JP4029833B2 - Group management method, mobile communication device and program thereof - Google Patents

Description

  The present invention relates to a group management method, a mobile communication device, and a program for a group composed of a plurality of mobile communication devices (hereinafter referred to as “mobile nodes”).

  In order to realize group communication in a group composed of a plurality of nodes, a group identifier (hereinafter referred to as “Group Identifier”) uniquely determined in the entire network is used as a destination address. Here, in order not to use the same group ID between different groups, it is usually necessary to provide a group management server in the network (see, for example, Patent Document 1). The group management server also manages the identification numbers unique to the nodes belonging to each group. Thereby, the node can acquire the position information of the node belonging to the group by accessing the group management server, and can realize the group communication. Such a technique can be said to be one of the efficient methods for group management in nodes spread over a wide range.

JP2003-141682A

  However, according to the conventional technology, since a group management server is required, it is difficult to realize in an ad hoc network that does not require a specific management server. On the other hand, since an ad hoc network is a broadcast type communication, a packet transmitted by a specific node is received by all nodes existing within the radio wave reachable range. A feature of such an ad hoc network is that if the same group ID is used between different groups, the packets will interfere.

  In ITS (Intelligent Transport Systems) applied to an environment where there are a large number of nodes in a certain direction of travel, if the host vehicle and other vehicles belong to the same group and are located in relatively close positions, in an ad hoc network Can be connected. According to the ad hoc network, nodes can communicate with each other directly or indirectly through other nodes. In this case, inquiring about the group ID to the group management server connected to the IP network is extremely inefficient.

  Therefore, the present invention provides a group management method, a mobile communication device, and a program thereof that prevent substantially the same group ID from being used between different groups even when there is no group management server as in an ad hoc network. The purpose is to provide.

  According to the group management method of the present invention, a unique identification number in a plurality of mobile communication devices constituting a group is input to a one-way hash function in a certain order, and the hash value is determined as a group identifier. Features.

According to another embodiment of the group management method of the present invention, the mobile communication device is capable of communication in an ad hoc network, and the first mobile communication device is
A first step of retaining the determined first group identifier;
Receiving a route request message including a second group identifier from the second mobile communication device; and
A third step of comparing the first group identifier and the second group identifier, and if both identifiers are the same, transmitting a route response message to the second mobile communication device;
A fourth step of broadcasting a route request message including a second group identifier;
It is also preferable to have a fifth step of transmitting the route response message to the destination mobile communication device when the route response message is received from the third mobile communication device.

  According to another embodiment of the group management method of the present invention, the route request message includes a flag indicating whether or not to perform the third and fourth steps, and the route response message includes It is also preferable that a flag indicating whether or not to perform the fifth step and position information of the mobile communication device that is the transmission source of the message are included.

  Furthermore, according to another embodiment of the group management method of the present invention, it is also preferable not to transmit a route request message when the limit number of hops of the received route request message becomes zero for the fourth step.

  Furthermore, according to another embodiment of the group management method of the present invention, the route response message preferably includes information on a moving direction and a moving speed of the mobile communication device.

  According to the mobile communication device performing group communication in the present invention, the unique identification numbers in the plurality of mobile communication devices constituting the group are input to the one-way hash function in a certain order, and the hash value is output. It has a directional hash function processing means and a group identifier storage means for storing a hash value as a group identifier.

According to another embodiment of the mobile communication device of the present invention,
Wireless communication means in an ad hoc network;
Group identifier comparison means for comparing a group identifier included in a route request message received from another mobile communication device and a group identifier stored in the group identifier storage means;
If both identifiers are the same, a route response message transmitting means for transmitting a route response message to another mobile communication device;
Route request message transmitting means for broadcasting a route request message including the second group identifier,
The route response message transmitting means is preferably configured to transmit the route response message to the destination mobile communication device when the route response message is received from another mobile communication device.

  According to another embodiment of the mobile communication device of the present invention, the route request message includes a flag indicating whether to perform the third and fourth steps, and the route response message includes It is also preferable that a flag indicating whether or not to perform the fifth step and position information of the mobile communication device that is the transmission source of the message are included.

  Furthermore, according to another embodiment of the mobile communication device of the present invention, when the limit hop number of the received route request message becomes 0, the route request message is not transmitted from the route request message transmitting means. It is also preferable.

  Furthermore, according to another embodiment of the mobile communication device of the present invention, the route response message preferably includes information on a moving direction and a moving speed of the mobile communication device.

  According to the mobile communication device program for group communication in the present invention, unique identification numbers in a plurality of mobile communication devices constituting a group are input to a one-way hash function in a fixed order, and the hash value is output. The computer is caused to function as a one-way hash function processing means for performing the above and a group identifier storage means for storing a hash value as a group identifier.

According to another embodiment of the program of the present invention,
Wireless communication means in an ad hoc network;
Group identifier comparison means for comparing a group identifier included in a route request message received from another mobile communication device and a group identifier stored in the group identifier storage means;
If both identifiers are the same, a route response message transmitting means for transmitting a route response message to another mobile communication device;
Causing the computer to function as a route request message transmitting means for broadcasting a route request message including the second group identifier;
The route response message transmitting means preferably causes the computer to function so as to transmit the route response message to the destination mobile communication device when the route response message is received from another mobile communication device.

  According to another embodiment of the program of the present invention, the route request message includes a flag indicating whether or not to perform the third and fourth steps, and the route response message includes a fifth flag. It is also preferable that a flag indicating whether or not to perform this step and position information of the mobile communication device that is the transmission source of the message are included.

  Furthermore, according to another embodiment of the program of the present invention, when the limit hop number of the received route request message becomes 0, the computer is caused to function so as not to transmit the route request message from the route request message transmitting means. Is also preferable.

  Furthermore, according to another embodiment of the program of the present invention, the route response message preferably includes information on the moving direction and moving speed of the mobile communication device.

  According to the group management method, the mobile communication device, and the program thereof according to the present invention, even when there is no group management server as in an ad hoc network, substantially the same group ID is not used between different groups. be able to. In addition, since the one-way hash value is used as a group identifier, it is impossible to specify a mobile communication device belonging to the group, and confidentiality is improved.

  Further, it is possible to acquire the position information and IP address of the mobile communication devices belonging to the group, and it is possible to realize ad hoc communication within the group using the route constructed by the acquired route information.

  Furthermore, by including information on the moving direction and moving speed of the mobile communication device in the route response message, it can be used in various applications.

  Hereinafter, the best embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a system configuration diagram according to the present invention.

  According to FIG. 1, each vehicle is moving with a mobile node 1 mounted thereon. Vehicles A, B, and D belong to group X, vehicles A and C belong to group Y, and vehicle E does not belong to the group. Each mobile node has an identification number assigned uniquely, and the position information (longitude and latitude) can be acquired by a GPS (Global Positioning System) 2. According to FIG. 1, since the mobile node is a vehicle, the identification number may be, for example, the vehicle number. If the mobile node is a mobile terminal, the identification number may be the manufacturing number or the physical address of the communication interface.

  FIG. 2 is a flowchart for determining a group ID in the present invention.

(S21) First, a group list for a plurality of mobile nodes belonging to a group is created. According to FIG. 2, vehicle numbers are used as identification numbers, which are arranged in a certain order, for example, ascending order. The order may be descending, and follows a method predetermined in the entire system. This identification number may be input from an input device or may be received from another mobile node.
(S22) The group list is input to the one-way hash function to obtain a hash value.
(S23) The obtained hash value is output as a group ID.

  Typical one-way hash functions include “MD5” or “SHA-1”. A hash function is a function that outputs fixed-length data (128-bit length in the case of MD5) called a hash value in response to input of variable-length data. The hash value is also called a message digest, and is used to obtain a small character string (digest) from large data. Further, being one-way means that the group list that is the original data cannot be estimated from the generated hash value.

  In the following, an embodiment applied to an ad hoc network using the group ID thus determined will be described. In particular, AODV (AdHoc On-Demand Distance Vector) is used as a location information request algorithm.

  Since AODV is a reactive protocol, route search is performed after data transmission / reception is attempted. That is, each node holds information on a node to be transferred next, and the packet does not contain route information. Therefore, two route requests are used for route search: route request message RREQ (Route Request) and route response message RREP (Route Reply).

  Here, the RREQ is flooded at each node and transferred. Flooding is a technique for transferring a message to the entire network by transferring a message by broadcast to all nodes existing within the wireless signal reachable range of the transmission source node and repeating the received node in the same manner. Since the existing AODV is basically a one-to-one route search protocol, the destination node of the RREQ does not have a flooding function. Accordingly, whether or not to use the function for acquiring position information according to the present invention is selected by a flag included in the RREQ header.

  Table 1 shows the RREQ format.

  For Table 1, the shaded portion is the portion expanded by the present invention. In particular, the RREQ includes a group ID (Group ID) and a flag (Flag).

  Table 2 shows the RREP format.

  Also for Table 2, the shaded area is an expanded part according to the present invention. Similar to RREQ, whether or not to use the function for acquiring position information according to the present invention is selected by a flag included in the RREP header. In particular, it includes the vehicle number of the response vehicle of the group, its current position (latitude and longitude), its speed and traveling direction. In this way, the ability to acquire position information and the like of other mobile nodes belonging to a group can be applied to various applications.

  For example, the traveling position of another vehicle belonging to the same group can be displayed on the display screen of the car navigation system in the requesting vehicle. It is also possible to display an expected travel position based on information on the speed and travel direction of other vehicles, traffic information based on history data of the information, and the like. The traffic jam information may be inferred from the speed and travel direction information obtained from the other vehicle by the requesting vehicle, or the traffic jam obtained from the speed and travel direction history information accumulated by the other vehicle itself. Information may be returned to the requesting vehicle.

  FIG. 3 is a flowchart when a route request message is received in the present invention.

  The mobile node that performs the processing of this flowchart has already calculated and held the group ID = XXX from the group list by the method of FIG. In addition, this mobile node has a function of acquiring current position information by GPS.

(S31) Assume that RREQ (YYY) with group ID = YYY is received. Here, it is assumed that the function for acquiring position information indicated by the flag is turned on in RREQ. On the other hand, if the RREQ flag is not on, normal AODV protocol processing is performed.
(S32) The received group ID = YYY is compared with the group ID = XXX held by itself. If both IDs are different, the following processing of S33 is not performed.
(S33) If both IDs are the same, it is determined that the RREQ is from a node belonging to the same group, and RREP is returned to the source node of the RREQ by unicast.
(S34) It is determined whether or not the number of RREQ restricted hops is zero. If it is 0, the process ends without performing the following processing of S35.
(S35) If the number of restricted hops is not 0, RREQ is flooded.

  FIG. 4 is a flowchart when a route response message is received in the present invention.

(S41) Assume that an RREP including position information is received. Here, it is assumed that the function for acquiring position information indicated by the flag is turned on in RREP. On the other hand, if the RREP flag is not on, normal AODV protocol processing is performed.
(S42) If the destination address of the RREP is not that of the local node, the RREP is further transferred to the destination.

  FIG. 5 is a sequence diagram for route search in the present invention.

  According to FIG. 5, each vehicle can acquire position information of vehicles belonging to a specific group. Each vehicle holds a group ID already calculated by the method of FIG. 2 from a group list in which vehicle numbers of vehicles belonging to the group are arranged in a certain order for each group to which the own vehicle belongs.

(S501) It is assumed that the vehicle A wants to acquire position information of vehicles belonging to the group ID = XXX. Initially, vehicle A broadcasts a RREQ (XXX) containing group ID = XXX, and the message is received by vehicle B. In this RREQ, a broadcast address is set as a destination address, a group ID = XXX is added to the option part, and a function for acquiring position information is turned on in the flag.
(S502) Vehicle B compares its own group ID = XXX with the group ID = XXX of the received RREQ. Here, it is determined that they are the same, and RREP (B position information) including the position information of the vehicle B is returned to the vehicle A. Thereby, the vehicle A can acquire the position information of the vehicle B.
(S503) Vehicle B further floods RREQ (XXX), and the message is received by vehicle C.
(S504) The vehicle C compares its own group ID = YYY with the group ID = XXX of the received RREQ. Here, it is determined that they are different, and RREP is not transmitted to vehicle B. Further, the vehicle C further floods RREQ (XXX), and the message is received by the vehicle D.
(S505) The vehicle D compares its own group ID = XXX with the group ID = XXX of the received RREQ. Here, it is determined that they are the same, and RREP (D position information) including the position information of the vehicle D is returned to the vehicle C.
(S506) The vehicle D further floods RREQ (XXX), and the message is received by the vehicle E.
(S507) The vehicle C transfers the RREP (D position information) received from the vehicle D to the vehicle B as it is by unicast.
(S508) The vehicle B transfers the RREP (D position information) received from the vehicle C to the vehicle A as it is by unicast. Thereby, the vehicle A acquires the position information of the vehicle D.

(S509) Next, it is assumed that the vehicle C wants to acquire position information of vehicles belonging to the group ID = YYY. Initially, vehicle C broadcasts an RREQ (YYY) containing group ID = YYY, and the message is received by vehicles B and D. Also for this RREQ, the broadcast address is set as the destination address, the group ID = YYY is added to the option part, and the function for acquiring position information is turned on for the flag.
(S510) The vehicle D compares its own group ID = XXX with the group ID = YYY of the received RREQ. Here, it is determined that they are different, and RREP is not transmitted to the vehicle C. Vehicle D further floods RREQ (YYY), and the message is received by vehicle E.
(S511) The vehicle B compares its own group ID = XXX with the group ID = YYY of the received RREQ. Here, it is determined that they are different, and RREP is not transmitted to the vehicle C. Vehicle D further floods RREQ (YYY), and the message is received by vehicle A.
(S512) The vehicle A compares its own group ID = XXX, YYY with the group ID = YYY of the received RREQ. Here, it is determined that they are the same, and RREP (A position information) including the position information of the vehicle A is returned to the vehicle B.
(S513) The vehicle B transfers the RREP (A position information) received from the vehicle A to the vehicle C by unicast. Thereby, the vehicle C acquires the position information of the vehicle A.
(S514) Ad hoc communication of vehicles A, B, and D belonging to group X can be performed.
(S515) Ad hoc communication between vehicles A and C belonging to group Y is possible.

  FIG. 6 is a functional configuration diagram of the mobile node in the present invention.

  According to FIG. 6, the mobile node 1 includes a group list storage unit 10, a one-way hash function processing unit 11, a group ID storage unit 12, a wireless communication interface 13, a message determination unit 14, and a group ID comparison. Unit 15, route response message transmitter 16, route request message transmitter 17, position information measuring unit 18, and input device 19.

  The group list storage unit 10 stores a list of identification numbers of mobile nodes that constitute a group. This identification number may be input from the input device 19 by the user, or may be received from another mobile node. In this group list, the identification numbers are arranged in ascending order or descending order. The one-way hash function processing unit 11 calculates a hash value for the identification number of the group list notified from the group list storage unit 10. The group ID storage unit 12 stores the hash value as the group ID of the mobile node.

  The wireless communication interface 13 transmits and receives packets to and from other mobile nodes via the wireless LAN. The message determination unit 14 determines whether the message is RREQ or RREP only when the flag of the received message turns on the function for acquiring position information. The RREQ includes the group ID of the request source, and the RREP includes the location information of the mobile node that is the response source. If the flag is not on, the existing AODV protocol processing is performed. RREQ is notified to the group ID comparison unit 15, and RREP is notified to the route response message transmission unit 16. The group ID comparison unit 15 compares the group ID of the mobile node stored in the group ID storage unit 12 with the group ID included in the received RREQ. If the two group IDs are the same, the group ID comparison unit 15 notifies the route response message transmission unit 16 that RREP is transmitted, and notifies the route request message transmission unit 17 that the RREQ is flooded. On the other hand, if the two group IDs are different, the group ID comparison unit 15 notifies the route request message transmission unit 17 only of flooding the route request message. However, when the limit number of hops of the received RREQ is 0, the group ID comparison unit 15 does not notify that the RREQ is flooded.

  The position information measuring unit 18 always measures the current position information. The route response message transmission unit 16 adds the location information notified from the location information measurement unit 18 to the RREP, and notifies the wireless communication interface 13 of the RREP. The route request message transmission unit 17 transmits the RREQ to the wireless communication interface 13. As a result, the RREQ is flooded.

It is a system configuration diagram in the present invention. It is a flowchart for determination of group ID in this invention. It is a flowchart at the time of receiving the route request message in the present invention. It is a flowchart at the time of receiving the path | route response message in this invention. It is a sequence diagram for the route search in this invention. It is a functional block diagram of the mobile node in this invention.

Explanation of symbols

1 Mobile node, mobile communication device,
DESCRIPTION OF SYMBOLS 10 Group list storage part 11 Unidirectional hash function processing part 12 Group ID storage part 13 Wireless communication interface 14 Message determination part 15 Group ID comparison part 16 Path response message transmission part 17 Path request message transmission part 18 Location information measurement part 19 Input Device 2 GPS

Claims (15)

  A group management method for a mobile communication device, wherein unique identification numbers in a plurality of mobile communication devices constituting a group are input to a one-way hash function in a predetermined order, and the hash value is determined as a group identifier . The mobile communication device is capable of wireless communication in an ad hoc network,
The first mobile communication device is
A first step of retaining the determined first group identifier;
Receiving a route request message including a second group identifier from the second mobile communication device; and
A third step of comparing the first group identifier and the second group identifier, and if both identifiers are the same, transmitting a route response message to the second mobile communication device;
A fourth step of broadcasting a route request message including the second group identifier;
5. The method according to claim 1, further comprising: a fifth step of transmitting the route response message to a mobile communication device that is the destination when the route response message is received from a third mobile communication device. Group management method for mobile communication devices. The route request message includes a flag indicating whether or not to perform the third and fourth steps.
3. The route response message includes a flag indicating whether or not to perform the fifth step and location information of a mobile communication device that is a transmission source of the message. A group management method for the mobile communication device as described.   4. The group management of the mobile communication device according to claim 2, wherein the route request message is not transmitted when the limit hop number of the received route request message becomes 0 in the fourth step. 5. Method.   5. The group management method for a mobile communication device according to claim 2, wherein the route response message includes information on a moving direction and a moving speed of the mobile communication device. A mobile communication device for group communication,
One-way hash function processing means for inputting unique identification numbers in a plurality of mobile communication devices constituting a group to a one-way hash function in a certain order and outputting the hash value;
A mobile communication device comprising group identifier storage means for storing the hash value as a group identifier. Wireless communication means in an ad hoc network;
Group identifier comparison means for comparing a group identifier included in a route request message received from another mobile communication device and a group identifier stored in the group identifier storage means;
If both identifiers are the same, a route response message transmitting means for transmitting a route response message to the other mobile communication device;
Route request message transmitting means for broadcasting a route request message including the second group identifier,
When the route response message is received from another mobile communication device, the route response message transmitting means is configured to transmit the route response message to the mobile communication device that is the destination. The mobile communication device according to claim 6. The route request message includes a flag indicating whether or not to perform the third and fourth steps.
8. The route response message includes a flag indicating whether or not to perform the fifth step, and location information of a mobile communication device that is a transmission source of the message. The mobile communication device described.   9. The route request message is configured not to be transmitted from the route request message transmitting means when the limit hop number of the received route request message becomes 0. Mobile communication device.   The mobile communication device according to claim 7, wherein the route response message includes information on a moving direction and a moving speed of the mobile communication device. A mobile communication device program for group communication,
One-way hash function processing means for inputting unique identification numbers in a plurality of mobile communication devices constituting a group to a one-way hash function in a certain order and outputting the hash value;
A program for a mobile communication device, which causes a computer to function as group identifier storage means for storing the hash value as a group identifier. Wireless communication means in an ad hoc network;
Group identifier comparison means for comparing a group identifier included in a route request message received from another mobile communication device and a group identifier stored in the group identifier storage means;
If both identifiers are the same, a route response message transmitting means for transmitting a route response message to the other mobile communication device;
Causing a computer to function as a route request message transmitting means for broadcasting a route request message including the second group identifier;
The route response message transmitting means causes a computer to function so as to transmit the route response message to a destination mobile communication device when the route response message is received from another mobile communication device. The program of the mobile communication apparatus of Claim 11. The route request message includes a flag indicating whether or not to perform the third and fourth steps.
13. The route response message includes a flag indicating whether or not to perform the fifth step and location information of a mobile communication device that is a transmission source of the message. The program of the mobile communication apparatus as described.   14. The computer according to claim 12, wherein the computer is caused to function so as not to transmit the route request message from the route request message transmission unit when the limit hop number of the received route request message becomes zero. A program for a mobile communication device. The program for a mobile communication device according to any one of claims 12 to 14, wherein the route response message includes information on a moving direction and a moving speed of the mobile communication device.

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