JP2009253647A - Wireless communication method, and wireless communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable communication control depending on a switching condition of a wireless network. <P>SOLUTION: Communication over a first wireless network is carried out during a communication period preliminarily defined in the first wireless network, and communication over a second wireless network is carried out during a non-communication period preliminarily defined in the first wireless network. When the communication in the second wireless network is carried out, information related to the communication period of the first wireless network is notified to a wireless communication apparatus in the second wireless network by the communication over the second wireless network. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wireless communication method and a wireless communication apparatus that perform communication by switching between a first wireless network and a second wireless network.

  Conventionally, a station (STA) performs communication in a first BSS (Basic Service Set) in an Awake period of the first BSS, and performs communication in a second BSS in a Doze period of the first BSS. As a result, a BSS for performing communication, that is, a technique for switching a wireless network in a time-sharing manner has been proposed (for example, see Patent Document 1).

Further, IEEE Std 802.11e-2005 defines a method for setting a communication period. Specifically, the Awake period and Doze period in the BSS are set in accordance with TSPEC (Traffic SPECification) of TS (Traffic Stream).
JP 2006-319444 A

  In the above-described conventional technology, when switching a wireless network for communication in a time-sharing manner, information on what kind of communication is performed in another wireless network is not provided, so communication control according to the switching state of the wireless network is performed. There was a problem that it could not be done.

  An object of the present invention is to enable communication control according to a switching situation of a wireless network.

  The present invention is a wireless communication method executed by a wireless communication apparatus that performs communication by switching between a first wireless network and a second wireless network, and a communication period that is predetermined in the first wireless network Performing communication in the first wireless network, performing communication in the second wireless network during a predetermined non-communication period in the first wireless network, and in the second wireless network A step of notifying a wireless communication device in the second wireless network of information related to a communication period of the first wireless network by communication in the second wireless network when performing communication. And

  The present invention is also a wireless communication apparatus that performs communication by switching between a first wireless network and a second wireless network, and the first wireless network is in a communication period that is predetermined by the first wireless network. Means for performing communication on the network and performing communication on the second wireless network during a non-communication period predetermined in the first wireless network, and performing communication on the second wireless network, And means for notifying information relating to a communication period of the first wireless network to a wireless communication device in the second wireless network through communication in the second wireless network.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to perform communication control according to the switching condition of a wireless network.

  The best mode for carrying out the invention will be described below in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a diagram illustrating an example of a configuration of a wireless communication system according to the first embodiment. In FIG. 1, reference numerals 101 and 102 denote access points (APs) that function as IEEE802.11 compliant communication devices. Reference numerals 111 to 114 denote stations (STAs) that function as wireless communication apparatuses compliant with IEEE 802.11. The configuration of each STA will be further described later with reference to FIG. 121 and 122 are BSS (Basic Service Set) of the wireless network corresponding to the IEEE802.11 standard. In this BSS 121 (first wireless network), the STAs 111 and 112 communicate in an infrastructure mode controlled by the AP 101. In the BSS 122 (second wireless network), the STAs 113 and 114 communicate in an infrastructure mode controlled by the AP 102.

  In the following embodiments, the wireless communication standard to be used is described implicitly as the IEEE 802.11 standard, but the present invention may apply other standards other than the IEEE 802.11 standard.

  FIG. 2 is a diagram illustrating an example of the configuration of the STA in the first embodiment. Here, the STA 112 is described as an example, but the other STAs 111, 113, and 114 are configured in the same manner.

  In FIG. 2, reference numeral 201 denotes an STA function unit, which includes a well-known wireless module and a program module describing processing for the STA 112 to function as a station. The STA function unit 201 performs communication between the AP and the STA having the STA function, that is, the AP 101 and the STA 111, and the BSS 121.

  Reference numeral 202 denotes a BSS information storage unit, which includes a memory that is an area for storing BSS information. Here, the configuration of the BSS information stored in the BSS information storage unit 202 will be described with reference to FIG.

  FIG. 3 is a diagram illustrating an example of the configuration of the BSS information in the first embodiment. Reference numeral 301 shown in FIG. 3 is an index for managing the BSS information, and is numbered by the number of different BSSs existing in the communication range of the STA. 302 is a beacon member in which the beacon of the AP that controls the BSS is stored. A TSPEC member 303 stores the TSPEC of the TS using APSD (Automatic Power Save Delivery) permitted by the AP. Here, TS is an abbreviation for Traffic Stream, and TSPEC is an abbreviation for Traffic SPECification.

  FIG. 3 shows the BSS information stored in the BSS information storage unit 202 of the STA 112 when the STA 112 receives the beacons of the APs 101 and 102 and performs communication using the TS using the APSD in the BSS 121. .

  Here, referring back to FIG. 2, reference numeral 203 denotes a BSS switching unit, which includes a program module describing a process of switching a BSS for communication. Here, a processing procedure executed by the BSS switching unit 203 will be described with reference to FIG.

  FIG. 4 is a flowchart illustrating an example of the switching process of the BSS switching unit according to the first embodiment. This process is started when, for example, the STA 112 permits the AP 101 to use the TS using the APSD.

  When the STA 112 starts processing, first, communication is performed in SP (Service Period) in accordance with the TSPEC of the TS using the APSD permitted by the AP 101 (S401). Then, waiting for the SP to end (S402), when the SP ends, the STA 112 reads the BSS information stored in the BSS information storage unit 202 (S403). Next, the BSS performing communication is switched to a different BSS (S404). Then, it is determined by referring to the BSS information whether there is a TS using the APSD in the switched BSS (S405).

  As a result of the determination in S405, if there is a TS using APSD in the switched BSS, the process returns to S401. On the other hand, if there is no TS using the APSD, the TS 101 applies to the AP 101 for the TS using the APSD (S406). Then, it is determined whether or not the TS using the APSD is permitted by the AP 101 (S407). Here, if permitted, the TSPEC of the TS is updated by storing it in the TSPEC field of the BSS information (S408), and the process returns to S401.

  If it is not permitted in S407, the BSS for communication is switched to the previous BSS (S409), and the process returns to S401. For example, if the TS using the APSD is permitted by the AP 101, the STA 112 starts the SP in accordance with the TSPEC of the TS using the APSD permitted by the AP 101. Then, the BSS information shown in FIG. 3 is read, and the BSS that performs communication is switched to the BSS 122 that is controlled by the AP 102. Note that the BSS 122 also performs communication using the TS using the APSD, updates the BSS information, and repeats the same processing.

  FIG. 5 is a diagram illustrating an example of a configuration of a wireless communication system after BSS switching in the first embodiment. Here, the STA 112 communicates with the STA 111 via the AP 101 during a communication period predetermined by the BSS 121. Then, in order to perform communication in the BSS 122 during a period (non-communication period) determined in advance by the BSS 121, the BSS 121 is switched to the BSS 122, and the BSS information is notified to the STAs 113 and 114 via the AP 102.

  Here, returning to FIG. 2, a configuration for transmitting / receiving and storing TSPEC will be described. A TSPEC transmission unit 204 includes a program module describing a process of transmitting TSPEC. Reference numeral 205 denotes a TSPEC receiving unit, which includes a program module describing processing for receiving TSPEC. Reference numeral 206 denotes a TSPEC information storage unit, which includes a memory that is an area for storing TSPEC information.

  FIG. 6 is a diagram illustrating an example of a configuration of a TSPEC transmission frame according to the first embodiment. The TSPEC transmission frame is an IEEE802.11-compliant data frame that is transmitted when the STA switches the BSS for communication.

  In FIG. 6, reference numeral 601 denotes a BSSID field, which stores BSSIDs of other BSSs with which the STA communicates. Reference numeral 602 denotes a TSPEC field, in which a TSPEC of a TS permitted by an AP that controls another BSS with which the STA performs communication is stored. For example, when the BSS with which the STA 112 communicates is switched from the BSS 121 to the BSS 122, a TSPEC transmission frame storing the next data is transmitted to the BSS 122. In other words, the BSSID field 601 stores the MAC address of the AP 101, and the TSPEC field 602 transmits the TSPEC transmission frame storing the TS TSPEC using the APSD permitted by the AP 101.

  FIG. 7 is a flowchart illustrating an example of processing of the TSPEC transmission unit in the first embodiment. This process is started, for example, when the BSS with which the STA 112 communicates is switched from the BSS 121 to the BSS 122.

  When the STA 112 starts processing, first, BSS information stored in the BSS information storage unit 202 is read (S701). Next, the AP MAC address is extracted from the beacon member of the BSS information corresponding to the index different from the switched BSS, and the BSSID field 601 of the TSPEC transmission frame is generated (S702).

  Next, the TSPEC field of the TSPEC transmission frame is generated from the TSPEC member (S703). Finally, the generated TSPEC transmission frame is transmitted to the switched BSS 122 (S704), and this process ends.

  FIG. 8 is a flowchart illustrating an example of processing of the TSPEC receiving unit in the first embodiment. This process is periodically started in the STA 114, for example.

  When the process is started, first, reception of a TSPEC transmission frame transmitted from another STA is awaited (S801). Thereafter, TSPEC information to be described later is updated according to the received TSPEC transmission frame (S802), and this process is terminated.

  FIG. 9 is a diagram illustrating an example of a configuration of TSPEC information according to the first embodiment. In FIG. 9, reference numeral 901 denotes an index for managing TSPEC information, which is numbered by the number of STAs that have transmitted TSPEC transmission frames. Reference numeral 902 denotes an SA member that stores the MAC address of the STA that has transmitted the TSPEC transmission frame, and is extracted from the 802.11 header field of the TSPEC transmission frame.

  Reference numeral 903 denotes a BSSID member, which is similarly extracted from the BSSID field of the TSPEC transmission frame. Reference numeral 904 denotes a TSPEC member, which is similarly extracted from the TSPEC field of the TSPEC transmission frame.

  FIG. 9 shows TSPEC information stored in the TSPEC information storage unit of the STA 114 when the STAs 112 and 113 transmit TSPEC transmission frames to the BSS 122 and the STA 114 receives these TSPEC transmission frames. Yes.

  Returning to FIG. 2, reference numeral 207 denotes a communication control unit, which includes a program module describing processing for controlling communication in accordance with stored TSPEC information.

  FIG. 10 is a flowchart illustrating an example of processing of the communication control unit in the first embodiment. This process is started when, for example, communication with another STA (STA 112) occurs in the STA 114.

  When the STA 114 starts processing, first, TSPEC information stored in the TSPEC information storage unit 206 is read (S1001). Then, it is determined whether or not the partner STA in which communication has occurred has a long communication period for communication performed in another BSS (S1002). Specifically, the determination is made by referring to the TSPEC member of the TSPEC information corresponding to the index in which the MAC address of the partner STA matches the MAC address stored in the SA member of the TSPEC information. If the result of determination is not great, this process is terminated. If it is larger, the communication amount with the partner STA is reduced (S1003), and this process is terminated.

  For example, in the STA 114, when communication of 10 Mbps with the STA 112 occurs in the BSS 122, the STA 114 reads the TSPEC information, and the STA 112 refers to the TSPEC of the TS using the APSD permitted to the AP 101. Here, if the communication indicates 20 Mbps, the communication performed by the STA 112 using the BSS 121 is large, and the 10 Mbps communication generated with the BSS 122 with the STA 112 is not performed satisfactorily.

  According to the first embodiment, it is possible to perform communication control according to the switching status of the BSS.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described in detail with reference to the drawings.

  Note that the configuration of the wireless communication system in the second embodiment is the same as that of the first embodiment, and a description thereof will be omitted. In addition, the configuration of the STA in the second embodiment is the same as that of the first embodiment, and a description thereof will be omitted.

  FIG. 11 is a flowchart illustrating an example of processing of the communication control unit in the second embodiment. This process is started when, for example, the STA 114 communicates with an STA (STA 111) that communicates only with the BSS 121 for some reason.

  When the STA 114 starts processing, first, TSPEC information stored in the TSPEC information storage unit 206 is read (S1101). Then, the BSSID member refers to the TSPEC member of the same TSPEC information, and compares which TSPEC information indicates the largest communication amount (S1102).

  Next, for each BSSID member, an index of TSPEC information having a TSPEC member indicating the largest communication amount is selected. Then, a relay STA with the BSS controlled by the AP having the MAC address of the AP stored in the BSSID member is determined based on the MAC address of the STA stored in the SA member of the TSPEC information corresponding to the selected index ( S1103). Then, this process ends.

  For example, when communication occurs with the STA 111 that communicates only with the BSS 121 for some reason, the STA 114 reads the TSPEC information. Then, the STA 112 compares the TS TSPEC using the APSD permitted to the AP 101 with the TS TSPEC using the APSD permitted to the AP 101. Here, when the communication amount that the STA 113 performs in the BSS 121 is larger, processing such as determining the STA 113 as a relay STA to the BSS 121 is performed.

  According to the second embodiment, it is possible to provide the BSS with information on how much role it can play as a relay STA with another BSS.

  Even if the present invention is applied to a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), it is applied to an apparatus (for example, a copier, a facsimile machine, etc.) composed of a single device. It may be applied.

  In addition, a recording medium in which a program code of software for realizing the functions of the above-described embodiments is recorded is supplied to the system or apparatus, and the computer (CPU or MPU) of the system or apparatus stores the program code stored in the recording medium. Read and execute. It goes without saying that the object of the present invention can also be achieved by this.

  In this case, the program code itself read from the computer-readable recording medium realizes the functions of the above-described embodiments, and the recording medium storing the program code constitutes the present invention.

  As a recording medium for supplying the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

  In addition, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also the following cases are included. That is, based on the instruction of the program code, an OS (operating system) running on the computer performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing. .

  Further, the program code read from the recording medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. After that, based on the instruction of the program code, the CPU of the function expansion board or function expansion unit performs part or all of the actual processing, and the function of the above-described embodiment is realized by the processing. Needless to say.

It is a figure which shows an example of a structure of the radio | wireless communications system in 1st Embodiment. It is a figure which shows an example of a structure of STA in 1st Embodiment. It is a figure which shows an example of a structure of BSS information in 1st Embodiment. It is a flowchart which shows an example of the switching process of the BSS switching part in 1st Embodiment. It is a figure which shows an example of a structure of the radio | wireless communications system after BSS switching in 1st Embodiment. It is a figure which shows an example of a structure of the TSPEC transmission frame in 1st Embodiment. It is a flowchart which shows an example of the process of the TSPEC transmission part in 1st Embodiment. It is a flowchart which shows an example of the process of the TSPEC receiving part in 1st Embodiment. It is a figure which shows an example of a structure of the TSPEC information in 1st Embodiment. It is a flowchart which shows an example of a process of the communication control part in 1st Embodiment. It is a flowchart which shows an example of the process of the communication control part in 2nd Embodiment.

Explanation of symbols

101 Access point (AP)
102 Access point (AP)
111 stations (STA)
112 stations (STA)
113 stations (STA)
114 stations (STA)
121 First wireless network (BSS)
122 Second wireless network (BSS)
201 STA function unit 202 BSS information storage unit 203 BSS switching unit 204 TSPEC transmission unit 205 TSPEC reception unit 206 TSPEC information storage unit 207 communication control unit

Claims (6)

A wireless communication method executed by a wireless communication device that performs communication by switching between a first wireless network and a second wireless network,
Communication in the first wireless network is performed in a predetermined communication period in the first wireless network, and communication in the second wireless network is performed in a non-communication period predetermined in the first wireless network. A process of performing
When communication is performed on the second wireless network, information on a communication period of the first wireless network is notified to a wireless communication device in the second wireless network by communication on the second wireless network. Process,
A wireless communication method comprising:   A wireless communication device in the second wireless network, and a wireless communication device in the first wireless network based on information related to a communication period of the first wireless network notified by communication in the second wireless network; The wireless communication method according to claim 1, further comprising a step of controlling the communication.   When a plurality of wireless communication devices in the second wireless network are notified of information related to a communication period of the first wireless network through communication in the second wireless network, communication of the plurality of wireless communication devices The wireless communication method according to claim 1, further comprising a step of determining a wireless communication device to perform relay in the second wireless network based on a quantity. A wireless communication device that performs communication by switching between a first wireless network and a second wireless network,
Communication in the first wireless network is performed in a predetermined communication period in the first wireless network, and communication in the second wireless network is performed in a non-communication period predetermined in the first wireless network. Means for
When communication is performed on the second wireless network, information on a communication period of the first wireless network is notified to a wireless communication device in the second wireless network by communication on the second wireless network. Means,
A wireless communication apparatus comprising:   A program for causing a computer to execute the wireless communication method according to any one of claims 1 to 3.   A computer-readable recording medium on which the program according to claim 5 is recorded.

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