JP2007013649A - Shared information updating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shared information updating method transmitting shared information from every radio terminal in a radio communication network, thereby updating the shared information for all terminals in the radio communication network. <P>SOLUTION: When it is detected that version information 23 in a beacon or probe request transmitted by a terminal A is older than version information 23 of shared information held by one's own (step S1-20), and if the version information 23 of the shared information held by the terminal B is reported to the terminal A by a probe request (step S1-25), the terminal A transmits a shared information update request frame F1 to the terminal B (step S1-35). The terminal B transmits a shared information frame F4 to the terminal A in each frame (step S1-40), and the terminal A updates the shared information after receiving all of the shared information frame F4 (step S1-45). The terminals A and B respectively update shared information of other terminals newly connected to the radio communication terminal and each terminal in an adjacent radio communication network with the beacon or probe request as a turning point. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a shared information update method.

  The wireless LAN communication terminal stores software for executing maintenance / addition functions of the communication terminal and shared information such as various types of information shared by the same network. Such shared information is often updated for reasons such as improving communication performance, adding additional functions, repairing defects, or updating network maintenance. Conventionally, when updating shared information, whether a maintenance person goes to the installation location of the communication terminal to perform the update work one by one, or whether it is collected once at the maintenance center, etc., and then installed again Alternatively, the user himself / herself obtains shared information to be updated from the manufacturer and updates it according to the instructed procedure. For this reason, it takes time to update the shared information of a plurality of terminals. In addition, in order to rewrite the memory inside the communication terminal during the update, it is necessary to open the case of the communication terminal or to interpose an external medium such as a wired LAN or USB memory. It was necessary.

On the other hand, there is a portable wireless system that updates a program through a wireless route. This portable wireless system includes a portable wireless terminal device, an external server, a center, and a wireless base station. Then, when there is a request for notification of model information and program version information from the external server or center to the portable wireless terminal device via the wireless base station, the portable wireless terminal device sends the model information and version information to the external server. Send an email with. Then, the external server transmits a data file for updating the program to the portable wireless terminal device in the form of an email attachment file. As a result, since the user can easily download the program, the effort of updating the program has been reduced (for example, Patent Document 1).
JP 2003-174404 A

  However, in the portable wireless system disclosed in Patent Document 1, for example, it is possible to reduce the trouble of updating work for a plurality of portable wireless terminal devices by e-mail broadcast transmission. However, the portable wireless terminal device is a newer version than the external server. Even when the program is held, the shared information held by the external server cannot be updated by the portable wireless terminal device.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to enable sharing information to be transmitted from any wireless terminal in the wireless communication network, and to share all terminals in the wireless communication network. It is to provide a shared information update method capable of updating information.

  In order to solve the above problem, the invention according to claim 1 is a shared information updating method for updating shared information respectively held by a plurality of terminals in the at least one wireless communication network through at least one wireless communication network. The version information of the shared information held by one terminal among the plurality of terminals is transmitted to the plurality of terminals, and the version information of the shared information held by the plurality of terminals and the received version information are respectively In comparison, a terminal that holds shared information of version information that is newer than the received version information among the plurality of terminals transmits the shared information to the first terminal, and the first terminal is held by the terminal. The shared information is updated to the shared information of the new version information.

According to the present invention, the version information of the shared information held by one terminal among the plurality of terminals is transmitted to the plurality of terminals, and the plurality of terminals compare the version information of the held shared information with the received version information. Then, among the plurality of terminals, a terminal holding shared information of version information newer than the received version information transmits the shared information to one terminal, and one terminal uses the shared information held by the terminal. Update to new version information sharing information. Therefore, shared information can be transmitted from any terminal in the wireless communication network, and shared information of all terminals in the wireless communication network can be updated. Note that the terminal of the present invention refers to a mobile terminal or an access point.

  The invention according to claim 2 is the shared information update method according to claim 1, wherein the version information of the shared information is mounted as an information element in a management frame, and each of the plurality of terminals is connected to the management information. By transmitting a frame, the version information of the shared information is notified to each other.

  According to the present invention, the version information is notified by transmitting a management frame carrying the version information of the shared information. As a result, it is possible to notify the version information without providing a sequence for notifying the version information, and to automatically update the shared information without contacting the terminal in response to the notification. Therefore, it is possible to reduce the work load required for updating the shared information.

  A third aspect of the present invention is the shared information update method according to the first aspect, wherein the plurality of terminals are provided with version information notification in which version information of the shared information is mounted after a SIFS interval has elapsed after transmitting a management frame. By transmitting each frame, the version information of the shared information is notified to each other.

  According to the present invention, after the management frame is transmitted, the version information is notified by the version notification frame transmitted after the SIFS interval has elapsed. As a result, the shared information can be automatically updated without touching the terminal, and a mixed network environment with other terminals that do not have a function for executing the shared information update process can be constructed. . Therefore, it is possible to reduce the work load required for updating the shared information while making use of the existing network environment.

  The invention according to claim 4 is the shared information update method according to claim 1, wherein the version information of the shared information is included in the information element of the management frame having a unique identifier defined in the information element in the management frame. And the plurality of terminals notify each other of the version information by transmitting the management frame.

  According to the present invention, the version information is notified by transmitting the management frame loaded with the version information. As a result, the shared information can be automatically updated without touching the terminal, and a mixed network environment with other terminals that do not have a function for executing the shared information update process can be constructed. . Therefore, it is possible to reduce the work load required for updating the shared information while making use of the existing network environment.

A fifth aspect of the present invention is the shared information updating method according to any one of the second to fourth aspects, wherein the management frame is a beacon or a probe request.
According to the present invention, since the management frame is a beacon or probe request, any terminal that holds new shared information and transmits a beacon or probe request transmits version information of the shared information. The shared information update process can be performed in response to the transmission of the version information. As a result, it is possible to update the shared information of the terminals of adjacent wireless communication networks within the range where the beacon or probe request arrives. Therefore, since the shared information can be updated also in the adjacent wireless communication network, the effort required for updating the shared information can be reduced.

  The invention according to claim 6 is the shared information update method according to claim 1, wherein the terminal holding the shared information of the new version information divides the shared information of the new version information into a plurality of frames. Transmitting the plurality of frames by complementing at least one of the plurality of frames between the plurality of terminals when the one terminal fails to receive at least one of the plurality of frames. Receive.

  According to the present invention, the terminal holding the shared information of the new version information divides the shared information into a plurality of frames and transmits the information, and when one terminal cannot receive at least one of the plurality of frames The plurality of frames are all received by complementing the frames with each other. As a result, the shared information can be updated more reliably.

  The invention according to claim 7 is the shared information updating method according to claim 6, wherein when the one terminal cannot receive at least one of the plurality of frames, the plurality of terminals The plurality of frames are all transmitted by broadcasting each other, and only the frames that are not held by each of the plurality of terminals are complemented between the plurality of terminals based on the holding information. Receive.

  According to the present invention, only a plurality of frames that are not held by each of the plurality of terminals are based on the holding information of the plurality of frames transmitted by broadcasting between the plurality of terminals holding at least one of the plurality of frames. Complement each other's devices. As a result, the amount of information transmitted and received when updating the shared information can be reduced.

  According to the present invention, shared information can be transmitted from any terminal in the wireless communication network, and shared information of all terminals in the wireless communication network can be updated.

  Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram for explaining a schematic configuration of an ad hoc network embodying the present invention. In FIG. 1, cell N1 and cell N2 each comprising an ad hoc network as a wireless communication network are provided. In this embodiment, cell N1 is a wireless LAN terminal (hereinafter referred to as a terminal) A to D. An area space in which mutual communication is possible, and the cell N2 is an area space in which the terminals D and E can communicate with each other. Further, in the present embodiment, the cell N1 and the cell N2 have the same SSID (Service Set Identifier), and even when each terminal A to E moves back and forth between the cell N1 and the cell N2, they instantly join the network. it can.

  Next, the configuration of each of the terminals A to E will be described with reference to FIG. In the present embodiment, the terminals A to E have the same configuration, so the terminal A will be described, and the other terminals B to E will have the same reference numerals and will not be described in detail. The terminal A includes a wireless transmission / reception unit 11, a transmission / reception data processing unit 12, a control unit 13, an external interface 14, a work memory 15, and a storage unit 16. The radio transmission / reception unit 11 modulates and demodulates a radio signal transmitted / received by the terminal A. The transmission / reception data processing unit 12 performs packetization of transmission data transmitted by the terminal A and disassembly processing of reception radio packets received by the terminal A. The control unit 13 controls the wireless transmission / reception unit 11 and the transmission / reception data processing unit 12 to perform control of the data transmission / reception protocol, various settings of the terminal A, and state management. The external interface 14 is a connection unit to an external device such as a host system and a processing unit for displaying the status of the terminal A.

  The work memory 15 is a memory area for developing software and temporarily storing data when executing various software. The storage unit 16 stores software for operating the control unit 13, shared information regarding settings of each terminal, and version information thereof. In the present embodiment, the shared information and its version information are in a state before being expanded in the work memory 15 at the time of execution, for example. In the present embodiment, the shared information is, for example, software for executing an additional function of the terminal A, and the version information is information indicating the version of the software.

  When the terminal A transmits the shared information to another terminal, the shared information stored in the storage unit 16 is divided into a plurality of frames and transmitted. The other terminals temporarily store the updated shared information transmitted in a divided manner in the work memory 15 and do not perform the update process until all frames can be received. Similarly, when the terminal A receives the updated shared information divided into a plurality of frames from another terminal, the terminal A temporarily stores the frame in the work memory 15 and performs update processing until all frames can be received. Absent.

  Next, a method for notifying version information of shared information will be described with reference to FIGS. As shown in FIG. 3, in this embodiment, a field indicating version information is provided in the SSID field 21 in a known MAC (Medium Access Control) frame such as a beacon or a probe request. That is, the k-octet-length SSID field 21 includes version information 23 as an information element that is a fixed-length field indicating version information of shared information. Each terminal A to E recognizes from the SSID main body 25 in the SSID field 21 whether the terminal that transmitted this MAC frame is a terminal of the same network, and confirms the version information of the shared information from the version information 23. It has become. The SSID field 21 is a management frame defined by IEEE 802.11, such as a beacon and a probe request, and is similarly applied to all frame types including the SSID.

  In the present embodiment, as shown in FIG. 4, the shared information update request frame F1 transmitted by unicast, the shared information search request frame F2 transmitted by broadcast, and the shared information search response frame F3 transmitted by broadcast It has. Further, in the present embodiment, as shown in FIG. 5, a shared information frame F4 that is a frame in which shared information is mounted and is transmitted by broadcast is provided. As described above, since the shared information is divided into a plurality of frames and transmitted, a plurality of shared information frames F4 are transmitted. Details thereof will be described later.

  As shown in FIG. 4, the shared information update request frame F1, the shared information search request frame F2, and the shared information search response frame F3 have the same configuration, but have different meanings depending on the SNAP (Type) described later.

  In the shared information update request frame F1, the terminal holding the shared information of the version information 23 older than the received version information 23 shares the new version with the terminal holding the shared information of the new version information 23. This is a frame for requesting transmission of information.

  The shared information search request frame F2 is a frame transmitted by a terminal that has not received all of the plurality of shared information frames F4 that have been transmitted, and among the plurality of shared information frames F4 that have been transmitted, This is a frame for notifying whether or not the information frame F4 is held.

Further, the shared information search response frame F3 is a frame transmitted by each terminal that has received the shared information search request frame F2. Among the plurality of shared information frames F4 transmitted, the shared information frame F4 Is a frame for notifying whether or not is held.

  By receiving the shared information search response frame F3, the terminal that has transmitted the shared information search request frame F2 can grasp which terminal holds the shared information frame F4 of a desired version. . Thereby, each terminal can determine to which terminal it is optimal to transmit the shared information update request frame F1. In the shared information update request frame F1, information indicating which shared information frame F4 is held or not held by the own terminal among the plurality of transmitted shared information frames F4 is mounted. As a result, the terminal that has received the shared information update request frame F1 can selectively transmit only the minimum necessary shared information frame F4 among the plurality of shared information frames F4 transmitted.

  The shared information update request frame F1 includes a known MAC Header, SNAP (Type), and FCS. The shared information update request frame F1 includes version information 23, a total number of frames 31, a polarity 33, and target frame information 35. Since the shared information update request frame F1, the shared information search request frame F2, and the shared information search response frame F3 have the same configuration, only the shared information update request frame F1 will be described, and the other frames have the same reference numerals. Detailed description thereof will be omitted.

  The total number of frames 31 is the total number of the plurality of shared information frames F4 to be transmitted, and the polarity 33 represents the polarity of information indicating the holding state of the plurality of shared information frames F4 to be transmitted. To do. The target frame information 35 is information indicating whether the own terminal holds any of the plurality of shared information frames F4. The target frame information 35 includes a number 41 of information and a plurality of update information 43. The information number 41 is the number of the update information 43. When the value of the information number 41 is 0, the update information 43 is also zero. The update information 43 includes an offset 51, length information 53, and a bitmap 55. The offset 51 indicates the first frame number of the target indicating whether or not it is held among the plurality of shared information frames F4, and the length information 53 is the octet length of the bitmap 55.

  Therefore, for example, when the offset 51 is “10” and the length information 53 is “1”, the 10th to 17th shared information frames F4 are targeted. The bitmap 55 is information of the shared information frame F4 for the value specified by the length information 53 × 8 frames from the frame number specified by the offset 51. For example, when the offset 51 is “10” and the length information 53 is “1”, the bit position 0 of the bitmap 55 indicates the tenth shared information frame F4. Similarly, bit position 1 of the bitmap 55 indicates the eleventh shared information frame F4.

  Then, the value of the polarity 33 determines whether each bit value of the bitmap 55 is held or not. That is, from the value of the polarity 33 and each bit value of the bitmap 55, it can be determined which shared information frame F4 the terminal itself holds.

  Specifically, when the value of the polarity 33 is “0” and each bit value of the bitmap 55 is “1”, the terminal does not hold the shared information frame F4 having the frame number corresponding to each bit. Yes, when each bit value of the bitmap 55 is “0”, it indicates that the terminal holds the shared information frame F4 of the frame number corresponding to each bit. Further, the shared information frame F4 having a frame number not shown in the update information 43 is already held.

On the other hand, when the polarity value is “1” and each bit value of the bitmap 55 is “1”, the terminal holds the shared information frame F4 of the frame number corresponding to each bit, and the bit When each bit value of the map 55 is “0”, the terminal indicates that the shared information frame F4 having the frame number corresponding to each bit is not held. In addition, the shared information frame F4 having a frame number not shown in the update information 43 is not held.

  This polarity 33 depends on whether the number of retained frames or the number of non-retained frames among the plurality of shared information frames F4 is large. The shared information update request frame F1 (shared information search request frame F2, shared information search response frame F3) The frame size is selected to be the smallest.

  Then, the shared information frame F4 is transmitted by broadcast in response to the shared information update request frame F1. As shown in FIG. 5, the shared information frame F4 includes a known MAC header, SNAP (Type), and FCS. Further, the shared information frame F4 includes version information 23, a frame number 61, a total number of frames 31, and shared information 65. The frame number 61 is the number of the plurality of shared information frames F4 constituting the shared information, and the total number of frames 31 is the plurality of shared information frames F4 constituting the shared information. The total number of The shared information 65 is shared information corresponding to the frame number 61 among the shared information divided into a plurality of frames.

  In the present embodiment, among the plurality of shared information frames F4, the process is interrupted when there is a shared information frame F4 that cannot be received in the middle or is missing during transmission and all the shared information cannot be updated. In order to do this, a shared information frame reception wait timer (hereinafter, reception wait timer) (not shown) is provided. Then, the reception waiting timer is activated simultaneously with the start of transmission of the shared information frame F4. When all the shared information frames F4 are received, the reception waiting timer is stopped. When all the shared information frames F4 have not been received, the terminal waits until the reception waiting timer reaches a predetermined value, and when the reception waiting timer exceeds the predetermined value, the terminal determines that reception has failed.

  Next, the shared information update process of each terminal A to E will be described with reference to FIGS. In this embodiment, it is assumed that each terminal A to E is in a state in which authentication, association, etc. are executed in a sequence conforming to IEEE 802.11 and various data can be exchanged before executing the shared information update process. .

(Version upgrade process)
The shared information update process when the shared information is updated will be described with reference to FIG. When the shared information of the terminal A is updated, the terminal A transmits the probe request by broadcasting, thereby transmitting the version information 23 of the shared information held by the terminal A (step S1-10). Thereby, in the case of an ad hoc network, the version information 23 can be notified in the cell N1 even when the beacon cannot be transmitted during the beacon transmission arbitration.

  Further, by transmitting by broadcast, all terminals in the cell N1 are notified at a time that the shared information has been updated. When the shared information of terminal A is updated and a probe request is transmitted, the updated version information 23 is also loaded in the SSID field 21 of the beacon transmitted by terminal A. When the terminal A can transmit a beacon at the time of beacon transmission arbitration after updating the shared information, the version information 23 of the shared information held by the terminal A is transmitted in the cell N1 by transmitting the beacon. .

Thereby, for example, when there are a plurality of terminals that hold new shared information, the terminal that transmitted the beacon can be set as the terminal that transmits the shared information. Thereby, when there are a plurality of terminals holding new shared information in the same cell N1, the arbitration mechanism for determining the terminal that transmits the shared information can be matched with the mechanism for transmitting the beacon. Therefore, when there are a plurality of terminals holding new shared information in the same cell, there is no need to newly provide a mechanism for determining a terminal that transmits shared information.

  When the terminal B in the cell N1 receives the probe request transmitted from the terminal A, the terminal B confirms the version information 23 in the probe request and compares it with the version information 23 of the shared information held by itself (step S1-15). When the version information 23 transmitted by the terminal A is newer than the version information 23 of the shared information held by the terminal A, the terminal B transmits a shared information update request frame F1 (see FIG. 4) to the terminal A. At this time, terminal B specifies the transmission source of shared information frame F4 by transmitting to terminal A by unicast.

  At this time, the shared information update request frame F1 is loaded with information indicating that all the shared information frames F4 are not retained. The terminal A that has received the shared information update request frame F1 transmits a plurality of shared information frames F4 to the terminal B for each frame. Then, by confirming that the terminal B can receive all the shared information frames F4 and the frame number 61 of the last received shared information frame F4 matches the total number of frames 31, the terminal B can detect all the shared information frames F4. When it is determined that the reception of F4 has been completed, the shared information is updated. After the shared information is updated, the terminal B transmits a probe request by broadcast, whereby the terminal A receives the version information 23 of the shared information held by the terminal B, and ends the shared information update process of the terminal B.

  On the other hand, when the terminal B determines that the version information 23 notified from the terminal A is older than the version information 23 of the shared information held by the terminal B (step S1-20), the terminal B retains itself in the terminal A. The shared information version information 23 is notified by a probe request (step S1-25).

  By receiving this probe request, terminal A detects new version information 23 (step S1-30), and transmits a shared information update request frame F1 to terminal B by unicast (step S1-35). . Thereby, the shared information frame F4 is transmitted from the terminal B to the terminal A (step S1-40). Then, the terminal A can receive all the shared information frames F4, and by confirming that the frame number 61 of the last received shared information frame F4 matches the total number of frames 31, the terminal A can detect all the shared information frames F4. When it is determined that the reception of F4 has been completed, the shared information is updated (step S1-45).

  After the shared information is updated, terminal A broadcasts a probe request (step S1-50), so that terminal B receives the shared information version information 23 of terminal A, and the shared information update process of terminal A Exit.

According to this shared information update processing, shared information can be updated based on a sequence based on IEEE802.11 using a wireless path without adding a new mechanism for updating shared information. In addition, a beacon can be used as a means for transmitting update information to surrounding terminals in an autonomous and distributed manner. That is, as long as it is a terminal that holds the latest shared information and transmits a beacon, the shared information can be transmitted even if it is not a terminal that has first manually updated the shared information. As a result, as shown in FIG. 1, if the terminal D holds the latest shared information and transmits a beacon, the shared information of the terminal E of the cell N2 as well as the cell N1 can be updated. Similarly, shared information of terminals existing in cells adjacent to cells N1 and N2 can be updated. Further, for example, even when the terminal that first updated the shared information manually has moved out of the cell N1, the shared information of each terminal in the cell N1 by another terminal having the latest shared information Can be updated. Furthermore, each terminal notifies each other of the version information 23, and all the terminals can always hold the latest shared information.

(Spilling process)
Next, processing when there is a shared information frame F4 that could not be transmitted or received (hereinafter referred to as “missing”) among the plurality of shared information frames F4 will be described with reference to FIG.

  When the shared information of the terminal A is updated, the terminal A transmits the probe request by broadcasting, thereby transmitting the version information 23 of the shared information held by the terminal A (step S1-10). The terminal B confirms the version information 23 in the beacon or probe request transmitted by the terminal A, and compares it with the version information 23 of the shared information held by itself (step S1-15). Then, terminal B transmits the shared information update request frame F1 to terminal A by unicast (step S2-10).

  Then, the shared information frame F4 is transmitted from the terminal A to the terminal B (step S2-15), and during the transmission of the plurality of shared information frames F4, the nth shared information frame F4 being transmitted is missed ( Step S3-10). After receiving the final shared information frame F4, the terminal B determines that the reception of the shared information frame F4 has failed when the reception waiting timer exceeds a predetermined value (step S3-15). At this time, since the terminal B has not received all the shared information frames F4, the terminal B does not update the shared information. Thereafter, the terminal B executes a recovery process.

(Recovery process)
The recovery process is a process for requesting retransmission of a shared information frame F4 that has been missed when a shared information frame F4 in the middle of the plurality of shared information frames F4 is missed, and a sequence as shown in FIG. The process is executed based on

  In the present embodiment, the terminal A transmits the shared information to the terminals B, C, and D, and the terminal A receives the cell N1 even though the data received by the terminals B to D is lost. Suppose that there is no terminal that completely holds a plurality of shared information frames F4 of the version being updated by the terminals B to D in the cell N1. Further, it is assumed that the missing shared information frame F4 is the first to sixth shared information frames F4 for the terminal B, the fifth to ninth terminals for the terminal C, and the first to fourth shared information frames F4 for the terminal D.

  First, the terminal D transmits a shared information search request frame F2 (see FIG. 4) by broadcasting (step S4-10). At this time, the shared information search request frame F2 transmitted by the terminal D indicates that the first to fourth shared information frames F4 are insufficient. Further, since terminal D is transmitting by broadcast, terminals B and C that have received this shared information search request frame F2 are held by terminal D together with the number of shared information frame F4 that terminal D is deficient in. The number of the shared information frame F4 can be acquired. That is, the terminal B can receive the sixth to ninth shared information frames F4 from the terminal D (step S4-15), and the terminal C can receive the fifth to ninth shared information frames F4 from the terminal D. It can be acquired (step S4-20). At this time, the target frame information 35 is generated in the shared information search request frame F2 so that the frame length of the shared information search request frame F2 is the shortest.

Then, terminal C transmits a shared information search response frame F3 (see FIG. 4) by broadcasting (step S4-25). At this time, the shared information search response frame F3 transmitted by the terminal C indicates that the fifth to ninth shared information frames F4 are insufficient. As a result, the terminal B can receive the first shared information frame F4 from the terminal C (step S4-30), and the terminal D can receive the first to fourth shared information frames F4 from the terminal C. (Step S4-35) can be acquired. At this time, the target frame information 35 is generated so that the shared information search response frame F3 has the shortest frame length.

  Furthermore, terminal B transmits a shared information search response frame F3 (see FIG. 4) by broadcasting (step S4-40). At this time, the shared information search response frame F3 transmitted by the terminal B indicates that the first, sixth to ninth shared information frames F4 are insufficient. As a result, terminal C can receive the fifth shared information frame F4 from terminal B (step S4-45), and terminal D can receive the second to fourth shared information frame F4 from terminal B. (Step S4-50) can be acquired.

  After that, each of the terminals B to D holds the largest number of shared information frames F4 having a frame number that it lacks based on the received shared information search request frame F2 and shared information search response frame F3. The shared information update request frame F1 (see FIG. 4) is transmitted by unicast. That is, the terminal D transmits a shared information update request frame F1 indicating that the terminal C needs to transmit the first to fourth shared information frames F4 (step S4-55). The shared information frame F4 is received (step S4-60). Thereby, since the terminal C transmits only the shared information frame F4 having the frame number required by the terminal D, the shared information frame F4 can be transmitted with the minimum size. And terminal D will update shared information, if all the 1st-4th shared information frames F4 which were insufficient are received (step S4-65). Similarly, the terminals B and C are also the terminals that have the largest number of shared information frames F4 having their own missing frame numbers based on the received shared information search request frame F2 and shared information search response frame F3. The shared information update request frame F1 (see FIG. 4) is transmitted by unicast. The shared information is updated after all the shared information frames F4 having the missing frame numbers are received.

  As a result, even if there are a plurality of terminals having the shared information frame F4 that could not be received among the plurality of shared information frames F4 in the cell N1, each terminal can share the shared information search request frame F2 and the shared information with each other. By transmitting / receiving the search response frame F3, it is possible to acquire information indicating which terminal holds which frame. Also, based on this information, the shared information update process can be completed by complementing the shared information frame F4 having a frame number that is insufficient between the terminals.

According to the above embodiment, the following effects can be obtained.
(1) According to the present embodiment, since the version information 23 of the shared information is mounted on the beacon, the version of the shared information can be used on any terminal as long as the terminal holds the latest shared information and transmits the beacon. The information 23 can be transmitted, and the shared information update process can be performed when the version information 23 is transmitted. As a result, the shared information of the terminals in the adjacent cells within the range where the beacon reaches can be updated. Accordingly, since it is possible to carry out transmission of shared information in an autonomous and distributed manner, it is possible to reduce the effort required for updating the shared information.

  (2) According to this embodiment, since the version information 23 of the shared information is mounted in the beacon and probe request, any terminal can be used as long as it is a terminal that holds the latest shared information and transmits the beacon and probe request. However, the version information 23 of the shared information can be transmitted, and the shared information update process can be performed in response to the transmission of the version information 23. As a result, since transmission of shared information can be carried around in the cell N1, for example, even when the terminal that first updated the shared information has moved from the cell N1, other terminals can share the shared information. Can be sent.

  (3) According to the present embodiment, the version information 23 of the shared information is installed in the beacon and probe request, and the shared information is transmitted / received in the shared information frame F4, so that it can be directly applied to an IEEE 802.11 compliant terminal, and Share information can be updated automatically without touching the terminal. As a result, the work burden required for updating the shared information can be reduced.

  (4) According to the present embodiment, the shared information version information 23 is installed in the beacon, and the shared information update process is performed only when the version information 23 is newer than the version information 23 of the shared information held by each terminal. . As a result, the shared information updated terminal is not updated again to the shared information of the same version information 23. Therefore, unnecessary shared information update processing can be reduced.

  (5) According to the present embodiment, when each terminal updates the shared information, the version information 23 of the updated shared information is transmitted by the probe request. As a result, for example, even when the order of transmitting the beacons does not immediately come to the terminal whose shared information has been updated, the new version information 23 can be reliably notified in the cell N1.

(6) According to this embodiment, since the shared information frame F4 is a broadcast frame, it is possible to transmit shared information to a plurality of terminals at the same time.
(7) According to the present embodiment, since shared information can be transmitted from all terminals in the cell N1, all terminals in the cell N1 can always hold the latest version of shared information. it can.

  (8) According to the present embodiment, even if each terminal in the cell N1 has the shared information only in a fragmentary manner, each terminal transmits the shared information search request frame F2 and the shared information search response frame F3. By performing transmission, a recovery process is executed that can mutually complement the shared information necessary for updating. As a result, the shared information can be reliably updated.

  (9) According to the present embodiment, during the recovery process, the shared information search request frame F2 and the shared information search response frame F3 are transmitted to notify the information of the shared information frame F4 held by each terminal. Fit. As a result, it is only necessary to transmit / receive the missing shared information frame F4 among the plurality of shared information frames F4, so that the amount of information to be transmitted / received can be minimized. Therefore, wasteful band occupation can be reduced and power required for transmission and reception can be reduced.

  (10) According to this embodiment, since the shared information search request frame F2 and the shared information search response frame F3 are transmitted by broadcast, a plurality of terminals can share the version information 23 of the shared information and the shared information frame F4 of each terminal. Can be acquired at the same time.

  (11) According to the present embodiment, the shared information frame F4 is transmitted only when the shared information update request frame F1 is received. As a result, unnecessary bandwidth occupation can be avoided in a connectionless network configuration such as an ad hoc network.

  (12) According to the present embodiment, since the update of the shared information is performed in accordance with the IEEE 802.11 compliant sequence, even if the shared information frame F4 is being transmitted, information that is not related to the shared information is displayed. The installed frame can be transmitted. Therefore, normal communication can be performed while updating the shared information.

Embodiment is not limited above, For example, you may actualize as follows.
In the above embodiment, the recovery process is performed on a terminal that has been missed in a plurality of transmitted shared information frames F4. You may perform this with respect to the terminal which participated in cell N1 in the middle of transmitting the shared information frame F4 (henceforth a halfway participation).

  More specifically, as shown in FIG. 9, while terminal A is transmitting a plurality of shared information frames F4 to terminals B and C, terminal D that has not updated shared information joins cell N1, Assume that data can be sent and received. Terminal A broadcasts the shared information frame F4 to terminals B and C (step S5-5). When a new terminal D participates during transmission of the m-th shared information frame F4 (step S5-10), the new terminal D receives from the time when the m-th shared information frame F4 is transmitted (step S5-10). S5-15). Since the version information 23 is also installed in the shared information frame F4, the version of the shared information that is updated in the shared information update process that has already been started, even when participating in the transmission of the shared information frame F4 If it is necessary to grasp the information and update the shared information, it is possible to participate in the shared information update process.

  When the terminal D receives the final shared information frame F4 from the terminal A (step S5-20), the terminal D waits until the reception waiting timer exceeds a predetermined value. Thereafter, recovery processing for receiving a frame that could not be received is performed. As a result, for example, as in an ad hoc network, a predetermined wireless LAN terminal is not always fixed in the cell, and there is a terminal that enters and exits the cell while transmitting the shared information frame F4. In addition, the shared information can be reliably updated. Also, shared information can be updated at the destination when moving between cells.

  In the above embodiment, the terminal A that has transmitted the shared information frame F4 during the update process leaves the cell N1, and the terminal that completely holds the version of the shared information being updated in the cell N1 Explained the recovery process when there is no. As shown in FIG. 10, the recovery process may be executed even when there is a terminal that completely holds the shared information other than the terminal A.

  That is, while terminal B is updating, terminal A that has transmitted shared information frame F4 to terminal B has left cell N1, but all of the plurality of shared information frames F4 of the version being updated are transferred to terminal C. May be performed when the terminal B detects from a beacon or probe request transmitted by the terminal C by broadcast.

  When the terminal C transmits a broadcast or a probe request (step S1-10), the terminal B detects that the terminal C holds the version of shared information that the terminal B is updating. Then, the terminal B transmits the shared information update request frame F1 loaded with the insufficient frame number to the terminal C by unicast (step S6-10). Thereafter, the shared information frame F4 is transmitted from the terminal C to the terminal B, and when the terminal B receives all the shared information frames F4, the updating process is performed.

  As a result, when all of the plurality of shared information frames F4 cannot be received, the plurality of shared information frames F4 are received by complementing the shared information frame F4 between the plurality of terminals. Therefore, shared information can be updated more reliably.

  In the above embodiment, the terminal A that has transmitted the shared information frame F4 during the update process leaves the cell N1, and the terminal that completely holds the version of the shared information being updated in the cell N1 Explained the recovery process when there is no. When the other terminal holds shared information that is not held by one terminal, the recovery process may be performed so that the shared information is complemented between the two terminals.

  More specifically, as shown in FIG. 11, there are terminals B and C whose share information has not been updated, the total number of frames 31 is “9”, the terminal B receives the third to ninth shared information frames F4, and the terminal C Assume that the first to fifth shared information frames F4 are held. Terminal B broadcasts shared information search request frame F2 to terminal C (step S7-10). Thereby, the terminal C can acquire information that the terminal B holds the third to ninth shared information frames F4. Then, the terminal C transmits the shared information search response frame F3 by broadcasting (step S7-15). Thereby, the terminal B can acquire information that the terminal C holds the first and second shared information frames F4. Next, terminal B transmits the shared information update request frame F1 to terminal C by unicast (step S7-20), and terminal C transmits the first and second shared information frames F4 to terminal B. Transmit (step S7-25). When terminal B receives all the shared information frames F4, it updates the shared information (step S7-30).

  Next, the terminal C transmits the shared information update request frame F1 to the terminal B by unicast (step S7-35), and the terminal B transmits the sixth to ninth shared information frames F4 to the terminal C. Transmit (step S7-40). When terminal B receives all the shared information frames F4, it updates the shared information (step S7-45). As a result, when all of the plurality of shared information frames F4 cannot be received, the plurality of shared information frames F4 are received by complementing the shared information frame F4 between the plurality of terminals. Therefore, shared information can be updated more reliably.

  In the above embodiment, when it is confirmed that the terminal that has transmitted the beacon or the probe request holds version information 23 that is older than the version information 23 of the shared information held by itself, the probe request is transmitted to the transmission source terminal. Then, the terminal is made to detect the presence of the new version information 23 and the shared information update process is performed. This is updated from the beacon, probe request, shared information search request frame F2, shared information search response frame F3, shared information frame F4, and the like transmitted by the terminal that joined the cell during the shared information update process. The version information 23 newer than the version information 23 may be detected, and the shared information may be updated.

  More specifically, as shown in FIG. 12, it is assumed that shared information determination processing is performed and a shared information frame F4 is transmitted from terminal A to terminal B by broadcasting (step S5-5). At this time, it is assumed that the terminal D having shared information of a newer version than the shared information held by the terminal A has joined the cell N1 (step S8-10). Then, the terminal D causes the terminal B to detect the presence of shared information whose version is newer than the version of the shared information being updated by a beacon or probe request (step S8-15). When the terminal B detects a new version of shared information from the terminal D (step S8-20), the terminal B discards the shared information frame F4 from the terminal A after the p-th shared information frame F4 (step S8-25). Then, the terminal B transmits the shared information update request frame F1 to the terminal D (step S8-30), receives all the shared information from the terminal D, and updates the shared information.

  As a result, even when update processing is in progress, when a new version of shared information is detected, shared information update processing is performed based on the new version of shared information, so each terminal always maintains the latest shared information. Can do. In addition, when moving between cells, a new version of shared information can be updated in a destination ad hoc network terminal.

In the above embodiment, shared information update processing between wireless LAN terminals in an ad hoc network has been described. This may be applied to update processing between wireless LAN terminals in an infrastructure network as a wireless communication network, and shared information update processing from a wireless LAN terminal to an access point as a terminal. Even in this case, after the shared information of the access point is manually updated, the shared information version information 23 can be notified in the cell along with the transmission of the beacon, and the shared information can be updated. Moreover, since the version information 23 can be notified also by a probe request, the latest shared information can be transmitted from the wireless LAN terminal of the infrastructure network to the access point, for example. As a result, the latest shared information can be transmitted from the wireless LAN terminal to the access point of the movement destination. Similarly, in the infrastructure network, the latest shared information can be transmitted from the access point to the peripheral access points when the probe request is transmitted.

  In the above embodiment, the version information 23 is installed in the SSID field 21, and the version information 23 of the shared information is notified by transmitting and receiving beacons, probe requests, and the like including the SSID field 21. Instead of mounting the version information 23 of the shared information in the SSID field 21, a version notification frame F5 as a version information notification frame for notifying the version information 23 of the shared information may be provided. More specifically, as shown in FIG. 13, the version notification frame includes version information 23 in a data frame defined in IEEE 802.11. Then, as shown in FIG. 14, each terminal A to E transmits a version notification frame F5 at SIFS (Short Interframe Space) intervals after transmitting a beacon or a probe request, whereby the shared information held by each terminal is transmitted. The version information 23 is notified. At this time, since the version notification frame F5 is transmitted at the SIFS interval, the priority is higher than the other frame intervals. Therefore, the version notification frame F5 can be transmitted without being interrupted by another frame. As a result, it is possible to construct a mixed network environment with IEEE802.11-compliant wireless communication terminals that do not have the function of executing the shared information update process while obtaining the same effect as the above embodiment.

  In the above embodiment, the version information 23 is installed in the SSID field 21, and the version information 23 of the shared information is notified by transmitting and receiving beacons, probe requests, and the like including the SSID field 21. As shown in FIG. 15, a vendor-unique ID (unique identifier) is defined in an information element in a beacon / probe request frame, and version information 23 is included in the contents of the frame. Good. That is, when Element ID = 221, WPA ID (Wireless Protected Access ID) is shown, but when the beginning of Contents is a value other than 00: 50: F2: 01, it is used as vendor unique information. Then, Contents ID and version information 23 are loaded in Contents. As a result, it is possible to construct a mixed network environment with IEEE802.11-compliant wireless communication terminals that do not have the function of executing the shared information update process while obtaining the same effect as the above embodiment.

  In the above embodiment, the shared information is one type, but may be a plurality of types. At this time, by including the identifier of the shared information in the version information 23, the version information 23 of a plurality of types of shared information can be managed.

  In the above embodiment, the shared information is stored in the storage unit 16 in the terminal, and the shared information is expanded in the work memory 15 and executed at the time of execution. If the terminal is connected to the host system via the external interface 14, the shared information and its version information 23 are stored in the storage unit provided in the host system without including the storage unit 16 in the terminal. May be. At this time, the shared information is transferred from the storage unit of the host system to the terminal via the external interface 14 when the terminal executes the shared information, and is executed in the work memory 15.

Schematic explanatory drawing of the ad hoc network of this embodiment. Similarly, a block diagram of the terminal. Similarly, the block diagram of the SSID field. Similarly, the block diagram of a shared information update request frame, a shared information search request frame, and a shared information search response frame. Similarly, the block diagram of a shared information frame. Similarly, the version upgrade process sequence. Similarly, the sequence of spill processing. Similarly, the recovery process sequence. Another example of the mid-participation process sequence. Similarly, the recovery process sequence. Similarly, the recovery process sequence. Similarly, a sequence of version upgrade processing during transmission of update information. Similarly, a configuration diagram of a version notification frame. Similarly, an explanatory diagram of the transmission timing of the version notification frame. Similarly, a configuration diagram of a frame on which version information is mounted.

Explanation of symbols

A, B, C, D, E ... terminal, F1 ... shared information update request frame, F2 ... shared information search request frame, F3 ... shared information search response frame, F4 ... shared information frame, F5 ... version notification frame, N1, N2 ... cell, 23 ... version information, 65 ... shared information.

Claims (7)

A shared information update method for updating shared information respectively held by a plurality of terminals in the at least one wireless communication network through at least one wireless communication network,
Transmitting version information of shared information held by one terminal among the plurality of terminals to the plurality of terminals;
The version information of the shared information held by the plurality of terminals is compared with the received version information,
A terminal holding shared information of version information newer than the received version information among the plurality of terminals transmits the shared information to the one terminal,
The said 1 terminal updates the shared information which the said terminal hold | maintains to the shared information of the said new version information, The shared information update method characterized by the above-mentioned. The shared information update method according to claim 1,
The version information of the shared information is mounted as an information element in the management frame,
The shared information update method, wherein the plurality of terminals respectively notify the version information of the shared information by transmitting the management frame. The shared information update method according to claim 1,
The plurality of terminals notify each other of the version information of the shared information by transmitting a version information notification frame in which the version information of the shared information is mounted after the SIFS interval has elapsed after transmitting the management frame. Shared information update method. The shared information update method according to claim 1,
The version information of the shared information is installed in the information element of the management frame having a unique identifier defined in the information element in the management frame,
The shared information update method, wherein each of the plurality of terminals notifies the version information to each other by transmitting the management frame. The shared information update method according to any one of claims 2 to 4,
The shared information update method, wherein the management frame is a beacon or a probe request. The shared information update method according to claim 1,
The terminal holding the new version information sharing information transmits the new version information sharing information divided into a plurality of frames,
Receiving all of the plurality of frames by complementing at least one of the plurality of frames between the plurality of terminals when the one terminal fails to receive at least one of the plurality of frames; A shared information update method characterized by the above. The shared information update method according to claim 6,
When the one terminal fails to receive at least one of the plurality of frames, the holding information of the plurality of frames is broadcasted between the plurality of terminals,
The shared information update method, wherein all the plurality of frames are received by complementing only the frames that are not held by the plurality of terminals based on the holding information.

Images