JPH11275106A - Communications system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve efficiency of network management by dividing communication equipment into plural groups and performing network management by a group unit. SOLUTION: This system is composed of an application interface part 1 for receiving transmission/reception requests from an application, a mode storage part 2 for storing which one of a server mode, a client mode and an initial mode its own operation mode is, a communication management part 6 for performing the processing of grow constitution composed of the plural communication equipments corresponding to the operation mode stored in the mode storage part, a communication group information storage part 3 for storing the identifier of the member of the group, a present equipment identification information storage part 4 for storing its own identifier, another equipment information storage part 5 for storing the identifier of another equipment recognized as communicable by itself, a transmission part 8 for transmitting data to a network, a reception part 9 for receiving the data from the network and a timer part 7 used in the processing of the group constitution by the communication management part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system for establishing a connection between a plurality of communication devices and performing communication, wherein at least one of the plurality of communication devices operates as a server and the other as a client. About.

[0002]

2. Description of the Related Art A technique for configuring an ad hoc network using a plurality of communication devices is disclosed in Japanese Patent Application No. 07-87937.
No. has been proposed. In a network configured based on the technology of this patent application, each device periodically transmits, as a beacon, a packet that describes information about itself and information about other communication devices that the device recognizes as being communicable. By broadcasting, receiving the beacon and recognizing the state of the mutual communication link between the communication devices existing in the vicinity, a network is autonomously formed without depending on the setting of the user.

[0003] In addition, by using information described in a beacon that is received periodically, the appearance of a new communication device due to power-on, disconnection of a communication link due to an obstacle, disappearance of the communication device due to power-off, and the like are detected as needed. To reconfigure the network.

In data transmission and reception, a group is formed by a plurality of mutually communicable communication devices based on the information on the recognized communication link, and the data is multicast to members of the group. This enables efficient data transmission between the devices.

[0005]

In the technology described above,
The number of beacons to be broadcast increases in proportion to the number of communication devices, and the amount of information described in the beacons also increases as the number of communication devices existing around increases.

[0006] Therefore, when the number of communication devices increases, there arises a problem that the beacon presses the band of the network.

[0007] Further, since each device manages the network by distributed processing using the information described in the received beacon, the number of devices increases. If the number of beacons increases, the processing amount for managing the network increases. In addition, there is a problem that the communication speed is reduced.

[0008] These problems have been obstacles to constructing a network comprising more communication devices.

Therefore, an object of the present invention is to select a server from a plurality of communication devices, generate a communication group by the selected server, and add the plurality of other devices to the communication group as clients. A communication group can be formed by using the method described in Japanese Patent Application No. 07-8793.
An object of the present invention is to provide a communication system capable of performing autonomous network management by transmission and reception of a beacon shown in the technology of No. 7 in units of the communication group and flexibly coping with an increase in the number of devices. .

[0010]

According to the present invention, there is provided a communication apparatus comprising: a plurality of communication devices;
In a communication system in which at least one is a server and another is operated as a client, a communication group is newly provided, a communication device belongs to any of a plurality of communication groups, recognition of surrounding communication devices by transmission and reception of beacons, and network By performing processing such as management in units of the communication group, it is possible to prevent the bandwidth of the network from being increased due to the increase in the number of communication devices and the increase in the processing amount of the communication devices.

The communication group is configured by first selecting a communication device to be a server of the communication group, and the server adds another device as a client to its own communication group.

The present invention comprises a plurality of communication devices,
In a communication system in which at least one is a server and another is operated as a client, a server is selected from a plurality of communication devices, the selected server generates a communication group, and the plurality of other devices are used as a client in the communication group. In addition, since a communication group can be configured by adding to the above, autonomous network management by transmission and reception of a beacon disclosed in Japanese Patent Application No. 07-87937 can be performed for each communication group.
A communication system capable of flexibly coping with an increase in the number of devices can be obtained.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 shows a configuration example of a communication apparatus according to the present invention. The configuration of this system and the function of each unit will be described with reference to the drawings. As shown in FIG. 1, the system includes an application interface unit 1,
Mode storage unit 2, communication group information storage unit 3, own device identification information storage unit 4, other device information storage unit 5, communication management unit 6,
It comprises a timer unit 7, a transmission unit 8, and a reception unit 9.

The application interface unit 1 has a function of transmitting the data to the network via the transmission unit 8 when receiving an instruction to transmit data from the application AP. However, if the communication management unit 6 determines that the data transmission / reception is not ready, the transmission is rejected. In addition, the data received by the receiving unit 9 and determined to be data destined for the own device transmitted by the application of the other device is passed to the application of the own device.

The mode storage unit 2 stores the operation mode of the device. The operation mode here is “server mode”,
There are three types: “client mode” and “initial mode”.

The communication group information storage unit 3 stores “identifiers of communication groups to which the own device belongs”, “list of identifiers of clients of the communication groups”, and “identifiers of servers of the communication groups”.

The own device identification information storage section 4 stores information used as an identifier of the own device. As the identifier of the own device, a value set by the user, a unique number given to the device at the time of manufacturing, a random number generated every time the power is turned on or the communication is started, and the like are used.

The other device information storage unit 5 stores a “communication group”.
The “device identifier” and the “identifier of the communication group managed by the server” are stored for the “device recognized as a server” by receiving the “server packet” transmitted by the device operating as the server of the server. .

The communication management unit 6 includes a transmission unit 8 and a reception unit 9
Communicates with another device via the application interface, and sets information such as an address necessary for the application of the own device and the application of the other device to communicate with each other via the application interface unit 1. Has a function of storing in each of the storage units 2 to 5.

The timer section 7 is set by the communication management section 6 and notifies the communication management section 6 when a designated time has elapsed. Upon receiving data to be transmitted from the application interface unit 1 and the communication management unit 6, the transmission unit 8 adds a header to the data and transmits the packet to the network as a packet.

The packet types are as follows.

[1] Application data packet [2] Server packet [3] Subscription application packet [4] Subscription permission packet [5] Subscription rejection packet These packets will be described below. [Application Data Packet] The application data packet is a packet describing data transmitted by the application AP. A transmission instruction is issued to the transmission unit 8 by the application interface unit 1,
When the receiving unit 9 receives it, it is passed to the application interface unit 1. Other packets are sent to the communication management unit 6.
Is generated and instructed to be transmitted to the transmission unit. When the reception unit 9 receives the data, it is transferred to the communication management unit 6.

[Server Packet] "Server Packet"
Is transmitted by a device operating as a server of a communication group to indicate to other devices that it is a server, and the identifier of the communication group is described therein.

[Subscription application packet] A subscription application packet is a packet sent to a server of a communication group, and indicates that the sender of the packet desires to join the communication group.

[Subscription permission packet and subscription rejection packet] The subscription permission packet and the subscription rejection packet are packets sent as a response from the server to the sender of the subscription application packet, and indicate whether or not it is possible to subscribe to the communication group. It is. When receiving the packet from the network, the receiving unit 9 checks the destination described in the header to determine whether the packet is addressed to the own device, and discards the packet if it is not addressed to the own device or a “broadcast packet”. If the packet is addressed to its own device or is a “broadcast packet”, the packet type described in the header is checked, and if the packet is an “application data packet”, the application interface unit 1
If the packet is any other packet, the data is passed to the communication management unit 6.

<Operations Before Communication Starts> Next, operations until communication starts will be described.

The flowcharts are shown in FIGS. FIG. 2 is an overall view, and FIGS. 3 and 4 are partially enlarged views thereof. The operation will be described with reference to the drawings. The operation mode of the communication device to newly communicate is set to either the “server mode” or the “initial mode”. The communication management unit 6 of the communication device that intends to perform the new communication includes the mode storage unit 2
Read the operation mode from. Then, the read operation mode is checked (S1, S2). As a result, if the read operation mode is the server, the communication management unit 6 newly generates a communication group managed by itself (S3). At the time of creation, only one server is a member of the communication group.

The server increases the number of members by sequentially adding, as clients, other initial mode apparatuses that desire to join the communication group to the communication group. The device that has joined the communication group changes the operation mode to “Initial mode”.
To "client mode".

The server determines the identifier of the generated communication group by “random number” or the like, and
To memorize. The “random number” is a number of digits sufficiently large so as not to collide with a random number generated by another server.

When the server generates the "communication group identifier", the server describes the "own device identifier" and the "communication group identifier" in order to notify other devices that the server is a server of the communication group. The broadcasted “server packet” is periodically broadcast (S4).

In step S1, if the read operation mode is the "initial mode", the communication manager 6 of the communication device waits for reception of a "server packet" transmitted by the server (S9). When receiving the "server packet", the server sends a "subscription application packet" for applying to join the communication group to the server that transmitted the packet (S10).

When a "server packet" is received from a plurality of servers, one of them is selected and a "subscription application packet" is sent to the selected server.

In the apparatus whose operation mode is the server, when the communication management section 6 receives the "subscription application packet", it refers to the communication group information storage section 3 and judges whether or not it is possible to join the communication group managed by itself. (S5, S6).

The criterion for the determination is, for example, that the total number of devices subscribing to the communication group does not exceed a predetermined number.

If it is determined that the subscription is permitted, the communication management unit 6 transmits a “subscription permission packet” describing the identifier of the communication group to which the subscription is permitted to the device that has transmitted the “subscription application packet” ( S8) The identifier of the device is newly added to the “list of device identifiers of the clients of the communication group” managed by the device manager stored in the communication group information storage unit 3.

If it is determined that the subscription is not permitted, a "subscription rejection packet" is transmitted (S7).

In a device whose operation mode is the "initial mode", when a "subscription permission packet" is sent from the server, the communication group information storage unit 3 is permitted to subscribe based on the "subscription permission packet". The “communication group identifier” and the “server device identifier” are described, and the operation mode of the own device stored in the mode storage unit 2 is rewritten from “initial mode” to “client mode” (S11, S1)
2, S13). And it becomes a client (S1
4).

The device in the “client mode” is:
Even if "Server packet" is received, it is ignored. If a “subscription rejection packet” is sent, a “server packet” sent from a server other than the server that rejected the subscription
Wait for the reception.

When the apparatus serving as a server determines that a new client can be added to a communication group managed by itself, it recruits clients by periodically broadcasting "server packets". Also,
If it is determined that no more clients can be added to the communication group managed by itself, the transmission of the “server packet” is stopped.

When it becomes possible to add a new client to the communication group due to the withdrawal of the client from the communication group or the like, the periodic transmission of the "server packet" is restarted.

Thus, a communication group can be generated for each server by sequentially adding a client to a communication group generated by one or a plurality of servers. Each communication group is a "communication group identifier" assigned by the server
Are distinguished from each other. By using different communication channels for each communication group, interference due to communication of other communication groups can be prevented, and communication efficiency is improved.

FIG. 5 is a diagram for explaining the operation of each communication device in the present embodiment. "Apparatus 1" and "Apparatus 4" set in the server mode, and "Apparatus 2", "Apparatus 3", "Apparatus 2", "Apparatus 3", "Apparatus 5", and "Apparatus 2" set in "Initial mode". “Apparatus 6” receives the “server packet” issued by “apparatus 1” and “apparatus 4”, and knows that the server is “apparatus 1” and “apparatus 4”. “Device 3” sends “subscription application packet” to “device 1”, and “device 5” and “device 6” send “subscription application packet” to “device 4”.

"Apparatus 2", "Apparatus 3", "Apparatus 5",
The “device 6” changes the operation mode to “client” when the subscription is permitted.

In this manner, "communication group 1" including "device 1", "device 2", and "device 3" and "communication group 2" including "device 4", "device 5", and "device 6". Is generated.

The server collects information about the client belonging to its own communication group, such as "device identifier" and "device user name", as "device information" from the client, and notifies other servers.

The server sends "device information" held by itself and "device information obtained from another server" to clients in its own communication group in response to a request.

As a result, all the devices existing in the network can acquire information on all other devices including the devices belonging to the communication group to which the device does not belong.
Based on this, a device to be a communication partner can be selected.

Devices belonging to different communication groups are
No direct communication is performed. When performing communication, relay communication is performed via a server of a communication group to which each device belongs.

In the above system, the server periodically recruits clients by broadcasting a "server packet" indicating that the server is a server. However, the server does not broadcast the "server packet". A device in the initial mode may broadcast a “server search packet” for searching for a server, and the server may transmit the “server packet” to only the device only when receiving the packet.

As described above, by transmitting the “server packet” by unicast only when there is a request from a device that wants to join the communication group, communication between devices that do not require the “server packet” is obstructed. Communication efficiency is improved.

As an improvement of the above method, not only the “communication group identifier” managed by the server but also the “number of clients joining the communication group” are described in the “server packet” transmitted by the server. Send
The other server can control the number of clients in the communication group described in the received “server packet” so that the client is not concentrated only in the specific communication group.

For example, when the number of clients in the communication group managed by the user is larger than the number of clients in other communication groups, the addition of a new client is stopped.

(Second Embodiment) In the first embodiment, the operation mode of the apparatus is set in advance, and the apparatus to be the server is determined. By automatically selecting a device, the trouble of setting the operation mode by the user can be eliminated. This method will be described below as a second embodiment.

First, points different from the first embodiment will be described. In this method, all devices that newly attempt communication start operating in the “initial mode”. The other device information storage unit 5 stores not only the device that is the server, but also the “identifiers” of all the devices whose own device has recognized the existence, and in addition to the “device identifier”, the operation mode of the device is
Any of the “server mode”, “client mode”, and “initial mode” is also stored.

In this embodiment, in addition to the “server packet” described in the first embodiment, a “own device identifier packet” describing the identifier of the own device is newly used. This “own device identifier packet” indicates that a device operating in “client mode” or “initial mode”
Sent to inform other devices of their presence.

In the “own device identifier packet”, the “device identifier of the sender” and the “operation mode” are described.

<Operations Up to Setting Communication Group> Next, operations up to setting a communication group will be described. The flowcharts are shown in FIGS. FIG. 6 is an overall view, and FIGS. 7 and 8 are partially enlarged views thereof. In communication devices that attempt to perform new communication by turning on the power,
After the communication management unit 6 sets the operation mode to the “initial mode” (S21), and requests the timer unit 7 to notify that a predetermined time (hereinafter referred to as an initial processing period) has elapsed (S22). A “device identifier packet” describing the identifier of the own device and the operation mode is periodically broadcast in a cycle shorter than the initial processing period (S22,
S23).

The receiving unit 9 monitors whether the “server packet” has been received (S 24). When the receiving unit 9 receives the “server packet”, the communication managing unit 6 replaces the device identifier described in the packet with the “server packet”. It is stored in the other device information storage unit 5 as a server (S25). When the “device identifier packet” is received, the “device identifier” and the “operation mode” described in the packet are stored in the other device information storage unit 5 (S25).

The communication management unit 6 continues to periodically broadcast its own device identifier packet until it is notified from the timer unit 7 that the initial processing period has elapsed (S26).

When a notification is received from the timer section 7 (S2
6), the communication management unit 6 stops transmitting the “device identifier packet”, and refers to the other device information storage unit 5 (S27).

The operation of the device stored in the other device information storage unit 5 with and without the device operating as a server will be described below.

If there is a server among the devices stored in the other device information storage unit 5, one of them is selected, and
A “subscription application packet” for applying to join the communication group is transmitted to the selected server (S33).

When the server receives the "subscription application packet", the communication management unit 6 refers to the communication group information storage unit 3 and determines whether or not it is possible to join the communication group managed by itself as a server.

If it is determined that the subscriber can be subscribed, the communication management unit 6 transmits the “subscription application packet” to the device that has transmitted the “subscription application packet”.
A “subscription permission packet” describing the identifier of the communication group permitted to subscribe is transmitted, and the “list of clients of the communication group” stored in the communication group information storage unit 3
Then, the above device is newly added. If it is determined that the subscriber cannot be subscribed, a “subscription rejection packet” is sent.

When the “subscription permission packet” is sent from the server, the communication management unit 6 rewrites the operation mode of its own device stored in the mode storage unit 2 from “initial mode” to “client mode” ( S36), the “communication group identifier” described in the “subscription permission packet” is stored in the communication group information storage unit 3. Thereafter, it operates as a client belonging to the communication group.

When the "subscriber rejection packet" is sent from the server, the communication manager 6 selects one of the remaining servers stored in the other device information storage 5 (S29).
Send “subscription application packet”.

This operation is repeated until a “subscription permission packet” is sent from any server.

If the subscription is refused from all the servers stored in the other device information storage unit 5 or if there is no server among the devices stored in the other device information storage unit 5, the server is Newly elected.

<New Selection of Server> When all the servers stored in the other device information storage unit 5 reject the subscription, or when the server stored in the other device information storage unit 5 If there is no server, a new server is selected. The procedure is as follows. The case where there is no device stored in the other device information storage unit 5 is when there is no device that can communicate with the own device. In this case, the communication management unit 6 changes the operation mode stored in the mode storage unit 2 from “initial mode” to “server”, and thereafter operates as a server.

That is, a communication group to be managed by itself is newly generated, its identifier is determined by a random number or the like, a “server packet” is transmitted periodically, and a “subscription application packet” is transmitted from the device in the “initial mode”. If so, it is determined whether or not it is possible to join the generated communication group, and a “subscription permission packet” or a “subscription rejection packet” is sent to the device according to the result.

When there is a device stored in the other device information storage unit 5, its own operation mode is determined by the following procedure. Each of the devices in the “initial mode” compares the identifier of the device in the other initial mode stored in the other device information storage unit 5 with the identifier of the own device, and becomes a server in descending order of the identifier value ( S
30, S31), the device which has not become a server becomes a client of a communication group managed by the server (S3).
2).

For example, when N initial mode devices are stored in the other device information storage unit 5 and the maximum number of devices per communication group is limited to M devices, N / N A minimum integer I equal to or larger than M is obtained, and the upper I units become servers in descending order of identifiers, and the remaining devices become clients.

When there is no limit on the maximum number of devices per communication group, only the device having the largest identifier becomes a server, and the remaining devices become clients.

An example of the above method will be described with reference to FIG. 9 in a case where there is no limit on the maximum number of communication devices per communication group. The dotted line in FIG. 9A indicates the range where the packet can reach. For example, the packet transmitted by “device 1” reaches “device 2” and “device 3”, but does not reach “device 4”. The packet transmitted by “device 4” reaches “device 3” but does not reach “device 1” and “device 2”.

Each communication device starts operating as an “initial mode” and broadcasts a “device identifier packet” describing its own device identifier and operation mode.

Since only the “device identifier packet” transmitted by “device 3” arrives at “device 4”, “device 4” compares “identifier 3” described in the received packet with its own “identifier 4”. As a result, it determines that its own identifier is the largest, changes its own operation mode to the server, and thereafter broadcasts a “server packet” instead of the “device identifier packet”.

Upon receiving the “server packet”, “device 3” sends “subscription application packet” to the communication group to “device 4”, and becomes a client of the communication group managed by “device 4”.

Thereafter, the “device 3” broadcasts the “device identifier packet” by describing its operation mode as “client”.

Since the packets transmitted by “device 4” do not reach “device 1” and “device 2”, “device 1” and “device 2” are “device 3” as the device having the largest identifier. Judge that there is.

As long as the operation mode is described as “initial mode” in the “device identifier packet” transmitted by “device 3”, “device 1” and “device 2” are “device 3” Judge that it will be, do nothing.

The “device 3” becomes a client of the communication group managed by the “device 4”, and a “device identifier packet” describing that its own operation mode is “client” is transmitted from the “device 3”. Then, the “device 2” determines that the device having the largest identifier among the devices in the initial mode is itself, changes its own operation mode to “server”, and broadcasts a “server packet”.

The “device 1” is the “server packet”
Is received, it joins the communication group managed by “device 2”.

As a result, two communication groups are formed as shown in FIG.

As described above, even when there are devices that cannot directly communicate with each other, a server can be appropriately selected and a communication group can be formed.

In the above description, the device to be the server is selected by comparing the sizes of the identifiers. In this method, when the identifier of the device is fixed, the device having the larger identifier becomes the server. There is a problem that it is easy.

The server performs much more processing than the client, such as determining whether or not the client can join the communication group. Therefore, the load is large. Therefore, it is unfair if only a specific device becomes the server.

However, if random numbers are used as follows,
The server is determined at random, and this problem is solved.

That is, each device generates a “random number”
The "random number" is described together with the "identifier" of the device in the "own device identifier packet" and broadcast. Each device stores the “random number” generated by itself and the “random number received from another device”, and compares them with each other so that the device that has generated the “large random number” can become a server in order. To

Considering that the server performs more processing than the client, it is desirable to use a device having excellent computational power for the server.

Therefore, the “own device identifier packet” includes
Describe the value of the device performance such as "communication speed", "storage capacity", "calculation speed", etc., and each device compares "own performance" with "device performance described in received packet" Alternatively, the servers may be arranged in order from the device having the highest performance.

In this case, a device having excellent computational power is preferentially assigned to the server, so that the communication efficiency of the entire network is improved.

As in the first embodiment, the "server packet" periodically transmitted by the server includes not only the "communication group identifier" managed by the server, but also the "client" added to the communication group. When the server receives the packet, the server can know the number of clients belonging to a communication group managed by another server. Then, the communication group can be reconfigured using this.

For example, by negotiating between servers in a communication group having a small number of clients, the plurality of communication groups can be merged into one communication group having a large number of clients. Also, a server of a communication group having a small number of clients can negotiate with a server of a communication group having a large number of clients, so that a part of the client can be transferred.

<Method of Eliminating Communication Group with Large Number of Clients> As a means of eliminating a communication group with many clients, other than the method of transferring a client to another communication group as described above, a communication group as follows: Can be divided.

A server in a communication group having many clients divides a client belonging to its own communication group into a device group to be left in its own communication group and a device group to be independent as another communication group.

Next, the server selects one device from a group of devices to be independent as another communication group, changes the operation mode of the selected device from “client” to “server”, and newly sets a communication group. Generate and instruct to operate as the server.

[0098] Further, of the devices that are not selected as a server among the devices that are made independent as another communication group, an instruction is issued to change the operation mode from "client" to "initial mode".

Upon receiving this instruction, the device whose operation mode has been set to the "initial mode" makes a subscription application to the newly created communication group, and upon joining, resumes operation as a client of the group.

Thus, the communication group is divided. Further, in the present embodiment, the operation of receiving a permission to join a communication group from the server by sending a subscription application packet from the device in the initial mode to the server is performed. A packet inviting a communication group to join may be sent to a device in the initial mode to be joined.

In this way, the invitation packet is sent only to the device permitted to join, and it is possible to eliminate the waste of processing such as sending and rejecting the subscription application packet.

When the server sequentially adds devices in the initial mode to the communication group as a client, it is guaranteed that the server and the client can directly communicate with each other, but the client can directly communicate with each other. Is not generally guaranteed. However, in the present embodiment, each device can know the identifier of another device that can communicate with itself by receiving the server packet or the device identifier packet. Thus, a communication group in which it is guaranteed that clients can directly communicate with each other can be formed.

<Construction of Communication Group in Which Clients Can Directly Communicate> A communication group in which it is guaranteed that clients can directly communicate with each other is constructed as follows.

A device in the initial mode that desires to join a communication group writes a list of identifiers of devices recognized as being communicable with itself in a “subscription application packet” transmitted to a server of the communication group. Send. The server is
Upon receiving the “subscription application packet”, it checks whether the identifiers of all the devices belonging to the communication group are included in the list described in the received “subscription application packet”. As a result, if all the devices are included, the device that transmitted the packet can communicate with all the devices belonging to the communication group, and thus permits the subscription.

If any of the devices belonging to the communication group is not included in the list described in the “subscription application packet”, the device refuses to join the communication group.

FIG. 10 shows an example. FIG.
The dotted line in (a) indicates the range where the packet can reach. For example, the packet transmitted by “device 1” reaches “device 2”, “device 3”, and “device 5”, but is transmitted by “device 4”.
Does not reach. The packet transmitted by “device 4” reaches “device 5”, but is transmitted by “device 1”, “device 2”,
It does not reach "device 3".

Each device starts operation in the initial mode, and periodically broadcasts a packet in which the identifier of the device and the operation mode are described periodically as a “device identifier packet”. Since the device identifier packets transmitted by “device 2”, “device 3”, and “device 5” arrive at “device 1”, “device 1” is replaced by “device 2”, “device 3”, and “device 5”. Know that communication is possible. The same applies to other devices.

In this example, since the device having the largest identifier is “device 5”, “device 5” is the server.
The server selection procedure has already been described and will not be described.

"Apparatus 1", "Apparatus 2", "Apparatus 3",
“Apparatus 4” sends a subscription application packet to each “apparatus 5”, applying to join the communication group.

In the subscription application packet transmitted by “device 1”, “device 2”, “device 3”, and “device 5” are described as identifiers of devices that can communicate with “device 1”.

Similarly, as an identifier of a communicable device,
The “subscription application packet” transmitted by “device 2” includes “device 1”, “device 3”, “device 5”, and “device 3”.
The “subscription application packet” transmitted by “device 1”, “device 2” and “device 5” is described, and the “subscription application packet” transmitted by “device 4” describes “device 5”. ing.

Here, it is assumed that the “subscription application packet” transmitted by “device 1” reaches “device 5” earliest. At this point, since there are no members other than the server in the communication group, "device 5" immediately permits the joining of "device 1" and adds "device 1" to the communication group. As a result, the members of the communication group are “apparatus 1” and “apparatus 5”.

Thereafter, when the “subscription application packet” arrives from “device 2”, “device 5” describes all “identifier 1” and “identifier 5” of the members of the communication group in the “subscription application packet” received. Find out if it is.

As a result, it can be understood that the information is described.
"Device 5" permits "device 2" to join the communication group, and adds "device 2" to the communication group.

As a result, the members of the communication group are “device 1”, “device 2”, and “device 5”.

Next, when a “subscription application packet” arrives from “device 4”, “device 5” adds “identifier 1”, “identifier 2”, and “identifier 5” of the members of the communication group to the received subscription application packet. Check that all are included.

As a result, since it is found that the information is not described, “device 5” refuses the “device 4” to join the communication group. Further, when the “subscription application packet” arrives from “device 3”, “device 5” receives the “identification 1”, “identifier 2”, and “identifier 5” of the communication group members in the “subscription application packet” that has arrived. Check that everything is listed.

As a result, it can be understood that the information is described.
"Device 5" permits "device 3" to join the communication group.

In this way, a communication group consisting of only devices that can communicate with each other can be configured.

(Third Embodiment) As described in the second embodiment, in the system in which information such as identifiers, random numbers, and device performances of respective devices are compared with each other to select a server, communication with the own device is performed. Since selection of a server cannot be performed until the above information is received from all possible devices, processing of server selection, communication group setting, etc. is completed,
There is a problem that it takes time until communication between applications becomes possible.

This can be solved by a configuration in which each device independently determines whether or not itself becomes a server without collecting information on other devices.

An embodiment for that will be described below.

The structure of the device is the same as that of the first embodiment shown in FIG. In the communication management unit 6, the probability of operating as a server is set and stored in advance by a user or a device manufacturer.

When starting communication, the communication management unit 6 selects whether or not to set its own operation mode to "server" according to the above-mentioned probability. Mode ”.

The communication management section 6 stores the result of the selection in the mode storage section 2. The device that has become a server broadcasts a “server packet” to notify other devices that it is a server. The device in the initial mode receives the "server packet", selects one of the devices recognized as the server, and sends the "subscription application packet" to the communication group.

When the server receives the “subscription application packet”, it determines whether or not it is possible to subscribe to the communication group managed by itself, and sends a “subscription permission packet” or a “subscription rejection packet” to the sender of the packet. .

In this method, since the device to be the server can be determined without performing communication between the devices, the time until the server is set is short, and the communication can be started immediately.

In the above method, the probability of operating as a server is fixed regardless of the number of communicable devices.
According to this method, when the probability of operating as a server is P, if there are n devices, the device follows the binomial distribution exactly, but approximately n ^* P devices will be the servers.

However, there is a possibility that all devices become clients and no device becomes a server.
c is given by Pc = (1−P) ^ n. In order to select at least one device to be a server, it is desirable to increase the probability P. However, in such a case, the number of devices to be a server can be increased more than necessary. Occurs.

Therefore, in order to solve these problems,
It is conceivable to adopt a method in which servers are not selected at once, but are selected several times and selected in stages. This method will be described below.

FIG. 11 is a flowchart. Description will be made with reference to the drawings. First, the user sets in the communication management unit 6 the probabilities P1, P2,..., Pn for selecting to become a server. It is preferable that P1 <P2 <... <Pn, but all may have the same value. These values may not be set by the user but may be given in advance at the time of manufacturing the device.

When starting communication, the communication management unit 6 selects whether or not to set its own operation mode as a server according to the probability P1. If not, the communication management unit 6 sets an "initial mode". (S41). The communication management unit 6 stores the result of the selection in the mode storage unit 2. Then, the counter i is set to "0"(initialization; S42), and i is incremented (S43). Then, a probability Pi is selected as to whether or not it can be a server (S44), and it is checked whether or not it has become a server (S45).

If the server has not become a server, a "subscription application packet" is transmitted to the server (S46).

When the first selection is completed, the server device changes the operation mode to the “server mode” (S47). Then, it operates as a server. That is, it broadcasts a "server packet" that informs another device that it is a server.

The device in the initial mode receives the “server packet”, selects one of the devices recognized as the server, and sends the “subscription application packet” to the communication group. There is (S46).

When the “subscription permission packet” is sent from the server, the server joins the communication group of the server and sets the operation mode to client (S49).

When a certain period has elapsed since the first selection,
The device in the initial mode that cannot join the communication group increments the counter i (S43).
As a result, since i is "2", whether or not it can be a server is selected with a probability Pi (S44). That is,
According to the probability P2, the user selects whether or not to set his / her own operation mode as a server. If not, the operation is continued in the initial mode. Then, the communication management unit 6 stores the result of the selection in the mode storage unit 2.

The device which has become the server in the second selection broadcasts a “server packet”.

The device in the initial mode is “server packet”.
, One of the devices recognized as a server is selected, and a "subscription application packet" to the communication group is sent (S46). When the "subscription permission packet" is sent from the server, the server joins the communication group of the server and sets the operation mode to "client" (S48, S4).
9).

When a certain period has elapsed since the second selection,
The device in the initial mode that has not been able to join the communication group increments i (S43) and obtains Pi = P3 from the obtained i = 3, so that the device itself becomes a server according to the probability P3. It is determined whether or not (S44).
This is the third selection.

The same operation is continued until there are no devices in the initial mode that cannot belong to the communication group.

According to this method, a small number of servers are initially selected, and then the number of servers is gradually increased until the number of servers reaches a sufficient number. Server can be selected.

(Fourth Embodiment) A method of stochastically selecting an appropriate number of servers by controlling the probability of becoming a server according to the number of peripheral devices will be described below. The configuration of each unit is the same as in the first embodiment. The communication management unit 6 of the device that is to start communication by turning on the power or the like requests the timer unit 7 to notify when a predetermined time (hereinafter referred to as an initial processing period) has elapsed. The operation mode stored in the mode storage unit 2 is referred to as an initial mode.

Next, the communication management unit 6 compares the own device identifier stored in the own device identification information storage unit 5 and the packet describing the operation mode stored in the mode storage unit 2 with the “own device identifier packet”. ".

When the “own device identifier packet” transmitted by another device is received, the “device identifier” and “operation mode” described in the packet are stored in the other device information storage unit 5.
To memorize. When notified by the timer unit 7 that the initial processing period has elapsed, the communication management unit 6 sets the number of initial mode device identifiers stored in the other device identification information storage unit 5 as the number of initial mode devices. read out.

The communication manager 6 calculates the probability P of operating itself as a server by using a calculation formula based on the number N of initial mode devices. For example, if the upper limit of the number of devices belonging to one communication group is determined to be M, it is desirable that N / M out of N devices be servers, so the probability is P = M / N And In this case, the number of devices to be servers is a binomial distribution with the highest probability of being M units.

The correspondence between the number of communicable devices and the probability of becoming a server may be calculated in advance and stored in a table, and the probability may be obtained from this table.

In this way, it is possible to use a complicated algorithm that requires a long calculation time to determine the probability, and to use an optimal value empirically obtained by experiment to select a more appropriate number of servers. Can be.

(Fifth Embodiment) In the fifth embodiment,
One device that determines which device should be the server is selected as a mode setting device, and this device is
A mode in which whether to operate as a server is instructed will be described. In this case, a device that is not instructed to operate as a server is a client.

The configuration is the same as that of the first embodiment, as shown in FIG. 1, but in this embodiment, the operation mode of the own device stored in the mode storage unit 2 is further changed to " A flag indicating whether or not the device is a "mode setting device" is added.

The operation mode of the "mode setting device" is not always the server. The operation mode and the mode setting device are determined independently.

At the start of communication, first, a "mode setting device" is selected. The selection method is as follows.

The communication management unit 6 of the device which is to start communication stores the operation mode of the own device in the mode storage unit 2 as the “initial mode”, and instructs the timer unit 7 for a predetermined time (initial mode). After the elapse of the processing period), a request for notification is issued, and a packet describing the own device identifier read out from the own device identifier storage unit 5 and the operation mode of the own device read out from the mode storage unit 2 is referred to as “own device identifier”. Broadcast periodically as "packets."

When the “own device identifier packet” is received,
The communication management unit 6 determines the “device identifier” described in the packet.
And the “operation mode” are stored in the other device information storage unit 5. When receiving the “mode setting device packet” transmitted by the “mode setting device”, the “device identifier” described in the packet is stored in the other device information storage unit 5 as the mode setting device.

The communication management unit 6 determines that the initial processing period has elapsed,
When the notification is received from the timer section 7, the stored contents are checked in the other apparatus information storage section 5.

The case where there is no device stored in the other device information storage unit 5 is when there is no device that can communicate with the own device. In this case, the communication management unit 6 rewrites the operation mode of its own device stored in the mode storage unit 2 from the “initial mode” to the “server mode”, and thereafter operates as a server.

Also, the flag stored in the mode storage section 2 is set, and the apparatus operates as a "mode setting device".

The “mode setting device” periodically broadcasts a packet describing its own identifier as a “mode setting device packet” in order to indicate to other devices that it is the mode setting device. In addition, since this device is both a mode setting device and a server,
"Server packets" are also broadcast periodically.

If there is a device stored in the other device information storage unit 5, its own operation mode is determined by the following procedure. If the identifier of the mode setting device is described in the other device information storage unit 5 of the own device, the mode setting device is not selected because the “mode setting device” has already been selected.

If the "identifier of the mode setting device" is not described, the "identifier of the other device" stored in the other device identifier storage unit 5 is compared with the "identifier of its own device". When the value of the identifier of the self is the largest, the self becomes the “mode setting device”. However, in this method, when the identifier of the device is fixed, a device having a larger identifier is more likely to be a “mode setting device”,
Injustice occurs.

Therefore, similarly to the server selection procedure in the second embodiment, the “random number” generated by each device is described in a packet and broadcasted, and the received “random number” is received.
The device that generated the largest random number was determined to be the "mode setting device", or a packet describing the calculation capability of its own device was broadcast, and the superiority of the calculation capability described in the received packet was determined for each device. Each device may be compared, and the device having the best calculation capability may be set as the mode setting device.

When the "mode setting device" is selected in this manner, the device selected as the mode setting device is set in the mode storage unit 2 of its own device by the "mode setting device flag". Is set, and the device to be the server is selected from the devices in the initial mode stored in the other device identifier storage unit 5.

For example, when N initial mode devices are stored in the other device identifier storage unit 5 and one communication group is composed of M devices, the "mode setting device"
N / M devices are selected from the devices in the initial mode stored in the other device identifier storage unit 5.

The selection may be performed at random. However, when the mode setting device is selected not by the identifier or random number of each device but by the calculation capability, the calculation capability of each device is known in advance. N /
If M units are selected, a device having excellent calculation ability can be used as a server.

When the device that has become the “mode setting device” selects the device to be the server, the device becomes
A “server mode instruction packet” for instructing operation as a server is sent.

Receiving the “server mode instruction packet”, the communication management unit 6 rewrites its own operation mode stored in the mode storage unit 2 from “initial mode” to “server mode”, and changes the operation as a server. Start.

That is, a communication group managed by itself is newly generated, and a “server packet” indicating a server is broadcast.

The device in the initial mode that has received the “server packet” determines that the device itself has not been selected as a server, and continues to receive the “server packet”. One of the stored server identifiers is selected, and a "subscription application packet" for applying to join the communication group is sent to the server.

Upon receiving the “subscription application packet”, the server determines whether or not the device that transmitted the packet can be added to the communication group managed by itself, and according to the result, the “subscription permission packet” or the “subscription packet”. Send "rejection packet".

The device that has received the “subscription permission packet”
The operation mode is rewritten from the “initial mode” to the “client mode”, and thereafter, it operates as a client.

"Subscriber refusal packet" from all servers
Device that cannot be joined to the communication group
A “server selection request packet” requesting selection of a new server is sent to the “mode setting device”.

When the "mode setting device" receives the "server selection request packet", it selects a device to be operated as a server from devices whose operation mode is "initial mode", and operates as a server for that device. And give instructions.

As a result, all the devices start operating in the “initial mode”. If there is no “mode setting device”, the device having the largest identifier becomes the mode setting device. Now, suppose that the device having the largest identifier is “device 6”. Then, in this case, “device 6” becomes the mode setting device.

The “device 6”, which has become the “mode setting device”, randomly selects a device to operate as a server, and issues an instruction to operate as a server.

Here, it is assumed that “device 2” and “device 3” have been selected as servers. The operation after the server is selected is the same as in the first embodiment.

That is, by transmitting the “subscription application packet” to the communication group to “apparatus 1”, “server 2” or “server 3”, respectively, the communication group managed by “server 2” or “server 3” is transmitted. Join each.

Although “device 6” is a mode setting device, after selecting a device to be a server, it operates as a client of a communication group managed by “server 3”.

(Sixth Embodiment) In the embodiments described above, once a server is selected, no server selection operation is performed thereafter. If there is a device that starts communication by inserting a device, the number of servers may be insufficient and some devices may not be included in any communication group.

To solve this problem, a new server is selected from devices that have not been placed in the communication group. Devices that are not included in the communication group have the operation mode set to “initial mode”. Since the operation mode of the device that can join the communication group is “server mode” or “client mode”, whether the operation mode is the initial mode indicates whether the device has joined the communication group. Can be identified.

In the server selection procedure between devices that could not join the communication group, the communication management unit 6 of each device refers to the mode storage unit 2 and if the operation mode is not the “initial mode”, Do nothing because you are in a group.

The device in the initial mode selects a device to be a server from the devices in the initial mode according to the same procedure as in the second and third embodiments described above, and selects a device not to be a server. Becomes a client of the communication group newly created by the selected server.

(Seventh Embodiment) Communication between devices belonging to different communication groups is performed by a server of a communication group to which each device belongs relaying packets. For this reason, if the server becomes unable to communicate due to power-off or the like, communication with devices belonging to other communication groups becomes impossible. Further, since it is the server that manages the clients of the communication group and determines whether or not to join the group, there is a problem that a new client cannot be added to the communication group without the server.

Therefore, it is necessary to detect that the server has disappeared from the communication group and to select a substitute server. This method is described below.

As described in the first, second, and third embodiments, the server uses its own identifier and the communication managed by itself to indicate to other devices that the server is operating as a server. A "server packet" describing the identifier of the group is broadcast periodically.

On the other hand, the client monitors whether a “server packet” is periodically transmitted from a server of the communication group to which the client belongs, and if the “server packet” is not transmitted for a certain period of time, it is determined that the server cannot communicate. Then, the own operation mode is rewritten to the initial mode, and a new server is selected again in the same procedure as in the second and third embodiments.

In the first embodiment, the server determines that it is not possible to add a new client to a communication group managed by itself, and stops sending a server packet when it stops recruiting clients. did.

However, when the transmission of the server packet is stopped in the present embodiment, there is a disadvantage that the client regards the server as having become unable to communicate.
Therefore, in order to distinguish between the suspension of client recruitment by the server and the server being unable to communicate,
A new flag is added to the "server packet" to indicate whether or not a client is being recruited, and the server sends "server packets" periodically regardless of whether or not a client is being recruited. To

The server turns on the "flag" when a new client can be added to a communication group managed by the server, and turns off the "flag" when a new client cannot be added.

A device whose operation mode is the "initial mode" applies only to the server that transmitted the packet to join the communication group only when receiving the "server packet" in which the "flag" is turned on. .

In this case, since the server always transmits the "server packet" regularly, the client may determine that the server cannot communicate if the "server packet" has not been transmitted for a certain period of time. it can.

In the above-described procedure, when a plurality of servers cannot communicate at the same time, all the devices in a plurality of communication groups managed by the plurality of servers set the operation mode to the initial mode. Changed and reconfigured the communication group by re-selecting the server from all of the devices independently of the original communication group, so the reconfigured group was different from the original communication group. Problem.

To avoid this, the “device identifier packet” transmitted by the device in the initial mode includes the “identifier of its own device”.
In addition to "operation mode" and "identifier of the communication group to which the device belonged before the server became unable to communicate"
When the "device identifier packet" is received, the "communication group identifier" described in the packet is checked, and if it is different from the communication group to which the own device belongs, it is ignored and discarded. What should I do?

In this way, a communication group can be reconfigured with the same members as before the server became unable to communicate.
Also, the client periodically transmits a packet indicating its existence to the server of the communication group to which the client belongs, and the server periodically transmits the packet from the client of the communication group managed by the client. If the client is monitored, it is possible to detect that the client has become unable to communicate.

When the server detects that the client of the communication group managed by the server has become unable to communicate, the server notifies the member of the communication group of the identifier of the device that has become unable to communicate by multicast, Also, the server of the communication group is notified that the device has become unable to communicate.

(Eighth Embodiment) In joining a device to a communication group, it is desirable that devices having a high frequency of mutual communication belong to the same group, since communication efficiency is improved. For example, in a joint work such as an electronic conference by mutual communication between a plurality of devices, “device 1”, “device 2”, and “device 3” participating in a first conference and “joining a second conference” If “device 4”, “device 5”, and “device 6” exist, the first communication group is “device 1”, “device 2”, and “device 3”, and “device 4” and “device 5”. "," Device 6 "
Creates a second communication group respectively.

An example of such a case will be described below. First, a device to be a server in each communication group is determined. Each device sets the operation mode to the “initial mode”, and includes a packet describing “information on whether the conference in which it participates is the first conference or the second conference” together with the “identifier of its own device”. Is broadcast as a “device identifier packet”.

By receiving the “device identifier packet”, the “identifier of another device” and the “meeting in which the device participates” are known, and the communication management unit 6 stores this in the other device information storage unit 5. I do.

Next, the communication management section 6 of each device
The device identifier stored in the other device identifier storage unit 5 is classified for each conference in which the device participates, and the device having the largest identifier among the devices participating in the same conference is defined as a server.

In selecting a server from devices participating in the same conference, in addition to using the identifier of the device as described above, similarly to the second embodiment, a random number generated by the device and calculation of the device can be selected. Ability may be used.

According to the above procedure, one server is selected for each device participating in the same conference. The device that has become a server includes, in a “server packet” indicating that it is a server, a “communication group identifier” and “information on whether the type of conference is the first conference or the second conference”.
And broadcast periodically.

The device which did not become a server sends a “subscription application packet” to the server participating in the same conference as itself.
Send. When the server receives the "subscription application packet", the server returns the "subscription permission packet" indicating permission to subscribe to the communication group, describing "the identifier of the communication group corresponding to the conference in which the server participates".

The device that has received the “subscription permission packet”
The "communication group identifier" described in the packet is stored in the communication group information storage unit 3, and thereafter, it operates as a client of the communication group.

[0203] The method of dividing the communication group is not limited to the conference as described above. For example, information on the affiliation of the user is used, and devices used by users working in the same department belong to the same communication group. It may be.

Further, a communication group may be divided for each application executed in the apparatus. For example, if there is an application of the electronic conference application game, and the user is executing any one of the applications, the device executing the application of the electronic conference enters “communication group 1” and the application of the game is To the “communication group 2”
It is said that each is added.

The frequency of communication between devices executing the same application is considered to be higher than the frequency of communication with devices executing different applications.
By dividing the communication groups in this way, communication efficiency can be improved.

(Ninth Embodiment) In the above description,
Although a random number is used as the identifier of the communication group, it is necessary to increase the number of digits of the random number in order to avoid accidental coincidence of the random numbers generated by a plurality of servers. "Identifier of communication group"
Is used as an address for communication, so when the number of digits increases, whether or not the packet is addressed to itself at the time of receiving the packet is determined by comparing the destination address of the packet with the address of the packet and determining whether or not they match. The filtering process takes time and is inefficient.

Therefore, a communication group identifier having a small number of digits is set by negotiation between servers, and is used as an address, thereby improving the efficiency of reception processing.

The configuration of the present embodiment is the same as that of the first embodiment, as shown in FIG. 1, but the communication group information storage unit 3 stores the “identifier of the communication group to which the own device belongs”. , "A list of identifiers of communication groups to which the own device does not belong" is stored as an "other communication group identifier list".

The procedure from generation of a communication group to setting of an address will be described below. First, a server is selected.

As in the second embodiment, the server may be selected by each device generating a random number, transmitting a packet describing the random number, and comparing the received random numbers with each other. However, as in the third embodiment, it may be possible to select whether or not each device becomes a server stochastically without relying on communication between the devices.

After the server is selected, the communication group identifier is set. FIGS. 12 to 14 show flowcharts of this setting procedure. FIG. 12 is an overall view, and FIG.
3, FIG. 14 is a partially enlarged view of FIG. The communication management unit 6 of each server randomly selects one of the numerical values used as the “communication group identifier” from, for example, an integer from “1” to “256” and stores it in the communication group information storage unit 3 (S71). ).

Next, the server requests the timer unit 7 to notify that a predetermined period (a communication group identifier setting period) has elapsed (S72), and then sends a packet describing the selected numerical value to the “communication group identifier”. The packet is broadcast as a "packet" to another server at a period shorter than the communication group identifier setting period (S73).

A device other than the server ignores the "communication group identifier packet" even if it arrives. Upon receiving the “communication group identifier packet” (S74), the server compares the numerical value described in the packet with the “own communication group identifier” stored in the communication group information storage unit 3 (S7).
5, S76). And if the result of the comparison is not the same,
The numerical value is added to the “other communication group identifier list” (S77).

On the other hand, as a result of the comparison, if they are the same, it is an overlap of the “communication group identifier”. Therefore, in this case, the communication management unit 6 resets the timer unit 7 and requests the timer unit 7 to notify the timer unit 7 again after a lapse of the communication group identifier setting period from the time when the identifier duplication is detected.

Further, in order to notify another server of the duplication of the "communication group identifier", a "communication identifier collision packet" describing the collision communication group identifier is broadcast to another server (S78). The sender of the “communication identifier collision packet” does not change the communication group identifier.

The communication management unit 6 of the device that has received the “communication identifier collision packet” resets the timer unit 7 in the same manner as the server that detected the collision of the “communication group identifier”, and writes the “communication group collision” described in the packet. The "identifier" is compared with its own "communication group identifier" (S81). As a result, if they are the same, the “communication group identifier” is set to “1”.
One is randomly selected from those not described in the “other communication group identifier list” and is an integer from “256” to “256” (S84), and a “communication group identifier packet” describing the newly selected numerical value is periodically transmitted. (S73).

In the “other communication group identifier list”,
When all identifiers from “1” to “256” are described and there is no vacant identifier, or when a collision is detected with respect to the reselected communication group identifier,
The communication management unit 6 stops operating as a server, and changes its own operation mode stored in the mode storage unit 2 from “server mode” to “initial mode” (S83).

Upon receiving a notification from the timer section 7 that the communication group identifier setting period has elapsed (S79), it is known that no collision of communication group identifiers was detected during that period. Is stored in the communication group information storage unit 3, and the procedure for setting the group identifier ends (S80).

According to the above procedure, the "communication group identifier"
Is set, the server next recruits clients. The server gives an integer identifier to a client belonging to a communication group managed by the server according to the order of subscription.

For example, it is assumed that the identifier of the server is “1”, the identifier of the client that has subscribed first is “2”, and the identifier of the client that subscribed second is “3”.

The procedure for setting the client identifier will now be described. FIG. 15 shows the sequence. The communication management unit 6 is provided with a counter i. This counter i is used by the server to issue an identifier to the client, and its initial value is “2”.

[Processing 1] The device serving as a server stores the “communication group identifier G” managed by itself and the “counter value i” in a “server packet” indicating that the device is a server. Write and broadcast.

[Process 2] The communication management unit 6 of the device in the initial mode that has received the “server packet” stores the “counter value i” and the “communication group identifier G” described in the “server packet”. Further, a "random number R" is generated, and a packet describing the "communication group identifier G" described in the received "server packet", the "counter value i", and the "generated random number R" is communicated. Broadcast as a "group join application packet".

The communication management section 6 also stores the generated random numbers.

[Processing 3] The communication management unit 6 of the server
When receiving the “communication group subscription application packet”, the “communication group identifier” described in the packet is the same as its own “communication group identifier”, and the “counter value” described in the packet is its own “counter value”. Check if they are the same. As a result, if both are the same, the “random number” described in the “communication group subscription application packet” is stored,
A "communication group join permission packet" describing the "random number" and the self-identified "communication group identifier" is broadcast.

[Process 4] The communication management unit 6 of the device that has received the “communication group join permission packet” stores the “random number R” and the “communication group identifier G” described in the packet in “[process 2]”. It compares with the “random number R” and the “communication group identifier G”, and if both match, it is determined that the joining to the group is permitted, and the stored “counter value” is set as its own “device identifier”. Further, a packet describing the “communication group identifier”, the “random number R”, and the “counter value i” is broadcast as a “subscription confirmation packet”.

[Processing 5] Upon receiving the “subscription confirmation packet”, the server compares the “communication group identifier G” and “random number R” described in the packet with its own “communication group identifier G” and “[processing 3]. ]], And compares it with the “random number R” described in the “communication group subscription application packet”. If both match, it is determined that the “communication group subscription permission packet” has arrived at the other party. The counter value i is incremented by one and the process returns to "[Process 1]".

The above processing is repeated until there are no more clients desiring to join the communication group, or until the value of the counter reaches a predetermined upper limit (for example, 256).

Thus, the "communication group identifier"
When the “device identifier” is set, each device is uniquely identified by a set of “communication group identifier” and “device identifier”. Therefore, it is possible to communicate with each other by using this set as an address. it can.

This address setting procedure is all performed by broadcasting, and since the specification of a device in transmitting and receiving a packet is based on a random number generated by the device, it is not necessary to assign a unique identifier to the device in advance. However, if a unique identifier is assigned to the device by the device manufacturer or user in advance, or if a unique serial number or the like is assigned to the application used in the device, instead of the random number, These values may be used.

In the above example, if the total number of communication groups is “2”
56 "and the number of devices that can join one communication group is limited to" 256 ", so the number of devices that can communicate simultaneously is limited to" 65536 ", but" 256 Is distinguished from “8”
A bit is enough.

Similarly, since 8 bits are sufficient for discriminating each of the 256 devices, all devices can be distinguished from each other by a total of 16-bit addresses, and a random number or a device-specific identifier is used as an address. Therefore, filtering at the time of packet reception can be performed quickly, and efficient communication can be performed.

(Tenth Embodiment) In the ninth embodiment, the server sequentially assigns device identifiers to the clients. However, the assignment of the device identifiers of the clients is similar to the determination of the group identifier of the server. You may make it set by negotiation.

In this case, the server sets the identifier of the communication group managed by itself, adds the device in the initial mode to the communication group as a client, but does not assign the identifier to the device that has become the client.

The method of setting the communication group identifier by the server is the same as in the ninth embodiment.

When the communication group identifier is set, the server adds the client to the communication group managed by the server in the following procedure. The server broadcasts a packet describing the identifier of the communication group managed by itself as a server packet.

The device in the initial mode that has received the server packet generates a random number and replaces the packet in which the “group identifier” described in the server packet and the “random number” are described with the random number.
It is transmitted as a “group join application packet”.

The communication management section 6 stores the “group identifier” and the generated “random number”. The server that has received the “group joining application packet” compares the “communication group identifier” described in the packet with the “communication group identifier” managed by itself, and if they are the same, the above “communication group identifier” The packet describing the “random number” is sent as a “communication group joining permission packet”.

The communication management unit 6 of the device that has received the “communication group join permission packet” compares the “communication group identifier” and “random number” described in the packet with the stored “group identifier” and “random number”. . As a result, if they are the same, it is determined that it is “subscription permission for self-existence”, and the “group identifier” is stored in the communication group information storage unit 3.
And thereafter operates as a client of the group.

When the communication group to which all the devices belong is determined in this way, the server belonging to the same communication group is executed in the same procedure as the ninth embodiment in which the servers set the “communication group identifier”. , A unique “device identifier” is set within the communication group among all the devices including the device group.

[Identifier] of the communication group to which the device belongs
By combining the set “device identifier” with the “device identifier”, it is possible to obtain an “address” that is unique among all devices including devices belonging to other communication groups.

In the above description, the random number generated by the device is used to identify the device for which a subscription to the communication group is applied. However, a unique identifier such as the serial number of the device is set in advance. If so, that identifier may be used instead of a random number. However, even if there is a preset device-specific identifier, the device identifier set by the procedure described here is used for the address in communication.

This is because, as described in the ninth embodiment, the address can be shortened, which contributes to the efficiency of communication.

According to this method, “setting of“ communication group identifier ”between servers” and “setting of“ device identifier ”between devices belonging to the same group” are performed in the same procedure. When this method is implemented by software, the two settings can be performed using a common program, and the number of program steps can be reduced by that amount, and the design becomes easy.

(Eleventh Embodiment) When there are a large number of communication groups, by dividing them into several upper groups and managing them, communication efficiency can be improved. Next, an example thereof will be described.

In a company, users belonging to “sections 1 and 2” of “sales department” and “sections 1 and 2” of “general affairs department” communicate with each other. Let's do it.

At this time, first, a communication group is generated between the devices of the users belonging to the same section. For example, “Sales Section 1 Communication Group”, “Sales Section 2 Communication Group”, and the like.

Next, a higher-order group consisting of a plurality of communication groups belonging to the same section is generated. For example, a “sales department 1 communication group belonging to the sales department” and a “sales department group composed of the sales department 2 communication group” are generated. This is because the communication traffic between devices belonging to the same unit is considered to be larger than the communication traffic between devices belonging to different units.

As described above, by providing a higher-level group and separately managing the communication groups, communication groups having a large traffic volume between the groups can be put together, and interference with other communication groups can be reduced. .

For example, in the case where radio waves are used for transmission and reception in the network and the frequency band can be selected from a plurality of frequency bands, the first frequency band is assigned to the device belonging to the sales department group, By assigning a second frequency band to, for example, interference due to communication between devices belonging to other higher-level groups can be prevented.

In this case, the procedure from the generation of a communication group to the provision of a server and a client for each communication group is the same as in the above-described embodiments.

After the server and client selection procedures are completed, a higher-level group having only the servers in the communication group as members is generated by negotiation between the servers. The server and client selection procedures for the upper group are the same as those for the server and client in the upper group except that both the server and the client in the upper group are selected only from the servers in the communication group, and the clients in the communication group are not involved in the procedure for generating the upper group at all. , Exactly as in the communication group.

When the number of communication groups increases, a plurality of upper groups are provided. When the number of higher-level groups increases with the increase in the number of communication groups, a higher-level group is created between the servers of the plurality of higher-level groups.

As described above, when higher-level groups are created in accordance with the increase in the number of groups, efficient management can be performed even when many devices exist. An example is shown in FIG. In this example, “apparatus 3”, which is a server of “communication group 1”, and “apparatus 4”, which is a server of “communication group 2”, constitute “upper group 1”. "Apparatus 8", "Apparatus 9" which is a server of "Communication Group 4",
“Apparatus 12”, which is a server of “communication group 5”, constitutes “upper group 2”.

In the “upper group 1”, “apparatus 4” is a server and “apparatus 3” is a client.

In “upper group 2”, “apparatus 8” is a server, and “apparatus 9” and “apparatus 12” are clients. In other words, “apparatus 4” and “apparatus 8” are servers of the communication group as well as servers of the upper group, and “apparatus 3”, “apparatus 9”, and “apparatus 12”
Is a server of the communication group and a client of the upper group.

[0257]

As described above, the present invention relates to a communication system comprising a plurality of communication devices, at least one of which operates as a server and the other as a client.
Since a server is selected from a plurality of communication devices, and the selected server generates a communication group, and the plurality of other devices are added to the communication group as clients, the communication group can be configured. 07-8
Autonomous network management based on transmission and reception of beacons disclosed in No. 7937 can be performed for each communication group, and a communication system that can flexibly cope with an increase in the number of devices can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the present invention, and is a block diagram showing a configuration example of a main part of a communication device of the present invention.

FIG. 2 is a diagram for explaining the present invention, and is a flowchart for explaining the first embodiment of the present invention.

FIG. 3 is a partially enlarged view of the flowchart in FIG. 2;

FIG. 4 is a partially enlarged view of the flowchart in FIG. 2;

FIG. 5 is a diagram for explaining the present invention, and is a diagram for explaining the first embodiment of the present invention.

FIG. 6 is a view for explaining the present invention, and is a flowchart (overall view) for explaining a second embodiment of the present invention.

FIG. 7 is a partially enlarged view of the flowchart in FIG. 6;

FIG. 8 is a partially enlarged view of the flowchart of FIG. 6;

FIG. 9 is a diagram for explaining the present invention, and is a diagram for explaining the operation of the second embodiment of the present invention.

FIG. 10 is a diagram for explaining the present invention, and is a diagram for explaining the operation of the second embodiment of the present invention.

FIG. 11 is a diagram for explaining the present invention, and is a flowchart for explaining a third embodiment of the present invention.

FIG. 12 is a diagram for explaining the present invention, and is a flowchart for explaining a ninth embodiment of the present invention.

FIG. 13 is a partially enlarged view of the flowchart in FIG. 12;

FIG. 14 is a partially enlarged view of the flowchart in FIG. 12;

FIG. 15 is a diagram for explaining the present invention, and is a diagram for explaining the sequence of the ninth embodiment of the present invention.

FIG. 16 is a diagram for explaining the present invention, and is a diagram for explaining an eleventh embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 application interface unit 2 mode storage unit 3 communication group information storage unit 4 own device identification information storage unit 5 other device information storage unit 6 communication management unit 7 timer unit 8 transmission unit 9 reception unit

Claims (11)

[Claims] A communication system comprising a plurality of communication devices, at least one of which operates as a server and the other as a client, determines whether or not it is possible to add a communication device capable of communicating with self to a communication group to which the self belongs. At least two modes, a server mode that operates as a server that operates as a server and a client mode that operates as a client that receives a permission to join a communication group from another communication device that operates as a server and subscribes to a communication group to which the server that has obtained the permission belongs. A communication system having a communication device. 2. The communication system according to claim 1, wherein negotiations are performed by communication with a communication device capable of communicating with the communication device, and a mode in which the communication device operates is set to one of the server mode and the client mode. 3. The communication system according to claim 1, wherein a mode in which the mobile terminal operates is set to one of a server mode and a client mode. 4. Each of the plurality of communication devices transmits a packet describing a random number or an identifier unique to the device, and upon receiving the packet, distinguishes each sender of the packet by the random number or the identifier described in the packet. By measuring the number of communication devices that have transmitted the packet, calculating the probability that the server itself will be a server from the measured number of communication devices by using a calculation formula or table, and selecting a mode that operates based on the probability The communication system according to claim 3, wherein: 5. A method for selecting one of a plurality of communication devices as a mode setting device and determining whether the selected mode setting device should operate in a server mode or a client mode for each of the plurality of communication devices. The communication system according to claim 1, wherein a mode of each of the plurality of communication devices is set by notifying each of the plurality of communication devices. 6. A communication device which is rejected from all the communicable servers to join a communication group, generates a new communication group, and becomes a server of the generated communication group. Item 2. The communication system according to Item 1. 7. A server of a communication group periodically transmits a packet indicating its existence to a client belonging to the communication group, and the client monitors whether or not the packet is periodically received. 2. The communication system according to claim 1, wherein it is determined that the server cannot communicate, and a substitute server is selected from the clients. 8. A communication device desiring to join a communication group transmits information on a user of the device to a server of the communication group as user information, and the server transmits information on its own user and the received user information. And determining whether or not to add the device to a communication group to which the device belongs by comparing the devices.
A communication system as described. 9. A plurality of communication devices operating in the server mode negotiate with each other to set a unique communication group identifier between communication groups, and each of the communication devices operating in the server mode is assigned to the same communication group as its own. A unique device identifier within the communication group is assigned to each communication device to which the communication device belongs, and the communication devices belonging to each communication group are assigned a communication group identifier of the communication group to which the device belongs and a device identifier assigned from the server of the communication group to which the device belongs. 2. The communication system according to claim 1, wherein an address that can communicate with a communication device belonging to another communication group is obtained by combining 10. A communication device belonging to the same communication group negotiates with each other to set a unique device identifier within the communication group, and a server of the communication group negotiates with a server of another communication group to perform communication. A communication group identifier that is unique between groups is set, and communication devices belonging to each communication group communicate with communication devices belonging to other communication groups by combining the communication group identifier of the communication group to which the communication device belongs and the device identifier of the communication device. The communication system according to claim 1, wherein a possible address is obtained. 11. When there are a plurality of communication groups, a group higher than the plurality of communication groups is further provided, and each of the servers of the plurality of communication groups is set to a mode of a server or a client in the higher group. 2. The communication system according to claim 1, wherein whether to operate is selected, and the selected operation in a higher-order group and an operation as a server in the plurality of communication groups are performed.