JP2007258811A - Mobile wireless communication system and communication control method thereof, mobile terminal, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile wireless communication system capable of improving the whole throughput by suppressing wasteful transmission of a radio wave. <P>SOLUTION: Each of mobile terminals being a component of the mobile wireless communication system acts like a terminal shiftable to three states of terminals that are: a management terminal belonging to a prescribed group, managing routing information shared by the prescribed group and carrying out wireless communication; a subordinate terminal belonging to the prescribed group and carrying out wireless communication according to the routing information notified from the management terminal by means of wireless communication; and an independent terminal not belonging to the prescribed group. Only communicable management terminals and subordinate terminals reconfigure a group. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mobile radio communication system, a communication control method thereof, a mobile terminal, and a program. For example, radio communication between mobile terminals equipped with radio communication means using a VHF band, such as a self-supporting disaster prevention radio communication system. This is applicable when

  Conventionally, some wireless communication systems include a mobile terminal such as a mobile phone and a base station that relays communication of the mobile terminal. In such a wireless communication system, when performing communication, mobile terminals do not directly communicate with each other, but a base station relays communication of a mobile terminal to be communicated. Moreover, the mobile terminal can continuously communicate by observing the propagation status of a plurality of base stations at the same time and automatically switching the base station according to the propagation status of the connection destination by a technique called handover. it can.

  As such a wireless communication system, for example, wireless communication systems described in Patent Document 1 and Patent Document 2 are known.

  However, in the above wireless communication system, since communication between mobile terminals is performed via the base station, communication cannot be performed if the base station is damaged due to a disaster or the like. In addition, since it is necessary to lay one or more base stations for each fixed range, in a mountainous area or the like, considering the frequency of normal use, the cost for laying is not practical.

  Therefore, in recent years, a communication mode using an ad hoc network has been proposed or realized (see, for example, Patent Document 3). An ad hoc network is a network that does not require a base station and communicates between mobile terminals directly or via other mobile terminals.

  For example, in an ad hoc network having a first mobile terminal, a second mobile terminal, and a third mobile terminal, the second mobile terminal is located between the first mobile terminal and the third mobile terminal, It is assumed that adjacent mobile terminals can directly communicate with each other, and the first mobile terminal and the third mobile terminal cannot directly communicate with each other.

  Then, wireless communication between mobile terminals when the first mobile terminal communicates with the third mobile terminal is performed as follows.

  That is, although the first mobile terminal can directly communicate with the second mobile terminal, there is a limit to the distance that the radio wave can reach, so the first mobile terminal is not directly connected to the third mobile terminal. The second mobile terminal relays communication, so that the first mobile terminal communicates indirectly with the third mobile terminal via the second mobile terminal. Can do.

In this case, the second mobile terminal needs to know in advance the existence of the first mobile terminal and the third mobile terminal, and the first mobile terminal requests the second mobile terminal to relay. Thus, it is necessary to know in advance that communication with the third mobile terminal can be performed. That is, each mobile terminal communicates based on route information.
JP 2005-176336 A JP-A-2005-184160 JP 2005-303896 A

  However, in the conventional ad hoc network, (1) the radio wave transmitted from the first mobile terminal does not reach the second mobile terminal due to the movement of the second mobile terminal to be relayed, or (2) the first mobile terminal Although the radio wave transmitted from the mobile terminal reaches the second mobile terminal, the radio wave transmitted from the second mobile terminal may not reach the third mobile terminal.

  Then, the first mobile terminal transmits a radio wave to perform direct communication with the second mobile terminal in the state of (1) based on the route information, or the above (1) or (2 ), A radio wave may be transmitted to relay the second mobile terminal to perform communication (indirect communication) with the third mobile terminal.

  This means that in any case, the first mobile terminal is useless although it cannot communicate directly with the second mobile terminal or indirectly with the third mobile terminal. It means sending radio waves.

  As described above, in a conventional ad hoc network, communication becomes impossible when the propagation environment deteriorates or when a mobile terminal (including a mobile terminal to be relayed) of a communication partner moves to a place away from the own terminal. Even in such a case, each mobile terminal transmits a useless radio wave without determining whether or not communication is possible, for example, to a mobile terminal whose propagation environment has deteriorated.

  An object of the present invention is to provide a mobile radio communication system, a communication control method thereof, a mobile terminal, and a program capable of suppressing useless transmission of radio waves and improving the overall throughput.

  In order to solve the above problems, a mobile radio communication system according to a first aspect of the present invention is a mobile radio communication system having a plurality of mobile terminals that perform radio communication, and each of the plurality of mobile terminals includes a predetermined group. A management terminal that manages route information shared by the predetermined group and performs wireless communication, a subordinate terminal that belongs to the predetermined group and performs wireless communication according to information of the route information notified by wireless communication from the management terminal, Alternatively, it functions as a terminal capable of transitioning to the state of an independent terminal that does not belong to any group.

  As a result, a group can be dynamically formed only by terminals that can perform wireless communication, and wireless communication between terminals in the group and wireless communication between terminals between groups can be reliably performed. . For this reason, useless transmission of radio waves can be suppressed and the overall throughput can be improved.

  In order to solve the above problem, the mobile radio communication system of the second aspect of the present invention has a plurality of groups formed by the management terminal of the first aspect of the present invention and the subordinate terminal of the first aspect of the present invention. A mobile radio communication system, wherein a management terminal or subordinate terminal belonging to a first group as a transmission source terminal communicates with a management terminal or subordinate terminal belonging to a second group as a desired destination terminal When performing, the transmission source terminal investigates the route information shared in the first group, and if the result of this investigation shows that the route information regarding the desired terminal does not exist in the route information, The desired terminal that has transmitted the data by broadcast and has received the broadcast search data returns the reply data to the transmission source terminal by unicast, Transmission source terminal, and acquires the routing information regarding the desired terminal belonging to the second group by receiving a uni-cast reply data from the desired terminal.

  Thus, when communication between groups is performed, the transmission source terminal searches for the route information of a desired terminal as a transmission destination when the route information of the group to which the transmission source terminal belongs does not exist. The broadcast data is transmitted, and the return data transmitted by unicast is received from the desired terminal that has received the search data, thereby obtaining route information regarding the desired terminal belonging to another group. it can. Therefore, the terminals in a plurality of adjacent groups can acquire the route information related to the terminals belonging to other groups and perform relay communication based on the acquired route information, thereby expanding the entire communication range. It becomes possible.

  Furthermore, in order to solve the above problem, the mobile radio communication system of the third aspect of the present invention has a plurality of groups formed by the management terminal in the first aspect of the present invention and the subordinate terminal in the first aspect of the present invention. In a mobile radio communication system, a management terminal or subordinate terminal belonging to a predetermined group intercepts a beacon transmitted from a neighboring terminal and a management terminal or subordinate terminal belonging to another group. Communication with respect to the other group is performed based on the route information related to the other group acquired based on the included route information.

  As a result, the transmission source terminal always obtains route information about the desired terminal before performing communication with the desired terminal as the transmission destination by intercepting beacons transmitted by other terminals. Can be recognized. Therefore, when the transmission source terminal does not know the route information regarding the desired terminal as the transmission destination, for example, it is not necessary to broadcast search data for searching for the desired terminal. Traffic volume can be reduced.

  Furthermore, in order to solve the above-described problem, a communication control method for a mobile radio communication system according to a fourth aspect of the present invention is a communication control method for a mobile radio communication system having a plurality of mobile terminals that perform radio communication. Each of the plurality of mobile terminals performs wireless communication in accordance with information on the route information belonging to the predetermined group and managing the route information shared by the predetermined group, and the route information belonging to the predetermined group and notified from the management terminal A management terminal that functions as a terminal capable of transitioning to the state of three terminals, that is, a dependent terminal and an independent terminal that does not belong to any group, or a group to which only a management terminal and a dependent terminal capable of communication belong Is constructed, and terminals belonging to the constructed group perform wireless communication based on route information related to the group.

  As a result, a group can be dynamically formed only by terminals that can perform wireless communication, and wireless communication between terminals in the group and wireless communication between terminals between groups can be reliably performed. . For this reason, useless transmission of radio waves can be suppressed and the overall throughput can be improved.

  In order to solve the above problem, a communication control method for a mobile radio communication system according to a fifth aspect of the present invention is a group formed by a management terminal according to the first aspect and a subordinate terminal according to the first aspect. Is a communication control method for a mobile radio communication system in which a management terminal or subordinate terminal belonging to a first group as a transmission source terminal belongs to a second group as a transmission destination desired terminal. When communicating with a terminal or a subordinate terminal, the transmission source terminal investigates the route information shared in the first group, and as a result of the investigation, the route information related to the desired terminal is included in the route information. If not, the desired terminal that transmits search data by broadcast and receives the broadcast search data receives the return data from the transmission source terminal. The transmission source terminal obtains route information regarding the desired terminal belonging to the second group by receiving the unicast reply data from the desired terminal. And

  As a result, when performing communication between groups, the transmission source terminal searches for the route information of the desired terminal as the transmission destination when the route information of the group to which the transmission source terminal belongs does not exist. By transmitting data by broadcasting and receiving reply data transmitted by unicast from a desired terminal that has received search data, it is possible to obtain route information regarding a desired terminal belonging to another group. . Therefore, the terminals in a plurality of adjacent groups can acquire the route information related to the terminals belonging to other groups and perform relay communication based on the acquired route information, thereby expanding the entire communication range. It becomes possible.

  Furthermore, in order to solve the above-described problem, a communication control method for a mobile radio communication system according to a sixth aspect of the present invention is a group formed by a management terminal according to the first aspect and a subordinate terminal according to the first aspect. A management terminal or subordinate terminal belonging to a predetermined group is a neighboring terminal and a beacon transmitted from a management terminal or subordinate terminal belonging to another group Intercepting and performing communication with respect to the other group based on the route information related to the other group acquired based on the route information included in the intercepted beacon.

  As a result, the transmission source terminal always obtains route information about the desired terminal before performing communication with the desired terminal as the transmission destination by intercepting beacons transmitted by other terminals. Can be recognized. Therefore, when the transmission source terminal does not know the route information regarding the desired terminal as the transmission destination, for example, it is not necessary to broadcast search data for searching for the desired terminal. Traffic volume can be reduced.

  Furthermore, in order to solve the above-described problem, a program according to a seventh aspect of the present invention stores a state transition condition in a computer capable of wireless communication in advance and connects the computer to a wireless network according to the state transition condition. A mobile terminal that has a wireless communication mode for performing wireless communication and a processing mode for performing predetermined processing other than wireless communication, and executes the predetermined processing when the processing mode is designated, When a wireless communication mode is designated, the mobile terminal belongs to a predetermined group, manages route information shared by the predetermined group and performs wireless communication, and belongs to the predetermined group from the management terminal Dependent terminal that performs wireless communication according to route information information notified by wireless communication, or an independent terminal that does not belong to any group Characterized in that to function.

  Accordingly, it is possible to provide a program that causes a computer capable of wireless communication to function as a mobile terminal, a management terminal, a dependent terminal, or an independent terminal.

  According to the present invention, a group can be dynamically formed only by terminals that can perform wireless communication, and a group can be reconstructed only by a management terminal and subordinate terminals that can perform wireless communication. This makes it possible to suppress the transmission of useless radio waves and improve the overall throughput.

  Further, according to the present invention, terminals in a plurality of adjacent groups acquire route information regarding terminals belonging to other groups, and perform relay communication based on the acquired route information, thereby The communication range can be expanded.

  Furthermore, according to the present invention, the transmission source terminal always intercepts a beacon transmitted by another terminal, thereby performing communication with a desired terminal as a transmission destination before performing communication with the desired terminal. Route information can be acquired and recognized. Therefore, when the transmission source terminal does not know the route information of the desired terminal as the transmission destination, for example, there is no need to broadcast a search packet for searching for the desired terminal. Traffic volume can be reduced.

  Furthermore, according to the present invention, there is provided a program for causing a management terminal, a slave terminal, or a mobile terminal that transitions to a state of an independent terminal and a computer capable of wireless communication to function as the mobile terminal, the management terminal, the slave terminal, or the independent terminal. Can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described more specifically with reference to the drawings. Here, in the accompanying drawings, the same components are denoted by the same reference numerals, and redundant description is omitted. In addition, since description here is the best form by which this invention is implemented, this invention is not limited to the said form.

  In the mobile radio communication system according to the present invention, a plurality of mobile terminals autonomously construct a radio communication network, for example, an ad hoc network. Each mobile terminal is not only a portable information terminal device such as a notebook personal computer, a PDA (Personal Digital Assistant), a mobile phone, or the like, but also a wireless communication mounted on a mobile body such as a vehicle such as an automobile. A device is also included.

(A) First Embodiment In the first embodiment, a case where mobile terminals communicate with each other in a group formed by a plurality of mobile terminals will be described.

(A-1) Configuration of Mobile Radio Communication System FIG. 2 shows a configuration example of the mobile radio communication system according to the first embodiment. In FIG. 2, the group 40 includes a plurality of mobile terminals (hereinafter referred to as “terminals”) 10, 20, and 30.

  Each of the terminals 10 to 30 can be connected to a wireless communication network (for example, an ad hoc network), and has a wireless communication mode for executing wireless communication and a processing mode for executing predetermined processing other than wireless communication. Each terminal 10 to 30 executes a predetermined process such as scheduling management and document creation when the processing mode is designated by an operation by an operation unit such as a key (not shown), while the wireless communication mode is designated. Performs wireless communication using a wireless communication protocol for remote communication such as IEEE802.11.

  In the first embodiment, each of the terminals 10 to 30 transitions to a state of three terminals, that is, a management terminal, a subordinate terminal, and an independent terminal, when a wireless communication mode is designated, that is, when wireless communication is executed. Functions as a possible terminal.

  The group is formed by a management terminal that manages the routing table and performs wireless communication, and a subordinate terminal that performs wireless communication according to the information of the routing table notified by wireless communication from the management terminal. In the first embodiment, the group includes one management terminal and a plurality of subordinate terminals.

  The management terminal creates and manages a routing table shared by the group, transmits a beacon (or control packet) including the information of the routing table to the subordinate terminal belonging to the group, and subordinates the information of the current routing table. Notify the terminal. This beacon is periodically notified (transmitted) to the subordinate terminal. That is, the latest routing table information is notified to the subordinate terminal.

  The subordinate terminal receives the beacon from the management terminal and performs relay communication based on information in the routing table included in the received beacon.

  The independent terminal does not belong to any group at a certain time, and tries to join the group by searching for surrounding (neighboring) management terminals.

  As shown in the state transition diagram of FIG. 1, there are three types of terminal states that behave as the management terminal 201, the subordinate terminal 202, or the independent terminal 203.

  When the management terminal 201 receives a beacon from the subordinate terminal 202 belonging to the group to which the management terminal 201 belongs (beacon transmitted from the subordinate terminal 202 to the management terminal 201) within a certain period of time, The state of the management terminal 201 is continued (204). The management terminal 201 continues the state of the management terminal 201 when there is at least one subordinate terminal 202 that can communicate. In addition, the management terminal 201 determines that the independent terminal 203 is not used when there is no dependent terminal 202 belonging to the group for a certain period due to the withdrawal of the dependent terminal 202 from the group to which the management terminal 201 belongs. The state is changed to (205).

  If the subordinate terminal 202 receives a beacon (a beacon transmitted from the management terminal 201 to the subordinate terminal 202) from the management terminal 201 belonging to the group to which the subordinate terminal 202 belongs within a certain period of time, The state of the terminal 202 is continued (206). Further, when the subordinate terminal 202 cannot receive the beacon transmitted from the management terminal 201 within a certain time, the subordinate terminal 202 changes the state to the independent terminal 203 (207).

  The independent terminal 203 continues the state of the independent terminal 203 while searching for the neighboring management terminal 201 (208). In addition, when the independent terminal 203 succeeds in searching for the management terminal 201 and is allowed to join the group to which the management terminal 201 belongs, the independent terminal 203 changes the state to the dependent terminal 202 (209). Here, the group entry method is not limited. Furthermore, when the independent terminal 203 cannot find the management terminal 201 even after searching for the management terminal 201 for a certain period of time, the independent terminal 203 changes the state to the management terminal 201 (210).

  Next, a format example of a beacon used for confirming the presence of a terminal will be described.

  FIG. 3 shows an example of a format of a beacon (hereinafter referred to as “management terminal beacon”) transmitted from a management terminal to a subordinate terminal. In FIG. 3, the management terminal beacon 300 includes a packet type 301, a transmission source address 302, position information 303, and a routing table 304.

  In the packet type 301, an identification number for distinguishing from other packets is set (described). Here, the packet type of the management terminal beacon is “1” (PT = 1 in FIG. 3). In the transmission source address 302, the address of the management terminal (own terminal) is set. In the position information 303, position information indicating the position of the management terminal acquired from GPS or the like is set. In the routing table 304, route information for performing communication with all the subordinate terminals managed by the management terminal is set. The number of route information to the subordinate terminal set in the routing table 304 can be variably increased according to the number of subordinate terminals to be managed.

  FIG. 4 shows an example of a format of a beacon (hereinafter referred to as “subordinate terminal beacon”) transmitted from the subordinate terminal to the management terminal. As shown in FIG. 4, the dependent terminal beacon 400 includes a packet type 401, a transmission source address 402, a transmission destination address 403, and position information 404.

  In the packet type 401, an identification number for distinguishing the type from other packets is set (description). Here, the packet type of the dependent terminal beacon is “2” (PT = 2 in FIG. 4). In the transmission source address 402, the address of the subordinate terminal (own terminal) is set. In the transmission destination address 403, the address of the management terminal belonging to the group to which the subordinate terminal belongs is set. In the position information 404, position information indicating the position of the subordinate terminal acquired from GPS or the like is set.

  Next, the configuration of the mobile terminal will be described with reference to FIG. Here, the configuration of terminal (mobile terminal) 10 shown in FIG. 2 will be described, but other mobile terminals have the same configuration.

  As illustrated in FIG. 5, the mobile terminal 10 includes an antenna 110, a wireless transmission / reception unit 120, a communication processing unit 130, a program storage unit 140, a control unit 150, a storage unit 160, a position information detection unit 170, and a timer 180. .

  The antenna 110 transmits and receives radio signals to and from other mobile terminals.

  The radio transmission / reception unit 120 performs predetermined modulation processing on the transmission signal supplied from the communication processing unit 130, outputs the modulated signal to the antenna 110, and outputs a predetermined signal to the reception signal received via the antenna 110. Demodulation processing is performed to generate a demodulated signal, which is output to the communication processing unit 130.

  In addition, the wireless transmission / reception unit 120 has a reception power detection function for detecting reception power related to data when data (for example, a beacon) is received. The detected received power information is notified to the control unit 150 via the communication processing unit 130.

  The communication processing unit 130 processes a wireless communication protocol for remote communication such as IEEE802.11 and passes received power information from the wireless transmission / reception unit 120 to the control unit 150.

  In the program storage unit 140, a program (software) corresponding to a processing procedure (see FIGS. 7 to 9) of a terminal to be described later, the mobile terminal transitions to the state of three terminals: a management terminal, a subordinate terminal, and an independent terminal Various programs such as a program for operating as a possible terminal, an operating system (OS), or a real-time OS are stored. The program storage unit 140 is realized by a storage medium such as a ROM or a small hard disk, for example.

  The storage unit 160 includes a routing table storage area 161 in which a routing table is stored, a position information storage area 162 in which position information indicating the position of the own terminal (mobile terminal 10) is stored, and the state of the own terminal, that is, management. Necessary when the control unit 150 performs data processing, and a terminal state storage area 163 for storing information (terminal state information) indicating the state of any one of the terminal state, subordinate terminal state, and independent terminal state Such as a work area 164 in which received data (packets, beacons, etc.) and transmission data (packets, beacons, etc.) are temporarily stored. The storage unit 160 is realized by, for example, a RAM or an EEPROM.

  Note that the storage contents of the routing table storage area 161 are appropriately updated so that the latest routing table is stored. The stored contents of the position information storage area 162 are updated as appropriate so that position information indicating the latest position of the terminal is changed as the terminal moves. The stored contents of the terminal state storage area 163 are updated as appropriate so that information indicating the state of the terminal that changes is stored.

  The position information detection unit 170 periodically detects the position of the own terminal (mobile terminal 10) using, for example, a received radio wave from a GPS (Global Positioning System) satellite. The detected position information is stored in the position information storage area 162 by the control unit 150. In the moving mobile terminal 10, the position information detection unit 170 periodically detects the position of the own terminal, so that the position information indicating the latest position of the own terminal that changes with the movement is stored in the position information storage area 162. Will be remembered.

  The timer 180 is a timer for confirming the existence of a management terminal or a subordinate terminal, and is started by the control unit 150, decrements from a preset initial value (timer value), and measures a certain time. . The timer value of the timer 180 is reset to the original initial value by the control unit 150. This timer value is acquired by the control unit 150.

  The control unit 150 reads out and executes a program stored in the program storage unit 140, thereby performing processing based on a processing procedure (see FIGS. 7 to 9) of a terminal described later, a mobile terminal, a management terminal, Predetermined processing is performed including processing corresponding to a program for functioning as a terminal capable of transitioning to the state of three terminals, a dependent terminal and an independent terminal. The control unit 150 is realized by a control unit such as a CPU.

  Although not shown, the control unit 150 includes an analysis function for analyzing received data (packets, beacons, etc.), a data creation function for creating data to be transmitted (packets, beacons, etc.), and a routing table. A routing table management function that is created and managed, a determination function that determines whether or not the received power information (received power value) passed from the communication processing unit 130 is equal to or greater than a predetermined threshold, and a position from the position information detection unit 170 It has a position information acquisition function for acquiring information and writing this position information in the storage unit 160, and a timer value acquisition function for starting the timer 180 and acquiring a timer value from the timer 180.

  In addition, the control unit 150 performs the following processes (1) to (3) in order to cause the mobile terminal to function as a terminal that can transition to the three terminal states of a management terminal, a subordinate terminal, and an independent terminal.

(1) Processing when transitioning to the state of the management terminal (1-1) When a beacon (dependent terminal beacon) transmitted from an arbitrary dependent terminal belonging to a predetermined group is received within a certain period of time The state of the management terminal is continued. In this case, the storage content of the terminal state storage area 163 of the storage unit 160 remains information indicating the state of the management terminal. Whether or not the dependent terminal beacon is received within a certain period of time is determined by referring to the timer value acquired from the timer 180 (hereinafter the same in this process).

  (1-2) When received power related to a dependent terminal beacon when a dependent terminal beacon transmitted from an arbitrary dependent terminal belonging to a predetermined group is received within a predetermined time has reached a predetermined threshold value The state of the management terminal is continued. In this case, the storage content of the terminal state storage area 163 of the storage unit 160 remains information indicating the state of the management terminal. The received power related to the dependent terminal beacon is set to a value (received power value) notified from the wireless transmission / reception unit 120 via the communication processing unit 130 (hereinafter the same in this process).

  (1-3) If a dependent terminal beacon transmitted from an arbitrary dependent terminal is not received within a certain period of time, the arbitrary dependent terminal is regarded as autonomously leaving the predetermined group.

  (1-4) When the reception power related to the dependent terminal beacon when the dependent terminal beacon transmitted from an arbitrary dependent terminal is received within a certain time, or the predetermined dependent terminal is not reached, or any dependent terminal If the subordinate terminal beacon transmitted from is not received within a certain time, it is assumed that any subordinate terminal autonomously leaves the predetermined group.

  (1-5) With respect to all dependent terminals belonging to a predetermined group, when the dependent terminal beacon transmitted from the dependent terminal is not received within a certain time, the state is changed from the management terminal to the independent terminal. . In this case, the storage content of the terminal state storage area 163 of the storage unit 160 is updated to information indicating the state of the independent terminal.

  (1-6) When all subordinate terminals belonging to a predetermined group autonomously leave the predetermined group and no subordinate terminals exist in the predetermined group, the state is changed from the management terminal to the independent terminal. Transition. In this case, the storage content of the terminal state storage area 163 of the storage unit 160 is updated to information indicating the state of the independent terminal.

(2) Processing when transitioning to the state of a subordinate terminal (2-1) When a beacon (management terminal beacon) transmitted from a management terminal is received within a certain period of time, the state of the subordinate terminal is changed. Let it continue. In this case, the storage content of the terminal state storage area 163 of the storage unit 160 remains information indicating the state of the subordinate terminal. Whether or not the management terminal beacon has been received within a certain period of time is determined by referring to the timer value acquired from the timer 180 (hereinafter the same in this process).

  (2-2) When the reception power related to the management terminal beacon when the management terminal beacon transmitted from the management terminal is received within a certain time has reached a predetermined threshold, the state of the dependent terminal is Let it continue. In this case, the storage content of the terminal state storage area 163 of the storage unit 160 remains information indicating the state of the subordinate terminal. In addition, the received power related to the management terminal beacon is set to a value (received power value) notified from the wireless transmission / reception unit 120 via the communication processing unit 130 (hereinafter the same in this process).

  (2-3) When the management terminal beacon transmitted from the management terminal is not received within a certain time, the state is changed from the subordinate terminal to the independent terminal. In this case, the storage content of the terminal state storage area 163 of the storage unit 160 is updated to information indicating the state of the independent terminal.

  (2-4) When the received power related to the management terminal beacon when the management terminal beacon transmitted from the management terminal is received within a certain time, has not reached the predetermined threshold, or is transmitted from the management terminal When the management terminal beacon cannot be received, the state is changed from the subordinate terminal to the independent terminal. In this case, the storage content of the terminal state storage area 163 of the storage unit 160 is updated to information indicating the state of the independent terminal.

(3) Processing when Transitioning to State of Independent Terminal (3-1) The state of the independent terminal is continued during the period of searching for a nearby management terminal by wireless communication. In this case, the storage content of the terminal state storage area 163 of the storage unit 160 remains information indicating the state of the independent terminal.

  (3-2) When entry from the management terminal found by the search to the group to which the management terminal belongs is permitted, the state is changed from the independent terminal to the subordinate terminal. In this case, the storage content of the terminal state storage area 163 of the storage unit 160 is updated to information indicating the state of the subordinate terminal.

  (3-3) If the management terminal discovered by the search is not allowed to join the group to which the management terminal belongs, or if the management terminal cannot be found as a result of the search, the independent terminal changes to the management terminal. Transition state. In this case, the storage content of the terminal state storage area 163 of the storage unit 160 is updated to information indicating the state of the management terminal.

(A-2) Processing Operation of Mobile Radio Communication System Next, the processing operation according to the communication control method of the mobile radio communication system according to the first embodiment will be described.

  Here, in the mobile radio communication system, as shown in FIG. 6, the group 104 includes a terminal (mobile terminal) 102 as one management terminal and terminals (mobile terminals) 101 and 103 as a plurality of subordinate terminals. It shall be configured.

  In FIG. 6, terminal 101 corresponds to mobile terminal 10 in FIG. 2, terminal 102 corresponds to mobile terminal 20 in FIG. 2, terminal 103 corresponds to mobile terminal 30 in FIG. 2, and group 104 corresponds to FIG. This corresponds to the group 40.

  These terminals 101 to 103 are assumed to be operating with the power turned on. Also, each of the terminals 101 to 103 stores the terminal state storage area 163 of the storage unit 160 in the state of its own terminal (mobile terminal) (the state of the management terminal, the state of the subordinate terminal, or the state of the independent terminal). Information indicating the state) is stored, so that the terminal itself can recognize which terminal is in the current state.

  In the first embodiment, when the terminal is activated (power-on state) or the wireless communication mode is designated, the terminal is set to the independent terminal state by default. Of course, the terminal state storage area 163 stores information indicating the state of the independent terminal.

  Processing of the management terminal will be described with reference to FIGS. FIG. 7 is a flowchart showing the processing procedure of the management terminal.

  As shown in FIG. 7, the management terminal (mobile terminal that has transitioned to (transitioned to) the state of the management terminal) 102 stores the routing table managed by itself, that is, the routing table storage area 161 of the storage unit 160. Based on the stored routing table, the management terminal beacon 300 according to the format shown in FIG. 3 is transmitted to the subordinate terminals belonging to the group 104 (step S101). At this time, the timer 180 is activated by the control unit 150 and decrements from a predetermined timer value (initial value). In this case, the timer 180 functions as a timer for confirming the existence of the subordinate terminal.

  The management terminal beacon may be transmitted at regular intervals, random intervals, or intervals determined by a collision avoidance algorithm or the like.

  The management terminal 102 is based on, for example, a packet (hereinafter referred to as “participation request packet”) that includes information (address) indicating a request to join a group and a requesting mobile terminal (that is, the status of an independent terminal). Then, it is confirmed whether or not there is an independent terminal requesting to join the group 104 among the neighboring terminals (step S102). The method for confirming the existence of an independent terminal and the method for entering a group are not limited.

  If the management terminal 102 determines in step S102 that there is an independent terminal requesting entry based on the received participation request packet, the management terminal 102 permits entry of the independent terminal into the group 104. Then, the routing table stored in the routing table storage area 161 is updated (step S103). In this case, route information related to a terminal that is permitted to enter (an independent terminal that is permitted to enter transitions to the state of a subordinate terminal) is added to the routing table.

  If the management terminal 102 does not receive the participation request packet within a certain period of time in step S102, and determines that there is no independent terminal requesting entry into the group 104, the management terminal 102 ends step S103. Confirms whether or not the dependent terminal beacon transmitted from the dependent terminal that is the transmission destination of the management terminal beacon transmitted in step S101 is received (step S104).

  Here, the management terminal 102 refers to the received data (packet) and the value of the packet type 401 is 2 (that is, PT = 2) in the dependent terminal beacon 400 in the format shown in FIG. Since the source address 402 is the address of the subordinate terminal and the destination address 403 is the management terminal 102, it can be confirmed that it is a subordinate terminal.

  When the management terminal 102 determines that the subordinate terminal beacon has been received in step S104 based on the received data (packet), the management terminal 102 temporarily stores the current timer value of the timer 180 in the work area 164 of the storage unit 160. After being saved, the timer 180 is reset to the original initial value (step S105), and the timer value of the temporarily saved timer 180 (a timer for confirming the existence of the subordinate terminal) is confirmed (step S105). S106).

  Since the timer 180 activated at the transmission timing of the management terminal beacon is decremented as time elapses, the management terminal 102 sets the temporarily stored timer value to a predetermined value (for example, “0”). If it has reached, it is determined that a timeout has occurred. In addition, when a dependent terminal beacon is not received in step S104, it is considered that it is time-out.

  If the management terminal 102 determines in step S106 that a timeout has occurred, or if it has determined that a timeout has occurred because it has not received a dependent terminal beacon in step S104, information (route) Information) is deleted from the routing table stored in the routing table storage area 161 (step S107).

  In the first embodiment, the management terminal 102 cannot communicate with the management terminal (own terminal) for the subordinate terminal that is determined to have timed out (or is considered to have timed out). In addition, it is considered that it has left the group autonomously.

  Next, in step S106, when the timer value of the temporarily stored timer 180 does not reach a predetermined value (when there is remaining time), or when step S107 is ended, the management terminal 102 stores the routing table in the routing table. It is determined whether or not all the subordinate terminals described have been checked (step S108). If there are subordinate terminals to be checked, the process returns to step S101 to check the next subordinate terminal. Execute after step.

  On the other hand, the management terminal 102 that has determined that all subordinate terminals have been checked in step S108 should be managed in the group 104 to which the own terminal belongs by referring to the routing table stored in the routing table storage area 161. It is confirmed whether or not there are subordinate terminals (step S109).

  Then, as a result of confirming the number of subordinate terminals to be managed, when there is at least one subordinate terminal to be managed in the group 104, the management terminal 102 continues to maintain the state of the management terminal (step S110). On the other hand, if the subordinate terminal autonomously leaves the group 104 and there is no subordinate terminal to be managed in the group 104, the group 104 is dissolved and the state is changed to the independent terminal itself (step S111). .

  When the state transitions from the management terminal to the independent terminal, the storage content of the terminal state storage area 163 is updated to information indicating the state of the independent terminal, and the processing of the independent terminal described later (see FIG. 9) is executed. Will be.

  Here, a specific example will be described. For example, in the example illustrated in FIG. 6, the management terminal 102 first transmits a management terminal beacon to the dependent terminal 101 to confirm the location of the dependent terminal 101, and then manages the dependent terminal 103. A terminal beacon is transmitted to confirm the location of the subordinate terminal 103.

  When the management terminal 102 receives a slave terminal beacon from at least one of the slave terminal 101 and the slave terminal 103 within a certain period, the management terminal 102 maintains the state of the management terminal. When neither the dependent terminal beacon from the terminal 101 nor the dependent terminal beacon from the dependent terminal 103 is received within a certain period, the state is changed to the independent terminal.

  In the management terminal processing described above, the management terminal 102 maintains the state of the management terminal or changes to the state of the independent terminal depending on whether or not the dependent terminal beacon in step S104 is received within a certain time. If the subordinate terminal beacon is received in addition to the process of determining whether or not the subordinate terminal beacon is received within a certain period of time, the value of the received power related to the subordinate terminal beacon It may be possible to execute a process for determining whether or not the threshold value has reached a predetermined threshold value.

  That is, if the management terminal 102 determines in step S104 that a dependent terminal beacon has been received, the management terminal 102 determines whether or not the value of the received power related to the dependent terminal beacon has reached a predetermined threshold value, and receives that reception. If the power value has reached the predetermined threshold value, the process proceeds to step S105. On the other hand, if the received power value has not reached the predetermined threshold value, it is assumed that the dependent terminal beacon has not been received, and step S105 is performed. The process proceeds to S106.

  Of course, also in this case, if the timer value has reached a predetermined value (for example, “0”), or if it is considered that the subordinate terminal beacon has not been received, it is timed out. As a result, step S107 is executed.

  Next, processing of the subordinate terminal will be described with reference to FIGS. FIG. 8 is a flowchart showing the processing procedure of the processing of the subordinate terminal.

  Here, although the process of the subordinate terminal 103 is demonstrated in the example shown in FIG. 6, the subordinate terminal 101 also performs the same process.

  The dependent terminal (mobile terminal that has transitioned to (transitioned to) the state of the dependent terminal) 103 transfers the dependent terminal beacon 400 having the format shown in FIG. 4 to the management terminal 102 belonging to the group 104 to which the terminal belongs. Transmit (step S201). At this time, the timer 180 is activated by the control unit 150 and decrements from a predetermined timer value (initial value). In this case, the timer 180 functions as a timer for confirming the existence of the management terminal.

  The dependent terminal beacons may be transmitted at regular intervals, random intervals, or intervals determined by a collision avoidance algorithm or the like.

  Next, the subordinate terminal 103 checks whether or not the management terminal beacon transmitted from the management terminal 102 of the group 104 (the management terminal beacon transmitted in step S101 in FIG. 7) has been received (step S202).

  Here, the slave terminal 103 refers to the received data (packet), and in the management terminal beacon 300 having the format shown in FIG. 3, the value of the packet type 301 is 1 (that is, PT = 1), and When the transmission source address 302 is the address of the management terminal 102, it can be confirmed that it is the management terminal.

  By the way, if the subordinate terminal 103 determines that the management terminal beacon is received in step S203 based on the received data (packet), the current timer value of the timer 180 is stored in the work area 164 of the storage unit 160. After temporarily saving, the timer 180 is reset to the original initial value (step S203), and the timer value of the temporarily saved timer 180 (timer for confirming the existence of the management terminal) is confirmed ( Step S204).

  Since the timer 180 activated at the transmission timing of the subordinate terminal beacon is decremented as time elapses, the subordinate terminal 103 sets the temporarily stored timer value to a predetermined value (for example, “0”). If it has reached, it is determined that a timeout has occurred. In step S202, if the management terminal beacon is not received, it is regarded as a timeout.

  When the timer value of the timer 180 temporarily stored in step S204 does not reach a predetermined value (when there is a remaining time), the dependent terminal 103 continues to maintain the state of the dependent terminal (step S205). On the other hand, if it is determined in step S204 that a timeout has occurred, or if it is determined in step S202 that the management terminal beacon has not been received and the timeout has occurred, the state is changed to an independent terminal (step). S206).

  When the state transitions from the dependent terminal to the independent terminal, the stored contents of the terminal state storage area 163 are updated to information indicating the state of the independent terminal, and the processing of the independent terminal (see FIG. 9) described later is executed. Will be.

  In the processing of the slave terminal described above, the slave terminal 103 maintains the slave terminal or transitions to the state of the independent terminal depending on whether or not the management terminal beacon in step S202 is received within a certain time. However, in addition to the process of determining whether or not the management terminal beacon has been received within a certain time, if the management terminal beacon is received, the value of the received power related to the management terminal beacon is a predetermined threshold value. It is also possible to execute a process of determining whether or not

  That is, if the subordinate terminal 103 determines in step S202 that the management terminal beacon has been received, the subordinate terminal 103 determines whether or not the value of the received power related to the management terminal beacon has reached a predetermined threshold, and receives the reception. If the power value has reached the predetermined threshold value, the process proceeds to step S203. On the other hand, if the received power value has not reached the predetermined threshold value, it is assumed that the dependent terminal beacon has not been received, and step S203 is performed. The process proceeds to S204.

  Of course, in this case as well, in step S204, if the timer value has reached a predetermined value (for example, “0”), or if it is considered that the management terminal beacon has not been received, it is timed out. As a result, step S206 is executed.

  Next, the processing of the independent terminal will be described with reference to FIG. FIG. 9 is a flowchart showing the processing procedure of the processing of the independent terminal.

  The independent terminal searches for a management terminal of a neighboring group and requests entry into the group (step S301). There is no limitation on the method of confirming the existence of the management terminal or the method of entering the group. For example, a participation request packet including information requesting participation in the group and information (address) indicating the requesting mobile terminal (that is, the status of the independent terminal) is transmitted, for example, by broadcast. At this time, the timer 180 is activated by the control unit 150 and decrements from a predetermined timer value (initial value).

  Next, the independent terminal checks whether or not the received data (packet) indicates, for example, permission of group entry transmitted from the management terminal that has received the participation request packet (step S302).

  In step S302, when the independent terminal receives permission to enter the group from a neighboring management terminal (indicating permission to enter the group), the independent terminal enters the group to which the management terminal permitted to enter belongs. Then, the state transits to the state of the subordinate terminal (step S303).

  When the state transitions from the independent terminal to the dependent terminal, the storage content of the terminal state storage area 163 is updated to information indicating the state of the dependent terminal, and the above-described processing of the dependent terminal (see FIG. 8) is executed. Will be.

  On the other hand, in step S302, when there is no permission to join the group (when the fact indicating permission to join the group is not received), the independent terminal continues to search for the management terminal based on the timer value of the timer 180. (Step S304), and if the timer value has not reached the predetermined value (when there is remaining time), the search for the management terminal is continued and the state of the independent terminal is continuously maintained. (Step S305) On the other hand, in step S304, the timer value reaches a predetermined value (for example, “0”) and is timed out. Therefore, when the search for the management terminal is stopped, the state transitions to the state of the management terminal. (Step S306).

  When the state transitions from the independent terminal to the management terminal, the storage content of the terminal state storage area 163 is updated to information indicating the state of the management terminal, and the above-described management terminal processing (see FIG. 7) is executed. Will be.

(A-3) Effects of the First Embodiment As described above, according to the first embodiment, the management terminal can be set to an arbitrary group in the group to which the management terminal belongs for reasons such as deterioration of the propagation environment. If a dependent terminal beacon transmitted from a dependent terminal is not received within a certain period of time, it is considered that an arbitrary dependent terminal has left the group autonomously, and within the group to which the management terminal belongs If all subordinate terminals autonomously leave the group, the group disbands and becomes an independent terminal itself, so the group is reconstructed only with the management terminal and subordinate terminals that can perform wireless communication. Is possible.

  In addition, each subordinate terminal that is determined to be difficult to communicate due to reasons such as deterioration of the propagation environment autonomously leaves the group, and the group management terminal is subordinate terminal when communication with the subordinate terminal is difficult Therefore, the management terminal can own and manage information (route information and the like) of subordinate terminals that can communicate sequentially.

  Further, information on terminals that can be communicated is notified from the management terminal to all subordinate terminals belonging to the group by the management terminal beacon, and all the terminals (management terminal and subordinate terminals) belonging to the group can communicate with each other. Since it is a terminal that can be used, a useless radio wave is not transmitted to a terminal that cannot communicate. As a result, it is possible to prevent interference with radio waves transmitted from the communicating terminal.

  Therefore, according to the first embodiment, useless transmission of radio waves can be suppressed and overall throughput can be improved.

(B) Second Embodiment In the second embodiment, processing when communication is performed between groups will be described.

(B-1) Configuration of Mobile Radio Communication System The mobile terminal configuring the mobile radio communication system according to the second embodiment has the same configuration as the mobile terminal according to the first embodiment shown in FIG. Therefore, the description is omitted here.

  Note that the routing table stored in the routing table storage area 161 of the storage unit 160 is provided with columns in which the route information of terminals in the group and the route information of terminals outside the group are described. In the initial stage, it is assumed that only route information of terminals in the group is described.

  In the second embodiment, the group is composed of one management terminal and a plurality of subordinate terminals as in the case of the first embodiment.

  FIG. 10 is a diagram illustrating communication between groups in the mobile radio communication system in which a plurality of groups are formed.

  In the mobile radio communication system, a first group 510 and a second group 520 are formed. The group 510 includes a terminal (subordinate terminal) 511 that has transitioned to a dependent terminal state, a terminal (management terminal) 512 that has transitioned to a management terminal state, and a terminal (subordinate terminal) that has transitioned to a dependent terminal 513. The group 520 includes a terminal (management terminal) 521 that has transitioned to the state of the management terminal and a terminal (subordinate terminal) 522 that has transitioned to the subordinate terminal.

  In the second embodiment, the subordinate terminal 511, the management terminal 512, and the subordinate terminal 513 are simply referred to as “terminals” such as the terminal 511, the terminal 512, and the terminal 513, respectively, and the management terminal 521 and the subordinate terminal 522 is also simply expressed as “terminal”, like the terminal 521 and the terminal 522, respectively. In addition, the description of a management terminal or a subordinate terminal is also used as needed.

  By the way, in communication within a group, each terminal (mobile terminal) uses a beacon to exchange information in a routing table within the group, and transmits a packet according to the routing table.

  On the other hand, when a transmission source terminal belonging to a predetermined group communicates with a terminal that does not exist in the predetermined group, it searches for a group to which a desired terminal as a transmission destination belongs. The search is performed by broadcasting a search packet (hereinafter referred to as “search packet”).

  The desired terminal that has received the search packet transmits a reply packet (hereinafter referred to as “reply packet”) to the search packet to the terminal that has transmitted the search packet. At this time, the address of the desired terminal that transmits the reply packet and the address of the management terminal of the group to which the desired terminal belongs are set (described) in the header of the reply packet.

  Then, the source terminal that has received the reply packet adds information on the desired terminal to the routing table based on the contents set in the header of the reply packet. As a result, the transmission source terminal can determine which management terminal group the desired terminal belongs to by referring to the latest routing table.

  In the second embodiment, there is a terminal that acts as a relay between the group and another group on the route to which the packet is returned. Hereinafter, a terminal operating as a relay role is referred to as an “intermediary terminal” (gateway). Here, one of the terminals belonging to the group is configured to function as an intermediary terminal (gateway). That is, any terminal in the group can be an intermediary terminal.

  Terminals belonging to a predetermined group communicate with terminals belonging to adjacent groups via an intermediary terminal. There may be a plurality of intermediary terminals in a group, and there is an intermediary terminal in charge corresponding to each adjacent group.

  The terminal of the transmission source receives the reply packet, and in the processing after the route information for the desired terminal can be acquired, even if it is a terminal outside the group, it is not broadcast but information of the owning routing table According to unicast.

(B-2) Processing Operation of Mobile Radio Communication System Next, the processing operation according to the communication control method of the mobile radio communication system according to the second embodiment will be described.

  In a plurality of communication target groups in which wireless communication is performed, a predetermined terminal among management terminals and subordinate terminals belonging to the own group functions as a terminal (mediation terminal = gateway) having a relay function of communication with respect to another group. .

  For example, when a transmission source terminal (management terminal or subordinate terminal) belonging to the first group communicates with a desired terminal (management terminal or subordinate terminal) belonging to the second group, the following (1) to (1) Communication is performed according to the processing procedure of 6).

  (1) The transmission source terminal investigates the routing table shared within the first group, and if the result of this investigation is that the routing information regarding the desired terminal does not exist in the routing table, the search packet is transmitted by broadcast. To do.

  (2) A desired terminal that has received the broadcast search packet returns a reply packet to the transmission source terminal by unicast.

  (3) The transmission source terminal receives the return packet unicast from the desired terminal, thereby acquiring the route information regarding the desired terminal belonging to the second group.

  (4) The transmission source terminal transmits a search packet by broadcast, and receives a reply packet transmitted by unicast from a desired terminal that has received the search packet. The route information related to the terminal is described in a routing table shared in the first group to which the transmission source terminal belongs.

  (5) The transmission source terminal is connected as a transmission destination via a terminal (mediation terminal) having a relay function related to the first group and a terminal (mediation terminal) having a relay function related to the second group. Route information to the second group is acquired, and communication with a desired terminal belonging to the second group is performed based on the acquired route information.

  (6) After the process of (5) above, for the desired terminals belonging to the second group, all the terminals belonging to the predetermined group including the transmission source terminal that has performed communication according to (5) above Terminals (management terminals and subordinate terminals) communicate according to the route information of the latest routing table.

  That is, when a transmission source terminal tries to communicate with an external group via an intermediary terminal, it does not know at first that a desired terminal exists in the external group. For example, it transmits a search packet by broadcast. The existence of the desired terminal is confirmed.

  Then, when the transmission source terminal can confirm the presence of the desired terminal by receiving the reply packet from the desired terminal, the route information regarding the desired terminal is described in the routing table. In the subsequent processing, all terminals in the group can communicate with terminals in the external group according to the routing table.

  Next, detailed processing operations of the mobile radio communication system according to the second embodiment will be described with reference to FIGS.

  Here, an example of communication between groups in the mobile radio communication system will be described with a specific example shown in FIG.

  In the mobile radio communication system shown in FIG. 10, each terminal can directly communicate only with an adjacent terminal. Further, it is assumed that the initial stage starts from a state in which communication is not possible with terminals outside the group.

  Here, processing when a terminal (subordinate terminal) 513 belonging to group 510 communicates with a terminal (management terminal) 521 belonging to group 520 will be described.

  The terminal 513 refers to the routing table owned by the terminal 513, that is, the routing table stored in the routing table storage area 161 of the storage unit 160.

  As described above, this routing table is provided with columns in which route information of terminals in the group and route information of terminals outside the group are described. In the initial stage, it is assumed that only route information of terminals in the group is described.

  Therefore, since the route information of the terminal 521 is not described in the route information column in the routing table and outside the group in the routing table, the terminal 513 determines that the terminal 521 is a terminal that exists outside the group. be able to. Therefore, the terminal 513 transmits a search packet by broadcast in order to search for the terminal 521 with respect to a terminal outside the group.

  An example of the format of this search packet is shown in FIG. In this format, the search packet 600 includes a packet type 601, a source address 602, a search terminal address 603, and a sequence number 604, as shown in FIG.

  As shown in FIG. 11, an identification number for distinguishing from other packets is set (description) in the packet type 601. Here, the packet type of the search packet is “3” (PT = 3 in FIG. 11). In the transmission source address 602, the address of the terminal that transmits the search packet is set. Here, the address of the terminal 513 is set. In the search terminal address 603, the address of the terminal to be searched is set. Here, the address of the terminal 521 is set. The sequence number 604 is set with a continuous number that is incremented each time a search packet is transmitted.

  In FIG. 10, when it is assumed that the search packet transmitted from the terminal 513 reaches the adjacent terminal, the search packet reaches the terminal 512 and the terminal 521 within the communication range of the terminal 513. Therefore, the terminal 521 receives the search packet and analyzes the content of the received search packet, thereby knowing that the terminal 513 is searching for itself. Therefore, the terminal 521 transmits a reply packet to the search packet to the terminal 513 in order to notify the terminal 513 of its own existence.

  An example of the format of this reply packet is shown in FIG. In this format, the reply packet 700 includes a packet type 701, a transmission source address 702, a search source address 703, and a group ID 704, as shown in FIG.

  In the packet type 701, as shown in FIG. 12, an identification number for distinguishing from other packets is set (described). Here, the reply packet type is “4” (PT = 4 in FIG. 12). In the transmission source address 702, an address of a terminal that transmits a reply packet is set. Here, the address of the terminal 521 is set. In the search source address 703, the address of the terminal that first requested the search is set. Here, the address of the terminal 513 is set. The group ID to which the user (terminal 521 that transmits the reply packet) belongs is set as the group ID 704. For example, the address of the group management terminal may be used. Here, since the terminal is the group management terminal, the address of the terminal 521 is set as the group ID.

  By the way, the terminal 513 that has received the reply packet can determine the address of the terminal 521 and the group ID of the group 520 to which the terminal 521 belongs by analyzing the contents of the reply packet. In addition, it can be seen that the terminal 513 is adjacent to terminals belonging to the group 520 and can directly communicate with the terminals 521 in the group 520.

  Similarly, it can be understood that the terminal 521 can directly communicate with the terminals 513 belonging to the group 510 by analyzing the contents of the search packet from the terminal 513.

  Therefore, in FIG. 10, the terminal 513 is in charge as an intermediary terminal (gateway) for the group 520 of the group 510, and the terminal 521 is in charge as an intermediary terminal (gateway) for the group 510 of the group 520. The selection of the mediation terminal will be described later.

  Within a group, beacon is used to exchange information of routing tables owned by each other. For example, in the group 510, the terminal 513 transmits a subordinate terminal beacon describing information of the routing table to the terminal 512 that is the management terminal.

  On the other hand, the terminal 512 serving as the management terminal transmits the information of the routing table to all the subordinate terminals belonging to the group 510 to which the terminal 512 belongs using the management terminal beacon. In this case, the management terminal beacon in which the latest routing table information is described is transmitted to terminals that are subordinate terminals other than the terminal 513 that transmitted the subordinate terminal beacon (the terminal 511 that is a subordinate terminal in this example). To do.

  Therefore, by transmitting and receiving a beacon by each terminal in the group 510, route information to the terminal 521 belonging to the group 520 is transmitted to all terminals belonging to the group 510.

  Similarly to the above, also in the group 520, the route information to the terminal 513 belonging to the group 510 is transmitted to all the terminals belonging to the group 520 by transmission / reception of beacons by each terminal in the group 520.

  Each terminal of group 510 and each terminal of group 520 store the latest routing table information (route information) transmitted as described above in routing table storage area 161 of storage unit 160.

  In the subsequent processing, for example, when the terminal 511 belonging to the group 510 performs communication with the terminal 521 belonging to the group 520, the routing table already owned by itself, that is, the routing table storage area 161 of the storage unit 160 is stored. Since the routing information of the terminal 521 exists in the routing table stored in the terminal 511, the terminal 511 can transmit the packet to the terminal 521 by unicast according to the information of the routing table. In this case, the packet is transmitted to the terminal 521 through the terminal (management terminal) 512 and the terminal (subordinate terminal = mediation terminal) 513.

  Similarly to the above, even when the terminal 522 belonging to the group 520 wants to perform communication with the terminal 513 belonging to the group 510, the terminal 522 transmits the packet by unicast according to the routing information of the already owned routing table. Can be sent to. In this case, the packet is transmitted to the terminal 513 via the terminal (management terminal = mediation terminal) 521.

  Next, selection of an intermediary terminal will be described with reference to FIG. The example shown in FIG. 13 has the same configuration as that of the example shown in FIG.

  In the group 510 illustrated in FIG. 13, the terminal 511 can directly communicate with the terminal 512 and each of the terminals 521 belonging to the group 520. Terminal 512 can communicate directly with each of terminal 511 and terminal 513. The terminal 513 can directly communicate with the terminal 512 and each of the terminals 521 belonging to the group 520.

  In the group 520, the terminal 521 can directly communicate with each of the terminal 522, the terminal 511 belonging to the group 510, and the terminal 513. Terminal 522 can communicate directly with terminal 521.

  Furthermore, in the first stage, it is assumed that the terminal belonging to the group 510 and the terminal belonging to the group 520 start from a state where communication is not possible.

  Consider a case where communication is performed from the terminal 512 belonging to the group 510 to the terminal 521 belonging to the group 520 under such preconditions.

  The terminal 512 can recognize that the terminal 521 does not exist at least in the group without referring to its own routing table. Therefore, the terminal 512 searches for the terminal 521 by transmitting a search packet by broadcasting. The search packet is received by the terminal 511 and the terminal 513 that exist in a range where the search packet can be directly communicated with the terminal 512.

  The terminal 511 and the terminal 513 that have received the search packet refer to the routing table (routing table stored in the routing table storage area 161) owned by the terminal, respectively, so that the terminal 521 is the same as the terminal 512. Therefore, it can be understood that the terminal 512 is a terminal outside the group.

  Therefore, the terminal 511 and the terminal 513 broadcast and transmit the received search packet, respectively. However, if the search packet is relayed by broadcast many times, the traffic increases, so the number of broadcasts may be limited and relaying may be performed only within a certain range.

  By the way, the search packets broadcast from the terminals 511 and 513 arrive at the terminals 521 belonging to the group 520, respectively.

  By analyzing the arrived search packet, the terminal 521 can know that the terminal 521 has arrived from a terminal that is not described in the routing table owned by the terminal 521 (the routing table stored in the routing table storage area 161). Therefore, the terminal 521 adds the information (route information) of the terminal 512 to the column describing the route information of the terminals outside the group provided in the routing table.

  In the second embodiment, a terminal 521 that receives a packet from a terminal of the group 510 for the first time is used as an intermediary terminal.

  There may be a time lag in the arrival of packets depending on the communication environment. Here, it is assumed that the search packet via terminal 513 arrives at terminal 521 before the search packet via terminal 511.

  In this case, with respect to the received search packet, the terminal 521 gives priority to the search packet from the terminal 513 that has arrived first, and transmits a reply packet to this search packet. Even if a search packet of terminal 511 that arrives later is received, it is ignored.

  At this time, it is necessary for the terminal 521 to confirm that the two search packets from the terminal 511 and the terminal 513 are packets having the same contents transmitted from the terminal 512 at the same time. Therefore, for example, it is possible to confirm whether or not packets having the same sequence number are received by adding consecutive numbers (sequence numbers) to the packet header. That is, in the two received search packets, if the sequence numbers set in the sequence number 604 of the search packet 600 having the format shown in FIG. 11 are the same, the two search packets are packets having the same contents. I understand.

  Now, the terminal 513 that has received the reply packet from the terminal 521 relays the reply packet to the terminal 512. By receiving the reply packet transmitted from the terminal 521 of the group 520, the terminal 513 is in charge of the existence of the group 520 and the terminal 521 as an intermediary terminal in the group 520, and operates as an intermediary terminal in the subsequent processing. Recognize that

  That is, since the reply packet 700 has the format shown in FIG. 12, the terminal 513 can recognize the presence of the group 520 by referring to the group ID 704 in the received reply packet, By referring to the original address 702, it can be recognized that the terminal that has transmitted the reply packet is the terminal 521, and as a result, the terminal 521 that has received the packet from the group 510 terminal for the first time is the intermediary terminal. Can be recognized.

  Note that the same reply packet as the reply packet sent from the terminal 521 to the terminal 513 arrives at the terminal 511, but the terminal 511 ignores this reply packet because it is not the destination.

  By the way, the terminal 512 that has received the reply packet from the terminal 513 knows that the terminal 521 is a terminal belonging to the group 520 for the first time by analyzing the reply packet. In addition, it can be understood that the terminal 512 can perform communication with the terminal 521 by requesting the terminal 513 to perform relay, with the terminal 513 serving as an intermediary terminal.

  In the group 510, beacons are periodically transmitted and received between the management terminal and the subordinate terminal. Therefore, the terminal 511 receives the beacon transmitted from the terminal 512, and analyzes the beacon to the group 520. When communicating with the terminal 521 to which it belongs, it turns out that it can communicate via the terminal 521 which is a management terminal.

  FIG. 14 is a diagram for explaining communication between groups in the mobile radio communication system when a plurality of intermediary terminals exist in the group.

  The mobile radio communication system shown in FIG. 14 has a configuration in which a third group 530 is added to the configuration of the mobile radio communication system shown in FIG. This group 530 is formed adjacent to the terminal 511.

  At this time, when the terminal 512 belonging to the first group 510 performs communication with the terminal 531 belonging to the third group 530, the same contents as described with reference to FIGS. By executing the processing, the terminal 511 is in charge of the mediation terminal in the group 510, and the terminal 531 is in charge of the mediation terminal in the group 530. Here, a description of a method for selecting an intermediary terminal and a process for the terminal 512 to communicate with the terminal 531 will be omitted. In this case, the group 510 includes a plurality (two) of intermediary terminals of the terminal 511 and the terminal 513.

  In the second embodiment, the terminal 521 that receives a packet for the first time from the terminals of the group 510 is used as an intermediary terminal. However, the present invention is not limited to this, and the following may be used.

  That is, a received packet may be monitored for a certain time, and a terminal having the strongest radio wave may be used as an intermediary terminal. Further, not only the strength of the radio waves of the adjacent terminals but also the stability of the route until the packet is sent may be considered. In this case, it can be realized by providing each terminal with a network monitoring function and transmitting the information in a packet.

(B-3) Effect of Second Embodiment As described above, according to the second embodiment, when communication between groups is performed, a terminal of a transmission source has a desired destination as a transmission destination. When the route information of the terminal does not exist in the routing table of the group to which the transmission source terminal belongs, the search packet is transmitted by broadcast, and a reply packet transmitted by unicast from the desired terminal that has received the search packet is transmitted. By receiving, it is possible to obtain route information regarding a desired terminal belonging to another group.

  Therefore, the terminals in a plurality of adjacent groups can acquire the route information related to the terminals belonging to other groups and perform relay communication based on the acquired route information, thereby expanding the entire communication range. it can.

(C) Third Embodiment In the third embodiment, processing when communication is performed between groups by a method different from that of the second embodiment will be described.

(C-1) Configuration of Mobile Radio Communication System The mobile terminal configuring the mobile radio communication system according to the third embodiment has the same configuration as that of the mobile terminal according to the first embodiment shown in FIG. Therefore, the description is omitted here.

  FIG. 15 shows an example of the configuration of a mobile radio communication system according to the third embodiment.

  In this mobile radio communication system, a first group 810 and a second group 820 are formed as in the case of the second embodiment shown in FIG.

  The group 810 includes a terminal (subordinate terminal) 811 that has transitioned to the dependent terminal state, a terminal (management terminal) 812 that has transitioned to the management terminal state, and a terminal (subordinate terminal) 813 that has transitioned to the dependent terminal. Consists of The group 820 includes a terminal (management terminal) 821 that has transitioned to the state of the management terminal and a terminal (subordinate terminal) 822 that has transitioned to the subordinate terminal.

  Also in the third embodiment, the subordinate terminal 811, the management terminal 812, and the subordinate terminal 813 are simply expressed as “terminal” as the terminal 811, the terminal 812, and the terminal 813, respectively. The terminal 822 is also simply expressed as “terminal”, like the terminal 821 and the terminal 822, respectively. In addition, a management terminal or a subordinate terminal is written together as needed.

  Each terminal is always transmitted from other terminals (for example, adjacent terminals) located within the communication range regardless of other terminals in the group to which the own terminal belongs or each terminal in the other group. Data signals (eg, beacons) to be intercepted. In addition, a terminal that intercepts a beacon transmitted from another terminal transmits information of a routing table included in the beacon to another terminal in the group to which the terminal belongs.

(C-2) Processing Operation of Mobile Radio Communication System Next, the processing operation according to the communication control method of the mobile radio communication system according to the third embodiment will be described.

  When a transmission source terminal (management terminal or subordinate terminal) belonging to the first group communicates with a desired terminal (management terminal or subordinate terminal) belonging to the second group, the following (1) to (5) Communication is performed in accordance with the processing procedure.

  (1) A transmission source terminal (management terminal or subordinate terminal) belonging to a predetermined group (first group) is a neighboring terminal that is a management terminal or subordinate terminal belonging to another group (second group). Intercept transmitted beacons.

  (2) A terminal belonging to a predetermined group that has intercepted a beacon transmitted from a neighboring terminal belonging to another group (transmission source terminal) is based on the routing table included in the intercepted beacon. The contents of the routing table owned by the transmission source terminal (the terminal that intercepted the beacon) are updated based on the routing table routing information related to the other group acquired in step (b).

  (3) The transmission source terminal communicates with another group based on the routing information of the routing table related to the other group acquired based on the routing table included in the intercepted beacon.

  (4) The transmission source terminal transmits a beacon including route information in the updated routing table to other terminals belonging to a predetermined group to which the transmission source terminal belongs.

  (5) Other terminals belonging to the predetermined group also communicate with other groups based on the updated routing table routing information included in the beacon transmitted from the transmission source terminal.

  Next, detailed processing operations of the mobile radio communication system according to the third embodiment will be described with reference to FIG.

  In the mobile radio communication system shown in FIG. 15, each terminal can communicate directly only with an adjacent terminal. Further, it is assumed that the terminals belonging to the first group 810 and the terminals belonging to the second group 820 cannot communicate with each other at an initial stage.

  Within a group, beacon is used to exchange information of routing tables owned by each other. This beacon reaches not only terminals in the group but all terminals within the communication range. For example, in the group 810, when the terminal 813 transmits a beacon (subordinate terminal beacon) in which routing table information is described to the terminal 812 that is the management terminal, the subordinate terminal beacon is the adjacent terminal 821. Also reach.

  Therefore, the terminal 821 intercepts the subordinate terminal beacon transmitted from the terminal 813 and analyzes the routing table included in the subordinate terminal beacon, thereby acquiring the routing table information (route information) of the group 810. be able to.

  In this way, each terminal can acquire information (route information) of the routing table outside the group by intercepting information (route information of the routing table) from a beacon generated in the vicinity.

  Further, the terminal 821 can transmit route information obtained by intercepting the beacon transmitted from the terminal 813 to the terminals in the group 820. This is feasible because a group always exchanges beacons with each other and exchanges routing information in a routing table owned by the terminal itself.

  Therefore, in the group 820, even if there is a terminal 822 located in a range where radio waves transmitted from terminals belonging to the group 810 do not reach directly, the terminal 822 transmits a beacon (management terminal beacon) transmitted from the terminal 821. By receiving and analyzing the management terminal beacon, the route information of the group 810 can be acquired at the same time.

  Similarly to the above, the terminal 813 can also acquire the route information of the routing table of the group 820 by intercepting the beacon (management terminal beacon) transmitted by the terminal 821 and acquiring the management terminal beacon.

  In addition, although the route information of the routing table described in the beacon changes in real time, each terminal overwrites the routing table based on the contents of the beacon each time a beacon is received. That is, since the routing table stored in the routing table storage area 161 of the storage unit 160 is updated (overwritten) based on the received beacon, the latest routing table can be maintained.

(C-3) Effect of Third Embodiment As described above, according to the third embodiment, each terminal can always intercept a beacon transmitted by another terminal, thereby obtaining a desired terminal. Route information regarding the desired terminal can be acquired and recognized. Therefore, when the transmission source terminal does not know the route information of the desired terminal as the transmission destination, for example, it is not necessary to broadcast a search packet for searching for the desired terminal. Traffic volume can be reduced.

(D) Other Embodiments In the first to third embodiments described above, a program that causes a computer capable of wireless communication to function as a mobile terminal, a management terminal, a subordinate terminal, or an independent terminal, and this A computer-readable recording medium (compact disc, ROM, etc.) in which the program is recorded can be provided. In this case, the program may be described in any programming language.

  In the first to third embodiments described above, the program corresponding to the processing procedure of the terminal described above (see FIGS. 7 to 9), the mobile terminal is the three terminals of the management terminal, the subordinate terminal, and the independent terminal. However, the present invention is not limited to this, and is recorded as follows in the program storage unit such as the ROM of the mobile terminal. May be.

  That is, the above program can be recorded on a computer-readable recording medium such as a compact disk, a flexible disk, a hard disk, a magneto-optical disk, a digital video disk, a magnetic tape, and a semiconductor memory, and these recording media are independent of the computer. In addition to being distributed and sold, the program can be directly distributed and sold by transmitting the program through a communication network including a wireless communication network.

  When the program is stored in a computer-readable recording medium and distributed, the program recorded on the recording medium is installed after the mobile terminal (for example, a notebook personal computer) is installed. The program is executed by a control means such as a CPU. As an installation destination of this program, there is a memory such as a RAM or a storage device such as a hard disk. The mobile terminal loads the program stored in the storage device into the main storage device and executes it as necessary.

  The mobile terminal is connected to a computer such as a server device or a host computer via a communication line network, and the mobile terminal downloads the program from the server device or the computer and then executes the program. May be. In this case, the download destination of the program includes a memory such as a RAM and a storage device (recording medium) such as a hard disk. And the said mobile terminal loads the said program memorize | stored in this memory | storage device to the main memory unit as needed, and executes it.

  Further, the format of the route information held between the mobile terminals and exchanged between the mobile terminals is not limited to the table format (routing table).

  INDUSTRIAL APPLICABILITY The present invention can be used in a mobile radio communication system, and in particular, in a mobile radio communication system that performs radio communication between mobile terminals equipped with radio communication means using the VHF band, such as a self-employed disaster prevention radio communication system. Is available.

It is a figure explaining the state transition of the mobile terminal which concerns on 1st Embodiment. It is a block diagram which shows the structure of the mobile radio | wireless communications system which concerns on 1st Embodiment. It is a figure which shows the example of a format of the management terminal beacon which concerns on 1st Embodiment. It is a figure which shows the example of a format of the dependent terminal beacon which concerns on 1st Embodiment. It is a block diagram which shows the structure of the mobile terminal which is a component of the mobile radio | wireless communications system which concerns on 1st Embodiment. It is a figure explaining the communication in the group in the mobile radio | wireless communications system which concerns on 1st Embodiment. It is a flowchart which shows the process sequence of the process of the management terminal which concerns on 1st Embodiment. It is a flowchart which shows the process sequence of the process of the subordinate terminal which concerns on 1st Embodiment. It is a flowchart which shows the process sequence of the process of the independent terminal which concerns on 1st Embodiment. It is a figure explaining the communication between groups in the mobile radio | wireless communications system which concerns on 2nd Embodiment. It is a figure which shows the example of a format of the search packet which concerns on 2nd Embodiment. It is a figure which shows the example of a format of the reply packet which concerns on 2nd Embodiment. It is a figure explaining selection of a mediation terminal at the time of communication between groups in a mobile radio communications system concerning a 2nd embodiment. It is a figure explaining the communication between groups in the mobile radio | wireless communications system which concerns on 2nd Embodiment. It is a figure explaining the communication between groups in the mobile radio | wireless communications system which concerns on 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 20, 30 ... Mobile terminal, 40 ... Group, 110 ... Antenna, 120 ... Radio transmission / reception unit, 130 ... Communication processing unit, 140 ... Program storage unit, 150 ... Control unit, 160 ... Storage unit, 161 ... Routing table storage Area 162, position information storage area, 163 terminal area storage area, 164 work area, 170 position information detection unit, 180 timer, 201 management terminal, 202 subordinate terminal, 203 independent terminal.

Claims (18)

A mobile radio communication system having a plurality of mobile terminals performing radio communication,
Each of the plurality of mobile terminals
A management terminal that belongs to a predetermined group and manages route information shared by the predetermined group and performs wireless communication, and performs wireless communication according to information on route information that belongs to the predetermined group and is notified by wireless communication from the management terminal. A mobile radio communication system, wherein the mobile radio communication system functions as a terminal capable of transitioning to a state of three terminals, a subordinate terminal to perform or an independent terminal not belonging to any group. The management terminal
When a dependent terminal beacon transmitted from any dependent terminal belonging to the predetermined group is received within a certain time, the state of the management terminal is continued,
If the beacon transmitted from the arbitrary subordinate terminal is not received within a certain period of time, the arbitrary subordinate terminal is regarded as autonomously leaving the predetermined group,
The state is changed from a management terminal to an independent terminal when a beacon transmitted from the dependent terminal is not received within a certain period of time for all the dependent terminals belonging to the predetermined group. The mobile radio communication system according to 1. The management terminal
If the received power related to the beacon when a beacon transmitted from an arbitrary subordinate terminal belonging to the predetermined group is received within a certain period of time has reached a predetermined threshold, the state of the management terminal is continued. And
When the received power related to the beacon when the beacon transmitted from the arbitrary dependent terminal is received within a predetermined time does not reach the predetermined threshold, or the beacon transmitted from the arbitrary dependent terminal is constant If it cannot be received in time, it is assumed that the arbitrary subordinate terminal has left the predetermined group autonomously,
When all subordinate terminals belonging to the predetermined group autonomously leave the predetermined group and no subordinate terminals exist in the predetermined group, the state is changed from the management terminal to the independent terminal. The mobile radio communication system according to claim 1 or 2. The subordinate terminal is
When the beacon transmitted from the management terminal is received within a certain time, the state of the subordinate terminal is continued,
The mobile radio communication system according to claim 1, wherein when the beacon transmitted from the management terminal is not received within a certain time, the state is changed from the subordinate terminal to the independent terminal. The subordinate terminal is
When the received power related to the beacon when the beacon transmitted from the management terminal is received within a certain time has reached a predetermined threshold, the state of the dependent terminal is continued,
When the received power related to the beacon when the beacon transmitted from the management terminal is received within a certain time does not reach a predetermined threshold, or when the beacon transmitted from the management terminal cannot be received The mobile radio communication system according to claim 1 or 4, wherein the state transitions from a dependent terminal to an independent terminal. The above independent terminal
During the period of searching for nearby management terminals by wireless communication, the state of the independent terminal is continued,
When entry from the management terminal discovered by the search to the group to which the management terminal belongs is permitted, the state is transitioned from the independent terminal to the subordinate terminal,
If entry from the management terminal discovered by the search to the group to which the management terminal belongs is not permitted, or if the management terminal cannot be found as a result of the search, the state is changed from the independent terminal to the management terminal. The mobile radio communication system according to claim 1. Mobile radio communication in which a plurality of groups formed by the management terminal in the mobile radio communication system according to any one of claims 1 to 3 and the subordinate terminal in the mobile radio communication system according to claim 1, 4 or 5 exist. A system,
When the management terminal or subordinate terminal belonging to the first group as the transmission source terminal communicates with the management terminal or subordinate terminal belonging to the second group as the desired destination terminal,
The transmission source terminal investigates the route information shared in the first group, and if the investigation result shows that the route information related to the desired terminal does not exist in the route information, the search terminal broadcasts the search data. Send in
The desired terminal that has received the broadcast search data returns the reply data to the transmission source terminal by unicast,
The mobile radio communication system, wherein the transmission source terminal receives the return data unicast from the desired terminal to acquire route information regarding the desired terminal belonging to the second group. In a plurality of communication target groups in which wireless communication is performed,
A predetermined terminal among the management terminals and subordinate terminals belonging to its own group functions as a terminal having a relay function of communication with respect to another group,
When the source terminal belonging to the first group communicates with the desired terminal belonging to the second group,
The transmission source terminal passes through the terminal having the relay function related to the first group and the terminal having the relay function related to the second group to the second group as a transmission destination. The mobile radio communication system according to claim 7, wherein communication with the desired terminal belonging to the second group is performed based on the acquired route information. The transmission source terminal transmits the search data by broadcasting, and receives the reply data transmitted by unicast from the desired terminal that has received the search data to the second group acquired. Describe the route information related to the desired terminal to which it belongs in the route information shared within the first group to which the transmission source terminal belongs,
The management terminal and subordinate terminal belonging to the predetermined group communicate with the desired terminal belonging to the second group according to the latest route information. Mobile radio communication system. Mobile radio communication in which a plurality of groups formed by the management terminal in the mobile radio communication system according to any one of claims 1 to 3 and the subordinate terminal in the mobile radio communication system according to claim 1, 4 or 5 exist. A system,
A management terminal or a subordinate terminal belonging to a predetermined group intercepts a beacon transmitted from a neighboring terminal and a management terminal or subordinate terminal belonging to another group, and based on the path information included in the intercepted beacon. A mobile radio communication system characterized in that communication is performed with respect to the other group based on the path information related to the other group acquired in (1).   A terminal that belongs to the predetermined group and has intercepted a beacon transmitted from a neighboring terminal belonging to the other group can be assigned to another group acquired based on the route information included in the intercepted beacon. Based on the related route information, the content of the route information owned by the terminal that intercepted the beacon is updated, and a beacon including the updated route information is transmitted to other terminals belonging to the predetermined group. The mobile radio communication system according to claim 10. A communication control method for a mobile radio communication system having a plurality of mobile terminals performing radio communication,
Each of the plurality of mobile terminals
A management terminal that manages path information that belongs to a predetermined group and that is shared by the predetermined group, a subordinate terminal that belongs to the predetermined group and performs wireless communication according to information on the path information notified from the management terminal, or any group Functions as a terminal that can transition to the state of three terminals, an independent terminal that does not belong to
Dynamically construct a communication management terminal, or a group to which only communication management terminals and subordinate terminals belong,
A communication control method for a mobile radio communication system, characterized in that terminals belonging to the constructed group perform radio communication based on route information of route information related to the group. Mobile radio communication in which a plurality of groups formed by the management terminal in the mobile radio communication system according to any one of claims 1 to 3 and the subordinate terminal in the mobile radio communication system according to claim 1, 4 or 5 exist. A communication control method for a system,
When the management terminal or subordinate terminal belonging to the first group as the transmission source terminal communicates with the management terminal or subordinate terminal belonging to the second group as the desired destination terminal,
The transmission source terminal investigates the route information shared in the first group, and if the investigation result shows that the route information related to the desired terminal does not exist in the route information, the search terminal broadcasts the search data. Send in
The desired terminal that has received the broadcast search data returns the reply data to the transmission source terminal by unicast,
The mobile terminal of the mobile radio communication system characterized in that the transmission source terminal obtains route information regarding the desired terminal belonging to the second group by receiving unicast reply data from the desired terminal. Communication control method. In a plurality of communication target groups in which wireless communication is performed,
A predetermined terminal among the management terminals and subordinate terminals belonging to its own group functions as a terminal having a relay function of communication with respect to another group,
When the source terminal belonging to the first group communicates with the desired terminal belonging to the second group,
The transmission source terminal is connected to the second group as a transmission destination via the terminal having the relay function related to the first group and the terminal having the relay function related to the second group. The communication control method for a mobile radio communication system according to claim 13, wherein route information is acquired and communication is performed with respect to the desired terminal belonging to the second group based on the acquired route information. The transmission source terminal belongs to the second group acquired by transmitting search data by broadcast and receiving reply data transmitted by unicast from the desired terminal that has received the search data. The route information related to the desired terminal is described in the route information shared in the first group to which the transmission source terminal belongs,
The management terminal and subordinate terminal belonging to a predetermined group communicate with the desired terminal belonging to the second group according to the latest information on the route information. A communication control method for a mobile radio communication system. Mobile radio communication in which a plurality of groups formed by the management terminal in the mobile radio communication system according to any one of claims 1 to 3 and the subordinate terminal in the mobile radio communication system according to claim 1, 4 or 5 exist. A communication control method for a system,
A management terminal or a subordinate terminal belonging to a predetermined group intercepts a beacon transmitted from a neighboring terminal and a management terminal or subordinate terminal belonging to another group, and based on the path information included in the intercepted beacon. A communication control method for a mobile radio communication system, characterized in that communication is performed with respect to the other group based on the path information relating to the other group acquired in (1).   A terminal that belongs to the predetermined group and has intercepted a beacon transmitted from a neighboring terminal belonging to the other group can be assigned to another group acquired based on the route information included in the intercepted beacon. Based on the related route information, the content of the route information owned by the terminal that intercepted the beacon is updated, and a beacon including the updated route information is transmitted to other terminals belonging to a predetermined group. A communication control method for a mobile radio communication system according to claim 16. State transition conditions are stored in advance in a computer capable of wireless communication,
According to the state transition condition, the computer
It is connectable to a wireless network, has a wireless communication mode for executing wireless communication and a processing mode for executing predetermined processing other than wireless communication, and executes predetermined processing when the processing mode is designated When the mobile terminal and the wireless communication mode are designated, the mobile terminal belongs to the predetermined group, manages the route information shared by the predetermined group, and performs wireless communication, and belongs to the predetermined group As a dependent terminal that performs wireless communication according to the information of route information notified by wireless communication from the management terminal, or as an independent terminal that does not belong to any group,
A program characterized by functioning.

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