JP5029131B2 - Mobile terminal device, control method, and mobile communication system - Google Patents

Description

    The present invention relates to a mobile terminal device (hereinafter also simply referred to as “terminal”), a control method, and a mobile communication system that form an ad hoc network.

A routing protocol in an ad hoc network consisting of only a plurality of mobile terminal devices does not require the infrastructure (infrastructure) of a mobile communication network, and sends control packets such as link information to all nodes in the network. The route is controlled based on flooding.
In the case of flooding as described above, when the number of terminals increases, a large amount of control packets flow through the network, which imposes pressure on the communication band. As a method for reducing this problem, OLSR (Optimized Link State Routing) uses an MPR (Multi Point Relay) set (see Non-Patent Document 1).

In OLSR, each terminal selects a minimum relay terminal (MPR) necessary for delivering a packet from its own device to all terminals connected in two hops from terminals connected in one hop. When a certain terminal floods a packet across the network, only the terminal selected as the MPR of the terminal that transmitted the packet relays the packet.
As a result, the packet can be delivered from the terminal that transmitted the packet to all the terminals in the 2-hop range. Further, the terminal selected as the MPR of the terminal that relayed the packet further relays, so that the packet is finally delivered to the entire network. In this way, OLSR realizes routing with low overhead by efficiently performing flooding.
T. Clausen and P. Jacquet, Project Hipercom, "Optimized Link State Routing Protocol (OLSR)", RFC3626, HYPERLINK "URL: www.ietf.org/rfc/rfc3626.txt" URL: www.ietf.org/rfc/rfc3626.txt (page18 -20 ... Disclosure regarding relay of TC message, page 38-41 ... Disclosure regarding determination of MPR, page 43-46 ... Disclosure regarding transmission of TC message)

  However, although OLSR considers efficient flooding of control packets, it does not consider optimization by selecting link information necessary for routing. In OLSR, a terminal selected as MPR for at least one terminal floods the link information between the own device and the terminal that has selected the own device as MPR, so that the link information of the entire network is transmitted to all terminals. Notification and routing is performed using the link information.

The link information in the above is composed of an ID of the own device and an ID of a terminal adjacent to the own device, and indicates that there is a link between both terminals having these IDs. “Flooding” refers to a communication mode in which a plurality of terminals deliver packets to all terminals by transferring packets transmitted by other terminals.
When routing is performed as described above, if two terminals A and B select each other as MPRs, the terminals A and B flood each other's ID. The link information is transmitted in duplicate.

As described above, in OLSR, duplicate link information is unnecessarily transmitted to all terminals, resulting in an increase in the amount of control packets related to routing and an increase in overhead related to routing.
Accordingly, an object of the present invention is to provide a mobile terminal device, a control method, and a mobile communication system that realize routing capable of ensuring reachability of transmitted information while reducing the amount of control packets related to routing. .

In order to solve the above-described problems, the present application proposes the following techniques.
In this specification, a “cluster head” is a mobile terminal device that belongs to a cluster and represents the cluster.
A “gateway” is a mobile terminal device that belongs to one cluster and relays transmitted information to mobile terminal devices that belong to another cluster.
Further, the “member” is a mobile terminal device that belongs to the cluster and does not correspond to the cluster head or the gateway.
Further, the “hello packet” is a packet including data related to a predetermined matter for one mobile terminal device to transmit the status of the own device to another mobile terminal device.

(1) A mobile terminal device adapted to form an ad hoc network together with one or more other devices having the same function as the own device, and each of the own device and each other device has an ID that can identify each device. Attached,
A state in which data indicating which state is currently selected among the three states that can be selectively taken by the own device, that is, a state that is a cluster head, a state that is a gateway, and a state that is a member is held Storage means;
ID of the own device, data representing the state of the own device, an ID of another device serving as the parent of the own device, an ID of another device adjacent to the own device, and the adjacent other device as a parent A hello packet including an ID of a mobile terminal device serving as a designated cluster head and a flag indicating whether or not the adjacent other device is designated as a gateway can be repeatedly transmitted, and is similar to the hello packet. When a packet is received from the outside, the ID of the other device that is the transmission source for the reception, the data indicating the state of the other device, the ID of the mobile terminal device that is the parent of the other device, and the other device a flag indicating whether it is designated as a gateway, the other device and the ID of the mobile terminal adjacent to the mobile terminal device in the form of cluster head said adjacent mobile terminal device designated as the parent A hello packet reception means for storing the ID, and the adjacent terminal list storage means for storing data relating to the adjacent terminal,
Based on the data stored in the neighboring terminal list storage means and based on the principle relating to the configuration of the ad hoc network, first, the mobile terminal device to be the cluster head is specified, and then the own device is specified as the gateway. and gateway the state of its own device when you are, when connected to the own device as a member state of the apparatus when it is no longer designated as the gateway, next contact the cluster head in the cluster is available in two hops, each mobile terminal A mobile terminal device is designated as a gateway among mobile terminal devices that are candidates for relay based on a predetermined first rule common to the devices, and connection to the cluster head of an adjacent cluster requires three hops. In such a case, two corresponding mobile terminal devices are acquired based on a predetermined second rule common to each mobile terminal device. Comprising clustering means for designating the gateways, and
Furthermore, in the case where a numerical value is assigned as the ID of each mobile terminal device,
When the status of its own device is the cluster head,
ID of own device,
The ID of the other device that is the state of the member that has designated the device as the parent,
The link information including the ID of the other device that is the node designated as the gateway by the own device is transmitted,
Two gateways connect to another device that is the cluster head of an adjacent cluster, and the ID of the own device is the largest among the cluster heads adjacent to the gateway with the larger ID of the two gateways. In some cases, the link information including the IDs of the two gateways is transmitted,
When link information similar to the link information is received from the other device, the state of the own device is a cluster head or gateway, and when link information similar to the received link information has not been transmitted in the past, A mobile terminal apparatus comprising link information transmitting / receiving means for relaying the received link information .

In the mobile terminal apparatus of (1) above, in one example, a plurality of movements having the same function as that of the own apparatus, such as numerical values (which can be integers), each of which is identifiable. An ad hoc network can be constructed by the terminal device.
The mobile terminal devices constituting this ad hoc network may be similar in their configuration, but it is not always necessary to be similar in configuration as long as the specifications related to a specific function are satisfied.

These mobile terminal devices selectively take one of the three states of being a cluster head, being a gateway, and being a member, and which state the device is in. Is stored in the state storage means, and its own state can be recognized, and other devices can also recognize the state based on the stored information.
The mobile terminal apparatus performs transmission / reception of hello packets formed by the hello packet transmission / reception means including the following information.

  That is, the hello packet transmission / reception means includes the ID of the own device, the data indicating the state of the own device as described above, the ID of the other device that is the parent of the own device, the ID of the other device adjacent to the own device, The adjacent other device repeatedly transmits a hello packet including an ID of a mobile terminal device which is a cluster head designated as a parent and a flag indicating whether or not the adjacent other device is designated as a gateway, and When a hello packet similar to the hello packet to be transmitted is received from the outside, the ID of the other device that is the transmission source for the reception, the data indicating the status of this other device, and the mobile terminal that is the parent of this other device ID of a device, ID of a mobile terminal device adjacent to the other device, ID of a mobile terminal device that is a cluster head designated by the adjacent mobile terminal device as a parent, and whether the mobile terminal device is adjacent Storing a flag indicating whether it is designated as a gateway, to the adjacent terminal list storage means for storing data relating to the adjacent terminal.

The mobile terminal apparatus further performs routing by specifying the gateway by the following procedure by the clustering means.
That is, the clustering means first designates the mobile terminal device to be the cluster head based on the data stored in the adjacent terminal list storage means and based on the principle relating to the configuration of the ad hoc network.

Next, when the own device is designated as a gateway, the state of the own device becomes a gateway, and when the own device is no longer designated as a gateway, the state of the own device becomes a member, and the connection to the cluster head of the adjacent cluster is 2 hops If possible, specify the corresponding mobile terminal device as a gateway among the mobile terminal devices that are candidates for relaying based on a predetermined first rule common to each mobile terminal device, and cluster of adjacent clusters When 3 hops are required for connection to the head, two corresponding mobile terminal devices are designated as gateways based on a predetermined second rule common to each mobile terminal device.
By making the above ID assignment and the first and second rules appropriate, the amount of link information in routing is reduced, and the number of transmissions and relays is also reduced, which is relatively small. It is possible to establish a route for transmitting data by the control packet.
Furthermore, since the link information transmitting / receiving means operates as described above, routing can be performed by transmitting only the link information constituting the cluster without transmitting all the links constituting the network as link information. The amount of control packets can be reduced.

(2) The principles related to the configuration of the ad hoc network are:
(1) All mobile terminal devices constituting the ad hoc network are cluster heads or are adjacent to the cluster head.
(2) Cluster heads are not adjacent to each other.
It satisfies the two requirements at the same time,
When a numerical value is assigned as the ID of each mobile terminal device,
The predetermined first rule is: stipulating that a gateway having the largest numerical value of ID among the corresponding mobile terminal devices is designated as a gateway;
The predetermined second convention is:
In the combination of the two mobile terminal devices that relay between the cluster heads of the adjacent clusters, when the total value of the numerical values of the two IDs is not the same:
A mobile terminal device closer to the mobile device of the combination of mobile terminal devices having the smallest total value is designated as a gateway;
If the sum is the same:
The combination including the mobile terminal device having the largest ID of the mobile terminal device having the smallest ID value among the two units is selected, and the movement closer to the own device among the two selected mobile terminal devices is selected. (1) The mobile terminal device according to (1), characterized in that the terminal device is specified as a gateway.

In the mobile terminal device of (2) above, in particular in the mobile terminal device of (1), the principle relating to the configuration of the ad hoc network, the first rule, and the second rule are specified as described above. Relying on routing is performed,
(1) All terminals are cluster heads or adjacent to cluster heads,
(2) The cluster heads are not adjacent to each other,
(3) The cluster heads of adjacent clusters are connected by one or two gateways.
The cluster structure can be configured by the mobile terminal device so as to satisfy the above three conditions, the amount of link information in routing is reduced, and the number of transmissions and relays is also reduced. It is possible to establish a data transmission path and ensure data reachability.

( 3 ) A control method for establishing routing related to a plurality of mobile terminal devices constituting an ad hoc network, wherein each of the plurality of mobile terminal devices is assigned an ID capable of identifying each one,
Indicates which of the three states that each of the plurality of mobile terminal devices can selectively take is a cluster head state, a gateway state, or a member state at the current time point. Have each one mobile terminal device hold data,
Each of the one mobile terminal devices includes an ID of the own device, data representing the state of the own device, an ID of another device serving as a parent of the own device, an ID of another device adjacent to the own device, Repeatedly transmitting a hello packet including an ID of a mobile terminal device that is a cluster head designated by the other device as a parent and a flag indicating whether the other device is designated as a gateway;
When a hello packet similar to the hello packet is received from the outside, the ID of the other device that is the transmission source for the reception, the data indicating the state of the other device, and the mobile terminal device that is the parent of the other device ID, the ID of the mobile terminal device adjacent to the other device, the ID of the mobile terminal device that is the cluster head specified by the adjacent mobile terminal device as a parent, and whether the mobile terminal device is specified as a gateway from the adjacent mobile terminal device And a flag indicating whether or not as data related to the neighboring terminal,
Based on the data stored as the data related to the adjacent terminal and based on the principle related to the configuration of the ad hoc network, first, the mobile terminal device to be the cluster head is specified, and then the own device is specified as the gateway. and gateway the state of its own device when you are, when connected to the own device as a member state of the apparatus when it is no longer designated as the gateway, next contact the cluster head in the cluster is available in two hops, each mobile terminal A mobile terminal device is designated as a gateway among mobile terminal devices that are candidates for relay based on a predetermined first rule common to the devices, and connection to the cluster head of an adjacent cluster requires three hops. In the case, the two corresponding mobile terminal devices based on a predetermined second rule common to each mobile terminal device Specified in the Towei,
Furthermore, in the case where a numerical value is assigned as the ID of each mobile terminal device,
When the status of its own device is the cluster head,
ID of own device,
The ID of the other device that is the state of the member that has designated the device as the parent,
The link information including the ID of the other device that is the node designated as the gateway by the own device is transmitted,
Two gateways connect to another device that is the cluster head of an adjacent cluster, and the ID of the own device is the largest among the cluster heads adjacent to the gateway with the larger ID of the two gateways. In some cases, the link information including the IDs of the two gateways is transmitted,
When link information similar to the link information is received from the other device, the state of the own device is a cluster head or gateway, and when link information similar to the received link information has not been transmitted in the past, A control method characterized by relaying the received link information .

In the control method of ( 3 ) above, each of the plurality of mobile terminal devices can identify each one of them by ID, and each mobile terminal device is a cluster head, which is three states that can be selectively taken It is possible to recognize from the data held in each one of the mobile terminal devices which state is being taken at the current point in time, the state being a gateway and the state being a member.

Each one mobile terminal device has its own device ID, data indicating its own device status, the ID of the other device that is the parent of its own device, the ID of the other device adjacent to its own device, and the other The apparatus repeatedly transmits a hello packet including the ID of the mobile terminal device that is the cluster head designated by the device and a flag indicating whether or not the adjacent other device is designated as a gateway,
When a hello packet similar to the above-described hello packet is received from the outside, the ID of the other device that is the transmission source for the reception, the data indicating the state of the other device, and the ID of the mobile terminal device that is the parent of the other device And the ID of the mobile terminal device adjacent to the other device, the ID of the mobile terminal device that is the cluster head specified by the adjacent mobile terminal device as a parent, and whether the mobile terminal device is specified as a gateway by the adjacent mobile terminal device Is stored as data related to neighboring terminals,
Based on the data stored as data related to the above-mentioned neighboring terminal and based on the principle concerning the configuration of the ad hoc network, first, the mobile terminal device to be the cluster head is specified, and then the own device is specified as the gateway. If the local device is not designated as a gateway, the local device state becomes a member, and if the connection to the cluster head of an adjacent cluster is possible in two hops, each move Based on a predetermined first rule common to the terminal devices, the corresponding mobile terminal device is designated as a gateway among the mobile terminal devices that are candidates for relay, and 3 hops are required for connection to the cluster head of the adjacent cluster. If necessary, two corresponding mobile terminal devices based on a predetermined second rule common to each mobile terminal device Specified in the gateway.
By making the above ID assignment and the first and second rules appropriate, the amount of link information in routing is reduced, and the number of transmissions and relays is also reduced, which is relatively small. It is possible to establish a route for transmitting data by the control packet.
Furthermore, by performing transmission and reception of link information as described above, it is possible to perform routing by transmitting only the link information constituting the cluster without transmitting all the links constituting the network as link information. The amount of control packets can be reduced.

( 4 ) The principles related to the configuration of the ad hoc network are:
(1) All mobile terminal devices constituting the ad hoc network are cluster heads or are adjacent to the cluster head.
(2) Cluster heads are not adjacent to each other.
It satisfies the two requirements at the same time,
When a numerical value is assigned as the ID of each mobile terminal device,
The predetermined first rule is: stipulating that a gateway having the largest numerical value of ID among the corresponding mobile terminal devices is designated as a gateway;
The predetermined second convention is:
In the combination of the two mobile terminal devices that relay between the cluster heads of the adjacent clusters, when the total value of the numerical values of the two IDs is not the same:
A mobile terminal device closer to the mobile device of the combination of mobile terminal devices having the smallest total value is designated as a gateway;
If the sum is the same:
The combination including the mobile terminal device having the largest ID of the mobile terminal device having the smallest ID value among the two units is selected, and the movement closer to the own device of the two selected mobile terminal devices is selected. The control method according to ( 3 ), characterized in that a terminal device is specified as a gateway.

In the control method ( 4 ) above, in particular, in the control method ( 3 ), the principle relating to the configuration of the ad hoc network, the first rule, and the second rule are specified as described above, and are based on this. Routing is performed,
(1) All terminals are cluster heads or adjacent to cluster heads,
(2) The cluster heads are not adjacent to each other,
(3) The cluster heads of adjacent clusters are connected by one or two gateways.
The cluster structure can be configured by the mobile terminal device so as to satisfy the above three conditions, the amount of link information in routing is reduced, and the number of transmissions and relays is also reduced. It is possible to establish a data transmission path and ensure data reachability.

( 5 ) A mobile communication system including a plurality of mobile terminal devices,
The mobile terminal device constitutes an ad hoc network together with one or more other devices having the same function as the own device, and each of the own device and each other device has an ID that can identify each of them,
A state in which data indicating which state is currently selected among the three states that can be selectively taken by the own device, that is, a state that is a cluster head, a state that is a gateway, and a state that is a member is held Storage means;
ID of the own device, data representing the state of the own device, an ID of another device serving as the parent of the own device, an ID of another device adjacent to the own device, and the adjacent other device as a parent A hello packet including an ID of a mobile terminal device serving as a designated cluster head and a flag indicating whether or not the adjacent other device is designated as a gateway can be repeatedly transmitted, and is similar to the hello packet. When a packet is received from the outside, the ID of the other device that is the transmission source of the hello packet, the data indicating the state of the other device, the ID of the mobile terminal device that is the parent of the other device, and the other device A flag indicating whether or not it is designated as a gateway, an ID of a mobile terminal device adjacent to the other device, and a mobile end serving as a cluster head designated by the adjacent mobile terminal device as a parent And ID of the device, the hello packet transmitting and receiving means for storing the adjacent terminal list storage means for storing data relating to the adjacent terminal,
Based on data stored in the adjacent terminal list storage means and based on the principle relating to the configuration of an ad hoc network, first, a mobile terminal device to be a cluster head is specified, and then the own device is specified as a gateway. Sometimes when the state of the own device is a gateway, when the own device is no longer designated as a gateway, the state of the own device is a member, and when connection to the cluster head of an adjacent cluster is possible in two hops, each mobile terminal device If the mobile terminal device is designated as a gateway among the mobile terminal devices that are candidates for relay based on the first common rule common to the two, and it takes 3 hops to connect to the cluster head of the adjacent cluster Gates two corresponding mobile terminal devices based on a predetermined second rule common to each mobile terminal device. And clustering means that you specify in E Lee,
It has
When a numerical value is assigned as the ID of each mobile terminal device,
The clustering means includes
When the state of the own device is a cluster head and there is a cluster head having an ID larger than that of the own device in the other device, the state of the own device is changed to a member, and an adjacent cluster head The mobile terminal device with the largest ID is specified as the parent,
If the state of the local device is a gateway or member, and there is no cluster head specified as the parent by the local device, the state of the local device is changed to a member, and the movement that takes the state of the cluster head The mobile terminal device with the largest ID among the terminal devices is designated as the parent,
Own device status of a gateway or member, and, if there is no cluster head in the adjacent mobile terminal device, moving body communication system that further comprising a function to shift the own device to the cluster head .

(6) The principles related to the configuration of the ad hoc network are:
(1) All mobile terminal devices constituting the ad hoc network are cluster heads or are adjacent to the cluster head.
(2) Cluster heads are not adjacent to each other.
It satisfies the two requirements at the same time,
When a numerical value is assigned as the ID of each mobile terminal device,
The predetermined first rule is: stipulating that a gateway having the largest numerical value of ID among the corresponding mobile terminal devices is designated as a gateway;
The predetermined second convention is:
In the combination of the two mobile terminal devices that relay between the cluster heads of the adjacent clusters, when the total value of the numerical values of the two IDs is not the same:
A mobile terminal device closer to the mobile device of the combination of mobile terminal devices having the smallest total value is designated as a gateway;
If the sum is the same:
The combination including the mobile terminal device having the largest ID of the mobile terminal device having the smallest ID value among the two units is selected, and the movement closer to the own device among the two selected mobile terminal devices is selected. Specifying a terminal device as a gateway
(5) The mobile communication system according to (5).
In the mobile communication system of (5) or (6) above, when the link information is transmitted to all mobile terminal devices in the network, only the cluster head and the gateway need to relay, and routing with a small number of relays is possible. It is. Therefore, it is possible to establish a data transmission path with relatively few control packets and to ensure data reachability.

(7) constituting the configured link information receiving means to receive the link information from the other device, and the topology information storing means for storing the link information received by said link information receiving means, the ad-hoc network A topology management device having routing means capable of creating a list of mobile terminal devices relaying between arbitrary mobile terminal devices and supplying the list to each mobile terminal device in the ad hoc network;
And link information transceiver section for transmitting the link information to the topology management device, corresponding the list to any one of the characterized in that it comprises a routing unit inquiring the topology management device (1) or (2) A mobile communication system comprising a plurality of mobile terminal devices.

  In the mobile communication system of the above (7), by collecting link information and routing processing by the topology management device, it is not necessary to transmit link information to all mobile terminal devices in the network, and the amount of control packets can be reduced. It can be kept small. Accordingly, it is possible to establish a data transmission path with relatively few control packets and to ensure data reachability.

  According to the present invention, the cluster head transmits link information, and the cluster head and the gateway relay link information, so that it is possible to collect topology information of only the cluster structure with a small number of relays. Compared to a device (system), the reachability of transmission data can be ensured with relatively few control packets.

Hereinafter, the present invention will be clarified by describing embodiments of the present invention in detail with reference to the drawings.
(Select gateway)
First, in an ad hoc network, when relaying between both the transmission source and destination cluster heads with one or two gateways, if there are multiple routes, exchange by an access point other than the terminal, etc. An outline of a general request and a solution method for properly establishing routing between any two terminals without adhering to the function (this type of access point is not included in an ad hoc network) will be described.

FIG. 26 is a diagram illustrating a situation in which one or two gateways are used to relay between both the transmission source and destination cluster heads of the transmitted information.
For example, as shown in FIG. 26A, in order to reach the cluster head CH2 from the cluster head CH1, the gateway GW1 (its ID is “1”) or the gateway GW2 (its ID is “2”) When there are two candidates for relaying either of the above, it is necessary to uniquely identify the gateway as a relay terminal in both cluster heads CH1 and CH2.

  In the case of FIG. 26 (a), all terminals that are members of the ad hoc network comply with a rule such as “specify the two gateways that are relay candidates that have the largest ID (for example, a number)”. Thus, as long as the gateway is selected based on this common rule, there is no possibility that the selection will be flawed in both cluster heads CH1 and CH2.

FIG. 26B shows a case where two gateways are used to reach the cluster head CH2 from the cluster head CH1. In this case, the path of cluster head CH1 → gateway GW1 (ID: 1) → gateway GW4 (ID: 4) → cluster head CH2 and cluster head CH1 → gateway GW2 (ID: 2) → gateway GW3 (ID: 3) → There are two routes of the cluster head CH2.
In this case, any one route is uniquely determined according to a rule that executes stepwise determination depending on the case as follows.
That is, first, “if the sum of the numerical values of the IDs of the two gateways is not the same: the mobile terminal device closer to the own device among the combinations of mobile terminal devices with the smallest total value is the gateway. Specify

  In addition, “If the total value is the same value: As a first step, a combination including the gateway having the largest ID of the two gateways with the smallest ID is selected, and then the second step. As a step, if a rule such as “designate a gateway closer to the own device among the two selected gateways” is shared by all terminals that are members of the ad hoc network, this common rule is used. As long as the gateway is selected based on the above, there is no possibility that the selection will be flawed in both cluster heads CH1 and CH2.

(First embodiment)
With reference to FIG. 1 thru | or FIG. 13, the structure of the mobile communication system which concerns on the 1st Embodiment of this invention is demonstrated.
FIG. 1 is a diagram showing a configuration of an ad hoc network as a mobile communication system according to the first embodiment of the present invention.
As shown in FIG. 1, mobile communication system 100 according to the present embodiment includes a plurality of mobile terminal apparatuses MT # 1 to MT # 9.
In the mobile communication system 100 illustrated in FIG. 1, each of the mobile terminal devices MT # 1 to MT # 9 that are constituent elements have the same configuration and the same function, but will be understood from the following detailed description. As described above, each of the mobile terminal devices MT # 1 to MT # 9 needs to satisfy similar specifications in specific functions as described later, but may have other functions after satisfying those specifications. It should not be excluded, and if it satisfies the above specifications (functional specifications), it is not necessarily essential that the configuration therefor be similar.

Each of these mobile terminal apparatuses MT # 1 to MT # 9 takes one of three states: (1) cluster head, (2) gateway, and (3) member.
In addition, a group called a cluster is formed around mobile terminal devices that take the cluster head state, and the cluster head of the cluster to which the own device belongs is designated as a parent.
The state of each mobile terminal device and the parent to be specified are not fixed, but dynamically change depending on the relative positional relationship with other terminals (mobile terminal devices).

(Status of mobile terminal device)
The state of each mobile terminal apparatus in the mobile communication system 100 is dynamically determined so as to comply with the principle that satisfies the following conditions.
(1) All terminals are cluster heads or are adjacent to the cluster head.
(2) Cluster heads are not adjacent to each other.
(3) Cluster heads of adjacent clusters are connected by one or two gateways.
However, the “adjacent cluster” in the above is defined as follows.
(A) a cluster to which an adjacent terminal of an adjacent terminal belonging to the cluster of the device belongs,
(B) Cluster to which an adjacent terminal of the own device belongs as seen from a certain cluster head In the example of FIG. 1, MT # 7 to which MT # 3 belonging to cluster A of cluster head MT # 1 is adjacent belongs to cluster C. Therefore, cluster A and cluster C are adjacent (adjacent cluster definition a).

Also, MT # 8 adjacent to cluster head MT # 6 belongs to cluster D. Therefore, cluster C and cluster D are adjacent (adjacent cluster definition b).
Similarly, cluster A and cluster B, and cluster A and cluster C are adjacent.
However, cluster B and cluster C do not meet the above definition and are not adjacent. MT # 3 as a gateway connecting cluster heads MT # 1 and MT # 4, MT # 3 and MT # 7 as gateways connecting cluster heads MT # 1 and MT # 6, and cluster heads MT # 6 and MT # MT # 8 is selected as a gateway for connecting 9.

In FIG. 1, the number of mobile terminal devices is nine, but the number of mobile terminal devices is not limited.
In the present embodiment, the cluster head is connected by two gateways to link information with a terminal adjacent to its own mobile terminal device (referred to as “own device”) and to the cluster head of the adjacent cluster. Link information between both gateways.
Further, when the cluster head and the gateway receive link information transmitted by another cluster head, the cluster head and the gateway transfer the received link information.

Through the above transmission or transfer, all terminals in this ad hoc network can recognize link information necessary for routing.
The “link information” in the above is composed of (1) the ID of the own device and (2) the IDs of one or more terminals adjacent to the own device, and has the IDs of (1) and (2). This indicates that a link exists between terminals.
For example, when the own device ID is MT # 7 and the adjacent terminal IDs are MT # 3 and MT # 6, between MT # 7 and MT # 3, and between MT # 7 and MT # 6 Shows that each link exists.

Next, the configuration of mobile terminal apparatuses MT # 1 to MT # 9 (hereinafter collectively referred to as “mobile terminal apparatus 200”) according to the present embodiment will be described.
(Configuration of mobile terminal device)
FIG. 2 is a functional block diagram showing a configuration of mobile terminal apparatus 200 according to the present embodiment.
The mobile terminal apparatus 200 includes a hello packet transmission / reception unit 201, a link information transmission / reception unit 202, a relay determination unit 203, a data transmission / reception unit 204, a clustering unit 205, a routing unit 206, an adjacent terminal list storage unit 207, a status A storage unit 208, a topology information storage unit 209, and a routing table storage unit 210 are provided. Hereinafter, each component will be described in order.
The adjacent terminal list storage unit 207 holds adjacent terminal tables 207A to 207B as shown in FIG.

(Example of adjacent terminal table)
FIG. 3 is an example of adjacent terminal tables 207A to 207B held in the adjacent terminal list storage unit 207 (FIG. 2) by the mobile terminal device MT # 1 which is a component of the ad hoc system of FIG.
In the adjacent terminal table 207A, the adjacent terminal ID, state (cluster head H; gateway GW; member M), gateway specification (GW), gateway specification (GW specification), ID of the mobile terminal device specified as the parent (Parent ID) and a pointer are included.
In FIG. 3, “adjacent terminal ID” is an ID of a terminal adjacent to the own apparatus. “State” indicates whether the adjacent terminal is a cluster head (H), a gateway (G), or a member (M).

“GW designation” indicates whether the own apparatus designates the adjacent terminal as a gateway (Y) or not (N).
“Specified GW” indicates whether the own device is designated as a gateway by the adjacent terminal (Y) or not (N).
“Parent ID” indicates the ID of the cluster head of the cluster to which the adjacent terminal belongs, that is, the ID of the terminal designated as the parent.
The “pointer” indicates a two-hop adjacency table related to the adjacent terminal.

In the example of FIG. 3, the “pointer” indicates the 2-hop adjacency table 207B related to the adjoining terminal MT # 3.
In the 2-hop adjacency table 207B, the adjoining terminal ID is an ID of a terminal adjacent to the adjoining terminal (hereinafter referred to as a 2-hop terminal), that is, a terminal located at a distance of 2 hops from the own apparatus.
“Parent ID” indicates the ID of the cluster head of the cluster to which the 2-hop terminal belongs, that is, the ID of the terminal designated as the parent.
The state storage unit 208 holds a state storage table 208A as shown in FIG. The state storage table 208A includes information on “state” and “parent ID” of the mobile terminal device 200.

(Example of state saving table)
FIG. 4 is an example of a state storage table related to MT # 1. Since MT # 1 is a cluster head, the “state” is H (cluster head), and the “parent ID” is MT # 1 designating its own device.
The routing table storage unit 210 holds a routing table 210A as shown in FIG. The routing table 210A includes an ID of a terminal other than the own apparatus and an ID (Next Hop) of an adjacent terminal that becomes a relay when a communication packet is transmitted to the terminal other than the own apparatus.

(Example of topology table)
The topology information storage unit 209 holds a topology table 209A as shown in FIG. One topology table 209A is held in each terminal in the network, and shows a list of IDs of the terminals and IDs of terminals adjacent to the terminals.
In the example of FIG. 6, for example, MT # 1 is adjacent to MT # 2 and MT # 3.
The topology information storage unit 209 is configured to create a routing table 210A with reference to the topology table 209A and store it in the routing table storage unit 210.
As a method of obtaining the routing table 210A from the topology table 209A, for example, a known method such as a Dijkstra method that is an algorithm for solving the shortest distance problem can be applied.

The hello packet transmitting / receiving unit 201 is configured to repeatedly (for example, periodically) transmit hello packets or receive hello packets from other terminals.
The hello packet transmission / reception unit 201 includes an ID (ID) of the own device, a state (state) of the own device, an ID (Head ID) of a terminal serving as a parent of the own device, an ID (Neighbor ID) of an adjacent terminal, A cluster head ID (Neighbor Head ID) designated by the adjacent terminal as a parent and a flag (GW Flag) indicating whether or not the adjacent terminal is designated as a gateway are put in a hello packet and periodically broadcast. To do.
“Broadcast” in the above description refers to a communication mode in which all terminals that can receive a transmission packet do not define a destination terminal.

(Example of Hello packet format)
Is shown in FIG. GW Flag indicates whether an adjacent terminal is designated as a gateway.
For example, when the GW Flag is “Y”, the set of the ID of the terminal designated as the gateway and the ID of the parent terminal of the terminal is described in the field below the GW Flag.
A plurality of sets of IDs of gateways and their parent terminals can be described, and Link Message Size indicates the number of sets.
Similarly, when GW Flag is “N”, the terminal not designated as the gateway and the ID of its parent are described.

The format of the hello packet is not limited to that illustrated in FIG. 7, but may be as shown in FIG. FIG. 8 is different from FIG. 7 in that it is described collectively for each terminal having a common GW Flag and a parent ID. By describing in this way, it is not necessary to describe the parent ID for each node, so the packet size can be reduced.
In addition, the hello packet transmitting / receiving unit 201 receives the same hello packet transmitted by another terminal as described above, and the “adjacent ID” of the other terminal, the “state” of the other terminal, and the adjacent terminal “Specified GW” indicating whether or not the gateway is specified and “parent ID” indicating the ID of the parent terminal of the other terminal are stored in the adjacent terminal table 207 A in the adjacent terminal list storage unit 207.

Furthermore, the “neighboring terminal ID” and the “parent ID” of the terminal adjacent to the other terminal are stored in the neighboring terminal table 207B in the neighboring terminal list saving unit 207. By doing in this way, each mobile terminal device 200 can recognize the network topology within 2 hops from its own device and the cluster to which the terminals within 2 hops belong.
The link information transmitting / receiving unit 202 is configured to repeatedly (for example, periodically) flood link information and receive link information transmitted from other terminals or transfer link information received from other terminals. .

The link information transmission / reception unit 202 refers to the state storage table 208A in the state storage unit 208, and when the state of its own device is the cluster head (H), the adjacent terminal table 207A in the adjacent terminal list storage unit 207, and The link information is created with reference to 207B. The link information includes the following link information.
(1) The link between the own device and the member that has specified the own device as the parent (2) The link between the own device and the node that the own device has specified as the gateway (3) To the cluster head of the adjacent cluster Link between relay gateways in case of 3 hops

In other words, the link information transmission / reception unit 202, when a numerical value is assigned as the ID of each mobile terminal device, and when the state of the own device is a cluster head,
Link information including the ID of the own device, the ID of the other device that is the state of the member that designates the own device as the parent, and the ID of the other device that is the node that the own device designates as the gateway is transmitted. ,
Two gateways connect to another device that is the cluster head of an adjacent cluster, and the ID of the own device is the largest among the cluster heads adjacent to the gateway with the larger ID of the two gateways. In some cases, the link information including the IDs of the two gateways is transmitted,
When link information similar to the link information described above is received from the other device, the status of the own device is a cluster head or gateway, and link information similar to the received link information has not been transmitted in the past The received link information is relayed.

(How to select a link)
FIG. 9 is a flowchart illustrating a method of selecting a link that the cluster head transmits as link information.
Each cluster head selects at least a link between the own device and a member that designates the own device as a parent (step S901).
Next, a link between the own device and a terminal that the own device designates as a gateway is selected as link information (step S902).
Furthermore, since the cluster head does not directly hold the link between gateways, it is necessary to determine which cluster head transmits as link information.

In the present embodiment, it is determined whether or not the cluster head adjacent to the gateway having the larger ID of the two corresponding gateways corresponds to the cluster head having the largest ID (step S903). When it corresponds (step S903: Yes), the link between applicable gateways is selected as link information (step S904).
Then, the link selected in step S901, step S902, and step S904 is transmitted as link information (step S905).

In the ad hoc network (mobile communication system) of FIG. 1, the cluster head MT # 1 of cluster A is selected between MT # 1 and MT # 2 (selected in step S901), between MT # 1 and MT # 3 (selected in step S902). ) Link information.
The cluster head MT # 4 of the cluster B transmits link information between MT # 4 and MT # 5 (selected in step S901) and between MT # 4 and MT # 3 (selected in step S902).

The cluster head MT # 6 of cluster C is MT # 6-MT # 7 (selected in step S902), MT # 6-MT # 8 (selected in step S902), and MT # 7- Link information between MT # 3 (selected in step S904) is transmitted (step S905).
As described above, all the links constituting the cluster are transmitted without duplication by the cluster head.

(Link information packet format)
FIG. 10 is a diagram illustrating a packet format of link information. Advertised Neighbor Main ID is the ID of an adjacent terminal, and Advertised 2hop Neighbor ID is the ID of a 2-hop terminal.
The packet is divided into a plurality of fields, and the length of each field is indicated by Link Message Size.
In the first field indicated by Link Message Size, a list of IDs of adjacent terminals that do not have an inter-gateway link to be transmitted is described.

In the ad hoc network (mobile communication system) of FIG. 1, the cluster head MT # 1 of cluster A describes the IDs of MT # 2 and MT # 3. As a result, the existence of a link between the cluster head and the members and gateways adjacent to the cluster head can be expressed.
In the second and subsequent fields indicated by Link Message Size, an adjacent terminal having an inter-gateway link to be transmitted is described as a Neighbor Main ID, and an ID of a 2-hop terminal is described as an Advertised 2hop Neighbor ID. As a result, it is possible to express the existence of a link between a terminal whose ID is Neighbor Main ID and a terminal whose ID is Advertised 2hop Neighbor ID, that is, a link between gateways.

Further, when link information transmission / reception unit 202 receives link information from another terminal, link information is stored in topology table 209 </ b> A in topology information storage unit 209.
Furthermore, the link information transmission / reception unit 202 inquires of the relay determination unit 203 whether to transfer the received link information. When there is a relay instruction from the relay determining unit 203, the link information transmitting / receiving unit 202 transfers the received link information.

When there is an inquiry about whether to transfer link information from the link information transmission / reception unit 202, the relay determination unit 203 refers to the state storage table 208A held in the state storage unit 208, and the own device is the cluster head or gateway. When it is in the state, it is configured to issue a transfer instruction to the link information transmitting / receiving unit 202.
However, even when the own apparatus is in a cluster head or gateway state, a transfer instruction is not issued if the link information is the same as the link information transmitted in the past.

The data transmitting / receiving unit 204 is configured to transmit, receive, or transfer communication packets such as data communication and voice call performed between terminals by unicast.
The “unicast” in the above is a communication mode in which a communication partner terminal is designated and a packet is delivered only to the designated communication partner terminal.
When transmitting a communication packet, the data transmitting / receiving unit 204 inquires of the routing unit 206 about the ID of an adjacent terminal serving as a relay terminal for delivering the communication packet to the destination terminal, and transmits the communication packet to the terminal having the corresponding ID.

In addition, when the data transmission / reception unit 204 receives a communication packet from another terminal, the data transmission / reception unit 204 inquires of the routing unit 206 about the ID of an adjacent terminal to which the received communication packet is transferred. When an ID is answered from the routing unit 206 in response to this inquiry, the communication packet is transferred to the terminal having the corresponding ID.
The clustering unit 205 refers to the adjacent terminal tables 207A and 207B held in the adjacent terminal list storage unit 207, determines the state and parent of the own device, and stores it in the state storage table 208A in the state storage unit 208.

Further, the clustering unit 205 is configured to determine an adjacent terminal to be designated as a gateway and store it in the adjacent terminal table 207A.
Basically, the cluster head is determined first, and then the gateway is determined.
FIG. 11 is a diagram illustrating a state transition of the terminal. Transitions from the cluster head, gateway, and member states to other states. As shown, there is no transition from the cluster head to the gateway.

FIG. 12 is a flowchart illustrating a process related to cluster head determination.
If the current state of the own device is a cluster head, if there is a cluster head having an ID larger than that of the own device in an adjacent terminal (S1201: Yes), the state of the own device is changed to a member, In addition, the terminal having the largest ID among the adjacent cluster heads is set as a parent (S1202, state transition diagram (1)).
When the state of the own device is a gateway or a member, when there is no cluster head among the adjacent terminals (S1203: Yes), the state of the own device is set as the cluster head (S1204, state transition diagram (2), (3)).

On the other hand, when the cluster head exists in the adjacent terminal (S1203: No), if the cluster head currently designated as the parent does not exist (S1205: Yes), the state of the own apparatus is a member, and The terminal having the largest ID among the existing cluster heads is designated as the parent (S1206, state transition diagrams (4) and (7)). By determining the cluster head in this way,
(1) All terminals are cluster heads or are adjacent to the cluster head.
(2) Cluster heads are not adjacent to each other.
A structure that satisfies the two requirements of the principle of this system can be created.

FIG. 13 is a flowchart illustrating a process related to gateway determination after cluster head determination.
If the state of the own device is a cluster head, to determine whether to which the adjacent terminal and the gateway.
First, the cluster head refers to the adjacent terminal list storage unit 207 and extracts the cluster head ID of the adjacent cluster (S1301).

Then, a gateway for connecting to the cluster head of each adjacent cluster is determined.
When connection to the cluster head of the adjacent cluster is possible with two hops (S1302: Yes), the terminal having the largest ID among the relay candidate terminals is designated as the gateway (S1303).
On the other hand, when the connection to the cluster head of the adjacent cluster can be made only with three hops (S1302: No), two terminals are selected as gateways.

In this selection method, the combination having the maximum ID total value is selected from the combinations of the two relay terminals up to the cluster head of the corresponding cluster. If the values are the same, the combination having the largest ID of the terminal with the smaller ID is selected (S1304).
Of the two selected terminals, a terminal adjacent to itself is selected as a gateway. The terminal that is not adjacent to its own device is selected as the gateway by the cluster head of the corresponding cluster. The selected gateway notifies an adjacent terminal by a hello packet (GW Flag).

The gateway selected as described above notifies an adjacent terminal by a hello packet (GW Flag).
A terminal currently in a gateway or member state can recognize whether or not its own device is designated as a gateway by receiving this hello packet.
When the member receives the hello packet and is designated as a gateway (S1305: Yes), the state of the own apparatus is set as the gateway (S1306, state transition diagram (5)).

On the other hand, when the terminal in the current gateway state is no longer designated as a gateway from any cluster head (S1307: No), the state of the own device is changed to a member (S1308, state transition diagram (6)).
By the above gateway determination process,
The third requirement of the principle in this system is:
(3) A structure in which the cluster heads of adjacent clusters are connected by one or two gateways can be satisfied. For example, a cluster structure as shown in FIG. 1 is completed.

In the present embodiment, the operation of the clustering unit 205 is an example for configuring a cluster, and the cluster may be configured by other operations.
The routing unit 206 is configured to notify the data transmission / reception unit 204 of the ID of an adjacent terminal that relays a communication packet by receiving a request from the data transmission / reception unit 204 and referring to the routing table 210A in the routing table storage unit 210. The The routing unit 206 notifies the data transmitter / receiver 204 of the NextHop ID of the destination terminal of the communication packet.

FIG. 14 is a diagram illustrating a hardware configuration example of mobile terminal apparatus 200 according to the present embodiment.
The mobile terminal device 200 includes a CPU 1401, a memory 1402, and a network interface 1403.
2 is realized by the CPU 1401 and the network interface 1403.
The link information transmission / reception unit 202 is realized by the CPU 1401 and the network interface 1403.
The relay determination unit 203 is realized by the CPU 1401.
The data transmission / reception unit 204 is realized by the CPU 1401 and the network interface 1403.

The clustering unit 205 is realized by the CPU 1401.
The routing unit 206 is realized by the CPU 1401.
The adjacent terminal list storage unit 207 is realized by the memory 1402.
The state storage unit 208 is realized by the memory 1402.
The topology information storage unit 209 is realized by the CPU 1401 and the memory 1402.
The routing table storage unit 210 is realized by the memory 1402.

Next, the operation of the mobile terminal apparatus according to the present embodiment will be described using FIG. 15 to FIG.
In the following, as the operation of the mobile terminal device,
(1) Operation during cluster configuration (2) Operation during link information transmission (3) Operation during communication packet transmission

First, (1) the operation of the mobile terminal apparatus in a cluster configuration will be described with reference to FIG.
FIG. 15 is a diagram illustrating an operation of the mobile terminal apparatus according to the present embodiment which is each terminal when participating in the mobile communication system 100 of FIG.
FIG. 15 corresponds to the topology of FIG. 1 and shows the operation of each terminal when participating in the mobile communication system 100 in the numerical order from MT # 1 to MT # 9.
In FIG. 15, for convenience of explanation, it is assumed that the initial state of the terminal is a member, but any state is possible.

When the mobile terminal device 200 participates in the mobile communication system 100, the mobile terminal device 200 periodically transmits a hello packet. In addition, a hello packet from another terminal is received, and the adjacent terminal tables 207A and 207B described above are updated with reference to FIG.
First, when MT # 1 joins the mobile communication system 100, since there is no adjacent terminal, its own state is set to the cluster head (S1501, state transition diagram (2)).
Next, MT # 2 will participate. MT # 2 recognizes that it is adjacent to cluster head MT # 1 by the hello packet, and designates MT # 1 as a parent while maintaining its own state as a member.
Similarly, when MT # 3 participates, MT # 3 designates MT # 1 as a parent while its own state remains a member.

Next, when MT # 4 participates, since the adjacent terminal is only MT # 3 and there is no cluster head, its own state is set to the cluster head (S1502). Then, MT # 3 is designated as a gateway for connecting to the cluster head MT # 1 of the adjacent cluster A.
Contrary to the above, MT # 1 designates MT # 3 as a gateway for connecting to MT # 4.
MT # 3 recognizes that it is designated as the gateway by MT # 1 and MT # 4 by the hello packet, and sets its own state as the gateway (S1503, state transition diagram (5)).

When MT # 5 participates, MT # 4 is designated as the parent.
When MT # 6 participates, there is no adjacent terminal in the vicinity, so that its own state is set as the cluster head (S1504, state transition diagram (2)).
Next, when MT # 7 participates, MT # 6 is connected to MT # 1 via MT # 7 and MT # 3, and designates MT # 7 as a gateway to MT # 1.
MT # 7 recognizes that it is designated as the gateway by MT # 6 by the hello packet, and sets its own state as the gateway (S1505, state transition diagram (5)).
Next, MT # 8 participates and designates MT # 6 as a parent.

When MT # 9 participates, since there is no cluster head in the adjacent terminal, its own state is set to the cluster head (S1506, state transition diagram (2)).
Furthermore, MT # 9 designates MT # 8 as a gateway for connecting to MT # 6.
Similarly, MT # 6 designates MT # 8 as a gateway to MT # 9.
MT # 8 recognizes that MT # 6 and MT # 9 are designated as gateways by the hello packet, and sets its own state as the gateway (S1507, state transition diagram (5)).
As described above, the cluster head and gateway are determined, and the cluster is configured.

Next, (2) operation at the time of link information transmission (link information transmission method) will be described.
Note that the transmission of link information uses the above-described cluster configuration.
Specifically, the cluster head has a link between the own device and the member that has specified the own device as a parent, a link between the own device and a terminal that has been specified as a gateway by the own device, and a cluster of adjacent clusters A link between gateways in the case of 3 hops to the head is transmitted as link information, and the cluster head and the gateway transfer the link information as described above.

  The terminal that has received this link information stores it in the topology information storage unit 209. By establishing a state in which each terminal holds the link information as described above in the topology information storage unit 209, all the terminals grasp the network topology, create a routing table using a known Dijkstra method, By storing in the routing table storage unit 210, route calculation becomes possible.

FIG. 16 is a diagram illustrating an operation of the mobile terminal apparatus when link information is transmitted.
FIG. 17 is a diagram illustrating a link information packet formed and transmitted by the operation of FIG.
The operation of mobile terminal apparatus 200 at the time of transmitting link information will be described below with reference to FIG. 17 as appropriate using FIG. FIG. 16 corresponds to the topology of FIG.
The cluster heads MT # 1, MT # 4, MT # 6, and MT # 9 periodically generate and transmit link information. The link information is generated according to the process described above with reference to FIG.
MT # 1 includes a link between MT # 1 and MT # 2 in S901, and a link between MT # 1 and MT # 3 in S902. FIG. 17a shows the link information packet at this time.

FIG. 17a shows that the ID is MT # 1 and the link information transmission terminal is MT # 1.
The Link Message Size indicates that a link between two adjacent terminals is transmitted, and the Advertised Neighbor Main ID indicates that a link exists between MT # 1 and MT # 2 and between MT # 1 and MT # 3. It is represented.
When MT # 1 generates link information, MT # 1 transmits the link information (S1601).
This link information is received by MT # 2 and MT # 3, which are neighboring terminals of MT # 1.
Among these, MT # 3 is a gateway, so it relays the received adjacent terminal and retransmits it (S1602).

The link information relayed by MT # 3 is received by MT # 1, MT # 4, and MT # 7 adjacent to MT # 3. Since MT # 4 and MT # 7 are respectively a cluster head and a gateway, the received link information is relayed (S1603, S1604).
On the other hand, although MT # 1 is a cluster head, relaying is not performed because the same link information has already been transmitted.

Similarly, MT # 6 relays the link information relayed by MT # 7 (S1605), and MT # 8 and MT # 9 relay sequentially (S1606, S1607), thereby generating MT # 1. The link information is transmitted to all terminals in the network.
Similarly, the cluster head MT # 4 generates and transmits the link information of FIG. 17b (S1608), is relayed by the cluster head and the gateway, and is transmitted to the entire network.

  The cluster head MT # 6 generates and transmits the link information of FIG. 17c (S1609). At this time, since the distance between the cluster head MT # 1 of the cluster A adjacent to MT # 6 is 3 hops (there are two gateways between them), MT # 1 or MT # 6 is the gateway MT # 3-MT # 7. However, since the MT # 6 gateway MT # 7 has a larger ID than the MT # 1 gateway MT # 3 (S903), MT # 6 is MT # 6. Link information between 3-MT # 7 is transmitted.

  Similarly, the cluster head MT # 9 generates and transmits the link information of FIG. 17d (S1610). As described above, all the terminals in the network grasp the link information held by the cluster head. Each terminal can recognize the topology of the network from the received link information, and can calculate a route to an arbitrary terminal.

Next, (3) operation at the time of transmission of a communication packet (packet for data communication, voice call, etc.) will be described.
Basically, a communication packet is transmitted according to the routing table 210A obtained by the above operation (2) at the time of link information transmission.
First, the operation of the mobile terminal apparatus when transmitting a communication packet will be described.
When transmitting a communication packet, the mobile terminal device 200 refers to the routing table 210A and confirms the ID of an adjacent terminal to be relayed to send the communication packet to the destination terminal.

Next, the mobile terminal apparatus 200 transmits a communication packet to the adjacent terminal (adjacent terminal to be relayed) obtained by the confirmation.
FIG. 18 is a diagram illustrating the operation of the mobile terminal apparatus when transmitting a communication packet.
Next, the operation of mobile terminal apparatus 200 when transmitting a communication packet from MT # 1 to MT # 9 will be described using FIG.
MT # 1 refers to the routing table, recognizes that Next # when transmitting a communication packet to MT # 9 is MT # 3, and transmits the communication packet to MT # 3.

When MT # 3 receives the communication packet, MT # 3 refers to the routing table, recognizes that Nexthop when transmitting the communication packet to MT # 9 is MT # 7, and transmits the communication packet to MT # 7.
Similarly, MT # 7, MT # 6, and MT # 8 are relayed and finally arrive at MT # 9. Thus, a communication packet is transmitted from MT # 1 to MT # 9. That is, reachability of transmission data is ensured.

The effect of the first embodiment will be described.
According to the mobile terminal apparatus according to the first embodiment, the connectivity of all terminals can be ensured by transmitting only the links constituting the cluster as link information.
Further, since only the cluster head and the gateway relay link information, transmission to all terminals in the network is guaranteed, and the number of transmissions for transmitting one link information to the entire network can be reduced. From these two effects, it is possible to reduce the amount of packets required for routing.

(Second Embodiment)
The configuration of the mobile communication system according to the second embodiment of the present invention will be described with reference to FIG. 19 to FIG.
FIG. 19 is a diagram illustrating a configuration of an ad hoc network serving as a mobile communication system according to the second embodiment of the present invention.
As shown in FIG. 19, a mobile communication system 1900 according to the present embodiment includes a plurality of mobile terminal apparatuses MT # 1 to MT # 9 and a topology management apparatus (installed on an infrastructure network 1901 such as a cellular network). 1902 (denoted as TS in the figure).

In this embodiment, the topology management apparatus 1902 is configured to cover part of the functions of the mobile terminal apparatus in the first embodiment.
The mobile terminal devices MT # 1 to MT # 9 all have the same configuration and the same function, but are in any one of the three states of cluster head, gateway, and member.
Further, a group called a cluster is formed around the cluster head, and the cluster head of the cluster to which the own device belongs is designated as the parent.

The state of each mobile terminal device and the designated parent are not fixed, but dynamically change depending on the relative positional relationship with other terminals. The state of each mobile terminal apparatus in the mobile communication system 1900 is dynamically determined so as to satisfy the following conditions.
(1) All terminals are cluster heads or are adjacent to the cluster head.
(2) Cluster heads are not adjacent to each other.
(3) Cluster heads of adjacent clusters are connected by one or two gateways.

However, the “adjacent cluster” in the above is defined as follows.
(A) a cluster to which an adjacent terminal of an adjacent terminal belonging to the cluster of the device belongs,
(B) Cluster to which an adjacent terminal of its own device belongs as seen from a certain cluster head In the example of FIG. Therefore, cluster A and cluster C are adjacent (adjacent cluster definition a).
Also, MT # 8 adjacent to cluster head MT # 6 belongs to cluster D. Therefore, cluster C and cluster D are adjacent (adjacent cluster definition b).

Similarly, cluster A and cluster B, and cluster A and cluster C are adjacent.
However, cluster B and cluster C do not meet the above definition and are not adjacent. MT # 3 as a gateway connecting cluster heads MT # 1 and MT # 4, MT # 3 and MT # 7 as gateways connecting cluster heads MT # 1 and MT # 6, and cluster heads MT # 6 and MT #. MT # 8 is selected as a gateway for connecting 9.

In FIG. 19, the number of mobile terminal devices is 9, but the number of mobile terminal devices is not limited.
In the present embodiment, the cluster head transmits to the topology management device 1902 link information between terminals adjacent to the cluster head. As a result, the topology management device 1902 can obtain link information necessary for routing, and can calculate a route between arbitrary terminals.
The “link information” in the above is composed of (1) the ID of the own device and (2) the IDs of one or more terminals adjacent to the own device, and has the IDs of (1) and (2). The point indicating that a link exists between terminals is the same as that described in the first embodiment.

Next, the configuration of mobile terminal apparatuses MT # 1 to MT # 9 (collectively referred to as “mobile terminal apparatus 2000” in the second embodiment) according to the present embodiment will be described.
FIG. 20 is a functional block diagram showing a configuration of mobile terminal apparatus 2000 according to the present embodiment.
The mobile terminal apparatus 2000 includes a hello packet transmission / reception unit 2001, a link information transmission / reception unit 2002, a data transmission / reception unit 2003, a clustering unit 2004, a routing unit 2005, an adjacent terminal list storage unit 2006, and a state storage unit 2007. is doing. Hereinafter, each component will be described in order.

The hello packet transmission / reception unit 2001, the clustering unit 2004, the adjacent terminal list storage unit 2006, and the state storage unit 2007 are the same as those in the first embodiment.
That is, the hello packet transmission / reception unit 2001 is configured to repeatedly (eg, periodically) transmit hello packets or receive hello packets from other terminals.
The hello packet includes the ID (ID) of the own device, the state of the own device, the ID of the terminal that is the parent of the own device (Head ID), the ID of the neighboring terminal (Neighbor ID), and the neighboring terminal The cluster head ID (Neighbor Head ID) designated as a parent and a flag (GW Flag) indicating whether or not the neighboring terminal is designated as a gateway are illustrated in FIG. 7 or FIG. It is formed so as to conform to a predetermined format, and is broadcasted periodically.

The clustering unit 2004 refers to the adjacent terminal tables 207A and 207B similar to those described above with reference to FIG. 3 held in the adjacent terminal list storage unit 2006, determines the state and parent of the own device, and the state storage unit The data is stored in the state storage table 208A in 2007.
Further, the clustering unit 2004 is configured to determine an adjacent terminal to be designated as a gateway and store it in the above-described adjacent terminal table 207A.
Basically, the cluster head is determined first, and then the gateway is determined as in the first embodiment.
On the other hand, the link information transmitting / receiving unit 2002 is configured to transmit link information to the topology management apparatus 1902.

The link information transmission / reception unit 2002 refers to the state storage unit 2007, and creates link information with reference to the adjacent terminal list storage unit 2006 when its own state is the cluster head. As described above, the information included in the link information is the same as that in the first embodiment.
The data transmission / reception unit 2003 is configured to transmit, receive, or forward a packet (communication packet) transmitted by data communication or voice call between terminals by unicast.
When transmitting / receiving a communication packet, the data transmitting / receiving unit 2003 inquires the routing unit 2005 about the list of IDs of adjacent terminals serving as relay terminals for delivering the communication packet to the destination terminal, and the first in the ID list of the adjacent terminal A communication packet and a list of the ID are transmitted to the terminal having the ID.

FIG. 21 is a diagram illustrating a list of IDs acquired and transmitted by the data transmitting / receiving unit 2003 in FIG.
The ID list is configured as shown in FIG. 21, for example, and shows terminals that relay communication packets from the transmission terminal to the destination terminal in the relay order.
When the data transmission / reception unit 2003 receives a communication packet from another terminal and the destination is not its own device, the data transmission / reception unit 2003 refers to the received ID list and sends the communication packet to the terminal having the ID described next to its own ID. And transfer the list of IDs.
At this time, if the ID of the device is described at the end of the list, the communication packet is transmitted to the destination terminal.

For example, if the ID list of FIG. 21 is received and the ID of the own device is MT # 7, the ID is transferred to the terminal having the ID (MT # 6) described next to MT # 7.
The routing unit 2005 is configured to notify the data transmission / reception unit 2003 of a list of IDs of relay terminals that relay communication packets by receiving a request from the data transmission / reception unit 2003 and inquiring the topology management apparatus 1902.

Next, the hardware configuration of the mobile terminal device 2000 of the second embodiment will be described with reference to FIG. 14 referred to regarding the hardware configuration of the first embodiment.
The mobile terminal device 2000 includes a CPU 1401, a memory 1402, and a network interface 1403.
20 is realized by the CPU 1401 and the network interface 1403.
Link information transmission / reception unit 2002 is realized by CPU 1401 and network interface 1403.

The data transmission / reception unit 2003 is realized by the CPU 1401 and the network interface 1403.
The clustering unit 2004 is realized by the CPU 1401.
The routing unit 2005 is realized by the CPU 1401 and the network interface 1403.
The adjacent terminal list storage unit 2006 is realized by the memory 1402.
The state storage unit 2007 is realized by the memory 1402.
FIG. 22 is a functional block diagram showing the configuration of the topology management apparatus 1902 in the mobile communication system.

Next, the configuration of the topology management apparatus 1902 according to the second embodiment will be described with reference to FIG.
The topology management device 1902 includes a link information receiving unit 2201, a routing unit 2202, and a topology information storage unit 2203.
The link information receiving unit 2201 is configured to receive link information from the mobile terminal device 2000 and store it in the topology information storage unit 2203.

The topology information storage unit 2203 holds the topology table 209A as described above with reference to FIG. The topology table 209A includes the ID of the cluster head that transmitted the link information and the ID of the terminal adjacent to the cluster head.
The routing unit 2202 is configured to receive a request from the mobile terminal device 2000, refer to the topology information storage unit 2203, calculate a list of relay terminal IDs, and transmit the list to the mobile terminal device 2000. The calculation of the list of IDs is executed using, for example, the Dijkstra method, as in the first embodiment.

FIG. 23 is a diagram illustrating a hardware configuration of the topology management apparatus 1902.
The topology management device 1902 includes a CPU 2301, a memory 2302, and a network interface 2303.
The link information receiving unit 2201 in FIG. 22 is realized by the CPU 2301 and the network interface 2303.
The routing unit 2202 is realized by the CPU 2301 and the network interface 2303, and the topology information storage unit 2203 is realized by the memory 2302.
24 and 25 are diagrams illustrating the operation of the mobile communication system of FIG.

Hereinafter, operations of mobile terminal apparatus 2000 and topology management apparatus 1902 in the present embodiment will be described with reference to FIGS.
Of the (1) operation at the time of cluster configuration, (2) the operation at the time of link information transmission, and (3) the operation at the time of communication packet transmission, (1) the operation of the mobile terminal apparatus at the time of cluster configuration is the first Since it is the same as that of embodiment, description is abbreviate | omitted.
Further, (2) the operation of the mobile terminal device 2000 at the time of link information transmission is that the link information is transmitted to the topology management device 1902 instead of flooding the link information and the link information is not transferred. This is different from the embodiment.

First, (2) operation | movement of the mobile communication system 1900 whole at the time of link information transmission is demonstrated using FIG. The link information to be transmitted is the same as that in the first embodiment. The cluster head periodically transmits link information to the topology management device 1902. The topology management device 1902 that has received the link information stores the received information in the topology information storage unit 2203.
In this way, the topology management device 1902 grasps the link information that the cluster head has. The topology management apparatus 1902 can recognize the topology of the network from the received link information, and can calculate a route between arbitrary terminals.

Next, (3) the overall operation of the mobile communication system 11 during transmission of communication packets (packets such as data communication and voice call) will be described with reference to FIG.
FIG. 25 shows a sequence for transmitting a communication packet from MT # 1 to MT # 9.
The data transmission / reception unit 2003 of MT # 1 that transmits the communication packet inquires the routing unit 2005 for a list of relay terminal IDs for delivering the communication packet to the destination terminal. The ID list is inquired (S2501).

Upon receiving the inquiry, the routing unit 2202 of the topology management apparatus 1902 creates a list of relay terminal IDs with reference to the topology information storage unit 2203, and returns the list of relay terminal IDs to the MT # 1 routing unit 2005. (S2502).
Through step S2502, the routing unit 2005 of MT # 1 obtains a list of IDs of the relay terminals.
Next, the routing unit 2005 of MT # 1 notifies the data transmitting / receiving unit 2003 of the list of relay terminal IDs. The data transmitting / receiving unit 2003 that has received the notification transmits a communication packet and an ID list to MT # 3 that is first described in the ID list of the relay terminal (S2503).

The data transmission / reception unit 2003 of MT # 3 that has received the communication packet and the list of IDs in step S2503 refers to the list of IDs and communicates with MT # 7 described next to its own device in the list of IDs. The list of packets and IDs is transferred (S2504).
Next, the data transmission / reception unit 2003 of MT # 7 that has received the communication packet and the list of IDs refers to the list of IDs and communicates with MT # 6 described next to its own device in the list of IDs. The list of packets and IDs is transferred (S2505).

Similarly, the data transmission / reception unit 2003 of MT # 6 that has received the communication packet and the list of IDs refers to the list of IDs and communicates with MT # 8 described next to its own device in the list of IDs. The list of packets and IDs is transferred (S2506).
Further, the MT # 8 data transmitting / receiving unit 2003 that has received the communication packet and the list of IDs refers to the list of IDs and determines that its own ID (MT # 8) is the last in the list.
That is, since the destination terminal (MT # 9) is adjacent to its own device, the data transmitting / receiving unit 2003 of MT # 8 transfers a list of communication packets and IDs to the destination terminal (MT # 9). (S2507). In this way, the list of communication packets and IDs is delivered to the destination terminal MT # 9. That is, reachability of transmission data is ensured.

The effects of the second embodiment will be described.
According to the mobile terminal device 2000 and the topology management device 1902 according to the second embodiment, only the cluster head transmits link information between adjacent terminals to the topology management device 1902, and the topology management device 1902 It is possible to calculate the route between terminals. With the above effects, routing with less overhead can be realized.

FIG. 27 is a diagram for briefly explaining the effects of the present invention.
FIG. 27A is a conceptual diagram showing a state of routing according to the conventional technique.
FIG. 27B is a conceptual diagram showing a state of routing performed by applying the present invention.
FIG. 27 (c) is a diagram showing a comparison of specifications with a high correlation with the required control packet amount in FIGS. 27 (a) and 27 (b).
The conventional technique shown in FIG. 27A is based on the above-described OLSR, and attempts to improve efficiency related to flooding of a TC (Topology Control) message by determining the MPR.

The MPR transmits link information with the MPR Selector as a TC message.
In the case where both are MPRs, TC messages having duplicate information are transmitted.
In FIG. 27A, link information is indicated by an arrow, and duplicate messages are exchanged on a link where the arrow exists in both directions.
On the other hand, according to the technique of the present invention shown in the conceptual diagram of FIG. 27B, as described above, flooding can be performed with a small number of relays, and only necessary link information is transmitted without duplication. Network connectivity is ensured.

Specifically, as shown in FIG. 27 (c) by comparing the required control packet amount and specifications having a high correlation, the conventional technique represented by OSLR and the technique of the present invention have a link to be transmitted. The amount of information is 13 to 9, the number of transmission / relay times is 3 to 4, and the amount of transmission of link information is 39 to 36.
Note that the comparative diagram of FIG. 27C is simply expressed for the convenience of conceptual comparison, but has a more remarkable effect when constructing an actual ad hoc network.

  INDUSTRIAL APPLICABILITY The present invention can be used for the construction of an ad hoc network in which a plurality of mobile terminal devices directly transmit and receive communication packets without intervening facilities that serve as a base (infrastructure) of a mobile communication network such as an access point. .

It is a figure showing the structure of the ad hoc network as a mobile communication system which concerns on the 1st Embodiment of this invention. It is a functional block diagram showing the structure of the mobile terminal device which concerns on this Embodiment. It is a figure showing the example of the adjacent terminal table which the mobile terminal device which is a component of the ad hoc system of FIG. 1 has in the adjacent terminal list preservation | save part. It is a figure showing the example of the state preservation | save table hold | maintained at the state preservation | save part in FIG. It is a figure showing the example of the routing table hold | maintained at the routing table storage part in FIG. It is a figure showing the example of the topology table hold | maintained at the topology information storage part in FIG. It is a figure showing an example of the format of the hello packet transmitted / received through the hello packet transmission / reception part in FIG. It is a figure showing the other example of the format of the hello packet transmitted / received through the hello packet transmission / reception part in FIG. It is a flowchart which illustrates the selection method of the link which a cluster head transmits as link information. It is a figure which shows the packet format of link information. It is a figure showing the state transition of a terminal. It is a flowchart which illustrates the process regarding cluster head determination. It is a flowchart which illustrates the process regarding the gateway determination after cluster head determination. It is a figure showing the structural example of the hardware of the mobile terminal device which concerns on this Embodiment. It is a figure showing operation | movement of the mobile terminal device which concerns on this Embodiment which is each terminal when participating in the mobile communication system of FIG. It is a figure showing operation | movement of the mobile terminal device at the time of link information transmission. It is a figure showing the link information packet formed and transmitted by the operation | movement of FIG. It is a figure showing operation | movement of the mobile terminal device at the time of communication packet transmission. It is a figure showing the structure of the ad hoc network as a mobile communication system which concerns on the 2nd Embodiment of this invention. It is a functional block diagram showing the structure of the mobile terminal apparatus which concerns on the 2nd Embodiment of this invention. It is a figure which illustrates the list | wrist of ID which the data transmission / reception part in FIG. 20 acquires and transmits. FIG. 20 is a functional block diagram illustrating a configuration of a topology management device in the mobile communication system of FIG. 19. FIG. 20 is a diagram illustrating a hardware configuration of a topology management apparatus 1902 in the mobile communication system of FIG. FIG. 20 is a diagram illustrating an overall operation of the mobile communication system in FIG. 19. FIG. 20 is a diagram illustrating an operation at the time of communication packet transmission of the mobile communication system of FIG. 19. It is a figure showing the situation which relays between the cluster head of the transmission origin of a to-be-transmitted information, and a destination by 1 unit | set or 2 units | sets of gateways. It is a figure for demonstrating the effect of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100, 1900 ... Mobile communication system 200, 2000 ... Mobile terminal apparatus 201, 2001 ... Hello packet transmission / reception part 202, 2002 ... Link information transmission / reception part 203 ... Relay judgment part 204, 2003 ... Data transmission / reception part 205, 2004 ... Clustering part 206, 2005 ... Routing unit 207, 2006 ... Neighboring terminal list storage unit 207A, 207B ... Neighboring terminal table 208, 2007 ... Status storage unit 209 ... Topology information storage unit 210 ... Routing table storage unit 1401, 2301 ... CPU 1402, 2302 ... Memory 1403 , 2303 ... network interface 1901 ... infrastructure network 1902 ... topology management device

Claims (7)

It is a mobile terminal device that forms an ad hoc network together with one or more other devices having the same function as the own device, and each of the own device and each other device has an ID that can identify each of them,
A state in which data indicating which state is currently selected among the three states that can be selectively taken by the own device, that is, a state that is a cluster head, a state that is a gateway, and a state that is a member is held Storage means;
ID of the own device, data representing the state of the own device, an ID of another device serving as the parent of the own device, an ID of another device adjacent to the own device, and the adjacent other device as a parent A hello packet including an ID of a mobile terminal device serving as a designated cluster head and a flag indicating whether or not the adjacent other device is designated as a gateway can be repeatedly transmitted, and is similar to the hello packet. When a packet is received from the outside, the ID of the other device that is the transmission source of the hello packet, the data indicating the state of the other device, the ID of the mobile terminal device that is the parent of the other device, and the other device A flag indicating whether or not it is designated as a gateway, an ID of a mobile terminal device adjacent to the other device, and a mobile end serving as a cluster head designated by the adjacent mobile terminal device as a parent And ID of the device, the hello packet transmitting and receiving means for storing the adjacent terminal list storage means for storing data relating to the adjacent terminal,
Based on the principle relating to the configuration of the ad hoc network based on the data stored in the adjacent terminal list storage means, first specify the mobile terminal device to be the cluster head,
Next, when the own device is designated as a gateway, the state of the own device is a gateway, and when the own device is no longer designated as a gateway, the state of the own device is a member,
If connection to the next adjacent cluster of the cluster head is possible in two hops, the mobile terminal corresponding among the common predetermined first convention mobile terminals that are candidates for relaying based on the respective mobile terminal devices Specify the device as a gateway,
When 3 hops are required for connection to a cluster head of an adjacent cluster, clustering means for designating two corresponding mobile terminal devices as gateways based on a predetermined second rule common to each mobile terminal device; ,
Equipped with,
Furthermore, in the case where a numerical value is assigned as the ID of each mobile terminal device,
When the status of its own device is the cluster head,
ID of own device,
The ID of the other device that is the state of the member that has designated the device as the parent,
The link information including the ID of the other device that is the node designated as the gateway by the own device is transmitted,
Two gateways connect to another device that is the cluster head of an adjacent cluster, and the ID of the own device is the largest among the cluster heads adjacent to the gateway with the larger ID of the two gateways. In some cases, the link information including the IDs of the two gateways is transmitted,
When link information similar to the link information is received from the other device, the state of the own device is a cluster head or gateway, and when link information similar to the received link information has not been transmitted in the past, A mobile terminal apparatus comprising link information transmitting / receiving means for relaying the received link information . The principles for the configuration of the ad hoc network are:
(1) All mobile terminal devices constituting the ad hoc network are cluster heads or are adjacent to the cluster head.
(2) Cluster heads are not adjacent to each other.
It satisfies the two requirements at the same time,
When a numerical value is assigned as the ID of each mobile terminal device,
The predetermined first rule is: stipulating that a gateway having the largest numerical value of ID among the corresponding mobile terminal devices is designated as a gateway;
The predetermined second convention is:
In the combination of the two mobile terminal devices that relay between the cluster heads of the adjacent clusters, when the total value of the numerical values of the two IDs is not the same:
A mobile terminal device closer to the mobile device of the combination of mobile terminal devices having the smallest total value is designated as a gateway;
If the sum is the same:
The combination including the mobile terminal device having the largest ID of the mobile terminal device having the smallest ID value among the two units is selected, and the movement closer to the own device among the two selected mobile terminal devices is selected. The mobile terminal device according to claim 1, characterized in that the terminal device is specified as a gateway. A control method for establishing routing related to a plurality of mobile terminal devices constituting an ad hoc network, wherein each of the plurality of mobile terminal devices is assigned an ID capable of identifying each one,
Indicates which of the three states that each of the plurality of mobile terminal devices can selectively take is a cluster head state, a gateway state, or a member state at the current time point. Have each one mobile terminal device hold data,
Each of the one mobile terminal devices includes an ID of the own device, data representing the state of the own device, an ID of another device serving as a parent of the own device, an ID of another device adjacent to the own device, Repeatedly transmitting a hello packet including an ID of a mobile terminal device that is a cluster head designated by the other device as a parent and a flag indicating whether the other device is designated as a gateway;
When a hello packet similar to the hello packet is received from the outside, the ID of the other device that is the transmission source for the reception, the data indicating the state of the other device, and the mobile terminal device that is the parent of the other device ID, the ID of the mobile terminal device adjacent to the other device, the ID of the mobile terminal device that is the cluster head specified by the adjacent mobile terminal device as a parent, and whether the mobile terminal device is specified as a gateway from the adjacent mobile terminal device And a flag indicating whether or not as data related to the neighboring terminal,
Based on the data stored as the data related to the adjacent terminal and based on the principle related to the configuration of the ad hoc network, first, the mobile terminal device to be the cluster head is specified, and then the own device is specified as the gateway. and gateway the state of its own device when you are, when connected to the own device as a member state of the apparatus when it is no longer designated as the gateway, next contact the cluster head in the cluster is available in two hops, each mobile terminal A mobile terminal device is designated as a gateway among mobile terminal devices that are candidates for relay based on a predetermined first rule common to the devices, and connection to the cluster head of an adjacent cluster requires three hops. In the case, the two corresponding mobile terminal devices based on a predetermined second rule common to each mobile terminal device Specified in the Towei,
Furthermore, in the case where a numerical value is assigned as the ID of each mobile terminal device,
When the status of its own device is the cluster head,
ID of own device,
The ID of the other device that is the state of the member that has designated the device as the parent,
The link information including the ID of the other device that is the node designated as the gateway by the own device is transmitted,
Two gateways connect to another device that is the cluster head of an adjacent cluster, and the ID of the own device is the largest among the cluster heads adjacent to the gateway with the larger ID of the two gateways. In some cases, the link information including the IDs of the two gateways is transmitted,
When link information similar to the link information is received from the other device, the state of the own device is a cluster head or gateway, and when link information similar to the received link information has not been transmitted in the past, A control method characterized by relaying the received link information . The principles for the configuration of the ad hoc network are:
(1) All mobile terminal devices constituting the ad hoc network are cluster heads or are adjacent to the cluster head.
(2) Cluster heads are not adjacent to each other.
It satisfies the two requirements at the same time,
When a numerical value is assigned as the ID of each mobile terminal device,
The predetermined first rule is: stipulating that a gateway having the largest numerical value of ID among the corresponding mobile terminal devices is designated as a gateway;
The predetermined second convention is:
In the combination of the two mobile terminal devices that relay between the cluster heads of the adjacent clusters, when the total value of the numerical values of the two IDs is not the same:
A mobile terminal device closer to the mobile device of the combination of mobile terminal devices having the smallest total value is designated as a gateway;
If the sum is the same:
The combination including the mobile terminal device having the largest ID of the mobile terminal device having the smallest ID value among the two units is selected, and the movement closer to the own device among the two selected mobile terminal devices is selected. The control method according to claim 3 , wherein the terminal device is specified to be designated as a gateway. A mobile communication system including a plurality of mobile terminal devices,
The mobile terminal device constitutes an ad hoc network together with one or more other devices having the same function as the own device, and each of the own device and each other device has an ID that can identify each of them,
A state in which data indicating which state is currently selected among the three states that can be selectively taken by the own device, that is, a state that is a cluster head, a state that is a gateway, and a state that is a member is held Storage means;
ID of the own device, data representing the state of the own device, an ID of another device serving as the parent of the own device, an ID of another device adjacent to the own device, and the adjacent other device as a parent A hello packet including an ID of a mobile terminal device serving as a designated cluster head and a flag indicating whether or not the adjacent other device is designated as a gateway can be repeatedly transmitted, and is similar to the hello packet. When a packet is received from the outside, the ID of the other device that is the transmission source of the hello packet, the data indicating the state of the other device, the ID of the mobile terminal device that is the parent of the other device, and the other device A flag indicating whether or not it is designated as a gateway, an ID of a mobile terminal device adjacent to the other device, and a mobile end serving as a cluster head designated by the adjacent mobile terminal device as a parent And ID of the device, the hello packet transmitting and receiving means for storing the adjacent terminal list storage means for storing data relating to the adjacent terminal,
Based on the principle relating to the configuration of the ad hoc network based on the data stored in the adjacent terminal list storage means, first specify the mobile terminal device to be the cluster head,
Next, when the own device is designated as a gateway, the state of the own device is a gateway, and when the own device is no longer designated as a gateway, the state of the own device is a member,
When connection to the cluster head of an adjacent cluster is possible in two hops, the corresponding mobile terminal from among mobile terminal devices that are candidates for relay based on a predetermined first rule common to each mobile terminal device Specify the device as a gateway,
When 3 hops are required for connection to a cluster head of an adjacent cluster, clustering means for designating two corresponding mobile terminal devices as gateways based on a predetermined second rule common to each mobile terminal device; ,
It has
When a numerical value is assigned as the ID of each mobile terminal device,
The clustering means includes
When the state of the own device is a cluster head and there is a cluster head having an ID larger than that of the own device in the other device, the state of the own device is changed to a member, and an adjacent cluster head The mobile terminal device with the largest ID is specified as the parent,
If the state of the local device is a gateway or member, and there is no cluster head specified as the parent by the local device, the state of the local device is changed to a member, and the movement that takes the state of the cluster head The mobile terminal device with the largest ID among the terminal devices is designated as the parent,
Own device status of a gateway or member, and, if there is no cluster head in the adjacent mobile terminal device, moving body communication system that further comprising a function to shift the own device to the cluster head .   The principles for the configuration of the ad hoc network are:
(1) All mobile terminal devices constituting the ad hoc network are cluster heads or are adjacent to the cluster head.
(2) Cluster heads are not adjacent to each other.
It satisfies the two requirements at the same time,
  When a numerical value is assigned as the ID of each mobile terminal device,
  The predetermined first rule is: stipulating that a gateway having the largest numerical value of ID among the corresponding mobile terminal devices is designated as a gateway;
  The predetermined second convention is:
  In the combination of the two mobile terminal devices that relay between the cluster heads of the adjacent clusters, when the total value of the numerical values of the two IDs is not the same:
  A mobile terminal device closer to the mobile device of the combination of mobile terminal devices having the smallest total value is designated as a gateway;
  If the sum is the same:
  The combination including the mobile terminal device having the largest ID of the mobile terminal device having the smallest ID value among the two units is selected, and the movement closer to the own device among the two selected mobile terminal devices is selected. Specifying a terminal device as a gateway
The mobile communication system according to claim 5, wherein: And link information receiving means from said other device is configured to receive the link information, and topology information storing means for storing the link information received by said link information receiving means, the movement of any constituting the ad-hoc network A topology management device having routing means capable of creating a list of mobile terminal devices that relay between the terminal devices and supplying the list to each mobile terminal device in the ad hoc network;
And link information transceiver section for transmitting the link information to the topology management device, the movement of a plurality of wherein said list to one of claims 1 or 2, characterized in that it comprises a routing unit querying the topology management device A mobile communication system composed of terminal devices.

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