JP4156533B2 - Wireless communication system, wireless communication terminal and base station - Google Patents

Description

  The present invention relates to a wireless communication system such as a multi-hop wireless network or an ad hoc wireless network, and also relates to a wireless communication terminal and a base station used in the wireless communication system.

  When a base station communicates with a communication terminal in an area where its own signal does not reach directly, the base station communicates with the communication terminal for communication purpose by relaying the signal from the base station in multiple stages. A wireless communication system that performs is called a multi-hop wireless network. A wireless communication system in which a communication terminal communicates with a communication terminal of a communication partner via a relay by another communication terminal without using a base station is called an ad hoc wireless network.

  As a communication path control method in a multi-hop wireless network and an ad hoc wireless network, there are a table driving method and an on-demand method. In the table drive method, the communication terminal updates the route table by periodically exchanging information in the route table with an adjacent communication terminal, and searches for the communication route in advance based on this route table.

  On the other hand, in the on-demand method, the communication terminal searches for a communication path when a communication request occurs. One of these on-demand methods is AODV (Ad hoc On-Demand Distance Vector Routing). In AODV, when transmission data is generated, a transmission source communication terminal (transmission source terminal) searches for a communication path to a destination communication terminal (destination terminal).

  In this case, the source terminal transmits (broadcasts) RREQ (Route Request), which is a packet for route search, to all the surrounding terminals. As this broadcast technique, a technique called flooding is usually used. . Flooding is a technique in which data is distributed to all peripheral terminals by repeatedly transmitting broadcast data from a transmission source terminal and transferring (broadcasting) the broadcast data to all other terminals that have received the broadcast data. It is.

  In AODV, the terminal that has received the RREQ describes the identifier of the transmitting terminal included in the RREQ (the terminal that relayed this RREQ immediately before) in the routing table. The terminal indicated by this identifier is a communication partner (next hop terminal) on the source terminal side, and a transfer path (reverse path) in the direction of the source terminal is set thereby. Subsequently, the terminal that has performed the above processing rewrites the transmitting terminal identifier in the RREQ with its own identifier, and broadcasts the RREQ to surrounding terminals. The RREQ includes information indicating the number of hops (the number of terminals that relayed the RREQ), and the terminal that relayed the RREQ increases the number of hops in the RREQ by one.

  When the destination terminal receives the RREQ, the destination terminal describes the transmission terminal identifier included in the RREQ in the routing table. When a plurality of RREQs are received, the destination terminal processes only the first received RREQ, or refers to the number of hops included in the RREQ and selects the RREQ having the smallest number of hops to perform the process. The destination terminal creates an RREP (Route REPly) packet having its own identifier as the transmission terminal identifier, and unicasts the RREP to the terminal (relay terminal) indicated by the identifier described in the routing table.

  The relay terminal that has received the RREP describes the identifier of the transmission terminal included in the RREP (the terminal that relayed this RREP immediately before) in the routing table. The terminal indicated by this identifier is a communication partner (next hop terminal) on the destination terminal side, and a transfer path (forward path) in the direction of the destination terminal is set thereby. In the relay terminal that has received the RREP, since the reverse path is set when the RREQ is received, both the forward path and the reverse path indicating the communication path are set.

  The relay terminal that has performed the above processing rewrites the transmitting terminal identifier in the RREP with its own identifier, and transfers the RREP to the next relay terminal indicated by the reverse path. When the transmission source terminal receives RREP, the transmission source terminal similarly sets a forward path. Thereby, the communication path from the transmission source terminal to the destination terminal is determined. The source terminal starts communication with the destination terminal using these paths. As described above, AODV can create a single path.

Non-Patent Document 1 describes a technique for searching for a backup path or a plurality of paths that can be used simultaneously as a technique developed from AODV. In this technique, relay terminal information is stored in the RRQ packet, and the destination terminal searches for a plurality of communication paths that do not use the same terminal as a relay terminal as much as possible based on the received relay terminal information in the plurality of RREQs. To do. According to this method, it is possible to search for a plurality of communication paths using different terminals as relay terminals.
Kenji Hasebe and two others, “Extension of AODV ad hoc routing for stable communication using multiple paths”, Audio Visual Complex Information Processing Study Group Report, Information Processing Society of Japan, 2002, No. 038-22, p. 119-124

  However, in the wireless communication system using the above-described conventional route search method, the intervals between the plurality of communication routes are not considered. Further, it has not been considered that the radio waves of the relay terminals on the communication path reach or do not reach the relay terminals on other communication paths. Thereby, for example, even if a plurality of communication paths can be formed, a communication path is formed in which radio waves from a relay terminal on one communication path reach a relay terminal on another communication path. Cheap. That is, when a plurality of these communication paths are used at the same time, a phenomenon such as a decrease in throughput occurs due to interference (radio wave interference).

  The present invention has been made in view of the above-described problems, and is capable of searching for a plurality of communication paths and spare relay terminals while considering a communication range between relay terminals on different communication paths. An object is to provide a communication system, a wireless communication terminal, and a base station.

  The present invention has been made to solve the above-described problem, and the invention according to claim 1 is directed to a transmission source apparatus that broadcasts route search information and a transmission path including one or more relay terminals. A destination device that communicates with the destination device, determines a next hop terminal based on the route search information and the first response information transmitted by the destination device, and relays the route search information and the first response information In the wireless communication system including the relay terminal, the transmission source device includes first transmission means for transmitting the route search information including route information, and the relay terminal receives the route search information. The first receiving means, the first storage means for storing the terminal that has transmitted the route search information, and the information of the own terminal are written in the route information in the received route search information. A writing unit; and a second transmission unit configured to transmit notification information for notifying the destination device of the terminal stored in the first storage unit when the terminal is located on the communication path. And the destination device includes: a second receiving unit configured to receive the route search information and the notification information; and the notification information among routes indicated by the route information when a plurality of the route search information is received. And a selection means for selecting a route that does not include the terminal indicated by and the relay terminal on the communication route as a backup route.

  The invention according to claim 2 is a transmission source device that broadcasts first route search information, a destination device that communicates with the transmission source device via a communication route including one or more relay terminals, and the first route A next hop terminal is determined based on search information and first response information transmitted by the destination device, and the relay terminal relays the first route search information and the first response information. In the wireless communication system, the transmission source device includes a first transmission unit that broadcasts second route search information, the relay terminal receives a first reception unit that receives information, and the terminal itself communicates with the communication unit. When it is located on the route, it broadcasts the instruction information for instructing the stop of the processing of the second route search information, and when the instruction information is not received, the received second information Second transmission means for broadcasting the route search information, stop means for stopping the transmission processing of the second route search information when the instruction information is received, the instruction information is not received, First destination means for storing a next hop terminal based on the route search information when the second route search information is received, and the destination device receives the second route search information. And a second storage means for storing the terminal indicated by the second route search information as the next hop terminal in the backup route.

  The invention according to claim 3 is a transmission source device that broadcasts first route search information, a destination device that communicates with the transmission source device via a communication route including one or more relay terminals, and the first route. A next hop terminal is determined based on search information and first response information transmitted by the destination device, and the relay terminal relays the first route search information and the first response information. In the wireless communication system, the transmission source device includes a first transmission unit that broadcasts second route search information, the relay terminal receives a first reception unit that receives information, and the terminal itself communicates with the communication unit. If it is located on the route, it broadcasts the first instruction information for instructing to stop the transmission processing of the second route search information, and when the first instruction information is received, When the second instruction information for instructing the transmission processing of the second route search information is broadcast and the second instruction information is received, and the first instruction information is not received Includes: a second transmission unit that broadcasts the second route search information; and the second route search information when the first instruction information is received or when the second instruction information is not received. When the second instruction information is received and the second instruction information is not received, the stop means for stopping the transmission processing of the second route search information is received, and the first instruction information is not received. A first storage unit that stores the terminal indicated by the second route search information as a next hop terminal, wherein the destination device receives a second reception unit that receives the second route search information; The terminal indicated by the route search information of And a second storage means for storing as a next hop terminal in the wireless communication system.

  The invention according to claim 4 is a transmission source device that broadcasts route search information, a destination device that communicates with the transmission source device via a communication path including one or more relay terminals, the route search information, and the destination device. In the wireless communication system including the relay terminal that relays the route search information and the first response information while determining a next hop terminal based on the first response information transmitted by the transmission source device Comprises first transmission means for transmitting the route search information including route information, and the relay terminal includes first reception means for receiving the route search information and a terminal that has transmitted the route search information. A first storage means for storing, a writing means for writing information of the own terminal into the route information in the received route search information, and a case where the own terminal is located on the communication route And second transmission means for transmitting notification information for notifying the terminal stored in the first storage means to the destination device, wherein the destination device stores the route search information and the notification information. When receiving a plurality of the second search means and the route search information, only the terminal indicated by the notification information excluding the relay terminal on the communication route from the terminal indicated by the notification information among the routes indicated by the route information And a selection means for selecting a route including the backup route as a backup route.

  According to a fifth aspect of the present invention, in the wireless communication system according to any one of the first to fourth aspects, the destination device transmits second response information to the next hop terminal in the backup route. And the transmission source device stores, as a next hop terminal in the backup route, a third receiving unit that receives the second response information and a terminal indicated by the second response information. And a third storage means, wherein the first storage means further stores the terminal indicated by the second response information as a next hop terminal, and the second transmission means further includes: The second response information is transmitted to the next hop terminal.

  The invention according to claim 6 is a transmission source device that broadcasts route search information, a destination device that communicates with the transmission source device via a communication path including one or more relay terminals, the route search information, and the destination device. In the wireless communication system comprising the relay terminal that relays the route search information and the response information, and determines the next hop terminal based on the response information transmitted by the transmission source device, the relay terminal, and One of the destination devices includes a storage unit that stores a terminal that has transmitted the route search information, and a terminal stored by the storage unit when the terminal is located on the communication route. Stored in the storage means for transmitting the notification information for notifying the upper terminal, the receiving means for receiving the notification information, and the storage means And said terminal, wherein when the terminal shown notification information are identical, a wireless communication system characterized by comprising selecting means for selecting the terminal as a backup relay terminal.

  The invention according to claim 7 is the wireless communication system according to any one of claims 1 to 6, wherein the transmission source device, the relay terminal, and the destination device have a wireless communication function. It is a wireless communication terminal.

  The invention according to claim 8 is the wireless communication system according to any one of claims 1 to 6, wherein the transmission source device is a base station, and the relay terminal and the destination device are wireless communication. It is a wireless communication terminal having a function.

  The invention according to claim 9 is the wireless communication system according to any one of claims 1 to 6, wherein the destination device is a base station, and the transmission source device and the relay terminal are wireless communication. It is a wireless communication terminal having a function.

  The invention according to claim 10 is a transmission source device that broadcasts route search information, a destination device that communicates with the transmission source device via a communication path including one or more relay terminals, the route search information, and the destination device. Wireless communication used in a wireless communication system including the next hop terminal based on the first response information transmitted by the relay terminal and the relay terminal relaying the route search information and the first response information In the terminal, the transmission source device includes a first transmission unit that transmits the route search information including route information, and the relay terminal receives a first reception unit that receives the route search information, and the route A first storage means for storing the terminal that has transmitted the search information; a writing means for writing information of the own terminal into the route information in the received route search information; A second transmission unit configured to transmit notification information for notifying the destination device of the terminal stored in the first storage unit when a terminal is located on the communication path; As a second receiving means for receiving the route search information and the notification information, and when a plurality of the route search information are received, the terminal indicated by the notification information and the communication among the routes indicated by the route information A wireless communication terminal comprising: selection means for selecting a route that does not include the relay terminal on the route as a backup route.

  The invention according to claim 11 is a transmission source device that broadcasts first route search information, a destination device that communicates with the transmission source device via a communication route including one or more relay terminals, and the first route. A next hop terminal is determined based on search information and first response information transmitted by the destination device, and the relay terminal relays the first route search information and the first response information. In a wireless communication terminal used in a wireless communication system, the transmission source device includes a first transmission unit that broadcasts second route search information, and the first reception unit that receives information as the relay terminal When the terminal is located on the communication path, the instruction information for instructing to stop the processing of the second route search information is broadcast, and the instruction information is received. A second transmission unit that broadcasts the received second route search information when not received, and a stop unit that stops transmission processing of the second route search information when the instruction information is received And the first storage means for storing a next hop terminal based on the route search information when the instruction information is not received and the second route search information is received, and the destination device Second receiving means for receiving the second route search information, and second storage means for storing the terminal indicated by the second route search information as the next hop terminal in the backup route. This is a featured wireless communication terminal.

  The invention according to claim 12 is a transmission source device that broadcasts first route search information, a destination device that communicates with the transmission source device via a communication route including one or more relay terminals, and the first route A next hop terminal is determined based on search information and first response information transmitted by the destination device, and the relay terminal relays the first route search information and the first response information. In a wireless communication terminal used in a wireless communication system, the transmission source device includes a first transmission unit that broadcasts second route search information, and the first reception unit that receives information as the relay terminal If the terminal is located on the communication path, the first instruction information for instructing to stop the transmission process of the second route search information is broadcast, and the first When the instruction information is received, the second instruction information for instructing the transmission processing of the second route search information is broadcast, and the second instruction information is received, and When the first instruction information has not been received, the second transmission means for broadcasting the second route search information, and when the first instruction information has been received or when the second instruction information has been received When the second route search information is not received but the second route search information is received, stop means for stopping the transmission processing of the second route search information, the second instruction information is received, and the first instruction First information storage means for storing a terminal indicated by the second route search information as a next hop terminal when the information is not received, and receiving the second route search information as the destination device Second receiving means for A wireless communication terminal comprising: a second storage unit that stores a terminal indicated by the second route search information as a next hop terminal in the backup route.

  The invention according to claim 13 is a transmission source device that broadcasts route search information, a destination device that communicates with the transmission source device via a communication path including one or more relay terminals, the route search information, and the destination device. Wireless communication used in a wireless communication system including the next hop terminal based on the first response information transmitted by the relay terminal and the relay terminal relaying the route search information and the first response information In the wireless communication terminal used in the system, the transmission source device includes first transmission means for transmitting the route search information including route information, and the relay terminal receives the route search information as a first terminal. Receiving means, first storage means for storing the terminal that transmitted the route search information, and the route information in the received route search information, Writing means for writing information, and second transmission for sending notification information for notifying the destination device of the terminal stored in the first storage means when the terminal is located on the communication path A second receiving means for receiving the route search information and the notification information as the destination device, and a route indicated by the route information when a plurality of the route search information is received, A wireless communication terminal comprising: a selecting unit that selects, as a backup route, a route including only a terminal excluding the relay terminal on the communication route from the terminal indicated by the notification information.

  According to a fourteenth aspect of the present invention, in the wireless communication terminal according to any one of the tenth to thirteenth aspects, the second response information is further transmitted to the next hop terminal in the backup route as the destination device. A third transmission means for transmitting, a third reception means for receiving the second response information as the transmission source device, and a next hop terminal in the backup path that is a terminal indicated by the second response information. Third storage means for storing as a first hop terminal, the first storage means further stores a terminal indicated by the second response information as a next hop terminal, and the second transmission means further includes the first storage means. 2 response information is transmitted to the next hop terminal indicated by the second route search information.

  The invention according to claim 15 is a transmission source device that broadcasts route search information, a destination device that communicates with the transmission source device via a communication path including one or more relay terminals, the route search information, and the destination device. In the wireless communication terminal used in the wireless communication system comprising the relay terminal that relays the route search information and the response information while determining the next hop terminal based on the response information transmitted by A storage unit that stores a terminal that has transmitted information, and a notification information for notifying the terminal stored in the storage unit to the terminal on the communication path when the terminal is located on the communication path The transmitting means, the receiving means for receiving the notification information, the terminal stored in the storage means, and the terminal indicated by the notification information are the same. In the case of a wireless communication terminal, characterized by comprising selecting means for selecting the terminal as a backup relay terminal.

  According to a sixteenth aspect of the present invention, a base station that broadcasts route search information, a destination device that communicates with the base station via a communication route including one or more relay terminals, and the route search information and the destination device transmit the information. And determining the next hop terminal based on the received response information, and transmitting the route search information in a base station used in a wireless communication system including the route search information and the relay terminal that relays the response information. Storage means for storing the received terminal, transmission means for transmitting notification information for notifying the terminal stored in the storage means to the terminal on the communication path, and reception for receiving the notification information from another terminal And the terminal stored in the storage means is the same as the terminal indicated by the notification information, the terminal is set as a spare relay terminal. A base station, characterized by comprising selecting means for-option.

  The invention according to claim 17 is a transmission source device that broadcasts route search information, a base station that communicates with the transmission source device via a communication path including one or more relay terminals, the route search information, and the base station In the base station used in a wireless communication system comprising a next hop terminal based on the response information transmitted by the relay terminal and relaying the route search information and the response information, the route search information Storing means for storing the terminal that transmitted the message, transmitting means for transmitting notification information for notifying the terminal stored in the storage means to the terminal on the communication path, and receiving the notification information from another terminal Receiving terminal, the terminal stored in the storage means, and the terminal indicated by the notification information are the same as a spare relay terminal A selecting means for selecting Te is a base station, characterized by comprising.

  According to the present invention, it is possible to search for a plurality of communication paths and spare relay terminals while considering a communication range between relay terminals on different communication paths.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a configuration of a wireless communication system according to the first embodiment of the present invention. In the figure, reference numeral 1 denotes a communication terminal, and the wireless communication system includes communication terminals 1S, 1D, and 1a to 1u. The communication terminal 1 in this embodiment is a terminal having a wireless communication function such as a mobile phone, PHS (registered trademark), PDA (Personal Digital Assistance). In the present embodiment, it is assumed that the communication terminal 1S communicates with the communication terminal 1D. Note that FIG. 1 shows the inter-terminal communication possible ranges of the communication terminals 1S, 1D, and 1a to 1c, respectively.

  FIG. 2 is a block diagram showing the configuration of the communication terminal 1. In the figure, 10 is an antenna for transmitting and receiving information. Reference numeral 11 denotes a transmission / reception unit that performs modulation processing on transmission information output from the control unit 12 and outputs the information to the antenna 10, and performs demodulation processing on reception information output from the antenna 10 and outputs the information to the control unit 12. To do. A storage unit 13 stores communication partner information, surrounding terminal information, setting information, and the like. The communication partner information indicates an identifier such as a terminal of a communication partner (next hop terminal) in the forward path and the reverse path. The surrounding terminal information indicates identifiers of surrounding terminals. The setting information indicates the number of hops limited in flooding. A plurality of identifiers can be written in the communication partner information and the surrounding terminal information.

  Next, the operation of the communication terminal 1 according to the first embodiment will be described. First, a first operation example will be described. The communication terminal 1S (transmission source device) creates an RREQ packet (route search information) and broadcasts it to surrounding terminals in order to search for a communication route to the communication terminal 1D (destination device) as a destination terminal. This RREQ includes an information identifier (indicating that it is RREQ), a transmission source identifier (identifier of the communication terminal 1S), a transmission terminal identifier, a destination identifier (identifier of the communication terminal 1D), route information (the terminal of the terminal that has processed the RREQ) Identifier column), and information such as the number of hops.

  In this case, in the communication terminal 1S, the control unit 12 creates an RREQ packet, writes the identifier of the own terminal as the transmission source identifier and the transmission terminal identifier, and writes the identifier of the communication terminal 1D as the destination identifier. Further, the identifier of the own terminal is added to the route information, and the hop count is set to zero. The control unit 12 outputs this RREQ to the transmission / reception unit 11. The transmitter / receiver 11 performs the modulation process and then broadcasts this RREQ via the antenna 10.

  The RREQ transmitted by the communication terminal 1S is received by the surrounding communication terminals 1a, 1d, 1e, and 1i. In these terminals, the transmission / reception unit 11 receives the RREQ via the antenna 10, performs demodulation processing, and then outputs the RREQ to the control unit 12. The control unit 12 refers to the destination identifier in the RREQ and determines whether this identifier is the same as the identifier of its own terminal. In this case, since the destination identifier is different from the identifier of the own terminal, the control unit 12 performs the following processing. The control unit 12 determines whether another RREQ is received within the time limit after the first RREQ is received. When there is no other RREQ, the control unit 12 refers to the transmission terminal identifier and writes the identifier in the communication partner information in the storage unit 13. The terminal indicated by this identifier becomes a communication partner in the reverse path. The control unit 12 also writes the transmission source identifier and destination identifier in the RREQ in the communication partner information.

  On the other hand, when there are a plurality of RREQs, the control unit 12 refers to the number of hops in each RREQ, and writes the transmission terminal identifier in the RREQ having the smallest number of hops in communication partner information in the storage unit 13. Thereby, it is possible to avoid the use of a route having the same terminal as a relay terminal. In addition, the control unit 12 writes the transmission source identifier and destination identifier in the RREQ in the communication partner information, and also writes the transmission terminal identifiers of all received RREQs in the surrounding terminal information in the storage unit 13. Note that the control unit 12 refers to the setting information in the storage unit 13, and when the number of hops in the RREQ exceeds the limit hop number, processing regarding the RREQ is not performed.

  Subsequently, the control unit 12 rewrites the transmitting terminal identifier in the RREQ with the identifier of the own terminal, and adds the identifier of the own terminal to the route information. Then, the control unit 12 increases the number of RREQ hops by 1, and outputs the RREQ to the transmission / reception unit 11. This RREQ is broadcast by the transmission / reception unit 11. As each terminal performs the above-described processing, the RREQ is transferred toward the communication terminal 1D.

  When the communication terminal 1D receives the RREQ, the control unit 12 determines whether another RREQ is received within the time limit after the first RREQ is received. When there is no other RREQ, the control unit 12 refers to the transmission terminal identifier and writes the identifier in the communication partner information in the storage unit 13. The terminal indicated by this identifier becomes a communication partner in the reverse path. On the other hand, when there are a plurality of RREQs, the control unit 12 refers to the number of hops in each RREQ, selects the RREQ having the smallest number of hops, and transmits the transmission terminal identifier in the RREQ to the communication partner in the storage unit 13. Write information. In this operation example, it is assumed that RREQs processed in the order of communication terminals 1S-1a-1b-1c-1D are selected. In this case, the identifier of the communication terminal 1c is written in the communication partner information. Further, the control unit 12 stores the received route information in all RREQs in the storage unit 13.

  Subsequently, the communication terminal 1D creates an RREP packet (response information) and unicasts it to the communication terminal 1c. This RREP includes information such as an information identifier (indicating that it is RREP), a transmission source identifier (identifier of the communication terminal 1D), a transmission terminal identifier, and a destination identifier (identifier of the communication terminal 1S). The operation of the control unit 12 when creating the RREP is substantially the same as the operation when creating the RREQ.

  In the communication terminal 1c that has received the RREP, the control unit 12 refers to the transmission terminal identifier in the RREP and writes the identifier in the communication partner information in the storage unit 13. The terminal indicated by this identifier becomes a communication partner in the forward path. By writing the identifier of the communication partner in the forward path and reverse path in the communication partner information, the control unit 12 recognizes that the own terminal is a relay terminal on the communication path (defined as the main path).

  Subsequently, the control unit 12 rewrites the transmission terminal identifier in the RREP with the identifier of the own terminal, and outputs this RREP to the transmission / reception unit 11 for transmission to the communication partner (communication terminal 1b) in the reverse path. The transmission / reception unit 11 transmits this RREP to the communication terminal 1b via the antenna 10. When each relay terminal on the main route performs the above-described processing, the RREP is transferred to the communication terminal 1S.

  The communication terminal 1S receives this RREP. At this time, the control unit 12 writes the transmission terminal identifier in the RREP in the communication partner information in the storage unit 13 as the communication partner in the forward path. With the above operation, the main route (communication terminals 1S-1a-1b-1c-1D) is established. Each relay terminal (communication terminals 1a to 1c) on the main route notifies the communication terminal 1D of the identifier recorded in the surrounding terminal information in the storage unit 13 when a predetermined time has elapsed after the transmission of RREP. For example, the communication terminal 1a creates notification information including identifiers (identifiers of the communication terminals 1S, 1b, 1e, and 1j) in the surrounding terminal information, and transmits the notification information to the communication terminal 1b that is the communication partner of the forward path.

  The communication terminal 1b that has received the notification information adds the identifier recorded in the surrounding terminal information in the storage unit 13 to the notification information and transmits it to the communication terminal 1c. As described above, the notification information is transferred to the communication terminal 1D while the identifier recorded in the peripheral terminal information of each relay terminal is added. When the communication terminal 1S processes RREP, the establishment of the main route may be notified to each relay terminal, and each relay terminal may transmit notification information to the communication terminal 1D based on the notification.

  The communication terminal 1D receives the notification information and performs the following processing. The control unit 12 reads the path information stored at the time of receiving the RREQ from the storage unit 13, and compares the identifier string included in the path information with the identifier included in the notification information. When a plurality of route information is stored in the storage unit 13, the control unit 12 performs the above comparison for each route information. As a result of the comparison, when there is route information that does not include any identifier included in the notification information as the identifier of the relay terminal, the control unit 12 registers the route indicated by the route information in the storage unit 13 as a backup route.

  For example, in FIG. 1, a route that does not include any of the communication terminals 1a to 1c, 1e to 1g, and 1j to 1l as a relay terminal is a backup route. That is, a route including only a terminal that does not receive radio waves from the relay terminals 1a to 1c on the main route becomes a backup route. Accordingly, the communication terminal 1S-1d-1n-1o-1p-1q-1h-1D and the communication terminal 1S-1i-1r-1s-1t-1u-1m-1D are used as backup paths and the storage unit of the communication terminal 1D. 13 is registered.

  Subsequently, the communication terminal 1D transmits RREP including the route information of the backup route to the terminal that is the communication partner on the backup route. In the relay terminal on the backup route, the reverse path communication partner is set by the RREQ transfer, but the forward path communication partner is not set. Therefore, it is necessary to transmit RREP to the relay terminal on the backup route. Receiving this, each relay terminal on the backup route stores the communication partner of the forward path based on the route information in the RREP, and transmits the RREP to the communication partner of the reverse path. The communication terminal 1S receives the RREP transferred by the relay terminal on the backup route, and writes the transmission terminal identifier in the RREP in the communication partner information in the storage unit 13 as the communication partner on the backup route. Thereby, a backup route is established. The communication terminal 1S communicates with the communication terminal 1D through the main route. When the communication of the main route is disconnected due to a failure, the communication terminal 1S performs communication by switching the route to the backup route.

  FIG. 3 shows the main route and the backup route established based on the first operation example. Note that the communication terminal 1D may perform communication using the main route and the backup route at the same time. In that case, the radio wave from the relay terminal on the main route does not reach the relay terminal on the backup route, and conversely, the radio wave from the relay terminal on the backup route does not reach the relay terminal on the main route. Interference between the route and the backup route can be prevented.

  Next, a second operation example in this embodiment will be described. First, as in the first operation example, a main route is established by RREQ and RREP processing by each terminal. However, in the second operation example, route information is not included in the RREQ.

  Each relay terminal (communication terminals 1a to 1c) on the main route broadcasts a packet including instruction information for giving an instruction to surrounding terminals when a predetermined time has elapsed after transmission of RREP (1-hop broadcast). This instruction information is information for instructing to ignore the second RREQ (stop the second RREQ transmission process) when the second RREQ originating from the communication terminal 1S is received. . Terminals (communication terminals 1e to 1g and 1j to 1l) located at a distance of 1 hop from the relay terminal on the main route receive a packet including this instruction information.

  The communication terminal 1S creates and broadcasts the second RREQ after the time point when the packet including the instruction information is received from the relay terminal on the main route. The communication terminals 1d and 1i receive this RREQ and perform processing related to the RREQ, but the communication terminal 1e that has received the packet including the instruction information and the communication terminal 1a on the main route ignore the second RREQ (2 The RREQ transmission process is stopped for the second time). Only the communication terminals 1d and 1i that have not received the instruction information and have received the second RREQ perform processing related to the RREQ, and broadcast the RREQ again.

  Since the terminal that received the packet including the instruction information and the relay terminal on the main route ignore the second RREQ, the RREQ includes the communication terminal 1S-1d-1n-1o-1p-1q-1h-1D, and the communication terminal. The data is transferred to the communication terminal 1D through the route 1S-1i-1r-1s-1t-1u-1m-1D. In the relay terminal and communication terminal 1D on this route that has received the second RREQ, the control unit 12 writes the transmission terminal identifier in the RREQ in the communication partner information in the storage unit 13. The terminal indicated by this identifier is a communication partner terminal on the reverse path on the backup route.

  Subsequently, the communication terminal 1D creates a second RREP and unicasts it toward the communication partner terminals (communication terminals 1h and 1m) on the backup path. Each relay terminal on the backup path transfers this RREP to the communication terminal 1S while storing the identifier of the communication terminal in the forward path. In the communication terminal 1S that has received the second RREP, the control unit 12 writes the transmitting terminal identifier in the RREP in the communication partner information in the storage unit 13. The main route and the backup route are established by the above operation.

  The main route and the backup route established based on the second operation example are as shown in FIG. 3 as in the first operation example. Since the relay terminal on the backup route is in a position where radio waves do not reach from the relay terminal on the main route, when communication using both the main route and the backup route is performed, interference between both routes should be prevented. Can do. The second operation example has a characteristic that the second RREQ diverges within the limited number of hops outward from the main route.

  Instead of each relay terminal on the main route broadcasting a packet including instruction information, the communication terminals 1e to 1g and 1j to 1l transmit the first RREP radio waves relayed by the relay terminal on the main route. It may be a form in which the communication terminals 1e-1g and 1j-1l ignore the second RREQ based on the detection. However, a terminal that has detected the first RREP from the communication terminal 1D but has not detected the first RREP from the communication terminals 1a to 1c operates in the same manner as a terminal that has not detected these RREPs at all. Shall.

  Next, a third operation example in this embodiment will be described. First, as in the first operation example, a main route is established by RREQ and RREP processing by each terminal. However, the route information is not included in the RREQ as in the second operation example. In addition, a process related to the second RREQ is not performed except for a terminal that has received second instruction information described later. In addition, the relay terminal on the main route does not perform the process related to the second RREQ.

  Each relay terminal (communication terminals 1a to 1c) on the main route broadcasts a packet including first instruction information for giving an instruction to surrounding terminals when a predetermined time has elapsed after transmission of RREP (1 hop). broadcast). The first instruction information is information for instructing to ignore the RREQ (stop the second RREQ transmission process) when the second RREQ originating from the communication terminal 1S is received. It is. Terminals (communication terminals 1e to 1g and 1j to 1l) located at a distance of 1 hop from the relay terminal on the main route receive the packet including the first instruction information.

  The terminal that receives the packet including the first instruction information creates and broadcasts a packet including the second instruction information described below. The second instruction information is information for instructing to perform processing related to the RREQ when the second RREQ originating from the communication terminal 1S is received. Terminals (communication terminals 1e to 1g and 1j to 1l) located at a distance of 1 hop from the relay terminal on the main route receive the packet including the second instruction information. Note that the terminal that has received the first instruction information does not perform the process related to the second RREQ even if it receives the second instruction information. Also, a terminal that has not received the first instruction information but has not received the second instruction information also does not perform the process related to the second RREQ (stops the second RREQ transmission process). The terminal that has received the second instruction information without receiving the first instruction information performs a second RRQ transmission process.

  The communication terminal 1S creates and broadcasts the second RREQ after receiving the packet including the instruction information. Among the terminals that have received the second RREQ, the communication terminals 1d and 1i that have received the packet including the second instruction information perform processing related to the RREQ, but have not received the packet including the second instruction information. The communication terminal 1e and the communication terminal 1e on the main route ignore the second RREQ. Therefore, only the communication terminals 1d and 1i perform processing related to RREQ, and broadcast RREQ again.

  Similarly to the second operation example, RREQ is a route of communication terminal 1S-1d-1n-1o-1p-1q-1h-1D and communication terminal 1S-1i-1r-1s-1t-1u-1m-1D. Is transferred to the communication terminal 1D. In the relay terminal and communication terminal 1D on this route that has received the second RREQ, the control unit 12 writes the transmission terminal identifier in the RREQ in the communication partner information in the storage unit 13. The terminal indicated by this identifier is a communication partner terminal on the reverse path on the backup route.

  Subsequently, the communication terminal 1D creates a second RREP and unicasts it toward the communication partner terminals (communication terminals 1h and 1m) on the backup path. Each relay terminal on the backup path transfers this RREP to the communication terminal 1S while storing the identifier of the communication terminal in the forward path. In the communication terminal 1S that has received the second RREP, the control unit 12 writes the transmitting terminal identifier in the RREP in the communication partner information in the storage unit 13. The main route and the backup route are established by the above operation.

  In the third operation example, only a terminal located around a terminal located at a distance of 1 hop from the relay terminal on the main route and not receiving radio waves from the relay terminal on the main route relays the second RREQ. Therefore, the second RREQ is different from the second operation example in that the second RREQ does not diverge outward from the main route. As a result, compared to the second operation example, the second RREQ flooding scale can be further suppressed.

  Instead of each relay terminal on the main route broadcasting the packet including the first instruction information, the first RREP radio wave relayed by the relay terminal on the main route is transmitted to the communication terminals 1e to 1g and 1j. The communication terminals 1e to 1g and 1j to 1l may broadcast a packet including the second instruction information based on the detection of .about.1l. However, a terminal that has detected the first RREP from the communication terminal 1D but has not detected the first RREP from the communication terminals 1a to 1c operates in the same manner as a terminal that has not detected these RREPs at all. Shall.

  Next, a fourth operation example in this embodiment will be described. In the fourth operation example, path information is included in the RREQ as in the first operation example. First, as in the first operation example, a main route is established by RREQ and RREP processing by each terminal.

  Each relay terminal (communication terminals 1a to 1c) on the main route notifies the communication terminal 1D of the identifier recorded in the surrounding terminal information in the storage unit 13 when a predetermined time has elapsed after the transmission of RREP. For example, the communication terminal 1a creates notification information including identifiers (identifiers of the communication terminals 1S, 1b, 1e, and 1j) in the surrounding terminal information, and transmits the notification information to the communication terminal 1b that is the communication partner of the forward path.

  The communication terminal 1b that has received this notification information adds the identifier recorded in the surrounding terminal information to the notification information and transmits it to the communication terminal 1c. As described above, the notification information is transferred to the communication terminal 1D while the identifier recorded in the peripheral terminal information of each relay terminal is added. When the communication terminal 1S processes RREP, the establishment of the main route may be notified to each relay terminal, and each relay terminal may transmit notification information to the communication terminal 1D based on the notification. The above operation is the same as the first operation example.

  The communication terminal 1D receives the notification information and performs the following processing. The control unit 12 reads the path information stored at the time of receiving the RREQ from the storage unit 13, and compares the identifier string included in the path information with the identifier included in the notification information. When a plurality of route information is stored in the storage unit 13, the control unit 12 performs the above comparison for each route information. As a result of the comparison, when there is route information including only the identifier included in the notification information as the identifier of the relay terminal, the control unit 12 registers the route indicated by the route information in the storage unit 13 as a backup route. However, the control unit 12 refers to the route information of the main route stored in the storage unit 13, and excludes the route including at least one relay terminal identifier on the main route from the backup route.

  Subsequently, the communication terminal 1D transmits RREP including the route information of the backup route to the terminal that is the communication partner on the backup route. Receiving this, each relay terminal on the backup route stores the communication partner of the forward path based on the route information in the RREP, and transmits the RREP to the communication partner on the reverse path. The communication terminal 1S receives the RREP transferred by the relay terminal on the backup route, and writes the transmission terminal identifier in the RREP in the communication partner information in the storage unit 13 as the communication partner on the backup route. Thereby, a backup route is established. The communication terminal 1S communicates with the communication terminal 1D through the main route. When the communication of the main route is disconnected due to a failure, the communication terminal 1S performs communication by switching the route to the backup route.

  For example, in FIG. 1, a route including the communication terminals 1e to 1g as a relay terminal is a backup route. That is, a route including only a terminal located within the communication range of any one of the relay terminals 1a to 1c on the main route is a backup route. Since this backup route interferes with the main route, it cannot be used simultaneously during communication. However, even when the main route is disconnected, the communication terminals 1S and 1D can continue communication by switching to the backup route close to the optimum main route.

  Note that the first operation example and the fourth operation example may be combined. As a result, it is possible to simultaneously search for a backup route that does not interfere with the main route and a backup route that is close to optimum.

  Next, a fifth operation example in this embodiment will be described. In the fifth operation example, a technique for searching for a spare relay terminal is shown. First, as in the first operation example, a main route is established by RREQ and RREP processing by each terminal. However, the route information is not included in the RREQ as in the second operation example.

  Each relay terminal (communication terminals 1a to 1c) on the main route notifies all the terminals on the main route of the identifier recorded in the surrounding terminal information in the storage unit 13 when a predetermined time has elapsed after the transmission of RREP. . In this case, notification is performed as follows. For example, in the communication terminal 1a, the control unit 12 refers to communication partner information in the storage unit 13 and recognizes that information should be transmitted to the communication terminals 1S and 1b. In addition, the control unit 12 stores the identifier recorded in the peripheral terminal information in the storage unit 13 in the notification information, and transmits the notification information to the communication terminals 1S and 1b via the transmission / reception unit 11 and the antenna 10.

  The communication terminal 1S receives the notification information and records the identifier included in the information in the storage unit 13. On the other hand, the relay terminal 1b records information included in the received notification information in the storage unit 13 and relays the notification information to the communication terminal 1c. Each relay terminal relays the notification information while recording the identifier included in the notification information in the storage unit 13, whereby the notification information is transferred to the communication terminal 1D. Other terminals (communication terminals 1S, 1b, 1c, 1D) also transmit notification information in the same manner. Through the above operation, each terminal on the main route shares the peripheral terminal information of other terminals.

  Subsequently, in each terminal, the control unit 12 compares the identifier in the received all notification information with the identifier recorded in the surrounding terminal information in the storage unit 13, and preliminarily relays the terminal having the identifier common to both. It records in the communication partner information in the memory | storage part 13 as a terminal. Thereby, a terminal located within the communication range of a plurality of terminals on the main route becomes a backup relay terminal. For example, in FIG. 3, communication terminals 1e, 1g, 1j, and 1l are backup relay terminals.

  As described above, even when a part of the relay route is disconnected in the communication between the communication terminals 1S and 1D, the communication can be continued using the backup relay terminal as the relay terminal. In this case, since at least a forward path is not set for the standby relay terminal, when the relay path is switched to a path including the standby relay terminal, the relay terminal having the standby relay terminal as the communication partner becomes the standby relay terminal. On the other hand, information regarding a communication partner may be transmitted.

  In addition, the above first to fifth operation examples may be combined to obtain a plurality of paths capable of simultaneous communication, a backup path near the main path, and a backup relay terminal.

  Next, a second embodiment of the present invention will be described. FIG. 4 is a schematic configuration diagram showing the configuration of the wireless communication system according to the second embodiment. In the figure, 2 is a base station. The base station 2 is connected to a core network (not shown), and communicates with other base stations via the core network. In the second embodiment, a wireless communication terminal connected to another base station connected to the base station 2 via the core network communicates with the communication terminal 1D. The main configuration of the base station 2 is the same as the configuration of the communication terminal in FIG.

  A wireless communication terminal connected to another base station requests another base station to make a call to the communication terminal 1D. The other base station that has received this request transmits a call request to the communication terminal 1D to the base station 2. Based on this transmission request, the base station 2 constructs a communication path to the communication terminal 1D. In this case, the base station 2 performs the same operation as that of the communication terminal 1S in the first embodiment, and searches for the main route, the backup route, and the backup relay terminal to the communication terminal 1D. Since the communicable range of the base station is much wider than the communicable range of the wireless communication terminal, as shown in FIG. 4, the arrow indicating the backup route from the base station 2 is not a large detour compared to FIG. . That is, the length of the main route and the length of the backup route can be made relatively close.

  In the second embodiment, the case where the base station 2 performs the same operation as the communication terminal 1S in the first embodiment has been described as an example. However, the base station 2 performs the communication terminal 1D in the first embodiment. The same operation may be performed. That is, when a certain communication terminal cannot communicate directly with the base station 2 and communicates with the base station 2 via another communication terminal, the search for the backup route and the backup relay terminal is similarly performed. Done.

  As described above, according to the first to third operation examples in the first embodiment, the route including only the terminal that does not reach the radio wave from the relay terminal on the main route becomes the backup route. The main route and the backup route do not interfere with each other. Therefore, it is possible to search for a plurality of routes that do not interfere with each other, and to simultaneously improve the throughput and expand the communicable range by using the plurality of routes simultaneously.

  According to the fourth operation example in the first embodiment, a backup route closest to the main route can be obtained. Further, according to the fifth operation example, a standby relay terminal can be obtained, and communication is continued by adding the standby relay terminal to the relay terminal even when a part of the main route is disconnected. be able to.

  Further, according to the second embodiment, even when the base station performs a route search, the same effect as that of the first embodiment can be obtained.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings, but the specific configuration is not limited to these embodiments, and includes design changes and the like within a scope not departing from the gist of the present invention. It is.

It is a schematic block diagram which shows the structure of the radio | wireless communications system by the 1st Embodiment of this invention. It is a block diagram which shows the structure of the communication terminal by the embodiment. It is the schematic which shows the main path | route and the backup path | route in the embodiment. It is a schematic block diagram which shows the structure of the radio | wireless communications system by the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Communication terminal, 2 ... Base station, 10 ... Antenna, 11 ... Transmission / reception part, 12 ... Control part, 13 ... Memory | storage part.

Claims (17)

A source device that broadcasts route search information, a destination device that communicates with the source device via a main route including one or more relay terminals, the route search information and first response information transmitted by the destination device A wireless communication system including the relay terminal that relays the route search information and the first response information while determining a next hop terminal on the main route based on
The transmission source device includes first transmission means for transmitting the route search information including route information,
The relay terminal is
First receiving means for receiving the route search information;
First storage means for storing a terminal that has transmitted the route search information;
Writing means for writing information of the terminal itself into the route information in the received route search information;
Second transmission means for transmitting notification information for notifying the destination device of the terminal stored in the first storage means when the terminal is located on the main path after the establishment of the main path; Comprising
The destination device is
Second receiving means for receiving the route search information and the notification information;
Selection means for selecting, as a backup route, a route that does not include the terminal indicated by the notification information and the relay terminal on the main route among the routes indicated by the route information when a plurality of the route search information is received; A wireless communication system comprising: Transmitted by the source device that broadcasts the first route search information, the destination device that communicates with the source device via a main route including one or more relay terminals, the first route search information, and the destination device A wireless communication system comprising: a next hop terminal on the main route based on the first response information; and the relay terminal that relays the first route search information and the first response information. ,
The transmission source device comprises first transmission means for broadcasting second route search information,
The relay terminal is
First receiving means for receiving information;
When the terminal is located on the main route after the main route is established, the instruction information for instructing to stop the processing of the second route search information is broadcast, and the instruction information is not received Second transmission means for broadcasting the received second route search information;
Stop means for stopping the transmission processing of the second route search information when the instruction information is received;
First instruction means for storing a next hop terminal on a backup route based on the route search information when the instruction information is not received and the second route search information is received;
The destination device is
Second receiving means for receiving the second route search information;
Wireless communication system, characterized by comprising a second storage means for storing terminal shown the second route search information as the next hop terminal in the preliminary route. Transmitted by the source device that broadcasts the first route search information, the destination device that communicates with the source device via a main route including one or more relay terminals, the first route search information, and the destination device A wireless communication system comprising: a next hop terminal on the main route based on the first response information; and the relay terminal that relays the first route search information and the first response information. ,
The transmission source device comprises first transmission means for broadcasting second route search information,
The relay terminal is
First receiving means for receiving information;
When the terminal is located on the main route after the establishment of the main route, the first instruction information for instructing to stop the transmission processing of the second route search information is broadcast, and the first route When the instruction information is received, the second instruction information for instructing the transmission processing of the second route search information is broadcast, and the second instruction information is received, and A second transmitting means for broadcasting the second route search information when the first instruction information is not received;
When the first instruction information is received or when the second instruction information is not received and the second route search information is received, the transmission processing of the second route search information is stopped. Stop means;
First storage means for storing the terminal indicated by the second route search information as the next hop terminal on the backup route when the second instruction information is received and the first instruction information is not received And
The destination device is
Second receiving means for receiving the second route search information;
Wireless communication system, characterized by comprising a second storage means for storing terminal shown the second route search information as the next hop terminal in the preliminary route. A source device that broadcasts route search information, a destination device that communicates with the source device via a main route including one or more relay terminals, the route search information and first response information transmitted by the destination device A wireless communication system including the relay terminal that relays the route search information and the first response information while determining a next hop terminal on the main route based on
The transmission source device includes first transmission means for transmitting the route search information including route information,
The relay terminal is
First receiving means for receiving the route search information;
First storage means for storing a terminal that has transmitted the route search information;
Writing means for writing information of the terminal itself into the route information in the received route search information;
Second transmission means for transmitting notification information for notifying the destination device of the terminal stored in the first storage means when the terminal is located on the main path after the establishment of the main path; Comprising
The destination device is
Second receiving means for receiving the route search information and the notification information;
When a plurality of the route search information is received, a route including only the terminal excluding the relay terminal on the main route from the terminal indicated by the notification information is selected as a backup route among the routes indicated by the route information. A wireless communication system comprising: a selecting unit; The destination device comprises third transmission means for transmitting second response information to the next hop terminal in the backup route,
The transmission source device is:
Third receiving means for receiving the second response information;
; And a third storage means for storing the terminal indicated by the response information of the second as the next hop terminal in the spare path,
In the relay terminal, the first storage means further stores the terminal indicated by the second response information as a next hop terminal on the backup route ,
The wireless communication system according to any one of claims 1 to 4, wherein the second transmission means further transmits the second response information to a next hop terminal on the backup route. . Based on a transmission source device that broadcasts route search information, a destination device that communicates with the transmission source device via a main route including one or more relay terminals, the route search information, and response information transmitted by the destination device In a radio communication system comprising a next hop terminal on the main route and the relay terminal that relays the route search information and the response information,
Any of the transmission source device, the relay terminal, and the destination device is
Storage means for storing a terminal that has transmitted the route search information;
Transmitting means for transmitting notification information for notifying the terminal stored on the main path to the terminal on the main path when the own terminal is located on the main path after the establishment of the main path ;
Receiving means for receiving the notification information;
A wireless communication system, comprising: a selection unit that selects a terminal as a backup relay terminal when the terminal stored in the storage unit and the terminal indicated by the notification information are the same.   The wireless communication system according to claim 1, wherein the transmission source device, the relay terminal, and the destination device are wireless communication terminals having a wireless communication function.   The said transmission source apparatus is a base station, The said relay terminal and the said destination apparatus are radio | wireless communication terminals provided with the radio | wireless communication function, The Claim 1 characterized by the above-mentioned Wireless communication system.   The said destination apparatus is a base station, The said transmission source apparatus and the said relay terminal are radio | wireless communication terminals provided with the radio | wireless communication function, The Claim 1 characterized by the above-mentioned Wireless communication system. A source device that broadcasts route search information, a destination device that communicates with the source device via a main route including one or more relay terminals, the route search information and first response information transmitted by the destination device In a wireless communication terminal used in a wireless communication system including the relay terminal that relays the route search information and the first response information, while determining a next hop terminal on the main route based on
As the transmission source device, comprising a first transmission means for transmitting the route search information including route information,
As the relay terminal,
First receiving means for receiving the route search information;
First storage means for storing a terminal that has transmitted the route search information;
Writing means for writing information of the terminal itself into the route information in the received route search information;
Second transmission means for transmitting notification information for notifying the destination device of the terminal stored in the first storage means when the terminal is located on the main path after the establishment of the main path; Comprising
As the destination device,
Second receiving means for receiving the route search information and the notification information;
Selection means for selecting, as a backup route, a route that does not include the terminal indicated by the notification information and the relay terminal on the main route among the routes indicated by the route information when a plurality of the route search information is received; A wireless communication terminal comprising: Transmitted by a transmission source device that broadcasts first route search information, a destination device that communicates with the transmission source device via a main route including one or more relay terminals, the first route search information, and the destination device. A wireless communication system comprising: a next hop terminal on the main route based on the first response information; and the relay terminal that relays the first route search information and the first response information. In the wireless communication terminal used,
The transmission source device comprises a first transmission means for broadcasting second route search information,
As the relay terminal,
First receiving means for receiving information;
When the terminal is located on the main route after the main route is established, the instruction information for instructing to stop the processing of the second route search information is broadcast, and the instruction information is not received Second transmission means for broadcasting the received second route search information;
Stop means for stopping the transmission processing of the second route search information when the instruction information is received;
First instruction means for storing a next hop terminal on a backup route based on the route search information when the instruction information is not received and the second route search information is received;
As the destination device,
Second receiving means for receiving the second route search information;
Wireless communication terminal, characterized by comprising a second storage means for storing terminal shown the second route search information as the next hop terminal in the preliminary route. Transmitted by the source device that broadcasts the first route search information, the destination device that communicates with the source device via a main route including one or more relay terminals, the first route search information, and the destination device A wireless communication system comprising: a next hop terminal on the main route based on the first response information; and the relay terminal that relays the first route search information and the first response information. In the wireless communication terminal used,
The transmission source device comprises a first transmission means for broadcasting second route search information,
As the relay terminal,
First receiving means for receiving information;
When the terminal is located on the main route after the establishment of the main route, the first instruction information for instructing to stop the transmission processing of the second route search information is broadcast, and the first route When the instruction information is received, the second instruction information for instructing the transmission processing of the second route search information is broadcast, and the second instruction information is received, and A second transmitting means for broadcasting the second route search information when the first instruction information is not received;
When the first instruction information is received or when the second instruction information is not received and the second route search information is received, the transmission processing of the second route search information is stopped. Stop means;
First storage means for storing the terminal indicated by the second route search information as the next hop terminal on the backup route when the second instruction information is received and the first instruction information is not received And
As the destination device,
Second receiving means for receiving the second route search information;
Wireless communication terminal, characterized by comprising a second storage means for storing terminal shown the second route search information as the next hop terminal in the preliminary route. A source device that broadcasts route search information, a destination device that communicates with the source device via a main route including one or more relay terminals, the route search information and first response information transmitted by the destination device wherein while determining the next hop terminal on the main path, is used in a wireless communication system for use in a wireless communication system comprising said relay terminal relaying the route search information and the first response information based on Wireless communication terminals
As the transmission source device, comprising a first transmission means for transmitting the route search information including route information,
As the relay terminal,
First receiving means for receiving the route search information;
First storage means for storing a terminal that has transmitted the route search information;
Writing means for writing information of the terminal itself into the route information in the received route search information;
Second transmission means for transmitting notification information for notifying the destination device of the terminal stored in the first storage means when the terminal is located on the main path after the establishment of the main path; Comprising
As the destination device,
Second receiving means for receiving the route search information and the notification information;
When a plurality of the route search information is received, a route including only the terminal excluding the relay terminal on the main route from the terminal indicated by the notification information is selected as a backup route among the routes indicated by the route information. A wireless communication terminal. The destination device further includes third transmission means for transmitting second response information to the next hop terminal in the backup route,
As the transmission source device,
Third receiving means for receiving the second response information;
; And a third storage means for storing the terminal indicated by the response information of the second as the next hop terminal in the spare path,
The first storage means further stores the terminal indicated by the second response information as a next hop terminal on the backup route ,
The wireless communication terminal according to any one of claims 10 to 13, wherein the second transmission means further transmits the second response information to a next hop terminal on the backup route. . Based on a transmission source device that broadcasts route search information, a destination device that communicates with the transmission source device via a main route including one or more relay terminals, the route search information, and response information transmitted by the destination device In a wireless communication terminal used in a wireless communication system including a next hop terminal on the main route and the relay terminal that relays the route search information and the response information,
Storage means for storing a terminal that has transmitted the route search information;
Transmitting means for transmitting notification information for notifying the terminal stored on the main path to the terminal on the main path when the own terminal is located on the main path after the establishment of the main path ;
Receiving means for receiving the notification information;
A radio communication terminal, comprising: a selection unit that selects the terminal as a backup relay terminal when the terminal stored in the storage unit and the terminal indicated by the notification information are the same. And a base station that broadcasts the route search information, the destination device communicating with the base station by the main path including one or more relay terminals, on the basis of the response information sent by the route search information and the destination apparatus main In a base station used in a wireless communication system including a next hop terminal on a route and the relay terminal that relays the route search information and the response information,
Storage means for storing a terminal that has transmitted the route search information;
Transmitting means for transmitting notification information for notifying the terminal stored in the storage means to the terminal on the main route;
Receiving means for receiving the notification information from another terminal;
Selecting means for selecting the terminal as a spare relay terminal when the terminal stored in the storage means and the terminal indicated by the notification information are the same;
A base station comprising: Based on a transmission source device that broadcasts route search information, a base station that communicates with the transmission source device via a main route including one or more relay terminals, and the route search information and response information transmitted by the base station In a base station used in a wireless communication system including a next hop terminal on the main route and the relay terminal relaying the route search information and the response information,
Storage means for storing a terminal that has transmitted the route search information;
Transmitting means for transmitting notification information for notifying the terminal stored in the storage means to the terminal on the main route;
Receiving means for receiving the notification information from another terminal;
Selecting means for selecting the terminal as a spare relay terminal when the terminal stored in the storage means and the terminal indicated by the notification information are the same;
A base station comprising:

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