JP6634863B2 - Wireless communication terminal - Google Patents

Description

  The present invention relates to a wireless communication terminal, a communication method, a program, and a communication system.

  2. Description of the Related Art In recent years, Wi-Fi Direct as an inter-terminal communication system has been receiving attention from the viewpoint of broadening a band, enhancing security, and the like. Wi-Fi networks before that operate in an infrastructure mode using a specific device as an access point (AP), whereas in a network compliant with Wi-Fi Direct, an arbitrary P2P terminal is used instead of a specific device. By becoming a group owner, communication within the group is enabled (for example, see Non-Patent Document 1). The group owner is a P2P terminal that operates as an access point of the group, and can form a group having another P2P terminal as a child (client) as a parent of the group.

  In the P2P group formed as described above, a technology for sharing data and transferring data at high speed between terminals without connecting to the Internet or the like is known as a first related technology related to the present invention. . In Wi-Fi Direct, a strong security protocol is supported, so that higher security can be realized as compared with a conventional ad hoc mode (IBSS: Independent Basic Service Set or the like).

  On the other hand, the following is known as another technique related to the present invention.

  First, a method in which a plurality of wireless communication terminals configuring a wireless PSP network directly share resources with each other is known as a second related technique related to the present invention (for example, see Patent Document 1). The second related art includes building a topology of a wireless network, storing a location and content related information associated with a first mobile device in the wireless network in a database, and a second mobile device in the wireless network. Searching a database for content-related information in response to a content request associated with the device; and providing a search result to a second mobile device for transferring content between the first mobile device and the second mobile device. Transmitting to the mobile device.

  In a wireless communication terminal equipped with a mobile phone and a wireless LAN, safety information can be sent to a specific partner (a home PC, a mobile phone of a family member, etc.) from a place where the mobile phone cannot be connected due to congestion in a disaster or damage to equipment. When sending an (emergency signal), performing communication across terminals using ad-hoc multi-hop communication of a wireless LAN has been proposed as a third related technique related to the present invention (for example, see Patent Document 2). ).

JP 2010-200305 A JP 2007-288259 A

Wi-Fi Peer-to-Peer Technical Specification Version 1.1 (Wi-Fi Alliance Technical Committee PSP Task Group, Wi-Fi Peer-to-Peer (P2P) Technical Specification Version 1.1)

  However, in the wireless P2P network according to the first related art described above, since each group is formed and operated independently, data sharing is limited within the group. In general, there is a physical upper limit on the maximum number of terminals in one group. For example, when the above-described Wi-Fi Direct is realized using an inexpensive wireless LAN device, the number of groups is limited to an upper limit of about 5 to 10 devices supported by the device. Such a limitation on the group size limits data sharing to only terminals in one group, and hinders information sharing with other wireless communication terminals outside the group. Therefore, in the wireless P2P network according to the first related technique described above, for example, emergency information such as emergency information, traffic information, an SOS signal, or a voice signal cannot be notified beyond a local group.

  Further, in the wireless P2P network according to the above-described second related technology, since data sharing is limited to wireless communication terminals belonging to the same wireless P2P network, there is a problem similar to that of the above-described first related technology.

  Further, according to the third related technique described above, it is possible to send safety information (emergency signal) to a specific partner (a PC at home, a mobile phone of a family, etc.) using ad hoc multi-hop communication of a wireless LAN. However, since communication across a plurality of wireless LANs cannot be performed, wireless communication terminals that can communicate with each other are limited to terminals belonging to the same wireless LAN. As a result, there is a problem similar to that of the first related art described above.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problem, that is, in a wireless P2P network, it is difficult for a wireless communication terminal belonging to a peer-to-peer group to transmit information to a wireless communication terminal outside the peer-to-peer group. Is to provide.

The wireless communication terminal according to one embodiment of the present invention,
A first wireless communication terminal,
A wireless communication unit using a communication method capable of forming a peer-to-peer group with another wireless communication terminal;
An automatic connection control unit that searches for other wireless communication terminals using the wireless communication unit, connects, transfers information, and disconnects,
Has,
The automatic connection control unit,
When the first wireless communication terminal belongs to a first peer-to-peer group, a function of determining whether or not to make the first wireless communication terminal a delivery node based on the content of the newly acquired content; If it is determined to be a node, a function of separating the first wireless communication terminal from the first peer-to-peer group, a function of searching for a second wireless communication terminal, and a function of connecting to the second wireless communication terminal A function of transmitting and receiving the content between a first wireless communication terminal and the second wireless communication terminal.

A communication method according to another embodiment of the present invention includes:
A wireless communication unit based on a communication method capable of forming a peer-to-peer group with another wireless communication terminal; and A communication method executed by a first wireless communication terminal having a connection control unit;
If the first wireless communication terminal belongs to a first peer-to-peer group, determine whether to make the first wireless communication terminal a delivery node based on the content of the newly acquired content;
If it is determined to be the delivery node, disconnect the first wireless communication terminal from the first peer-to-peer group, search for a second wireless communication terminal,
The first wireless communication terminal is connected to the second wireless communication terminal to transfer the content between the first wireless communication terminal and the second wireless communication terminal.

The program according to another embodiment of the present invention includes:
Computer
A wireless communication unit using a communication method capable of forming a peer-to-peer group with another wireless communication terminal;
An automatic connection control unit for searching for, connecting to, exchanging information with, and disconnecting from another wireless communication terminal using the wireless communication unit, wherein the first wireless communication terminal belongs to a first peer-to-peer group A function of determining whether to make the first wireless communication terminal a delivery node based on the content of the newly acquired content; and a function of determining whether to make the first wireless communication terminal a delivery node. A function of separating from the first peer-to-peer group, a function of searching for a second wireless communication terminal, and a function of connecting to the second wireless communication terminal to connect the first wireless communication terminal and the second wireless communication terminal. An automatic connection control unit having a function of transmitting and receiving the content between
Function.

  A communication system according to another embodiment of the present invention includes a plurality of wireless communication terminals according to the above-described embodiment of the present invention.

  According to the present invention, by having the above-described configuration, a wireless communication terminal belonging to the first peer-to-peer group can exchange content with a wireless communication terminal outside the first peer-to-peer group.

FIG. 1 is a diagram illustrating a configuration example of a communication system according to a first embodiment of the present invention. 5 is a flowchart illustrating an example of a process executed by a node (wireless communication terminal) according to the first embodiment of the present invention. FIG. 3 is a state transition diagram of the communication system according to the first embodiment of the present invention. FIG. 3 is a state transition diagram of the communication system according to the first embodiment of the present invention. It is a block diagram of a node concerning a 1st embodiment of the present invention. FIG. 4 is a diagram illustrating an example of group information stored by a node according to the first embodiment of the present invention. FIG. 5 is a diagram illustrating an example of emergency content control information stored by a node according to the first embodiment of the present invention. FIG. 3 is a diagram illustrating a Wi-Fi Direct connection flow used for automatic connection by the communication system according to the first embodiment of the present invention. FIG. 4 is a diagram illustrating an operation flow of DEVICE DISCOVERY used by the communication system according to the first embodiment of the present invention for device discovery. FIG. 7 is a diagram illustrating an operation flow of DEVICE DISCOVERY used by the communication system according to the first embodiment of the present invention for discovering an existing group. FIG. 6 is a diagram illustrating an operation flow of GO NEGOTION used by the communication system according to the first embodiment of the present invention for automatic connection. FIG. 4 is a diagram illustrating an operation flow of PROVISION DISCOVERY used by the communication system according to the first embodiment of the present invention for automatic connection. FIG. 5 is a diagram showing an operation flow of INVATION used by the communication system according to the first embodiment of the present invention for automatic connection. FIG. 4 is a diagram illustrating an operation flow of node detachment used by the communication system according to the first embodiment of the present invention for automatic connection. 5 is a flowchart illustrating an example of an operation of the communication system according to the first exemplary embodiment of the present invention. FIG. 2 is a diagram illustrating an example of emergency content in the communication system according to the first embodiment of the present invention. It is a figure showing signs that a node concerning a 2nd embodiment of the present invention searches for a neighboring other node. FIG. 13 is a diagram illustrating an example of an IE format added to a management frame by a node according to the second embodiment of the present invention. It is a figure showing an example of a judgment table used by a node concerning a 2nd embodiment of the present invention. FIG. 14 is a diagram illustrating a state where a node according to the third embodiment of the present invention determines whether to start transmission to a connected partner or wait for reception. It is a figure showing the example of the emergency contents in the communication system concerning a 4th embodiment of the present invention. FIG. 14 is a configuration diagram of a node according to a fifth embodiment of the present invention.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
[First Embodiment]
Referring to FIG. 1, a communication system 100 according to the first embodiment of the present invention includes a plurality of nodes (wireless communication terminals) 101. Each node 101 is, for example, a wireless communication terminal mounted on a vehicle such as an automobile or a wireless communication terminal such as a smartphone carried by a pedestrian. Each node 101 can perform wireless communication according to a communication method that can form a peer-to-peer group (P2P group). In the present embodiment, the communication method is Wi-Fi Direct. However, the present invention is not limited to Wi-Fi Direct, but may be applied to any communication method that can form a peer-to-peer group with another node.

  In FIG. 1, a plurality of nodes 101 constitute three peer-to-peer groups (hereinafter simply referred to as groups) G1 to G3. The group G1 is formed with the node 101-1 as a parent (group owner), and the nodes 101-2 to 101-3 are its children (clients). In the group G2, the node 101-4 is formed as a group owner, and the node 101-5 is its client. In the group G3, the node 101-6 is formed as a group owner, and the nodes 101-7 and 101-8 are clients thereof. On the other hand, the node 101-9 is a single node that does not form a group with another node.

  The nodes 101-1 to 101-3 belonging to the group G1 can perform communication by Wi-Fi Direct using the node 101-1 as an access point. Further, between the nodes 101-4 to 101-5 belonging to the group G2, communication by Wi-Fi Direct can be performed using the node 101-4 as an access point. Also, between the nodes 101-6 to 101-8 belonging to the group G3, communication using Wi-Fi Direct can be performed using the node 101-6 as an access point. However, between the nodes 101-1 to 101-3 belonging to the group G1, the nodes 101-4 to 101-5 belonging to the group G2, the nodes 101-6 to 101-8 belonging to the group G3, and the single node 101-9. In this case, communication using Wi-Fi Direct cannot be performed directly because the groups are different. Therefore, even if one of the nodes 101 acquires the content, the content cannot be propagated to another node outside the group with the current group configuration. Therefore, if the content obtained by any one of the nodes 101 is a critical and urgent content such as emergency information such as disaster information, traffic information, and SOS signal, etc., an unexpected May lead to the situation.

  Thus, in the present embodiment, if the content acquired by any one of the nodes 101 is an urgent content, rapid propagation of the content outside the group is realized. Therefore, in the present embodiment, when the node 101 that has acquired the urgent content finishes notifying the other nodes in the group of the urgent content, the node 101 becomes a delivery node, immediately leaves the group, and transmits to another node outside the group. By connecting and notifying the other node of the emergency content, the sharing of the emergency content with a node outside the group is realized. Hereinafter, a case will be described as an example in which the node 101-1 among the nine nodes 101 illustrated in FIG. 1 has acquired emergency content. However, the node 101 that obtains the urgent content first is not limited to the specific node 101-1 and may be another node 101, and there are a plurality of nodes that obtain the emergency content first. Is also good.

  FIG. 2 is a flowchart illustrating an example of processing executed by the node 101. Hereinafter, the operation of the present embodiment will be described with reference to FIGS.

  Upon acquiring the content, the node 101-1 starts executing the processing illustrated in FIG. There are a plurality of routes for the node 101-1 to acquire the content. For example, it is conceivable that a user (person) of the node 101-1 inputs content to the node 101-1 through a keyboard, an external input terminal, or the like provided in the node 101-1. Alternatively, it is conceivable that the node 101-1 has a mobile phone function and receives contents by a short message, mail, or the like. Alternatively, it is conceivable that the node 101-1 has a data broadcast receiving function and receives contents by data broadcast. Alternatively, it is conceivable that the node 101-1 receives the content from another node in the same group by Wi-Fi Direct communication.

  The node 101-1 first determines whether or not the acquired content is an emergency content (step S101). There are several methods for determining whether the content is urgent. For example, when the content is described in a predetermined language and an urgent content is inserted with an attribute value indicating urgency or less and described as an urgent attribute value), it is determined whether the acquired content has an urgent attribute value. There is a way to check. Alternatively, if an attribute value indicating the degree of urgency (hereinafter referred to as an urgent level attribute value) is always inserted into the content, and the urgent level attribute value is greater as the urgency is higher, the urgent level attribute is used. There is a method of checking whether the value is equal to or more than a predetermined value. Alternatively, the meaning of the text included in the content may be analyzed irrespective of the predetermined attribute value to determine whether the content is highly urgent. If the acquired content is not the emergency content, the node 101-1 ends the process illustrated in FIG.

  Further, if the acquired content is an emergency content, the node 101-1 determines whether the acquired content is new (step S102). There are several methods for determining whether the content is new content. For example, when the node 101 is configured to store the acquired content in a content storage unit including a memory or the like for a fixed period in the past, it is determined whether or not the same content as the acquired content exists in the content storage unit. By checking, it is determined whether the acquired content is new. Alternatively, if the node 101 is configured to store the acquired summary or identification information of the content in the content storage unit for a fixed period of time in the past, the same summary or identification information as the acquired summary or identification information of the content is stored in the content storage unit. It is determined whether or not the acquired content is new by checking whether or not the content exists. If the acquired content is not new content, the node 101-1 ends the process illustrated in FIG.

  If the acquired content is urgent and new content, the node 101-1 executes the following processing. First, the node 101-1 transmits the acquired urgent and new content to the nodes 101-2 and 101-3 in the group (step S103). Then, the node 101-1 leaves the group G1 (step S104). Since the node 101-1 is the group owner of the group G1, the group G1 disappears when the group G1 leaves the group G1. As a result, each of the nodes 101-1 to 101-3 becomes a single node.

  The node 101-1 that has become a single node searches for a predetermined time period to determine whether or not there is a node to which emergency content is to be notified (step S105). When the node 101-1 finds a node to be notified of the emergency content, it connects to the node (step S106). For example, referring to FIG. 1, a node 101-4, which is the owner node of the group G2, exists around the node 101-1. Therefore, when the node 101-1 finds the node 101-4, it connects to the node 101-4 (step S106). As a result, the node 101-1 becomes a client of the group G2 as shown in FIG. Next, the node 101-1 transmits the emergency content to the connected node 101-4 (step S107). Next, when the transmission of the urgent content is completed, the node 101-1 disconnects the connection with the node 101-4 as shown in FIG. 4 (step S108), becomes a single node again, and returns to step S105. Return to processing.

  If the node to which the emergency content is to be notified cannot be found even after continuing the search for a predetermined time in step S105, the node 101-1 determines whether or not the delivery end condition is satisfied (step S109). . As the delivery end condition, for example, the expiration date set for the urgent content has elapsed, a certain time has elapsed since the urgent content was received, or a delivery stop instruction has been input from the user of the node 101-1. , And so on. If the delivery end condition is not satisfied, the process returns to step S105 and repeats the same processing as the above-described processing. On the other hand, if the delivery end condition is satisfied, the processing in FIG. 2 ends.

  On the other hand, the node 101-4 receiving the emergency content from the node 101-1 starts the processing shown in FIG. As a result, if the received emergency content is new, the node 101-4 transmits the emergency content to the node 101-5 of the group G2 (step S103), and leaves the group G2 (step S104). As a result, each of the nodes 101-4 to 101-5 becomes a single node as shown in FIG.

  The node 101-2 that has received the emergency content from the node 101-1 starts the processing illustrated in FIG. As a result, if the received emergency content is new, the node 101-2 substantially skips steps S103 to S104, becomes a single node, and proceeds to the processing of step S105. The node 101-2 substantially skips steps S103 to S104 because the node 101-2 has been disconnected from the node 101-1 immediately after receiving the emergency content, and has already become an independent node. Because it is. The node 101-3 that has received the emergency content from the node 101-1 starts the processing illustrated in FIG. 2 for the same reason, becomes an independent node, and proceeds to the processing of step S105. Thus, each of the nodes 101-2 and 101-3 searches for a predetermined time period to determine whether or not there is a node to which emergency content is to be notified.

  Referring to FIG. 1, a single node 101-9 exists around the node 101-2. Therefore, when the node 101-2 discovers the node 101-9, it connects to the node 101-9 as shown in FIG. 3 (step S106), and notifies the node 101-9 of the emergency content (step S107). . Next, as illustrated in FIG. 4, the node 101-2 disconnects from the node 101-9 (step S108), becomes an independent node again, and returns to the processing in step S105.

  Referring to FIG. 1, a node 101-6, which is the owner node of the group G3, exists around the node 101-3. Therefore, when the node 101-3 finds the node 101-6, it connects to the node 101-6 as shown in FIG. 3 (step S106), and notifies the node 101-6 of the emergency content (step S107). . Next, as illustrated in FIG. 4, the node 101-3 disconnects from the node 101-6 (step S108), becomes an independent node again, and returns to the processing in step S105.

  Further, the node 101-6 that has received the emergency content from the node 101-3 starts the processing illustrated in FIG. As a result, if the received emergency content is new, the node 101-6 transmits the emergency content to the nodes 101-7 and 101-8 of the group G3 (step S103), and leaves the group G3 (step S104). . As a result, the nodes 101-6 to 101-8 become independent nodes as shown in FIG.

  As described above, the emergency content acquired by the node 101-1 of the group G1 is quickly propagated to all the nodes beyond the group. Until the delivery termination condition is satisfied, each node 101 searches for a node to be notified of emergency content, connects to the discovered node, and transmits / receives emergency content. Also, emergency contents can be transmitted.

  Hereinafter, the configuration and operation of the communication system according to the present embodiment will be described in more detail.

  FIG. 5 is a block diagram illustrating a configuration example of a node N used as the node 101. The node N in this example includes a wireless communication interface unit (hereinafter, referred to as a wireless communication I / F unit) 10, 20, an operation input unit 30, a screen display unit 40, a storage unit 50, an arithmetic processing unit 60, It is composed of

  The wireless communication I / F units 10 and 20 are formed of dedicated wireless communication circuits, and have a function of performing wireless communication with various devices such as other wireless communication terminals connected via a wireless communication line. I have. The wireless communication I / F unit 10 is a wireless LAN interface compatible with Wi-Fi Direct, and the wireless communication I / F unit 20 is a wireless interface compatible with cellular communication such as 3G and LTE.

  The operation input unit 30 includes an operation input device such as a keyboard and a mouse, and has a function of detecting an operation of an operator and outputting the operation to the arithmetic processing unit 60.

  The screen display unit 40 includes a screen display device such as an LCD (Liquid Crystal Display) or a PDP (Plasma Display Panel), and has a function of displaying various information such as an operation menu on the screen in response to an instruction from the arithmetic processing unit 60. Have.

  The storage unit 50 is composed of a storage device such as a hard disk or a memory, and has a function of storing processing information and a program 50P necessary for various processes in the arithmetic processing unit 60. The program 50P is a program that realizes various processing units by being read and executed by the arithmetic processing unit 60. The program 50P is connected to an external device via a data input / output function of the communication I / F units 10 and 20 and the operation input unit 30. The data is read in advance from a device (not shown) or a storage medium (not shown) and stored in the storage unit 50. Main processing information stored in the storage unit 50 includes shared information 50A, group information 50C, and emergency content control information 50D.

  The shared information 50A is data shared with other nodes and is, for example, disaster information or traffic information.

  The group information 50C is information on a group (P2P group) to which the terminal belongs. When participating in any group, information specifying the group owner and information specifying the client node are registered in the group information 50C. If the user has not participated in any group, that fact is registered. The node N manages whether its own node is a group owner or a client based on the group information 50C, and executes processing according to the group owner and processing according to the client. FIG. 6 is a configuration example of the group information 50C. The group information 50C of this example has entries for storing sets of the node identifier, the MAC address, and the owner bit as many as the members of the group. The owner bit is set to a value of 1 when the node specified by the node identifier or the MAC address of the group is the group owner, and is set to a value of 0 otherwise, that is, to a client.

  The emergency content control information 50D is information indicating whether or not the node N has emergency content. FIG. 7 is a configuration example of the emergency content control information 50D. The emergency content control information 50D in this example is configured from an emergency content holding flag, an emergency level, and an expiration date. The emergency content holding flag is set to a value of 1 if the node N holds the emergency content, and is reset to a value of 0 if the node N does not. As the urgent level, a value of the urgent level having the largest value among the retained urgent contents is set. As the expiration date, the expiration date of the urgent content whose value is set to the urgent level is set. The initial values of the urgent content holding flag, the urgent level, and the expiration date are NULL, and when the node N acquires a certain urgent content, the urgent content holding flag, the urgent level, and the expiration date are required according to the acquired urgent content. Will be updated accordingly. Further, when the expiration date of any one urgent content expires in a state where the node N has a plurality of urgent contents, the urgent content holding flag, the urgent level and the expiration date are updated as necessary. You. When the expiration date of all the urgent contents held expires, the urgent content holding flag, the urgent level, and the expiration date are updated to NULL, which is the initial value.

  The arithmetic processing unit 60 includes a microprocessor such as an MPU and peripheral circuits, and reads and executes the program 50P from the storage unit 50, thereby realizing various processing units in cooperation with the hardware and the program 50P. It has the function to do. The main processing units realized by the arithmetic processing unit 60 include a Wi-Fi connection control unit 60A, a cellular communication control unit 60B, and an automatic connection control unit 60C.

  The Wi-Fi connection control unit 60A is a block that generates a Wi-Fi Direct packet, transmits the generated packet through the wireless communication I / F unit 10, and receives a Wi-Fi Direct packet through the wireless communication I / F unit 10. is there. The Wi-Fi connection control unit 60A performs control in units such as "Device Discovery", "Group Formation", "Wi-Fi Protected Setup (WPS) Provisioning Phase 1," and "WPS Provisioning Phase 2." Further, the Wi-Fi connection control unit 60A receives an event (command) from the automatic connection control unit 60C, starts control, and notifies the result to the automatic connection control unit 60C as an event (response).

  The cellular communication control unit 60 </ b> B is a block that generates a cellular communication packet, transmits the packet through the wireless communication I / F unit 20, and receives a cellular communication packet through the wireless communication I / F unit 20. Upon receiving an event (command) from the automatic connection control unit 60C, the cellular communication control unit 60B executes control according to the event, and notifies the automatic connection control unit 60C of the result as an event (response).

  The automatic connection control unit 60C is a control unit located at a higher layer than the Wi-Fi connection control unit 60A and the cellular communication control unit 60B. The automatic connection control unit 60C controls transmission and reception of messages across P2P groups of Wi-Fi Direct by controlling the cellular communication control unit 60B. The automatic connection control unit 60C realizes automatic connection by Wi-Fi Direct by controlling the Wi-Fi connection control unit 60A. More specifically, for example, when a node approaches each other, one group is automatically constructed, and communication between nodes is realized within the group. Also, when a new node approaches an already constructed group, it automatically joins the already constructed group. Further, the node is automatically detached from the established group. Then, the automatic connection control unit 60C realizes the information sharing method described with reference to FIG. 2 in the Wi-Fi P2P network by the connection and disconnection processing of Wi-Fi Direct.

  Hereinafter, the function of the automatic connection control unit 60C will be described in more detail. First, the Wi-Fi Direct connection and disconnection functions will be described, and then the control functions related to information sharing described with reference to FIG. 2 will be described.

<Connection and disconnection of Wi-Fi Direct>
As shown in FIG. 8, when a group is formed between nodes (CASE 1), first, a neighboring P2P node is searched by a Device Discovery process, and when a P2P node is found, one of the groups is determined by a GO Negotiation process. (GO), the other connects as a client. Subsequently, WPS Provision Phase-1 (authentication phase) and Pahse-2 (encryption phase) are sequentially executed.

  When connecting to an existing GO (CASE 2), first, a neighboring P2P node is searched for by a Device Discovery process, and if the discovered P2P node is a GO, the GO is connected to the GO by a Provision Discovery process, and then the WPS Provision is performed. Phase-1 (authentication phase) and Pahse-2 (encryption phase) are sequentially executed.

  When connecting to Persistent GO (CASE 3), first, a neighboring P2P node is searched for by Device Discovery processing, and if the discovered P2P node is Persistent GO, connection is made to the Persistent GO by Invitation processing, and subsequently, WPS Provision Pose- 2 (encryption phase) are sequentially executed.

  As illustrated in FIG. 9, a Device Discovery operation is performed. That is, upon receiving a search request from the automatic connection control unit, the Wi-Fi connection control unit in each node starts searching for an adjacent node, and alternately repeats the Search state and the Listen state. In the Search state, a Probe Request is transmitted while sequentially switching a predetermined channel, and a Probe response which is a response to the Probe Request is awaited. In the Listen state, it waits for a Probe Request from another node, and upon receiving a Probe Request, returns a Probe Response to it. When the node N1 is a client of the group, if the Wi-Fi connection control unit of the node N1 receives a Probe Response from the node N2, the node N1 notifies the information of the adjacent node N2 to the group owner of the own group as adjacent node information.

  As illustrated in FIG. 10, a Device Discovery operation for the existing GO is executed. If a group having the node N2 as a group owner has already been constructed, the GO node N2 returns a Probe Response to the Probe Request from the node N1. At this time, the P2P Device Info Attribute of the Probe Response from the GO node N2 includes a list of clients belonging to the group (here, information on the nodes N2 and N3).

  As illustrated in FIG. 11, a GO Negotiation operation for forming a group between terminals is performed. By exchanging GO Negotiation Request, GO Negotiation Response, and GO Negotiation Configuration between nodes, one of the nodes becomes GO and starts broadcasting a beacon.

  As illustrated in FIG. 12, a Provision Discovery operation for connecting to an existing GO is executed. The node N1 is connected to the node N2 by the GO node N2 returning a provision discovery response to the node N1 in response to the provision discovery request from the node N1 to the node N2.

  As illustrated in FIG. 13, an invitation operation for connecting to the Persistent-GO is executed. In response to the Invitation Request from the node N1 to the node N2, the persistent-GO node N2 returns an Invitation Response to the node N1, whereby the node N1 is connected to the node N2.

  As shown in FIG. 14, in the client-initiated detachment, the client node N1 can send out Deauthentication or Disassociation Indication to the GO node N2, so that the detachment is possible. Conversely, in the group-led leave, the GO node N2 can cause the client to leave by transmitting Deauthentication or Disassociation Indication to the client node N1.

<Control functions related to information sharing>
FIG. 15 is a flowchart illustrating an example of the operation of the communication system according to the present embodiment. Hereinafter, the operation of the node 101 when the emergency content acquired by the node 101-1 is shared with the other nodes 101-2 to 101-9 will be described with reference to FIG.

  First, the automatic connection control unit 60C of the node 101-1 inputs the emergency content from the operation input unit 30, or receives a message having the emergency content by the wireless communication I / F unit 20 and inputs the message from the cellular communication control unit 60B. Is performed (step S111).

  FIG. 16 shows an example of emergency content. The urgent content in this example is described in XML (Extensible Markup Language) language. This urgent content is tornado caution information issued to Saitama Prefecture, with the highest urgent level of 3 and an expiration date of February 15, 2016, 14:00. FIG. 16 is for convenience of explanation, and is simplified by omitting the XML declaration. Here, the urgent content described in the XML language is illustrated, but it goes without saying that the urgent content used in the present invention is not limited to the one described in the XML language.

  If the input emergency content is a new content, the automatic connection control unit 60C of the node 101-1 stores the emergency content in the storage unit 50 as the shared information 50A, and updates the emergency content control information 50D. Specifically, the automatic connection control unit 60C sets the urgent content holding flag in FIG. 7 to 1, sets the urgent level to 3, and sets the expiration date to 14:00 on February 15, 2016. Then, the automatic connection control unit 60C of the node 101-1 notifies the emergency contents to the nodes 101-2 to 101-3 of the group G1 using the Wi-Fi connection control unit 60A (step S112). When the emergency content is received by the wireless communication I / F unit 10 and input through the Wi-Fi connection control unit 60A, the automatic connection control unit 60C of the nodes 101-1 to 101-3 stores the emergency content in the storage unit 50 as the shared information 50A. And updates the emergency content control information 50D in the same manner as the node 101-1.

  Thereafter, the automatic connection control units 60C of the nodes 101-1 to 101-3 execute a disconnection procedure using the Wi-Fi connection control unit 60A (step S113). As a result, each of the nodes 101-1 to 101-3 becomes a single node.

  The automatic connection control unit 60C of each of the nodes 101-1 to 101-3 that has become a single node searches for a nearby node. This search is performed in accordance with the Device Discovery procedure of the Wi-Fi Direct specification. On the other hand, the Wi-Fi connection control units 60A of the nodes 101-4 and 101-6, which are the group owners of the groups G2 and G3, broadcast a beacon, and the node 101-9, which is a single node, has the node 101- Similar to 1 to 101-3, a nearby node is searched.

  FIG. 15 illustrates a case where the node 101-1 discovers the node 101-4 and the node 101-2 discovers the node 101-9 by searching for a neighboring node.

  The Wi-Fi connection control unit 60A of the node 101-1 transmits a probe request to the discovered node 101-4 (step S114), and receives a probe response from the node 101-4 (step S115). Then, the automatic connection control unit 60C of the node 101-1 executes a connection procedure with the automatic connection control unit 60C of the node 101-4 (step S116). As a result, the node 101-1 connects to the node 101-4 as a client of the group G2. Next, the automatic connection control unit 60C of the node 101-1 notifies the emergency content of FIG. 16 stored in the shared information 50A to the node 101-4 by using the Wi-Fi connection control unit 60A (step). S117). When the emergency content is received by the wireless communication I / F unit 10 and input through the Wi-Fi connection control unit 60A, the automatic connection control unit 60C of the node 101-4 stores the emergency content in the storage unit 50 as shared information 50A, Further, the emergency content control information 50D is updated. Further, the automatic connection control unit 60C of the node 101-4 notifies the acquired emergency content to the node 101-5. When the emergency content is received by the wireless communication I / F unit 10 and input through the Wi-Fi connection control unit 60A, the automatic connection control unit 60C of the node 101-5 stores the emergency content in the storage unit 50 as shared information 50A, Further, the emergency content control information 50D is updated. Thereafter, the automatic connection control unit 60C of each of the nodes 101-1 and 101-4 to 101-5 executes a disconnection procedure using the Wi-Fi connection control unit 60A (step S118). As a result, each of the nodes 101-1 and 101-4 to 101-5 becomes a single node.

  On the other hand, the Wi-Fi connection control unit 60A of the node 101-2 transmits a probe request to the discovered node 101-9 (step S121), and receives a probe response from the node 101-9 (step S122). . Then, the automatic connection control unit 60C of the node 101-2 executes a connection procedure with the automatic connection control unit 60C of the node 101-9 (step S123). As a result, one of the nodes 101-2 and 101-9 becomes a group owner and is connected to each other. Next, the automatic connection control unit 60C of the node 101-2 notifies the emergency content of FIG. 16 stored in the shared information 50A to the node 101-9 using the Wi-Fi connection control unit 60A (step). S124). When the emergency content is received by the wireless communication I / F unit 10 and input through the Wi-Fi connection control unit 60A, the automatic connection control unit 60C of the node 101-9 stores the emergency content in the storage unit 50 as shared information 50A, Further, the emergency content control information 50D is updated. Thereafter, the automatic connection control units 60C of the nodes 101-2 and 101-9 execute a disconnection procedure using the Wi-Fi connection control unit 60A (step S125). As a result, each of the nodes 101-2 and 101-9 becomes a single node.

  Although not described in FIG. 15, when the node 101-3 that has become a single node discovers the node 101-6 of the group G3, the same operation as the node 101-1 that discovers the node 101-4 of the group G2 is performed. I do. The node 101-6 of the group G3 performs the same operation as the node 101-4 of the group G2, and the nodes 101-7 and 101-8 of the group G3 perform the same operation as the node 101-5 of the group G2. Do. As a result, the emergency content acquired by the node 101-3 is notified to the nodes 101-6 to 101-8.

  Thus, according to the present embodiment, the emergency content acquired by the node 101-1 of the group G1 is promptly propagated to all nodes beyond the group.

[Second embodiment]
Next, a second embodiment of the present invention will be described. This embodiment is different from the first embodiment in the configuration and operation related to step S105 in FIG. 2, and the rest is the same as the first embodiment.

  The node 101 according to the present embodiment includes information on the presence / absence of retained emergency content and the emergency level information of the retained emergency content (hereinafter referred to as emergency content information) in a management frame of a wireless LAN such as Wi-Fi Probe Request, Probe Response, or Beacon. ) Is added. Specifically, before transmitting the management frame, the Wi-Fi connection processing unit 60A of the node 101 refers to the emergency content control information 50D to determine whether or not the emergency content holding flag is set and whether the expiration date is valid. Check if it has passed. If the emergency content holding flag is set and the expiration date has not expired, the Wi-Fi connection processing unit 60A transmits emergency content information including an emergency content and an emergency level if the expiration date has not passed. Add to management frame. Also, if the emergency content holding flag is not set or the expiration date has passed even if the emergency content holding flag is set, the Wi-Fi connection processing unit 60A does not add the emergency content information to the management frame to be transmitted or sets the NULL value. Add emergency content information.

  In the search for a node to which emergency content is to be notified in step S105 in FIG. 2, the Wi-Fi connection processing unit 60A of the node 101 according to the present embodiment adds a management frame transmitted from a nearby node when receiving the management frame. The system is configured to determine a node to be notified of emergency content based on the emergency content information thus obtained. Specifically, the Wi-Fi connection processing unit 60A determines that the emergency frame information is not added to the management frame received from a certain neighboring node or that the emergency frame is NULL even if it is added. , The node to be notified of the emergency content. Also, the Wi-Fi connection processing unit 60A adds the emergency content information to the management frame received from a certain nearby node, but the emergency level is lower than the emergency level set in the emergency content control information 50D. If this is the case, the node is determined to be the node to which emergency content is to be notified. In cases other than the above, the Wi-Fi connection processing unit 60A excludes the node because it is a node already holding the urgent content, and continues searching for another node.

  Generally, a management frame of a wireless LAN including each frame of a probe request / probe response and a beacon can have additional information called IE (Information Element). FIG. 18 shows the format of the IE. The IE is a variable length format including a 1-byte field ID, a 1-byte field length, and a content having a size defined by the field length. Therefore, as one specific example of adding emergency content information to the management frame, it is conceivable to use the above-described IE. Specifically, a unique value indicating the notification of emergency content information is entered in the field ID, and the emergency content information is entered in the content. However, the method for adding the emergency content information to the management frame is not limited to the method using the IE. For example, other arbitrary methods such as adding emergency content information to a part of the P2P device name or adding emergency content information using a vendor attribute or a group capability bit can be adopted.

  FIG. 17 illustrates a situation in which the disconnection procedure of step S113 in FIG. 15 is executed, and the nodes 101-1 to 101-3 become single nodes and search for nearby nodes. The nodes 101-1 to 101-3 broadcast a probe request to which emergency content information is added to the surroundings in order to hold emergency content. On the other hand, the owner nodes 101-4 and 101-6 of the groups G2 and G3 do not have emergency content, and therefore broadcast a beacon without emergency content information to the surroundings. Also, since the node 101-9, which is a single node, does not have emergency content, it broadcasts a probe request without emergency content information to the surroundings.

  The node 101-1 discovers the node 101-4 by receiving the beacon from the node 101-4. The node 101-1 discovers the nodes 101-2 and 101-3 by receiving the probe requests from the nodes 101-2 and 101-3. Therefore, if the node 101-1 finds the nodes 101-2 and 101-3 earlier than the node 101-4, the node 101-1 may connect to the nodes 101-2 and 101-3. However, in this embodiment, since the probe requests sent from the nodes 101-2 and 101-3 include urgent content information, the node 101-1 ignores the discovered nodes 101-2 and 101-3, Continue searching. Then, upon receiving the beacon from the node 101-4, the node 101-1 determines that the node 101-4 is a node to be connected, since emergency content information is not added to the beacon.

  For the same reason, the node 101-2 connects to the node 101-9 that does not have emergency content among the nodes 101-1, 101-3, and 101-9 existing in the vicinity, and the node 101-3 connects to the node 101-3. , Among the nodes 101-1, 101-2, and 101-6 existing in the vicinity, connects to the node 101-6 that does not have emergency content.

  As described above, according to the present embodiment, the node 101 that has acquired the emergency content can connect to a node that does not yet have the emergency content in searching for a node to which the emergency content is to be notified. Thereby, there is no waste connecting to the node having the emergency content, and the emergency content can be more quickly propagated between the nodes.

[Third embodiment]
Next, a third embodiment of the present invention will be described. This embodiment is different from the second embodiment in the configuration and operation related to step S107 in FIG. 2, and is otherwise the same as the second embodiment.

  Upon completion of the connection with the other node, the node 101 according to the present embodiment, upon connection with the other node, receives a management frame received from the other node (a wireless LAN such as the above-described Probe Request, Probe Response, or Beacon of Wi-Fi). It is configured to determine whether to start transmission or wait for reception based on the urgent content information added to the management frame (i.e., the management frame) and the urgent content control information 50D stored in the storage unit 50. Specifically, the automatic connection control unit 60C of the node 101 follows the determination table shown in FIG.

  The determination table shown in FIG. 19 maps the emergency content flag set and reset states of the emergency content control information 50D in the horizontal axis direction, and maps the presence or absence of emergency content information in the received management frame in the vertical axis direction. The judgment result is described at the intersection of the axis and the horizontal axis.

  According to this determination table, if the emergency content flag of the emergency content control information 50D is set, that is, if the node 101 has emergency content, if there is no emergency content information in the management frame received from another node, That is, if the other node does not hold the emergency content, the node 101 determines to start transmission within a certain time.

  According to the determination table, when the emergency content flag of the emergency content control information 50D is reset, that is, when the node 101 does not have the emergency content, the management frame received from another node has the emergency content information. In other words, if the other node has the emergency content, the node 101 determines to wait for a certain period of time.

  According to the determination table, when the emergency content flag of the emergency content control information 50D is set, that is, when the node 101 has the emergency content, the emergency content information is included in the management frame received from another node. In other words, if the other node has emergency content, the two emergency levels are compared. If the emergency level of the node 101 exceeds the emergency level of the other node, the node 101 transmits the emergency content within a certain time. Is determined to start, and if the emergency level of the node 101 is equal to or lower than the emergency level of another node, it is determined to wait for a certain period of time.

  According to the determination table, when the emergency content flag of the emergency content control information 50D is reset, that is, when the node 101 does not hold the emergency content, the emergency content information is not included in the management frame received from another node. For example, if the other node does not have emergency content, the node 101 determines that there is no restriction on transmission and reception. That is, the node 101 determines that transmission may be started within a fixed time or reception may be waited for a fixed time.

  FIG. 20 illustrates a situation in which the connection procedure of steps S116 and S123 in FIG. 15 is executed, the node 101-1 is connected to the node 101-4 of the group G2, and the node 101-2 is connected to the node 101-4. I have. FIG. 20 illustrates a screen in which the node 101-3 is connected to the node 101-6 of the group G3.

  When the connection between the nodes 101-1 and 101-4 is completed, each node determines whether to start transmission or wait for reception based on the determination table in FIG. In this case, since the node 101-1 has the emergency content, transmission of the emergency content to the node 101-4 starts within a certain time after the connection. On the other hand, since the node 101-4 has no emergency content, the node 101-4 waits for reception for a certain period of time after connection. As a result, transmission / reception of emergency content is performed between the nodes 101-1 and 101-4. If the control as in the present embodiment is not performed, a situation in which the node 101-4 transmits some information to the node 101-1 before the node 101-1 transmits the emergency content to the node 101-4 may occur. Can occur. Then, until the transmission is completed, the emergency content cannot be notified from the node 101-1 to the node 101-4, and prompt transmission of the emergency content becomes difficult.

  For the same reason, when the node 101-2 completes the connection with the node 101-9, the node 101-2 starts transmitting the urgent content within a certain period of time. By waiting for the reception, the emergency content is promptly notified from the node 101-2 to the node 101-9. When the connection with the node 101-6 is completed, the node 101-3 starts transmitting the urgent content within a predetermined time. When the connection with the node 101-3 is completed, the node 101-6 waits for reception for a predetermined time. By doing so, the emergency content is immediately notified from the node 101-3 to the node 101-6.

  As described above, according to the present embodiment, when the connection between the node 101 that has acquired the emergency content and the node 101 that has not acquired the emergency content is completed, the node 101 that has not acquired the emergency content is waiting for reception. In this state, transmission of emergency content from the node 101 that has acquired emergency content to the node 101 that has not acquired emergency content can be started.

[Fourth embodiment]
Next, a fourth embodiment of the present invention will be described. This embodiment is different from the first embodiment in that a delivery control command is described in the emergency content and that the node 101 that has acquired the emergency content controls the delivery operation according to the delivery control command. Otherwise, the configuration is the same as that of the first embodiment.

  FIG. 21 shows an example of an emergency content having a delivery control instruction. The emergency content of this example is different from the emergency content shown in FIG. 16 in that a control command is added by an element “control”. In this example, a delivery control command is described that saves a network topology at the time of content acquisition, starts a content delivery operation, and configures a network based on the saved network topology after an expiration date. The node 101 according to the present embodiment is configured to perform an operation according to a delivery control command described in the emergency content when the emergency content is acquired.

  For example, upon acquiring the emergency content shown in FIG. 21 in step S111 of FIG. 15, the node 101-1 performs the following operation according to the delivery control command. First, the node 101-1 stores the fact that the nodes 101-1 to 101-3 form the group G1 in the storage unit 50 as the network topology at the time of content acquisition. Then, the node 101-1 starts the emergency content delivery operation, notifies the nodes 101-2 to 101-3 of the emergency content, disconnects the connection with the nodes 101-2 to 101-3, and performs a first operation. The operation as described in the embodiment is performed (steps S112 to S118). Then, for example, assuming that the expiration date described in the urgent content has reached 14:00 on February 15, 2016 at the time when step S118 is executed to become a single node, the node 101-1 will: The stored network topology is read out from the storage unit 50, and the nodes 101-2 and 101-3 are searched for from the neighborhood in order to reconfigure the network.

  On the other hand, the nodes 101-2 and 101-3 which have acquired the urgent content from the node 101-1 form a network topology at the time of content acquisition in accordance with the acquired emergency content delivery control command, and the nodes 101-1 to 101-3 are grouped. The fact that G1 is configured is stored in the storage unit 50. Then, the node 101-2 starts the urgent content delivery operation, and performs operations such as disconnection with the node 101-1 and connection with the node 101-9, as described in the first embodiment ( Steps S113, S121 to S125). Then, for example, if the expiration date described in the urgent content has reached 14:00 on February 15, 2016 at the time when step S125 is executed to become a single node, the node 101-2 will The stored network topology is read out from the storage unit 50, and the nodes 101-1 and 101-3 are searched for from the neighborhood in order to reconfigure the network. Further, the node 101-3 starts the operation of delivering the urgent content, and performs the operation described in the first embodiment, such as disconnection with the node 101-1 and connection with the node 101-6. Then, assuming that the expiration date described in the urgent content has reached 14:00 on February 15, 2016 at the time of becoming a single node, the node 101-3 updates the saved network topology. It reads out from the storage unit 50 and searches for the nodes 101-1 and 101-2 from the neighborhood to reconfigure the network.

  In this way, when the nodes 101-1 to 101-3 search and find each other, they connect to each other. As a result, one group is reconfigured with the nodes 101-1 to 101-3.

  For the same reason, the nodes 101-4 to 101-5, which have once become single nodes, connect with each other to form one group after the acquired emergency content expires. Also, the nodes 101-6 to 101-8, which have once become single nodes, connect to each other to form one group after the acquired emergency content expires. Further, the node 101-9 remains as a single node because the stored network topology is a single node.

  As described above, according to the present embodiment, the operation of the node that has acquired the emergency content can be controlled based on the delivery control command inserted into the emergency content.

  The emergency contents described in FIG. 21 are merely examples, and the present invention is not limited to the emergency contents described in FIG. Various delivery control instructions described in the urgent content can be considered in addition to those described in FIG. For example, the following delivery control command may be used.

  For example, the delivery control command stores the history of other nodes connected at the time of acquisition of the emergency content and after the acquisition, and searches for a node not described in the history when searching for a node to which the emergency content is to be notified. May be.

  Further, the delivery control command may be a command for reconfiguring the network topology at the time of acquiring the urgent content after a predetermined time has elapsed from the time of acquiring the urgent content.

[Fifth Embodiment]
Referring to FIG. 22, a wireless communication terminal 500 according to the fifth embodiment of the present invention includes a wireless communication unit 501 and an automatic connection control unit 502.

  The wireless communication unit 501 has a function of performing wireless communication with another wireless communication terminal by a communication method capable of forming a peer-to-peer group.

  The automatic connection control unit 502 has a function of searching for another wireless communication terminal using the wireless communication unit 501, connecting, transmitting / receiving information, and disconnecting. More specifically, when the wireless communication terminal 500 belongs to the first peer-to-peer group, the automatic connection control unit 502 determines whether to make the wireless communication terminal 500 a delivery node based on the content of the newly acquired content. Has a function to determine. In addition, the automatic connection control unit 502 has a function of separating the wireless communication terminal 500 from the first peer-to-peer group when it is determined to be a delivery node, and a function of searching for another wireless communication terminal. Further, the automatic connection control unit 502 has a function of connecting to another wireless communication terminal discovered by the search and exchanging the content between the wireless communication terminal 500 and the other wireless communication terminal.

  The wireless communication terminal 500 according to the present embodiment having such a function operates as follows. That is, when the wireless communication terminal 500 belongs to the first peer-to-peer group, the automatic connection control unit 502 determines whether to make the wireless communication terminal 500 a delivery node based on the content of the newly acquired content. If the automatic connection control unit 502 determines to be the delivery node, the automatic connection control unit 502 disconnects the wireless communication terminal 500 from the first peer-to-peer group using the wireless communication unit 501 and searches for another wireless communication terminal. When the automatic connection control unit 502 finds another wireless communication terminal, the automatic connection control unit 502 uses the wireless communication unit 501 to connect to the found other wireless communication terminal, and connects the wireless communication terminal 500 and the other wireless communication terminal. The above-mentioned contents are exchanged between.

  The wireless communication terminal 500 according to the present embodiment can transmit and receive contents to and from a wireless communication terminal outside the first peer-to-peer group by operating as described above. The reason is that when the wireless communication terminal 500 becomes a delivery node based on the content of the newly acquired content, it leaves the first peer-to-peer group, searches for another wireless communication terminal, and searches for another wireless communication terminal. To transfer the content to and from the other wireless communication terminal.

  As described above, the present invention has been described with reference to some embodiments, but the present invention is not limited to the above examples, and various additions and changes can be made within the scope of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be used for all communication systems that share contents such as emergency contents between wireless communication terminals by a communication method capable of forming a peer-to-peer group.

10 wireless communication I / F unit 20 wireless communication I / F unit 30 operation input unit 40 screen display unit 50 storage unit 50A shared information 50C group information 50D urgent content control information 50P program 60 calculation Processing unit 60A Wi-Fi connection control unit 60B Cellular communication control unit 60C Automatic connection control unit 100 Communication system 101 Node (wireless communication terminal)
500 wireless communication terminal 501 wireless communication unit 502 automatic connection control unit

Claims (8)

A first wireless communication terminal,
A wireless communication unit using a communication method capable of forming a peer-to-peer group with another wireless communication terminal;
An automatic connection control unit that searches for other wireless communication terminals using the wireless communication unit, connects, transmits information, and disconnects,
Has,
The automatic connection control unit,
When the first wireless communication terminal belongs to a first peer-to-peer group, a function of determining whether or not to make the first wireless communication terminal a delivery node based on the content of the newly acquired content; A function of separating the first wireless communication terminal from the first peer-to-peer group; a function of searching for a second wireless communication terminal outside the first peer-to-peer group ; wireless communication terminal having a function of transmitting the content to the second wireless communication terminal connected to the wireless communication terminal from the first wireless communication terminal. In the search for the second wireless communication terminal, the automatic connection control unit obtains the content in a management frame transmitted from the second wireless communication terminal before connecting to the second wireless communication terminal. Confirming whether or not content information indicating that the content information has been added is configured to search for the second wireless communication terminal transmitting the management frame to which the content information is not added as a connection partner,
The wireless communication terminal according to claim 1. The automatic connection control unit, the first in the transmission of the content from the wireless communication terminal to the second wireless communication terminal, a fixed rear connected to the first wireless communication terminal and the second wireless communication terminal you start the transmission of the content in time,
The wireless communication terminal according to claim 2 . The content is configured to include a control instruction,
The automatic connection control unit controls an operation of the first wireless communication terminal determined by the delivery node based on the control command,
The wireless communication terminal according to claim 1. The content is configured to include an attribute value indicating whether or not the content has urgency,
The automatic connection control unit determines whether to make the first wireless communication terminal a delivery node, based on the presence or absence of the attribute value.
The wireless communication terminal according to claim 1. Using a wireless communication unit by the communication mode which can form other wireless communication terminal and peer-to-peer group, the wireless communication unit to search for the other wireless communication terminal, connected, transmits information, to disconnect automatically A communication method executed by a first wireless communication terminal having a connection control unit;
If the first wireless communication terminal belongs to a first peer-to-peer group, determine whether to make the first wireless communication terminal a delivery node based on the content of the newly acquired content;
If it is determined to be the delivery node, disconnect the first wireless communication terminal from the first peer-to-peer group, and search for a second wireless communication terminal outside the first peer-to-peer group ;
Transmitting the content by connecting to the second wireless communication terminal from the first wireless communication terminal to the second wireless communication terminal,
Communication method. A computer constituting the first wireless communication terminal ,
A wireless communication unit using a communication method capable of forming a peer-to-peer group with another wireless communication terminal;
An automatic connection control unit for searching, connecting, transmitting information, and disconnecting another wireless communication terminal using the wireless communication unit, wherein the first wireless communication terminal belongs to a first peer-to-peer group A function of determining whether to make the first wireless communication terminal a delivery node based on the content of the newly acquired content; and a function of determining whether to make the first wireless communication terminal a delivery node. a function to separate from the first peer-to-peer group, a function of searching for the first peer-to-peer group outside of the second wireless communication terminal, from the first wireless communication terminal connected to the second wireless communication terminal an automatic connection control unit having a function of transmitting the content to the second wireless communication terminal,
Program to make it work.   A communication system comprising a plurality of the wireless communication terminals according to claim 1.

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