab (step S1002: YES), it proceeds to step S1003. On the other hand, in step S1002, when the mode selection unit 111 determines that the operation mode is not PCP / AP100ab (step S1002: NO), it proceeds to step S1004.

[0056] In step S1003, the mode selection unit 111 sets PCP / AP100ab as the operation mode. Then, it returns to step S901 of the flowchart shown in FIG. 9.

[0057] In step S1004, the mode selection unit 111 sets station 100c (STA) as the operation mode. Then, it returns to step S901 of the flowchart shown in FIG. 9.

[0058] Returning to the flowchart shown in FIG. 9 to continue the explanation. In step S902, the control unit 110 determines whether the operation mode is "PCP / AP". In step S902, when the control unit 110 determines that the operation mode is "PCP / AP" (step S902: YES), it proceeds to step S903. On the other hand, in step S902, when the control unit 110 determines that the operation mode is not "PCP / AP" (step S902: NO), it proceeds to step S904.

[0059] (Beacon Interval Configuration Process) In step S903, the beacon interval configuration unit 112 configures the beacon interval. Specifically, for the configuration of the beacon interval, the subroutine process of "Beacon Interval Configuration" (beacon interval configuration) shown in FIG. 11 is executed. The subroutine process of "Beacon Interval Configuration" in FIG. 11 will be described.

[0060] In step S1101, the DTI configuration unit 114 reads out the information of "data type" and "allowable delay time" from the terminal information regarding each station STA stored in the storage unit 120.

[0061] In step S1102, the DTI configuration unit 114 determines whether there is control system data based on the read "data type". In step S1102, when the DTI configuration unit 114 determines that there is control system data in the information such as the data type (step S1102: YES), it proceeds to step S1103. On the other hand, in step S1102, when the DTI configuration unit 114 determines that there is no control system data in the information such as the data type (step S1102: NO), it proceeds to step S1104.

[0062] In step S1103, the DTI configuration unit 114 performs SP allocation. In step S1103, the DTI configuration unit 114 determines the SP allocation order in the DTI based on the "allowable delay time" information of the control system data transmitted wirelessly. Specifically, the SPs are allocated in ascending order of the "allowable delay time".

[0063] In step S1104, the DTI configuration unit 114 performs CBAP allocation. Specifically, the DTI configuration unit 114 allocates CBAP as DTI to the station STA whose "data type" is information system data.

[0064] In step S1105, the control information generation unit 115 generates control information (beacon frame) such as a beacon frame including access period allocation information in the DTI. Specifically, the control information generation unit 115 generates control information including the DTI allocation information in the BTI included in the BHI of the beacon interval. Note that the BTI is included in the BHI as shown in the beacon interval of FIG. 3.

[0065] In step S1106, the control information transmission unit 116 performs transmission processing of the generated control information (beacon frame). Specifically, the generated control information is transmitted to each station STA. Then, the process returns to the flowchart shown in FIG. 9.

[0066] (Wireless communication processing) In step S904, the wireless communication processing unit 113 performs wireless communication processing. Specifically, the processing of the subroutine regarding "wireless communication processing" shown in FIG. 12 is executed. Using FIG. 12, the processing regarding "wireless communication processing" will be described.

[0067] In step S1201, the DTI configuration acquisition unit 117 acquires the DTI configuration. Specifically, the DTI configuration acquisition unit 117 acquires the configuration information of the DTI from the DTI allocation information transmitted from the PCP / AP 100ab in the BHI included in the beacon interval.

[0068] In step S1202, the wireless communication processing unit 113 determines whether the DTI has started based on the acquired configuration information. In step S1202, if the wireless communication processing unit 113 determines that the DTI has started (step S1202: YES), the process proceeds to step S1203. On the other hand, in step S1202, if the wireless communication processing unit 113 determines that the DTI has not started (step S1202: NO), the process of step S1202 is repeated.

[0069] In step S1203, the wireless communication processing unit 113 determines whether the DTI allocation information is SP. In step S1203, if the wireless communication processing unit 113 determines that the DTI allocation information is SP (step S1203: YES), it proceeds to step S1204. On the other hand, in step S1203, if the wireless communication processing unit 113 determines that the DTI allocation information is not SP (step S1203: NO), it proceeds to step S1210.

[0070] In step S1204, the access period determination unit 118 determines whether the access period in the DTI is for the own node. In step S1204, if the access period determination unit 118 determines that the DTI is the access period for the own node (step S1204: YES), it proceeds to step S1205. On the other hand, in step S1204, if the access period determination unit 118 determines that the DTI is not the access period for the own node (step S1204: NO), it proceeds to step S1208.

[0071] In step S1205, the access period determination unit 118 determines whether the DTI is the data transmission access period. In step S1205, if the access period determination unit 118 determines that the DTI is the data transmission access period (step S1205: YES), it proceeds to step S1206. On the other hand, in step S1205, if the access period determination unit 118 determines that the DTI is not the data transmission access period (step S1205: NO), it proceeds to step S1207.

[0072] In step S1206, the data transmission / reception unit 119 performs data transmission processing. Then, the wireless communication processing unit 113 proceeds to step S1208.

[0073] In step S1207, the data transmission / reception unit 119 performs data reception processing. Then, the wireless communication processing unit 113 proceeds to step S1208.

[0074] In step S1210, the data transmission / reception unit 119 determines whether there is a data transmission request. In step S1210, if the data transmission / reception unit 119 determines that there is a data transmission request (step S1210: YES), it proceeds to step S1211. On the other hand, in step S1210, if the data transmission / reception unit 119 determines that there is no data transmission request (step S1210: NO), it proceeds to step S1212.

[0075] In step S1211, the data transmission / reception unit 119 performs data transmission processing. After that, the wireless communication processing unit 113 proceeds to step S1208.

[0076] In step S1212, the data transmission / reception unit 119 performs data reception processing. After that, the wireless communication processing unit 113 proceeds to step S1208.

[0077] In step S1208, the access period determination unit 118 determines whether the access period has ended. More specifically, it determines whether one of the data transmissions of SP or CBAP processed in the DTI has ended. In step S1208, if the access period determination unit 118 determines that the access period has ended (step S1208: YES), it proceeds to step S1209. On the other hand, in step S1208, if the access period determination unit 118 determines that the access period has not ended (step S1208: NO), it returns to the process of step S1208 and repeats the process of step S1208.

[0078] In step S1209, the wireless communication processing unit 113 determines whether the DTI has ended. In step S1209, if the wireless communication processing unit 113 determines that the DTI has ended (step S1209: YES), it returns to step S904 of the flowchart shown in FIG. 9. On the other hand, in step S1209, if the wireless communication processing unit 113 determines that the DTI has not ended (step S1209: NO), it returns to step S1203 and repeats the process from step S1203.

[0079] Return to the description of the flowchart shown in FIG. 9. After the wireless communication process in step S904 ends, return to step S903, and the process from step S903 is repeatedly executed.

[0080] By executing the processes of the flowcharts shown in FIGS. 9 to 12 described above, the wireless communication system 10 in the present embodiment can improve the usage efficiency of wireless resources while guaranteeing the transmission delay time.

[0081] FIGS. 13A and 13B show a DTI allocation example of the present embodiment for the terminal information of the station STA and a comparison example with transmission patterns A and B when the DTI allocation of the present embodiment is not applied. Transmission pattern A shows an example when the DTI allocation is set as a period (SP) of a non - collision access method in ascending order of the identification numbers of the stations STA. Further, transmission pattern B shows an example in which a period (CBAP) of a collision access method is provided first in the DTI, and then a period (SP) of a non - collision access method is provided in ascending order of the identification numbers of the stations STA in the same manner as in transmission pattern A. Note that the example shown in FIG. 13A shows an example of access period allocation during high traffic.

[0082] As shown in FIG. 13B, in transmission pattern A, it is shown that STAs 0 and 5 of control - system data with high priority indicated by hatching are included in the DTI and transmitted. Also, in transmission pattern B, it is shown that only STA0 of control - system data with high priority indicated by hatching is included in the DTI and transmitted. On the other hand, in the transmission pattern of the present embodiment, it is shown that STAs 0 to 5 of control - system data with high priority are included in the DTI and transmitted in ascending order of the short allowable delay time.

[0083] That is, in transmission pattern A and transmission pattern B shown in FIGS. 13A and 13B, regardless of the data priority, there is an omission in the allocation of high-priority control system data into the same frame, and the transmission delay time increases. On the other hand, in the present embodiment, by preferentially allocating high-priority control system data to DTI, it is possible to perform data transmission that improves the usage efficiency of radio resources while guaranteeing the transmission delay time.

[0084] As described above, the wireless communication device 100 includes a storage unit 120 that stores terminal information including type information of a plurality of terminals constituting the network. The wireless communication device 100 also includes a DTI configuration unit 114 (Data Transmission Interval), a control information generation unit 115, and a control information transmission unit 116. The DTI configuration unit 114 configures DTI information indicating a data transmission period of data communicated in the network based on the terminal information. The control information generation unit 115 generates control information in the network including the DTI information based on the DTI information generated by the DTI configuration unit 114. The control information transmission unit 116 transmits the control information to terminals in the network.

[0085] Thereby, in the wireless communication device 100 that adopts the collision type and non-collision type access methods in the present embodiment, by configuring the DTI based on the terminal information, it is possible to improve the usage efficiency of radio resources while guaranteeing the transmission delay time.

[0086] In addition, the DTI configuration unit 114 allocates a transmission method for data transmitted from the station STA based on information indicating the data type of the terminal information. Specifically, the DTI configuration unit 114 allocates the transmission method of the data to a non-collision type access method in which communication time is allocated in advance, or a collision type access method in which communication time is not allocated in advance. Thereby, in the network to which the wireless communication device 100 is applied, it is possible to apply an appropriate transmission method according to the priority of data transmission, and it is possible to more appropriately guarantee the transmission delay time and improve the usage efficiency of radio resources.

[0087] Further, when the DTI component 114 determines that data transmission from the station STA has a high priority based on the type information of the terminal information, the DTI component 114 allocates the data transmitted from the station STA to a non-collision access method. Thereby, for data with a high priority, it is possible to preferentially transmit, and it is possible to more reliably guarantee the transmission delay time.

[0088] Furthermore, in the above-described embodiment, when the DTI component 114 allocates data with a high priority to a non-collision access method, the DTI component 114 determines the allocation order based on the allowable delay time information of the terminal information. Thereby, since data transmission is performed in order from the station STA with a short allowable delay time, it is possible to more reliably guarantee the transmission delay time.

[0089] (Second Embodiment) As described above, although one specific embodiment has been described, the above-described embodiments are examples and do not limit the embodiments. For example, in the above-described embodiment, in the operation mode selection, a mode of selecting an operation mode based on information regarding the operation mode stored in the storage unit 120 in advance is exemplified. Here, a wireless communication system 10 according to a second embodiment in which the wireless communication device 100 performs operation mode selection based on a search process will be described with respect to a configuration different from that of the first embodiment.

[0090] FIG. 14 shows an example of a flowchart (subroutine process) of a process related to "operation mode selection" based on a search process. The flowchart shown in FIG. 14 is implemented instead of the subroutine process of "operation mode selection" shown in FIG. 10 in step S901 of the flowchart shown in FIG. 9. Note that in the wireless communication device 100 in the second embodiment, the process related to "operation mode selection" may include only the flowchart shown in FIG. 14. Alternatively, in the wireless communication device 100 in the second embodiment, the process related to "operation mode selection" may include both the flowcharts shown in FIGS. 10 and 14 and may be configured to be selectable by setting.

[0091] In step S1401 of the flowchart shown in FIG. 14, the mode selection unit 111 resets a "PCP / AP search timer" that times out within a predetermined time after the start of the station STA.

[0092] In step S1402, the mode selection unit 111 determines whether a beacon frame has been received. If a beacon frame has been received, since the PCP / AP 100ab that transmits this beacon frame already exists, the wireless communication device 100 that has received the beacon frame becomes the station 100c. On the other hand, if the beacon frame is not received within a predetermined time, since the PCP / AP 100ab that transmits the beacon frame does not exist, this wireless communication device 100 becomes the PCP / AP 100ab.

[0093] In step S1402, when the mode selection unit 111 determines that a beacon frame has been received (step S1402: YES), it proceeds to step S1403. On the other hand, in step S1402, when the mode selection unit 111 determines that a beacon frame has not been received (step S1402: NO), it proceeds to step S1404.

[0094] In step S1403, the mode selection unit 111 sets the station 100c (STA) as the operation mode. Then, it returns to step S901 of the flowchart shown in FIG. 9.

[0095] In step S1404, the mode selection unit 111 determines whether the "PCP / AP search timer" has timed out. That is, it determines whether a predetermined period has elapsed since the "PCP / AP search timer" was reset in step S1401. In this embodiment, the predetermined period from when the "PCP / AP search timer" is reset until it is determined to have timed out can be set between 20 ms and 1000 ms, for example, 100 ms. Note that the predetermined period from when the "PCP / AP search timer" is reset until it is determined to have timed out is not limited to the above range, and for example, a value of 1000 ms or more may be set as the predetermined period.

[0096] In step S1404, if the mode selection unit 111 determines that the "PCP / AP search timer" has timed out (step S1404: YES), it proceeds to step S1405. On the other hand, in step S1404, if the mode selection unit 111 determines that the "PCP / AP search timer" has not timed out (step S1404: NO), it returns to step S1402 and repeatedly executes the processing from step S1402.

[0097] In step S1405, the mode selection unit 111 sets PCP / AP100ab as the operation mode. Then, it returns to step S901 of the flowchart shown in FIG. 9.

[0098] As described above, the wireless communication device 100 in the second embodiment performs operation mode selection based on the "PCP / AP search process". Thereby, the wireless communication system 10 can flexibly construct the system according to the situation of the stations STA constituting the network. That is, the wireless communication system 10 including the wireless communication device 100 in the second embodiment can improve the communication quality in response to a dynamic radio environment.

[0099] (Third Embodiment) Next, a third embodiment will be described. In the following description, when the same reference numerals as those in the first and / or second embodiments are used, the same configuration as that in the first and / or second embodiments is indicated, and the preceding description is referred to unless otherwise specified. Here, a wireless communication system 10 according to a third embodiment that updates and uses terminal information based on actually transmitted data will be described with respect to configurations different from those in the first and / or second embodiments.

[0100] FIG. 15 is a flowchart showing an example of the operation of the wireless communication system 10 in the third embodiment. In the flowchart shown in FIG. 15, it is different in that step S1505 is added as compared with the flowchart shown in FIG. 9 in the first and second embodiments.

[0101] In the third embodiment, a field for identifying data types and the like as shown in FIG. 16 is provided in the data transmission frame exchanged within the wireless communication system 10. Also, in the third embodiment, the data transmission / reception unit 119 of the wireless communication device 100 that has become the PCP / AP 100ab collects information such as the data type in the data transmission frame transmitted by the station 100c and updates the "data type" and the like of the terminal information in the storage unit 120. For example, in the third embodiment, the terminal information to be updated is the "data type" (Type), "data size" (Length), and "acceptable delay time" (Acceptable Delay Time) shown in FIG. 16. Note that in this embodiment, the data transmission frame corresponds to the transmission data.

[0102] In step S1505 of the flowchart shown in FIG. 15, the data transmission / reception unit 119 updates the transmission data type information. Specifically, the data transmission / reception unit 119 collects information such as the data type in the data transmission frame, and updates the "data type" etc. of the terminal information in the storage unit 120. Note that the form of updating the "data type" etc. of the terminal information by the data transmission / reception unit 119 does not limit the configuration of the present embodiment, and it may be a form of updating only the difference from the "data type" etc. already stored in the storage unit 120. Alternatively, it may be a form of updating by storing all the received "data type" etc. in the "data type" etc. of the terminal information in the storage unit 120.

[0103] Also, in the third embodiment, the update of the information such as the data type in the data transmission frame is performed on the terminal information in the storage unit 120 of the wireless communication device 100 that has become the PCP / AP 100ab. Further, the PCP / AP 100ab may be configured to broadcast and transmit the updated terminal information to other stations 100c to maintain the consistency between the terminal information of the PCP / AP 100ab and the terminal information stored in the storage unit 120 of each station 100c.

[0104] As described above, in the wireless communication system 10 according to the third embodiment, the data transmission / reception unit 119 collects information such as the data type in the data transmission frame, and updates the "data type" etc. of the terminal information in the storage unit 120. Thereby, it becomes possible to save the labor of confirming the data type etc. in advance at the time of system construction and storing them in the storage unit 120, and it becomes possible to improve the efficiency of network system construction.

[0105] (Other Embodiments) Although the embodiments have been described in detail with reference to the drawings, the present embodiment is not limited by the contents described in the above embodiments. Further, the constituent elements described above include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the configurations described above can be combined as appropriate. Also, various omissions, substitutions, or changes in the configuration can be made without departing from the gist of the embodiment.

[0106] In the above-described embodiment, it may be configured to preferentially allocate a period (SP) of a non-collision access method to the station 100c that includes information indicating whether the data to be retransmitted is included in the terminal information stored in the storage unit 120 and transmits the retransmitted data. For example, by preferentially implementing data transmission that could not be normally performed due to some cause, it is possible to improve the data arrival rate at the destination node.

[0107] Also, in the above-described embodiment, it may be configured to preferentially allocate a period (SP) of a non-collision access method to the station 100c that includes information indicating whether the data to be relayed is included in the terminal information stored in the storage unit 120 and transmits the relayed data. Here, relayed transmission is data transmission that is performed by detouring through another station STA when direct transmission from the source STA to the destination STA cannot be performed due to some factor such as shielding by an obstacle. For example, by preferentially implementing data transmission that could not be normally performed due to some cause, it is possible to improve the data arrival rate at the destination node. Furthermore, since the data to be relayed is likely to have a longer transmission time compared to the data of direct communication, it is possible to suppress an increase in the delay time by preferentially allocating the relayed data in this way.

[0108] Furthermore, in the above-described embodiment, it may be configured to include information indicating whether the communication is directional communication with the antenna directivity narrowed down in the terminal information stored in the storage unit 120. The information indicating whether the communication is directional communication with the antenna directivity narrowed down allocates a period (CBAP) of a collision access method to the directional communication. On the other hand, when performing omnidirectional communication, a period (SP) of a non-collision access method is preferentially allocated. This makes it possible to perform multiple simultaneous communications by spatial division during the period (CBAP) of the collision access method and improve the channel usage efficiency.

[0109] In addition, a computer program (wireless communication program) that causes a computer to execute the processing (wireless communication method) in the wireless communication device 100 described above, and a computer-readable recording medium on which the program is recorded are included in the scope of the present embodiment. Here, the type of the computer-readable recording medium is arbitrary. Further, the computer program is not limited to being recorded on the recording medium, and may be transmitted via a telecommunication line, a wireless or wired communication line, a network typified by the Internet, or the like.

[0110] The features of the wireless communication device 100, the wireless communication system 10, the wireless communication method, and the wireless communication program of the present embodiment will be described below.

[0111] The wireless communication device 100 according to the first aspect includes a storage unit 120 that stores terminal information including type information of a plurality of terminals constituting a network. Further, the wireless communication device 100 includes a DTI configuration unit 114 that configures DTI information (Data Transmission Interval) indicating a data transmission period of data communicated in the network based on the terminal information. Further, the wireless communication device 100 includes a control information generation unit 115 that generates control information in the network including the DTI information based on the DTI information generated by the DTI configuration unit 114. Furthermore, the wireless communication device 100 includes a control information transmission unit 116 that transmits the control information to terminals in the network.

[0112] According to the above configuration, the wireless communication device 100 that employs a collision type and a non-collision type access method can improve the usage efficiency of wireless resources while guaranteeing the transmission delay time by configuring the DTI based on the terminal information.

[0113] The DTI configuration unit 114 according to the second aspect may allocate the transmission method of data transmitted from the terminal to a first access method in which communication time is allocated in advance or a second access method in which communication time is not allocated in advance based on the type information of the terminal information.

[0114] According to the above configuration, in the network to which the wireless communication device 100 is applied, it is possible to apply an appropriate transmission method according to the priority of data transmission, and it is possible to improve the usage efficiency of wireless resources while more appropriately guaranteeing the transmission delay time.

[0115] When the DTI component 114 of the wireless communication device 100 according to the third aspect determines that the data transmission from the terminal has a high priority based on the type information of the terminal information, the data transmitted from the terminal may be assigned to the first access method.

[0116] According to the above configuration, it is possible to preferentially transmit data with a high priority, and it is possible to more reliably guarantee the transmission delay time.

[0117] The terminal information of the wireless communication device 100 according to the fourth aspect further includes allowable delay time information for data transmission. When assigning to the first access method, the DTI component 114 may determine the assignment order based on the allowable delay time information of the terminal information.

[0118] According to the above configuration, since data transmission is performed in order from the station STA with a short allowable delay time, it is possible to more reliably guarantee the transmission delay time.

[0119] The wireless communication device 100 according to the fifth aspect further includes a data transceiver 119 that transmits and receives transmission data transmitted between the wireless communication device 100 and other terminals. The data transceiver 119 may update the terminal information based on the received transmission data.

[0120] According to the above configuration, the wireless communication device 100 can save the trouble of checking and storing data types, etc. in the storage unit 120 in advance at the time of system construction, and it is possible to improve the efficiency of network system construction.

[0121] The wireless communication system 10 according to the sixth aspect includes a plurality of wireless communication devices 100.

[0122] According to the above configuration, the wireless communication system 10 including the wireless communication device 100 that employs the collision type and non-collision type access methods can improve the usage efficiency of wireless resources while guaranteeing the transmission delay time by configuring the DTI based on the terminal information.

[0123] The wireless communication method according to the seventh aspect is a wireless communication method executed by a computer. The wireless communication method configures DTI information indicating the data transmission period of data communicated in the network based on terminal information including type information of a plurality of terminals constituting the network stored in the storage unit 120. Further, the wireless communication method generates control information in the network including the DTI information based on the DTI information. Furthermore, the wireless communication method transmits the control information to terminals in the network.

[0124] According to the above configuration, according to the wireless communication method that employs the collision type and non-collision type access methods, it is possible to improve the usage efficiency of wireless resources while guaranteeing the transmission delay time by configuring the DTI based on the terminal information.

[0125] The wireless communication program according to the eighth aspect is a wireless communication program for causing a computer to execute. The wireless communication program includes steps of configuring DTI information indicating the data transmission period of data communicated in the network based on terminal information including type information of a plurality of terminals constituting the network stored in the storage unit 120. Further, the wireless communication program includes steps of generating control information in the network including the DTI information based on the DTI information. Furthermore, the wireless communication program includes steps of transmitting the control information to terminals in the network.

[0126] According to the above configuration, according to the wireless communication program that employs the collision type and non-collision type access methods, it is possible to improve the usage efficiency of wireless resources while guaranteeing the transmission delay time by configuring the DTI based on the terminal information.

Description of Reference Numerals

[0127] 10 Wireless communication system 100 Wireless communication device 100a AP, Access Point 100b PCP 100ab PCP / AP 100c Station 110 Control unit 111 Mode selection unit 112 Beacon interval configuration unit 113 Wireless communication processing unit 114 DTI configuration unit 115 Control information generation unit 116 Control information transmission unit 117 DTI configuration acquisition unit 118 Access period determination unit 119 Data transmission / reception unit 120 Memory unit 130 External I / F 140 PHY unit 300 External device 400 Antenna

Claims

1. A storage unit that stores terminal information including type information of a plurality of terminals constituting a network and tolerance delay time information regarding a tolerance delay time of data transmission; A DTI configuration unit that configures DTI information (Data Transmission Interval) indicating a data transmission period composed of a period of a first access method in which communication time is allocated in advance and a period of a second access method in which communication time is not allocated in advance after the period of the first access method, based on the type information of the terminal information; A control information generation unit that generates control information in the network including the DTI information based on the DTI information generated by the DTI configuration unit; A control information transmission unit that transmits the control information to the terminals in the network, and comprises: Based on the type information of the terminal information, when there is a terminal with a high priority of data transmission from the terminal, the DTI configuration unit allocates the data transmitted from the terminal with the high priority to the first access method in ascending order of the tolerance delay time; A wireless communication device, wherein the DTI configuration unit allocates data transmitted from a terminal with a low priority of data transmission from the terminal to the second access method based on the type information of the terminal information.

2. The terminal information includes information indicating whether it is retransmitted data, When the data transmission from the terminal is the retransmitted data, the DTI configuration unit allocates the retransmitted data transmitted from the terminal to the first access method. The wireless communication device according to claim 1.

3. The terminal information includes information indicating whether it is relay data, When the data transmission from the terminal is the relay data, the DTI configuration unit allocates the relay data transmitted from the terminal to the first access method. The wireless communication device according to claim 1 or 2.

4. The terminal information includes information indicating whether it is directional communication with restricted antenna directivity, When the data transmission from the terminal is the directional communication, the DTI configuration unit allocates the data transmitted from the terminal to the second access method, When the data transmission from the terminal is omnidirectional communication that is not the directional communication, the DTI configuration unit allocates the data transmitted from the terminal to the first access method. The wireless communication device according to any one of claims 1 to 3.

5. Further comprising a data transceiver for transmitting and receiving transmission data transmitted between the other terminals, Based on the received transmission data, the data transceiver updates the terminal information. The wireless communication device according to any one of claims 1 to 4.

6. Comprising the wireless communication device according to any one of claims 1 to 5, A wireless communication system.

7. A wireless communication method executed by a computer, Based on the type information of the terminal information including the type information of a plurality of terminals constituting the network stored in the storage unit and the allowable delay time information regarding the allowable delay time of data transmission, during the period of the first access method in which the communication time is allocated in advance, and after the period of the first access method, for the DTI information (Data Transmission Interval) indicating the data transmission period composed of the period of the second access method in which the communication time is not allocated in advance, based on the type information of the terminal information, when there is a terminal with a high priority of data transmission from the terminal, the data transmitted from the terminal with the high priority is allocated to the first access method in ascending order of the allowable delay time, Based on the type information of the terminal information, data transmitted from the terminal with a low priority of data transmission from the terminal is allocated to the second access method, Based on the DTI information, control information in the network including the DTI information is generated, The control information is transmitted to the terminals in the network. A wireless communication method.

8. Based on the type information of the terminal information including the type information of a plurality of terminals constituting the network stored in the storage unit and the allowable delay time information regarding the allowable delay time of data transmission, during the period of the first access method in which the communication time is allocated in advance, and after the period of the first access method, for the DTI information (Data Transmission Interval) indicating the data transmission period composed of the period of the second access method in which the communication time is not allocated in advance, based on the type information of the terminal information, when there is a terminal with a high priority of data transmission from the terminal, the step of allocating the data transmitted from the terminal with the high priority to the first access method in ascending order of the allowable delay time, A step of allocating data transmitted from a terminal with a low priority of data transmission from the terminal to the second access method based on the type information of the terminal information with respect to the DTI information; A step of generating control information in the network including the DTI information based on the DTI information; A wireless communication program for causing a computer to execute a step of transmitting the control information to the terminal in the network.

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