WO2014174746A1

WO2014174746A1 - Method for determining access point

Info

Publication number: WO2014174746A1
Application number: PCT/JP2014/001041
Authority: WO
Inventors: 則夫山垣; 藤田　範人; 啓文植田; ブンパデイットカンニヤウオン
Original assignee: 日本電気株式会社
Priority date: 2013-04-22
Filing date: 2014-02-27
Publication date: 2014-10-30
Also published as: JPWO2014174746A1; JP6365531B2

Abstract

A first communication terminal having the functionality of an access point performs a negotiation with a second communication terminal having the functionality of an access point to determine that the first communication terminal or the second communication terminal is an access point. In the negotiation, an index value dependent on the number of data each of the first communication terminal and the second communication terminal possesses is exchanged between the two, and an access point is determined on the basis of the respective index values.

Description

Access point decision method

The present invention relates to an access point determination method for determining an access point of a wireless network, a communication terminal, a communication terminal control method, and a program.

As a wireless network that determines an access point among a plurality of communication terminals, there is a wireless network that conforms to the Wi-Fi Direct specification. In the Wi-Fi Direct specification, each communication terminal participating in a certain network is defined as a P2P device, and the network is defined as a P2P group. In the P2P group, a P2P device that actually uses the function of an access point is a P2P group owner (Group Owner (GO), hereinafter simply referred to as a group owner), and a P2P device other than the group owner is a P2P client (hereinafter simply referred to as a client). It is defined as Further, a procedure for determining a group owner from two P2P devices is defined as group owner negotiation.

In the above group owner negotiation, information such as an intent value and an tie break bit (Tie Break Bit) value, which are index values indicating the degree of desire to become a group owner, is exchanged between communication terminals. Here, the intent value and the tie break bit value are set randomly or manually. Then, the group owner is determined according to the following criteria.

(1) A communication terminal having a large intent value is set as a group owner.
(2) If the intent values are the same and both are smaller than 15, the communication terminal having a tie break bit value of 1 is set as the group owner.
(3) If the intent values are the same and both are 15, the group owner determination procedure is determined to be unsuccessful.

In the group owner negotiation described above, the intent value and tie break bit value of each communication terminal are used as a criterion for determining the group owner, but various techniques for determining the group owner using other information have been proposed. ing.

For example, the application information indicating whether the application of the communication terminal is the content providing side or the usage side is exchanged between the communication terminals, and each communication terminal is connected to the own communication terminal and the surrounding communication terminals. In accordance with the relationship between the number of providing terminals serving as contents and the number of utilizing terminals serving as users, a parameter indicating the priority for operating as a group owner, that is, an access point is set. As a first related technique related to the present invention, negotiation with surrounding communication terminals for determining a communication terminal that operates as an access point using a network is proposed (see, for example, Patent Document 1).

Also, as a second related technique related to the present invention, it is proposed that a client allowable number indicating the maximum number of connectable clients is exchanged between communication terminals and a communication terminal having a larger client allowable number is determined as an access point. (See, for example, Patent Document 2).

Further, the present invention is to exchange parameters (for example, TCP / IP layer throughput values) indicating the transmission processing capability of communication terminals between the communication terminals and determine a communication terminal having a higher transmission processing capability as an access point. It has been proposed as a related third related technique (see, for example, Patent Document 3).

On the other hand, there is a method of sharing data among individual communication terminals in a distributed manner without using a central management device such as a server, as a kind of method of sharing data among a plurality of communication terminals. For example, when communication terminals contact each other by movement, it is proposed as a fourth related technique related to the present invention to exchange each other's information and synchronize possessed information using the epidemic method ( For example, refer nonpatent literature 1). In the epidemic method, as shown in FIG. 13, when a communication terminal in the network detects another communication terminal, it exchanges a holding list (also called a summary vector) that is a list of data (content) held by itself. Understand the contents of the possession list of the communication terminal. Then, the communication terminal exchanges communication messages with other communication terminals having a holding list that does not match the holding list of the own communication terminal, and shares data. That is, a communication terminal that has data transmits the data to a communication terminal that does not have the data.

JP 2012-199884 A JP 2012-186555 A JP 2012-186663 A

Various methods described above have been proposed or put into practical use as a method for determining an access point among a plurality of communication terminals having a wireless network access point function, but a wireless network as described in the fourth related art In the case where the data held by each communication terminal is shared, the waste of data transferred via the access point for data sharing can be reduced by any of the first to third related technologies. It is difficult. The reason is that in the first to third related technologies, there is a possibility that a communication terminal having the smallest number of data is selected as a group owner, that is, an access point.

An object of the present invention is to provide an access point that solves the above-mentioned problem, that is, the problem that there is a waste of data being transferred via an access point when data held by each communication terminal that forms a wireless network is shared. To provide a decision method.

An access point determination method according to the first aspect of the present invention includes:
A method for determining an access point of a wireless network, comprising:
The first communication terminal having the access point function negotiates with the second communication terminal having the access point function to access the first communication terminal or the second communication terminal. As a point,
In the negotiation, an index value depending on the number of data held by the first communication terminal and the second communication terminal is exchanged, and the access point is determined based on the index value. To do.

A communication terminal according to the second aspect of the present invention provides:
A communication terminal having a wireless network access point function,
A wireless communication unit that exchanges communication messages with other communication terminals forming the wireless network;
Retained data number storage unit for storing the number of data held by the own communication terminal;
Negotiating with other communication terminals forming the wireless network to determine the self-communication terminal or the partner communication terminal as the access point, and in the negotiation, the index value depending on the number of data held by the self-communication terminal Notifying another communication terminal and obtaining the index value depending on the number of data held by the other communication terminal, and accessing the index based on the index value of the own communication terminal and the index value of the partner communication terminal And a control unit for determining points.
A program according to the third aspect of the present invention is:
A computer constituting a communication terminal having a wireless network access point function,
A wireless communication unit that exchanges communication messages with other communication terminals forming the wireless network;
Retained data number storage unit for storing the number of data held by the own communication terminal;
Negotiating with other communication terminals forming the wireless network to determine the self-communication terminal or the partner communication terminal as the access point, and in the negotiation, the index value depending on the number of data held by the self-communication terminal Notifying another communication terminal and obtaining the index value depending on the number of data held by the other communication terminal, and accessing the index based on the index value of the own communication terminal and the index value of the partner communication terminal It functions as a control unit that determines points.
A communication terminal control method according to the fourth aspect of the present invention includes:
An access point determination method executed by a communication terminal having an access point function of a wireless network,
The communication terminal negotiates with another communication terminal having the function of the access point to determine the communication terminal or the other communication terminal as the access point;
In the negotiation, an index value depending on the number of data held by the communication terminal and the other communication terminal is exchanged, and the access point is determined based on the index value.

Since the present invention has the above-described configuration, when data is shared by forming a network in which a plurality of communication terminals communicate with a specific communication terminal as an access point, data is transferred via the access point for data sharing. It is possible to reduce waste.

It is a block diagram of the communication terminal concerning the 1st Embodiment of this invention. In the 1st Embodiment of this invention, it is a figure which shows an example of the table for determining an intent value according to the number of holding data. It is a flowchart which shows operation | movement of the communication terminal concerning the 1st Embodiment of this invention. It is a sequence diagram which shows the outline | summary of the device discovery procedure and group owner negotiation in the 1st Embodiment of this invention. It is a flowchart which shows the procedure which determines a group owner in the group owner negotiation in the 1st Embodiment of this invention. It is explanatory drawing of the data transfer cost required for data sharing in the 1st Embodiment of this invention. It is explanatory drawing of the data transfer cost for data sharing required when the communication terminal with the smallest number of possession data becomes an access point. It is a block diagram of the communication terminal concerning the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the communication terminal concerning the 2nd Embodiment of this invention. It is a sequence diagram which shows the outline | summary of the device discovery procedure and group owner negotiation in the 2nd Embodiment of this invention. It is a block diagram of the communication terminal concerning the 3rd Embodiment of this invention. In other embodiment of this invention, it is a figure which shows an example of the table for determining an intent value and a tie break bit value according to the number of holding data. It is a figure which shows an example of the procedure of data sharing by Epidemic method.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
[First embodiment]
Referring to FIG. 1, a communication terminal 110 according to the first embodiment of the present invention is a wireless communication terminal that forms a wireless network compliant with the Wi-Fi Direct specification. The communication terminal 110 includes a wireless communication unit 111, a data storage unit 112, a data exchange unit 113, a retained data number storage unit 114, a control unit 115, and an antenna 116.

The wireless communication unit 111 has a function of transmitting and receiving communication messages wirelessly with other communication terminals. At the time of transmission, the wireless communication unit 111 creates a communication message packet in response to a request from an upper layer such as the control unit 115 or the data exchange unit 113, and adds a header or an error detection code to the created packet. Processing is performed, a modulated signal in a carrier frequency band is generated from the processed data, and transmitted from the antenna 116 as a radio signal. Further, upon reception, the wireless communication unit 111 demodulates the wireless signal received by the antenna 116, decodes the communication message packet, and transmits a communication message that has been confirmed to have no error based on the error detection code to the control unit 115 or Notification is made to an upper layer such as the data exchange unit 113.

The data storage unit 112 includes a storage device such as a RAM (Random Access Memory) and a hard disk, and stores one or more data. Individual data is arbitrary. For example, any of text data, image data, and audio data may be used, or they may be mixed. The data may be called content.

The data exchange unit 113 has a function of detecting the number of data (the number of retained data) stored in the data storage unit 112 and storing it in the retained data number storage unit 114. The data exchange unit 113 has a function of exchanging communication messages with other communication terminals via the wireless communication unit 111 to share data. The data exchange unit 113 exchanges data held by each other using, for example, the epidemic method shown in the fourth related technique related to the present invention. That is, the data exchange unit 113 periodically transmits a holding list, which is a list of data stored in the data storage unit 112, to another communication terminal through the wireless communication unit 111, and receives the other communication received from the holding list. When the data acquisition request is received from the terminal, the data specified by the data acquisition request is read from the data storage unit 112 and transmitted to the other communication terminal that has made the request through the wireless communication unit 111. In addition, when the data exchange unit 113 receives the possession list from another communication terminal through the wireless communication unit 111, the data exchange unit 113 compares the possession list of the own terminal with the received possession list of the other communication terminal, First, when a data acquisition request specifying data held by another communication terminal is transmitted to the other communication terminal through the wireless communication unit 111 and a response to the data acquisition request is received, data is acquired from the response, and data storage is performed. The data is stored in the unit 112. At this time, the data exchange unit 113 updates the number of retained data stored in the retained data number storage unit 114 according to the number of stored data.

However, the present invention is not limited to the epidemic method, and any other data sharing method can be used.

The retained data number storage unit 114 is configured by a storage device such as a RAM or a hard disk and has a function of storing the retained data number given from the data exchange unit 113.

The control unit 115 has a function of controlling the entire communication terminal 110 such as determination of a use frequency in the wireless communication unit 111, creation and transmission instructions of various control messages, interpretation of various received control messages, control of connection processing, and the like. For example, the control unit 115 performs control to negotiate with other communication terminals forming the wireless network and determine the own communication terminal or the other communication terminal as the group owner. In this negotiation, the control unit 115 notifies the other communication terminal 110 through the wireless communication unit 111 of an index value that depends on the number of data stored in the retained data number storage unit 114, and also possesses the other communication terminal 110. An index value depending on the number of data to be acquired is acquired from the other communication terminal 110 through the wireless communication unit 111, and a group owner is determined based on the index value of the own communication terminal and the index value of the partner communication terminal. Further, the control unit 115 holds the information of the determined group owner. When the own communication terminal 110 is determined as the group owner, the control unit 115 controls the wireless communication unit 111 to function as the access point of the wireless network. Let

In this embodiment, an intent value is used as the index value. The intent value is an integer from 0 to 15, and is determined depending on the number of data stored in the retained data number storage unit 114. Specifically, a larger intent value is determined as the number of retained data is larger.

FIG. 2 shows an example of a table for determining the intent value according to the number of retained data. In this example, the number of retained data is classified into 16 categories, and intent values are assigned in order from 0 in order from the smallest number of retained data. For example, one of the 16 categories has 21 to 40 retained data, and an intent value 1 is assigned to this category. The control unit 115 stores a table as shown in FIG. 2, and determines an intent value depending on the number of retained data based on the number of retained data stored in the retained data number storage unit 114 and the table.

Next, the operation of the communication terminal 110 according to this embodiment will be described.

When the communication terminal 110 is activated, it starts executing the process shown in FIG. First, the data exchange unit 113 of the communication terminal 110 scans the data stored in the data storage unit 112 to detect the number of data, and stores it in the retained data number storage unit 114 (step S101).

Next, the control unit 115 of the communication terminal 110 discovers surrounding communication terminals (step S102). Discovery of the surrounding communication terminals is performed in accordance with the Device Discovery Procedure of the Wi-Fi Direct specification. FIG. 4 is a sequence diagram showing an overview of the Wi-Fi Direct specification Device Discovery Procedure and Group Owner Negotiation. For example, when the communication terminal 110 starts a search operation, as shown in FIG. 4, a probe request (Probe Request) is transmitted to the surroundings. If another communication terminal 120 having the same configuration as that of the communication terminal 110 exists in the vicinity, the control unit (115) of the other communication terminal 120 detects the probe request as shown in FIG. A response (Probe Response) is returned. By receiving the probe response, the communication terminal 110 recognizes that another communication terminal 120 exists around the terminal.

Next, the control unit 115 of the communication terminal 110 performs negotiation with the discovered communication terminal 120 to determine a group owner (step S103). This negotiation is basically performed in accordance with the Group Formation Procedure of the Wi-Fi Direct specification.

In the negotiation, first, the control unit 115 of the communication terminal 110 transmits a negotiation request (GO Negotiation Request) to the communication terminal 120 as shown in FIG. This negotiation request includes information such as an intent value and a tie break bit value. The intent value is determined depending on the number of retained data as described above. On the other hand, the tie break bit value is set to 1 or 0 at random by the communication terminal 110 that has transmitted the negotiation request in this embodiment.

Further, the control unit (115) of the communication terminal 120 that has received the negotiation request returns a negotiation response (GO Negotiation Response) as shown in FIG. This negotiation response includes information such as an intent value and a tie break bit value. Similar to the communication terminal 110, the intent value is determined depending on the number of data held by the communication terminal 120. The tie break bit value is set to a value obtained by inverting (toggling) the tie break bit value included in the received negotiation request.

Then, the control unit 115 of the communication terminal 110 that has received the negotiation response determines the group owner according to the procedure of the flowchart shown in FIG. 5, and the result is shown in FIG. 4, and the communication terminal 120 is received upon completion of negotiation (GO Negotiation Configuration). Notify In addition, the control unit (115) of the communication terminal 120 that has received the negotiation request determines the group owner according to the procedure of the flowchart shown in FIG.

The procedure for determining the group owner shown in FIG. 5 conforms to the Group Formation Procedure of the Wi-Fi Direct specification. In FIG. 5, X1 is an intent value of the communication terminal 110, and X2 is an intent value of the communication terminal 120. If both intent values are different (NO in step S121) and X1 <X2 (YES in step S122), control unit 115 determines communication terminal 120 as the group owner (step S123), and if X1> X2. If (NO in step S122), the communication terminal 110 is determined as the group owner (step S124). On the other hand, if both intent values are the same (YES in step S121), it is determined whether the intent value is less than 15 (step S125). If it is less than 15 (YES in step S125), the communication terminal having the tie break bit value set to 1 is determined as the group owner (step S126). If both intent values are 15 (NO in step S125), the group owner determination procedure is failed (step S127).

Thereafter, the control unit 115 of the communication terminal 110 controls a connection procedure for forming a communication group with the communication terminal 120 according to the determined group owner (step S104 in FIG. 3).

Thus, in the present embodiment, in the group owner negotiation, the

communication terminals

110 and 120 exchange intent values depending on the number of retained data, and determine a communication terminal having a larger intent value as the group owner. Therefore, even if another communication terminal subsequently joins the group as a client in response to an invitation from the group owner, the communication terminal with the smallest number of data held in the previous stage of the group formation is the group owner. Never become. Therefore, when data stored in the data storage unit 112 of the own terminal is transmitted to another communication terminal by the data exchange unit 113 and data is shared within the group, waste of data transferred via the access point is reduced. It becomes possible to do. Hereinafter, the effect of this embodiment will be described with a simple example.

As shown in FIG. 6, there are two

communication terminals

120 and 130 around the communication terminal 110, and a group owner negotiation is performed between the communication terminal 110 and the communication terminal 120 so that the communication terminal 110 is a group. Assume that the owner is determined and then the remaining communication terminal 130 joins the group as a client of the communication terminal 110 that is the group owner. The number of retained data at this time is 120 for the

communication terminal

110, 10 for the

communication terminal

120, and 40 for the communication terminal 130, and the same data does not exist in the total of 170 data. The data sizes are all the same.

In order for all the communication terminals to hold a total of 170 pieces of data by exchanging the data held between the three communication terminals shown in FIG. 6, the cost of data transfer between the communication terminals as follows: Will occur. In the exchange of the retained data in this example, it is assumed that the data is always transferred from the communication terminal that was originally retained.

First, for the communication terminal 110, a total of 10 data is transferred from the communication terminal 120 in one hop, and a total of 40 data is transferred from the communication terminal 130 in one hop, so the transfer cost is (10 data × 1 hop) + (40 data × 1 hop) = 50. Next, for communication terminal 120, a total of 120 data is transferred from communication terminal 110 in one hop, and a total of 40 data is transferred from communication terminal 130 in two hops, so the transfer cost is (120 data × 1 hop) + (40 data × 2 hops) = 200. Next, for communication terminal 130, a total of 120 data is transferred from communication terminal 110 in one hop, and a total of 10 data is transferred from communication terminal 110 in two hops, so the transfer cost is (120 data × 1 hop) + (10 data × 2 hops) = 140. Eventually, the total transfer cost is 390.

On the other hand, when the group owner negotiation is performed without considering the number of data held by the communication terminal, as shown in FIG. 7, the case where the communication terminal 120 having the smallest number of held data is determined as the group owner occurs. . Since the data held between the three communication terminals shown in FIG. 7 is exchanged and all the communication terminals hold a total of 170 pieces of data, the following data transfer costs occur between the communication terminals. .

First, for the communication terminal 110, a total of 10 data is transferred from the communication terminal 120 in one hop, and a total of 40 data is transferred from the communication terminal 130 in 2 hops, so the transfer cost is (10 data × 1 hop) + (40 data × 2 hops) = 90. Next, since a total of 120 data is transferred from the communication terminal 110 in one hop to the communication terminal 120 and a total of 40 data is transferred in one hop from the communication terminal 130, the transfer cost is (120 data). × 1 hop) + (40 data × 1 hop) = 160. Next, for communication terminal 130, a total of 120 data is transferred from communication terminal 110 in two hops, and a total of 10 data is transferred from communication terminal 120 in one hop, so the transfer cost is (120 Data × 2 hops) + (10 data × 1 hop) = 250. Eventually, the total transfer cost is 500, which is about 30% higher than that in FIG.

By applying this embodiment in this way, it is possible to reduce the useless cost of transferring data via an access point for data sharing.

[Second Embodiment]
Referring to FIG. 8, a communication terminal 210 according to the second embodiment of the present invention is a wireless communication terminal that forms a wireless network compliant with the Wi-Fi Direct specification, and includes a wireless communication unit 211, a data storage unit 212, The data exchange unit 213, the retained data number storage unit 214, the control unit 215, and the antenna 216 are included. Among these, the wireless communication unit 211, the data storage unit 212, the data exchange unit 213, the retained data number storage unit 214, and the antenna 216 are the wireless communication unit 111, the data storage unit 112, and the data of the communication terminal 110 illustrated in FIG. The exchange unit 113, the retained data number storage unit 114, and the antenna 116 have the same functions.

The control unit 215 further includes a negotiation partner determination unit 217 in addition to the functions of the control unit 115 of the communication terminal 110 illustrated in FIG. Prior to the negotiation for determining the group owner, the negotiation partner determination unit 217 acquires an intent value depending on the number of data held by a plurality of other communication terminals existing around the own communication terminal, and performs the negotiation A function of determining a communication terminal; Specifically, the negotiation partner determination unit 217 determines, as a negotiation partner, a communication terminal having the maximum intent value among a plurality of other communication terminals existing around the own communication terminal.

Next, the operation of the communication terminal 210 according to this embodiment will be described.

When the communication terminal 210 is activated, it starts executing the process shown in FIG. First, the data exchange unit 213 of the communication terminal 210 scans the data stored in the data storage unit 212 to detect the number of data, and stores it in the retained data number storage unit 214 (step S201).

Next, the control unit 215 of the communication terminal 210 finds a surrounding communication terminal (step S202). Discovery of the surrounding communication terminals is performed in accordance with the Device Discovery Procedure of the Wi-Fi Direct specification. FIG. 10 is a sequence diagram showing an overview of the Device Discovery Procedure and Group Owner Negotiation of Wi-Fi Direct specifications. For example, when the communication terminal 210 starts the search operation, as shown in FIG. 10, a probe request (Prove Request) is transmitted to the surroundings. If another communication terminal having the same configuration as that of the communication terminal 210 exists in the vicinity, the control unit (215) of the other communication terminal returns a probe response (Prove Response) when detecting the probe request. . In this embodiment, this probe response has an intent value that depends on the number of retained data. In the example shown in FIG. 10, there are two communication terminals, a communication terminal 220 and a communication terminal 230, around the communication terminal 210, and probe responses including intent values are communicated from the

respective communication terminals

220 and 230. It has been transmitted to the terminal 210.

The control unit 215 of the communication terminal 210 can recognize that there are

other communication terminals

220 and 230 around the terminal by receiving the probe response having the intent value, and can also recognize these

communication terminals

220 and 230. Can be recognized.

Next, the control unit 215 of the communication terminal 210 uses the negotiation partner determination unit 217 to determine a negotiation partner to perform negotiation for determining the group owner from the discovered communication terminal (step S203). Specifically, the negotiation partner determination unit 217 determines the communication terminal having the largest intent value included in the probe response as the negotiation partner. For example, if the intent value included in the probe response received from the communication terminal 220 is 1 and the intent value included in the probe response received from the communication terminal 230 is 0, the communication terminal 220 is determined as the negotiation partner. If there are a plurality of communication terminals having the maximum intent value, an arbitrary communication terminal among them is determined as a negotiation partner.

Next, the control unit 215 of the communication terminal 210 performs negotiation for determining the group owner with the communication terminal 220 determined as the negotiation partner (step S204), and then the control unit 215 of the communication terminal 210 determines The connection procedure for forming a communication group with the communication terminal 220 is controlled according to the group owner (step S205). The operations in steps S204 and S205 are the same as the operations in steps S103 and S104 shown in FIG.

Thus, in this embodiment, prior to the negotiation for determining the group owner, a communication terminal having the maximum intent value depending on the number of retained data is negotiated from among a plurality of other communication terminals existing around the own communication terminal. Decide on your opponent. Then, in the group owner negotiation, as in the first embodiment, the intent value depending on the number of retained data is exchanged with the communication terminal of the negotiation partner, and the communication terminal having a larger intent value is assigned to the group owner. decide. For this reason, it is possible to select a communication terminal having the largest number of data holdings as a group owner, that is, an access point, among a plurality of communication terminals existing in the vicinity including the own communication terminal. Therefore, when the data exchange unit 213 transmits data stored in the data storage unit 212 of its own terminal to another communication terminal for data sharing, it is possible to reduce waste of data being transferred via the access point. It becomes possible.

[Third embodiment]
FIG. 11 shows an example of a hardware configuration when the communication terminal in each of the above-described embodiments is configured by an electronic information processing apparatus such as a computer. The communication terminal 310 in this example includes a CPU (Central Processing Unit) peripheral part, an input / output part, and a legacy input / output part. The CPU peripheral section includes a CPU 902, a RAM 903, a graphic controller 904, and a display device 905 that are connected to each other by a host controller 901. The input / output unit includes a communication interface (I / F) 907, a hard disk drive 908, and a CD-ROM (Compact Disk Read Only Memory) drive 909 connected to the host controller 901 by an input / output (I / O) controller 906. Have. The legacy input / output unit includes a ROM (Read Only Memory) 910, a flexible disk (FD) drive 911, and an input / output (I / O) chip 912 connected to the input / output controller 906.

The host controller 901 connects the RAM 903, the CPU 902 that accesses the RAM 903 at a high transfer rate, and the graphic controller 904. The CPU 902 operates based on programs stored in the ROM 910 and the RAM 903 to control each unit. The graphic controller 904 acquires image data generated by the CPU 902 or the like on a frame buffer provided in the RAM 903 and displays the image data on the display device 905. Instead of this, the graphic controller 904 may include a frame buffer for storing image data generated by the CPU 902 or the like.

The input / output controller 906 connects the host controller 901 to the hard disk drive 908, the communication interface 907, and the CD-ROM drive 909, which are relatively high-speed input / output devices. The hard disk drive 908 stores programs and data used by the CPU 902. The communication interface 907 is connected to another communication terminal 320 to transmit / receive a program or data. The CD-ROM drive 909 reads a program or data from the CD-ROM 992 and provides it to the hard disk drive 908 and the communication interface 907 via the RAM 903.

The input / output controller 906 is connected to a ROM 910, a flexible disk drive 911, and a relatively low-speed input / output device such as an input / output chip 912. The ROM 910 stores a boot program executed when the communication terminal 310 is started, a program depending on the hardware of the communication terminal 310, and the like. The flexible disk drive 911 reads a program or data from the flexible disk 993 and provides it to the hard disk drive 908 and the communication interface 907 via the RAM 903. The input / output chip 912 connects various input / output devices via the flexible disk drive 911 or a parallel port, a serial port, a keyboard port, a mouse port, and the like.

The program executed by the CPU 902 is stored in a recording medium such as the flexible disk 993, the CD-ROM 992, or an IC (Integrated Circuit) card and provided by the user. The program stored in the recording medium may be compressed or uncompressed. The program is installed in the hard disk drive 908 from the recording medium, read into the RAM 903, and executed by the CPU 902. The program executed by the CPU 902 causes the communication terminal 310 to function as a wireless communication unit, a data storage unit, a data exchange unit, a retained data number storage unit, a control unit, and the like in each of the above-described embodiments.

The programs shown above may be stored in an external storage medium. As storage media, in addition to the flexible disk 993 and CD-ROM 992, optical recording media such as DVD (Digital Versatile Disk) or PD (Phase Disk), magneto-optical recording media such as MD (MiniDisk), tape media, IC cards A semiconductor memory or the like can be used. In addition, an information sharing system may be provided as a program via a network by using a storage medium such as a hard disk or a RAM provided in a server system connected to a dedicated communication network or the Internet as a recording medium.

[Other embodiments]
The present invention is not limited to the above embodiments, and various other additions and changes can be made. For example, the following embodiments are also included in the present invention.

For example, in the first and second embodiments, the intent value is determined according to the number of retained data, but the intent value and the tie break bit value may be determined according to the retained data number. FIG. 12 shows an example of a table for determining the intent value and the tie break bit value according to the number of retained data. In this example, the number of retained data is classified into 16 categories, intent values are assigned in order from the smallest retained data number in order from 0, and the same segment is further divided into two, with the tie break bit on the side with the smaller number of retained data A value of 0 is assigned, and a tie break bit value of 1 is assigned to the side with the larger number of retained data. For example, one of the 16 categories has a retained data number of 21 to 40, and an intent value of 1 is assigned to this segment, and this segment is classified into a retained data number of 21 to 30 and a retained data number of 31 to 40. The tie break bit value 0 is assigned to the former section, and the tie break bit value 1 is assigned to the latter section. The

control units

115 and 215 of the communication terminal store the table shown in FIG. 12, and based on the number of stored data stored in the stored data

number storage units

114 and 214 and the above table, the intent value and the tie break bit value And decide. In the case where not only the intent value but also the tie break bit value is determined depending on the number of retained data as in this example, a case occurs in which the tie break bit values are the same between the communication terminals that perform negotiation. Therefore, if both tie break bit values are the same in step S126 of FIG. 5, the group owner determination procedure is determined to be unsuccessful.

Further, for example, a specific intent value such as the maximum value (15) or the minimum value (0) of the intent value may be assigned only with the administrator authority.

Further, the method for determining the intent value (and tie break bit value) according to the number of retained data is not limited to the method using a table as shown in FIG. 2 or FIG. May be used.

Also, only the tie break bit value may be determined according to the number of retained data, and the intent value may be set randomly or manually.

In the second embodiment, the intent value determined depending on the number of retained data is included in the probe response. However, prior to the negotiation for determining the group owner, there are other methods for knowing the intent values of other communication terminals existing around the own communication terminal, such as a service discovery query (Service Discovery Query) and a service discovery response. (Service Discovery Response) may include an intent value (and tie break bit value) determined depending on the number of retained data.

In the above embodiment, the intent value is determined depending only on the number of retained data, but the intent value may be determined in consideration of information other than the number of retained data. For example, the intent value is determined depending on the number of held data and the moving speed (including 0) of the communication terminal. The larger the number of held data and the lower the moving speed, the larger the intent. The value may be determined. Alternatively, the intent value may be determined depending on the number of retained data and the data size of the retained data, and the larger intent value may be determined as the total data size of the retained data is larger.

Note that the present invention enjoys the benefit of the priority claim based on the patent application of Japanese Patent Application No. 2013-089388 filed on April 22, 2013 in Japan, and is described in the patent application. The contents are all included in this specification.

The present invention is applicable when data such as various contents is shared between communication terminals mounted on a vehicle such as an automobile or between portable communication terminals.

DESCRIPTION OF SYMBOLS 110 ... Communication terminal 111 ... Wireless communication part 112 ... Data storage part 113 ... Data exchange part 114 ... Holding data number storage part 115 ... Control part 116 ... Antenna 120 ... Communication terminal 130 ... Communication terminal 210 ... Communication terminal 211 ... Wireless communication part 212 ... Data storage unit 213 ... Data exchange unit 214 ... Retained data number storage unit 215 ... Control unit 216 ... Antenna 217 ... Negotiation partner determination unit 220 ... Communication terminal 230 ... Communication terminal 310 ... Communication terminal 901 ... Host controller 902 ... CPU
903 ... RAM
904 ... Graphic controller 905 ... Display device 906 ... Input / output (I / O) controller 907 ... Communication interface (I / F)
908 ... Hard disk drive 909 ... CD-ROM drive 910 ... ROM
911 ... Flexible disk (FD) drive 912 ... Input / output (I / O) chip 992 ... CD-ROM
993 ... Flexible disk

Claims

A method for determining an access point of a wireless network, comprising:
The first communication terminal having the access point function negotiates with the second communication terminal having the access point function to access the first communication terminal or the second communication terminal. As a point,
In the negotiation, an index value depending on the number of data held by each of the first communication terminal and the second communication terminal is exchanged, and the access point is determined based on the index value. How to determine access points.
Prior to the negotiation, the first communication terminal determines the second communication terminal to perform the negotiation from among a plurality of surrounding communication terminals,
In the determination, the index value that depends on the number of data held by the plurality of surrounding communication terminals is acquired, and the second communication terminal that performs the negotiation is determined based on the acquired index value. Item 4. The access point determination method according to Item 1.
The first communication terminal acquires the index value from a response to a request sent from the communication terminal to a plurality of other communication terminals in the surroundings prior to the negotiation in acquiring the index value. The access point determination method described in 1.
4. The access point determination method according to claim 1, wherein the wireless network is a wireless network that conforms to Wi-Fi Direct specifications.
A communication terminal having a wireless network access point function,
A wireless communication unit that exchanges communication messages with other communication terminals forming the wireless network;
Retained data number storage unit for storing the number of data held by the own communication terminal;
Negotiating with other communication terminals forming the wireless network to determine the own communication terminal or the partner communication terminal as the access point, and in the negotiation, the index value depending on the number of data held by the own communication terminal Notifying another communication terminal and obtaining the index value depending on the number of data held by the other communication terminal, and based on the index value of the own communication terminal and the index value of the partner communication terminal A communication terminal having a control unit for determining points.
Prior to the negotiation, the control unit acquires the index value depending on the number of data held by a plurality of other communication terminals existing around the communication terminal, and based on the acquired index value The communication terminal according to claim 5, wherein a communication partner terminal for negotiation is determined.
The said control part acquires the said index value from the response with respect to the request | requirement sent to the several other communication terminal which exists in the circumference | surroundings from the own communication terminal prior to the said negotiation in the acquisition of the said index value. Communication terminal.
The communication terminal according to claim 5, further comprising a data exchange unit that exchanges the data with the other communication terminal through the wireless communication unit.
The communication terminal according to claim 5, wherein the wireless network is a wireless network that conforms to a Wi-Fi Direct specification.
A computer constituting a communication terminal having a wireless network access point function,
A wireless communication unit that exchanges communication messages with other communication terminals forming the wireless network;
Retained data number storage unit for storing the number of data held by the own communication terminal;
Negotiating with other communication terminals forming the wireless network to determine the own communication terminal or the partner communication terminal as the access point, and in the negotiation, the index value depending on the number of data held by the own communication terminal Notifying another communication terminal and obtaining the index value depending on the number of data held by the other communication terminal, and based on the index value of the own communication terminal and the index value of the partner communication terminal A program for functioning as a control unit that determines points.
A method of controlling a communication terminal having an access point function of a wireless network,
The communication terminal negotiates with another communication terminal having the function of the access point to determine the communication terminal or the other communication terminal as the access point;
In the negotiation, an index value depending on the number of data held by the communication terminal and the other communication terminal is exchanged, and the access point is determined based on the index value. Control method.
Prior to the negotiation, the communication terminal determines the other communication terminal to perform the negotiation from among a plurality of other communication terminals in the vicinity,
In the determination, the index value depending on the number of data held by the other plurality of surrounding communication terminals is acquired, and the other communication terminal that performs the negotiation is determined based on the acquired index value. The communication terminal control method according to claim 11.
13. The communication terminal control method according to claim 12, wherein, in the acquisition of the index value, the index value is acquired from a response to a request transmitted from the communication terminal to a plurality of other communication terminals existing in the vicinity prior to the negotiation. .
The method of controlling a communication terminal according to any one of claims 11 to 13, wherein the wireless network is a wireless network that conforms to a Wi-Fi Direct specification.