WO2005104458A1

WO2005104458A1 - Wireless communication device, wireless communication program and route search method

Info

Publication number: WO2005104458A1
Application number: PCT/JP2005/007744
Authority: WO
Inventors: Hirokazu Kobayashi; Toyoki Kawahara; Takeshi Kanazawa; Naoto Oka
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2004-04-20
Filing date: 2005-04-18
Publication date: 2005-11-03
Also published as: JP2005311576A

Abstract

Provided are a route request information recording section (107) recording identifiers specifying wireless communication devices as targets of route search on an ad-hoc network, a route control message generation processing section (106) including the identifiers of the wireless communication devices one to a plurality in the number recorded therein and for generating a route request message, a transmitting section (103) for broadcasting the route request message generated in the same, and a route control message reception processing section (108) for receiving a route response message transmitted from the wireless communication device as a target of route search, which has received the route request message and deleting the identifier of the wireless communication device as the target of route search from the route request information recording section (107). Accordingly, a plurality of wireless communication device identifiers on a target of route can be put together on one route request message.

Description

DESCRIPTION WIRELESS COMMUNICATION DEVICE, WIRELESS

COMMUNICATION PROGRAM AND ROUTE SEARCH METHOD

TECHNICAL FIELD The present invention relates to a wireless communication device in a wireless ad-hoc network system, and more particularly to a route search method to search for a route to a plurality of destinations on an ad-hoc network system.

BACKGROUND ART Due to the diversified wireless communication devices haven by users, the use of e-mails or the Internet and data exchange becomes available on the wireless communication device at the office, in the street or on transportation means in traveling. Those networks are premised on the existence of infrastructures. On the contrary, attentions are being drawn to the ad-hoc network that allows the wireless communication device to have communications with wireless communication devices sporadically existing in the neighborhood thereof through a network temporarily architected without the need of infrastructure. The ad-hoc network refers to a system that a certain wireless communication device, even where it cannot have mutual, direct communications with a desired wireless communication device, is allowed to have multiple access to and hence communications with the same by way of several wireless communication devices. Packet communication is realized by suitably searching a route to a desired wireless communication device. The ad-hoc network is easy to constitute a network at any time and anywhere. Consequently, applications are to be considered for a distribution system at disaster site, a messaging service based on a community formed between particular users, and so on. For example, there is a use method that an ad-hoc network is architected by several tens of wireless communication devices so that particular users, in part thereof, can form a group and make use of services including mail exchange and online chat. At this time, because the users are to utilize the service while moving independently, there encounters a route change to the user's wireless communication device from time to time. For this reason, it is important to search a route to a wireless communication device with rapidness and efficiency. The conventional route search method over an ad-hoc network is based on the following scheme. Namely, the wireless communication device, when a communication request is caused with a particular wireless communication device, starts up a route search in the case of not possessing the route information to a wireless communication device as a destination. By storing the route request message with an own identifier and an identifier of the destination wireless communication device, a route request signal is broadcast. The route request message is re-broadcasted to the destination wireless communication device or to a wireless communication device having a route to the destination wireless communication device. When the route request message is received at the destination wireless communication device or the wireless communication device having a route to the destination wireless communication device, a route response message is sent to the source wireless communication device, thus acquiring a route (e.g. JP-A-8-97821). Meanwhile, there is also a similar route search method, in which method the wireless communication device does not manage the relaying wireless communication devices included on the route to a desired wireless communication device (see C. Perkins and E. Royer, "Ad-hoc On-Demand Distance-Vector Routing", Proceedings of the 2nd IEEE Workshop on Mobile Computing Systems and Applications, pages 90-100, February 1999, for example). However, in the above conventional configuration, a plurality of packets destined for wireless communication devices are caused in the wireless communication device. Where the route to the wireless communication device is not secured, the route request messages is broadcast-relayed to/from each wireless communication device. This results in an increased burden over the network.

DISCLOSURE OF THE INVENTION It is an object of the present invention to provide a wireless communication device and route search method for gaining a route to a plurality of destination wireless communication devices without increasing the burden over the network. A wireless communication device of the invention comprises: a route request information recording section recording identifiers specifying wireless communication devices as targets of route search on an ad-hoc network; a route control message generation processing section for generating a route request message including the identifiers of the wireless communication devices one to a plurality in the number recorded in the route request information recording section; a transmitting section for broadcasting the route request message generated at the route control message generation processing section; and a route control message reception processing section for receiving a route response message transmitted from the wireless communication device on a target of route received the route request message and deleting the identifier of the wireless communication device as the target of route search fallen under from the route request information recording section. This can put a plurality of search targets of wireless communication device identifiers together on one route request message. Accordingly, it is possible to greatly reduce the route control messages that are to be distributed within the network. Meanwhile, in a wireless communication device according to the invention, included are a route request section for sequentially recording the identifiers of the wireless communication devices requiring route search to the route request information recording section, and a route request instructing section for instructing a generation timing of a route request message to the route control message generation processing section, the route request instructing section counting a route search wait time of from a start of recording to the route request information recording section, to instruct the route control message generation processing section after elapsing a predetermined time. This can transmit the route search requests occurred in a certain time period by means of one route request message. Accordingly, it is possible to further reduce the route control messages that are to be distributed within the network. - Meanwhile, in a wireless communication device according to the invention, the route request instructing section decides whether or not the data requiring route search is synchronous data, and counts the route search wait time when the data is asynchronous data. This can select asynchronous data allowed for delay and transmit route requests for destination wireless communication device, based on asynchronous data generated as another communication request, by means of one route request message. Accordingly, it is possible to greatly reduce the route control messages that are to be distributed within the network, without affecting synchronous data not allowed for delay. Meanwhile, in a wireless communication device according to the invention, further included are a response time managing section for managing a route response wait time of from a transmission of a route request message that a transmission source is the own device to a reception of the route response message, and a transmission counter for counting the number of transmission executions of route request messages effected before receiving route response messages from the wireless communication devices of all the targets of search contained in the route request message, whereby, the route control message generation processing section, at within a predetermined number of times as to the number of transmission executions, again generates a route request message to the wireless communication device as a target of search not responded despite elapsing the route response time so that the transmitting section broadcasts the route request message. This can again broadcast-relay a route request message only to the wireless communication devices not responded in the absence of responses from all the wireless communication devices requests has been made within a predetermined time. Even in case there are variations occurred in the arrivals of route request messages, route search can be continued without making a route request to the destination wireless communication devices already acquired. Meanwhile, it is possible to eliminate the necessity to endlessly continue the route search for the wireless communication devices not found in route. Meanwhile, a wireless communication device of the invention comprises: a receiving section for receiving a route request message containing one to a plurality of identifiers specifying wireless communication devices as targets of route search over an ad-hpc network; a target-of-route deciding section for deciding whether or not the target of route search in the route request message received include the own device; a route control message generation processing section for generating a route response message to the wireless communication device as a transmission source of route search and a route request message deleted of an identifier of the wireless communication device concerned from wireless communication device identifiers described in the route request message, in the case the target-of-route deciding section decided the own device as a target of route search; a, transmitting section for transmitting a route response message generated by the route control message generation processing section and broadcast-transferring a route request message generated. Because this deletes the data required for a route search in an amount reached destinations, the route request message to be transferred has a length of data including only the required data, thus enabling to prevent traffic amount from increasing over the network. Meanwhile, a wireless communication device of the invention comprises: a route request information recording section for recording identifiers specifying wireless communication devices as targets of route search; a route control message generation processing section for generating a route request message containing the identifiers of one or a plurality of the wireless communication devices recorded in the route request information recording section; a transmitting section for broadcasting the route request message generated in the route control message generation processing section; a route control message reception processing section for receiving a route response message transmitted from the wireless communication device as a target of search received the route request message and deleting the identifiers fallen under of the wireless communication devices as targets of route search from the route request information recording section; and a target-of-route deciding section for deciding whether or not a target of route search in the route request message received include the own device; the route control message generation processing section, when the target-of-route deciding section decided the own device as a target of route search, generating a route response message to the wireless communication device as a transmission source of route search, and a route request message removed of an identifier of the wireless communication device concerned from wireless communication device identifiers described in the route request message; the transmitting section making a transmission of the route response message generated by the route control message generation processing section and a broadcast-transfer of the route request message generated. Due to this, in the case of a transmission source of route search, because a plurality of search targets of wireless communication device identifiers can be put on one route request message, it is possible to greatly decrease the route control message to be distributed over the network. Meanwhile, when receiving a route request message from another wireless communication device, deleted is the data required in a route search in an amount reached the destinations. Accordingly, the route request message to be transferred has a length of data including only the required data, thus enabling to prevent traffic amount from increasing over the network. Meanwhile, in a wireless communication device according to the invention, the route control message generation processing section generates a route request message containing a route request identifier for identifying unambiguously a route request message and a new identification code, corresponding to the wireless communication device as a target of search, less in data amount than the identifier of the wireless communication device concerned, or generating the route response message containing only the route request identifier and the own identification code. This can make, during the occurrence of a communication request, a route request message including a plurality of destination wireless communication device identifiers and temporary identifiers for the plurality of destination wireless communication devices effective limitedly within the effective time of the route request message to be transmitted for searching a route to those wireless communication devices, i.e. within a route response wait time, thus making it possible to utilize the temporary identifiers upon making a route response. Accordingly, when searching for a route to the plurality of destination wireless communication devices, the number of bits can be reduced of the wireless communication device identifier in the route response message, thus enabling to reduce the burden over the network. A route search method of the invention comprises: a step for a first wireless communication device for searching a route over an ad-hoc network to store identifiers specifying wireless communication devices as targets of route search in a route request information recording section; a step for the first wireless communication device to generate and broadcast a route request message- containing one to a plurality of wireless communication device identifiers recorded; a step for a second wireless communication device received the route request message, when a wireless communication device as a target of search, to transmit a route response message to the first wireless communication device as a transmission source; a step for the second wireless communication device to generate and broadcast-transfer a route request message removed of the own identifier of the wireless communication device from the wireless communication device identifiers described in the route request message; and a step for the first wireless communication device to receive the route response message from the second wireless communication device and delete the identifier of the second wireless communication device from the targets of route search stored in the route request information recording section. Because this can put a plurality of search targets of wireless communication device identifiers together on one route request message, it is possible to greatly decrease the route control messages to be distributed over the network. Meanwhile, because deleted is the data required in a route search in an amount reached the destinations, the route request message to be transferred has a length of data including only the required data, thus enabling to prevent traffic amount from increasing over the network. Meanwhile, in a route search method according to the invention, further included is a step for the first wireless communication device to count route search wait time of from a start of recording to the route request information recording section, to generate and broadcast the route request message after elapsing a predetermined time. Due to this, because the route search requests occurred during a certain time can be transmitted in one route request message, it is possible to further decrease the route control messages to be distributed over the network. Meanwhile, in a route search method according to the invention, provided is a step for the first wireless communication device to count a route response wait time of from a transmission of a route request message to a reception of a route response message, and generate again and broadcast a route request message when not received a route response message from the wireless communication device as a target of search within a predetermined time, which step is repeated until the number of transmission executions of the route request message exceeds a predetermined number of times. Due to this, when there are no responses within a predetermined time from all the wireless communication device requests were made, a route request message is again broadcast-relayed only to the wireless communication devices not responded. Even where there are variations in the arrival of route response messages, route search can be continued without making a request for a route to the destination wireless communication devices already acquired. Meanwhile, it is possible to eliminate the necessity to endlessly continue the route search for the wireless communication devices not found in route. As described above, the invention can reduce the burden over the network because of the capability of acquiring a route to a plurality of destination wireless communication devices by means of one route request message.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing a configuration of a wireless communication device in embodiment 1 of the present invention. Fig. 2 is a figure showing tables in a route request information recording section in embodiment 1 of the invention. Fig. 3 is a diagram showing an example of ad-hoc network constituted by the wireless communication devices in embodiment 1 of the invention. Fig. 4 is a figure showing a flow of route search in embodiment 1 of the invention. Fig. 5 is a figure showing an example of source route-request table at time T1 in embodiment 1 of the invention. Fig. 6 is a figure showing a format of route request message in embodiment 1 of the invention. Fig. 7 is a figure showing an example of route request message in embodiment 1 of the invention. Fig. 8 is a chart showing a flow of route response wait process in embodiment 1 of the invention. Fig. 9 is a chart showing a flow of route response receiving process in embodiment 1 of the invention. Fig. 10 is a figure showing the route information to be recorded in a route recording section in embodiment 1 of the invention. Fig. 11 is a figure showing an example of route request message in embodiment 1 of the invention. Fig. 12 is a figure showing an example of source route-request table in embodiment 1 of the invention. Fig. 13 is a chart showing a flow of a process to receive a route request message for making a route request to the apparatus concerned, in the wireless communication device in embodiment 1 of the invention. Fig. 14 is a figure showing an example of route-request table in embodiment 1 of the invention. Fig. 15 is a figure showing a format of route response message in embodiment 1 of the invention. Fig. 16 is a figure showing an example of route response message in embodiment 1 of the invention. Fig. 17 is a figure showing an example of route request message to be transmitted from the destination wireless communication device in embodiment 1 of the invention. Fig. 18 is a figure showing an example of source route-request table at time T2 in embodiment 1 of the invention. Fig. 19 is a chart showing a flow of route response receiving process at the wireless communication device serving for relay in embodiment 1 of the invention. Fig. 20 is a diagram showing the distributions of route request messages in embodiment 1 of the invention. Fig. 21 is a figure showing an example of source route-request table in embodiment 2 of the invention. Fig. 22 is a figure showing a format of route request message in embodiment 2 of the invention. Fig. 23 is a figure showing a format of an alias option in the route request message in embodiment 2 of the invention. Fig. 24 is a figure showing an example of route-request message in embodiment 2 of the invention. Fig. 25 is a figure showing an example of route-request table in embodiment 2 of the invention. Fig. 26 is a figure showing a format of route response message in embodiment 2 of the invention. Fig. 27 is a figure showing an example of route response message in embodiment 2 of the invention. Fig. 28 is a figure showing an example of route request message to be transmitted from the destination wireless communication device in embodiment 2 of the invention. Fig. 29 is a chart showing a flow of route response receiving process at the wireless communication device serving for relay in embodiment 2 of the invention. Fig. 30 is a chart showing a flow of route response receiving process at the source wireless communication device generated the route request message in embodiment 2 of the invention. Fig. 31 is a diagram showing a configuration of a wireless communication device in embodiment 3 of the invention. Fig. 32 is a chart showing a flow of route search in embodiment 3 of the invention. BEST MODE FOR CARRYING OUT THE INVENTION Referring to the drawings, explanations will be made below on the embodiments of the present invention. Note that like references are attached to like constituent elements.

Embodiment 1 Fig. 1 is a block diagram showing a configuration of a wireless communication device according to the present invention. This is constituted with a physical interface 101 , a data-link control section 102, a network controller

103, a higher-layer processing section 104 and a routing control section 111.

The routing control section 111 is configured with a route-control-message transmission processing section 105, a route-control-message generation processing section 106, a route-request-information recording section 107, a route-control-message reception processing section 108, a route recording section 109 and a route-control-process deciding section 110. The physical interface 101 is configured with an antenna, an RF circuit and a base-band processing circuit. This is to carry out a processing to modulate the signal received from the data-link control section 102 and convert it into a wireless signal to be transmitted at the antenna, and a processing to demodulate the wireless signal received at the antenna and delivering a digital signal to the data-link control section 102. The data-link control section 102 is to carry out a processing to make a framing of the signal obtained from the network controller section 103 conforming to a format as defined by a predetermined data-link layer and deliver it to the physical interface 101, a processing to remove a data-link-layer header/tailer from the digital signal received from the physical interface 101 and deliver it to the network controller 103, and a processing to get an access right to a wireless media conforming to an access scheme as defined by the data-link layer. Meanwhile, in the case of setting in a promiscuous mode to receive also the other frames than that destined for the own address, frame analysis is also made for a received frame not destined for the unicast to the own address. When received a frame correctly, the frame header is removed into packetization for delivery to the network controller. The physical interface 101 and the data-link control section 102 are defined under IEEE802.11a, IEEE802.11b, IEEE802.11e, IEEE802.11g, Bluetooth (registered trademark), UWB (Ultra Wide Band) or the like. The network controller section 103 is to make a decision for any of and carry out the respective ones of a processing to add an IP header to the message received from the higher layer and deciding a destination depending upon the information in the route recording section 109 thereby delivering it to the data-link control section 102, a processing to deliver the packet received from the data-link control section 102 to the higher-layer processing section 104, a processing of relay to another wireless communication device, and a processing of delivery to the route-control-message receiving processing section 108. In the case that the packet contains therein a route request message and a route response message, those messages are extracted and delivered to the route- control-message reception processing section 108. When the packet is destined for the own address and contains a message of higher layer, it is delivered to the higher-layer processing section 104. When the packet is not destined for the own address, the destination of transfer is decided depending upon the information in the routing recording section 109. The packet header revised, as required, for delivery to the data-link control section 102. The higher-layer processing section 104 is to carry out the layer processing of a transport layer, a session layer, a presentation layer and an application layer, and exchanges data with the network controller 103, as required. The route-control-message transmission processing section 105 is to carry out a processing to deliver the route request message/route response message received from the route-control-message generation processing section 106 to the network controller 103, in order transmit the same. The route-control- message transmission processing section 105, the network controller section 103, the data-link control section 102 and the physical interface 101 correspond to a transmitting section of the invention. The route-control-message generation processing section 106 is to be instructed by the route-control-process deciding section 110 to generate any of route request message and route response message, thereby generating a routing control message depending upon the route-control information received from the route-control-process deciding section 110. The route-request-information recording section 107 is provided with a source route-request table 201 and a route-request table 202, as shown in Fig. 2. In the route-request-information recording section 107, when a route request message is newly generated/transmited in/from the wireless communication device concerned, a source wireless communication device identifier, i.e. wireless-communication device-concerned identifier, route-request identifier and destination wireless communication device identifier, is recorded in the source route-request table 201 by distinguishing it based on the combination of {source wireless communication device identifier, route-request identifier}. As for the route request message, there are recorded the number of transmission executions, the presence or absence of a response as to a routing up to a destination wireless communication device, and the recent update time of entries. Those entries are to be deleted upon lapse of a constant time or when acquired a routing to all the wireless communication devices of within the entry. Furthermore, the source-wireless-communication device identifier, route-request identifier, destination-wireless-communication device identifier and received time in the received route request message is recorded in the route-request table 202 by distinguishing it based on the combination of {source wireless communication device identifier, route-request identifier}. Those entries are to be deleted upon lapse of a constant time. The route-control-message reception processing section 108 receives the route request message extracted in the network controller 103 and detects whether or not there is the corresponding one to the entry of {wireless- communication device-concerned identifier, route request identifier} in the route request information. Namely, decision is made as to whether or not received a route request message already transmitted from or received by itself. When already received, the route request message is discarded. When not received, the wireless communication device identifier of the neighbor wireless communication device transmitted the route request message is recoded, as an immediately preceding hop on the route to the destination wireless communication device identifier of within the route request message and as an immediately succeeding hop on the route to the source wireless communication device identifier of within the route request message, to the route recording section 109, and the route request message is delivered to the route-control- process deciding section 110. Meanwhile, in the case of receiving a route response message, when the response is to a route request message by the own device as a source, update is made to the corresponding entry in the route- request-information recording section 107, to make or update the corresponding entry, referred later, in the route recording section 109. Meanwhile, in the case that the route request message is from a source that is^{^}not the own device, the wireless communication device identifier neighbor the one transmitted the route response message is recoded, as an immediately succeeding hop on the route to the destination wireless communication device identifier of within the route request message and as an immediately preceding hop on the route to the source wireless communication device identifier of within the route request message, to the route recording section 109, and then delivered to the route- control-process deciding section 110. The route-control-message reception processing section 108, the network controller section 103, the data-link control section 102 and the physical interface 101 correspond to a receiving section of the invention. The route recording section 109 is a memory for recording the route information to a desired wireless communication device. This records, on an 18- entry basis, a destination wireless communication device identifier 1001 , an immediately succeeding hop wireless communication device identifier 1002 and an immediately preceding wireless communication device identifier 1003, as shown in Fig. 10. Meanwhile, in order to show the number of relays to the destination wireless communication device and whether the entry is effective or not or fresh or not, it is possible to additionally record such pieces of information such as of sequence number, entry effective time, valid/invalid flags, etc. correspondingly to the destination wireless communication device identifier. Meanwhile, neighbor wireless communication device can be recorded as an effective entry by emptying the immediately-succeeding and immediately- preceding wireless communication device identifier. The route-control-process deciding section 110 is to carry out a process to start up a route search for gaining a route to a wireless communication device as a destination, in the case there is no route information of the data to be sent at the network controller 103 in the route recording section 109. The section where to carry out this process corresponds to a route-request section of the invention. The route-control-process deciding section 110 records and manages therein a route-request identifier for distinguishing a route request message generated by the own device. In this case, the route-control-process deciding section 110 adds 1 to the own route-request identifier and instructs the route-control-message generation processing section 106 to generate a route request message. Also, it makes up and records the corresponding entry to the route-request-information recording section 107. In the case there are no response on route to all the destination wireless communication devices contained in the route request message within a predetermined time, 1 is added to each of the route-request identifier and the number of executions, to instruct the route-control-message generation processing section 106 to generate a route request message containing only an identifier of a destination wireless communication device a route has not been gained. At this time, update is made to the corresponding entry in the route-request-information recording section 107. The number of executions is to be added by a transmission counter 112 while the time is to be measured by a response-time managing section 113. Meanwhile, the route-control-process deciding section 110 carries out a processing to look up the information in the route-request-information recording section 107 and route recording section 109 depending upon a routing control message received from the route-control-message reception processing section 108, and instruct the route-control-message generation processing section 106 to make again a route response message or route response message. The section for carrying out this process corresponds to a target-of-route deciding section in the invention. When received a route request message, decision is made as to whether to make a response, a relaying of the route request message or both thereof. When the own device is a destination wireless communication device, the destination-wireless-communication device identifier field in the route request message is deleted of the wireless-communication device-concerned identifier, and instruction is made to the route-control-message generation processing section 106 to generate a route response message. At this time, in the absence of an effective route to the source wireless communication device, the foregoing route search process is started up in order to acquire a route to the source wireless communication device. Furthermore, in the presence of another wireless communication device identifier in the destination wireless communication device identifier field of within the route request message, only when a limit-number-of-relays field of IP header has a value greater than 1 , 1 is added to the number of relays of within the route request message. Thus, the route-control-message generation processing section 106 is instructed to make again a route request message in order for relaying. At this time, the corresponding entry is made up and recorded in the route-request-information recording section 107. In the case that the own device does not exist in the destination-wireless-communication device identifier field, only when the limit-number-of-relays field of IP header has a value greater than 1 , 1 is added to the number of relays of within the route request message. Thus, the route-control-message generation processing section 106 is instructed to make again a route request message in order to effect a relay. Also, the corresponding entry is made up and recorded in the route-request-information recording section 107. Incidentally, in place of the destination wireless communication device, the wireless communication device possessing the route to the destination wireless communication device may make up and transmit a route response message. Meanwhile, in the case of receiving a route response message from the route-control-message reception processing section^ 08, instruction is made to the route-control-message generation processing section 106 to look up the route recording section 109 and make up a route response message in order to relay a route response message to the next hop wireless communication device to the source wireless communication device. Incidentally, the route-control-process deciding section 110 may record and manage therein a sequence number representative of a freshness degree of route information. In this case, where newly generating a routing control message storing an own identifier of wireless communication device, the sequence number is updated by 1 and added onto the routing control message in order for transmission. By using this, each wireless communication device is allowed to record same as the newest information. Now exemplified is a route search method based on the wireless communication device in the present embodiment. Fig. 3 shows an example of ad-hoc network constituted with wireless communication devices. The ad-hoc network in this example is constituted with eleven wireless communication devices 301 from N1 to N11. The wireless communication devices connected by solid lines have communication links 302 through which direct communications are available. Explanation is made on the operation where there is caused a communication request to send a mail from wireless communication device N1 to wireless communication devices N5, N10, N11 or so, on the ad-hoc network constituted as in the above. Fig. 4 shows a flow of route search process in the wireless communication device N1. In the wireless communication device N1 , when there is the occurrence of a communication request to the wireless communication devices N5, N10, N11, the route-control-process deciding section 110 searches through the entries in the route recording section 109 as to whether or not there is route information to the wireless communication devices N5, N10, N11 , and makes a listing of the destination wireless communication devices where there is no effective route information (step S401). Then, the route-cόntrol-process deciding section 110 makes up a {route request identifier, destination wireless communication device identifier} entry in the source route-request table 201 of the route-request-information recording section 107 (step S402). Here, there is shown in Fig. 5 a source route-request table 201 at time T1. At the time T1 , created is an entry of {source wireless communication device identifier 501 = N1 , route request identifier 502 = 1 , the number of executions 503 = 1 , update time 504 = T1 , destination wireless communication device identifier 505 = N5, N10, N11 , route response 506 = N5: none, N10: none, N11: none}. Thereafter, the route-control-message generation processing section 106 makes up a route request message (step S403). Fig. 6 shows a format of route request message. In Fig. 6, type field 601 (8 bits) stores a number for representing a route request message. Flag field 602 (5 bits) stores a flag representing a mode, e.g. making effective only the route response of from the destination wireless communication device. Number-of-relays field 603 (8 bits) represents the number of relays of from the source wireless communication device to the wireless communication device sent a route request message. Values are respectively stored in route-request-identifier field 604 (32 bits), destination- wireless-communication device-identifier field 605 (32 bits), source-wireless- communication device-identifier field 606 (32 bits) and source-wireless- communication device-sequence-number field 607 (32 bits). Meanwhile, number-of-destination-nodes field 608 is set with a total number of wireless communication devices 1 to n as targets of route search: Incidentally, where the source wireless communication device records the corresponding destination- wireless-communication device-identifier sequence number, the corresponding destination-wireless-communication device sequence number field (32 bits) may be added to store a value thereof, for each destination wireless communication device identifier 605. Meanwhile, although this example provided the wireless communication device identifier with IPv4 address, the field for storing a wireless communication device identifier, if based on IPv6 address, has a length of 128 bits. Then, the route request message is delivered from the route-control- message transmission processing section 105 to the network controller 103 where it is added with an IP header having a destination address as a broadcast address and a source address as wireless-communication device-concerned address, and transmitted by way of the data-link control section 102 and physical interface 101 (step S404). Fig. 7 shows an example of route request message in the present embodiment. The route request message stores 3 in number-of-destination- nodes field 608, 1 in route-request identifier 604, identifiers of wireless- communication device N5, N10, N11 in destination-wireless-communication device-identifier field 605, N1 in source-communication device-identifier field, respectively. Then, route-response wait process, referred later, is carried out (step S405). Then, the route-control-process deciding section 110 decides whether ending the route-response wait process results from an acquisition of all the requested routes or results from an expiration of route-response wait time (step S406). In the case of ending the route-response wait process due to an acquisition of all the requested routes, the entries indicated by the route-request identifier fallen under are deleted from the source route request table 201 (step S410), thereby ending the route search process. Meanwhile, in case it is due to a route-response wait time expiration, it is decided whether the number of executions exceeds the maximum allowable number of executions (step S407). When not exceeding the maximum allowable number of executions, the route request information is updated (step S408) and the process returns to step S403. At the step S403, the route-control-message generation processing section 106 generates a route request message for searching for a route as to only the wireless communication devices a route could not have been acquired (step S403). From then on, the similar process is carried out. When the maximum allowable number of executions is exceeded at the step S407, the route-control-process deciding section 110 makes a decision as a route search error and delivers the information of destination wireless communication device a route could not have been acquired to the higher layer

(step S409). Fig. 8 shows a flow of route-response wait process (step S405). In a route-response wait process, at first the route-control-process deciding section 110 establishes a route-response wait time (step S801), to wait for receiving a route response message until the timer expires. Then, the route-control-process deciding section 110, when received a route response from the corresponding destination (step S802), carry outs a route-response receiving process (step S803), referred later, to update the route request information in the source route-request table 201. Thereafter, it is decided whether or not acquired all the routes to the requested wireless communication devices (step S804). When acquired the all, the route-response wait process is ended. When not acquired the all, the process returns to the decision of step S802. Meanwhile, in Step S802, the route-control-process deciding section 110, when not received a route response from the corresponding destination, decides whether or not the route-response wait time expired (step S805). When expired, 1 is added to the number of executions (step S806) thus ending the route- response wait process. Fig. 9 shows a flow of route-response receiving process (step S803). At first, the route-control-message reception processing section 108, when receiving a route response message to a route request message sent by the own device, searches a destination-wireless-communication device identifier contained in the route response message out of the destination-wireless-communication device field of the source route-request table 201 (step S901). When there is a relevant one (step S902), the route-response field of a relevant entry is set as response present (step S903). For example, when wireless communication device N1 at time T2 received a route response message from wireless communication device N5, the route-control-message reception processing section 108 updates,. as shown irr Fig. 18, the content of the source route-request table 201 into {route- request identifier 502 = 1 , the number of executions 503 = 1 , update time 504 = T2, destination-wireless-communication device identifier 505 = N5, N10, N11 , route response 506 = N5: present, N10: absent, N11 : absent}. Furthermore, the route-control-message reception processing section 108 makes, in the route recording section 109, an entry of {destination wireless communication device identifier 1001 = in-route-response-message destination wireless communication device identifier, next hop wireless communication device identifier 1002 = neighbor wireless communication device sent a route response message, immediately-preceding hop wireless communication device identifier 1003 = absent} (step S904). In this case, in case there are entries, those are updated. Meanwhile, entry effective time, flags indicative of validity/invalidity, the number of relays to the destination wireless communication device, etc. may be recorded additionally. Fig. 11 shows an example of route-request signal message to be sent again when the route-response wait time expired in a state there is a route response only from wireless communication device N5. In the route request message, the wireless communication device N5 identifier in the destination wireless communication device identifier field is deleted from the first round of route request message, to set identifiers of wireless communication devices N10,

N11. Number-of-destination-nodes field is set with 2, route-request identifier with

2 and source-wireless-communication device identifier field with N1 , respectively. Meanwhile, Fig. 12 shows the content of the source route-request table

201 at time T3 immediately before transmitting again a route-request-signal message, at that time. At time T3, there are stored the route-request identifier of the source route-request table 201 shown in Fig. 18, the number of executions added by 1 and update time T3. Incidentally, in the route search process of Figs. 4, 8 and 9, the route acquired by receiving a route response message is usable at any time even when the route response wait process is not ended, and hence to be employed in packet transmission. Using Fig. 13, explanation is now made on the operation the wireless communication device received the route request message. At first, the wireless communication device looks up the {source identifier, route request identifier} in the route request table 202, and verifies whether or not there is the same content as the source wireless communication device identifier 606 and route request identifier 604 of within the received route request message, to decide whether or not it is a route request message already received at the own wireless communication device. Meanwhile, when the source wireless communication device identifier 606 within the route request message agrees with that of the own device, the route request message sent by the own device is decided as the one relay-transferred by another wireless communication device (step S1301). In the case of a decision, at step S1301 , as a route request message transmitted by the owη device or a route request message already received, the route-request-signal receiving process is ended. In the case of a decision at the step S1301 as a route request message unreceived, source-wireless-communication device information is extracted out of the route request message, to record, in the route recording section 109, {destination wireless communication device identifier = source wireless communication device identifier within the route request message, next hop wireless communication device identifier = identifier of immediately-preceding, neighbor wireless communication device transmitted the received route request message, immediately-preceding hop wireless communication device identifier = empty} wherein, otherwise, update is made when there is already an entry (step S1302). - Meanwhile, where the number of relays and sequence numbers are also managed, recorded (updated) is the number of relays and source-wireless- communication device sequence number of within the received route request message. Furthermore, the information of entry effective time, valid/invalid flags, etc. can be recorded (updated) additionally. Here, there is shown in Fig. 10 the record data of within the routing recording section 109 when wireless communication device N5 received the route request message from wireless communication device N1. Furthermore, entry of {source identifier, route request identifier} is made in the route-request table 202 of the route-request-information recording section 107, to record additionally received time and destination-wireless-communication device identifier (step S1303). Fig. 14 is an example of the route-request table 202 of the wireless communication device N5 at time T4 when wireless communication device N5 received the route request message. Thereafter, it is decided whether or not there is stored another wireless communication device identifier in the destination-wireless-communication device identifier field of within the route request message (step S1304). When it is not stored, the process proceeds to step S1307. Meanwhile, when another wireless communication device identifier is stored, it is decided whether or not the limit-number-of-relays field of the IP header has a value greater than 1 (step S1305). When smaller, the process proceeds to step S1307. Only when greater, the number of relays in the received route request message is added by 1 , to generate and transmit a route request message deleted of the wireless-communication device-concerned identifier from the destination-wireless-communication device identifier field of within the route request message (step S1306). There is shown in Fig. 17 a route request message to be transferred at this time by wireless communication device N5. In Fig. 17, there is omitted an identifier of wireless communication device N5 from the destination wireless communication device identifier field of the received route request message, having a setting with identifiers of wireless communication devices N10, N11. Accordingly, 2 is set in the number-of- desti nation-nodes field. Furthermore, there are settings of "2" added by 1 in the number-of-relays field and N1 in the source wireless communication device identifier field. Then, the route-control-process deciding section 110 decides whether or not the route request message is destined for the own device (step S1307). When not destined for the own device, the process is ended. Meanwhile, when destined for the own device, tire route-control-message generation processing section 106 is instructed to make a route response message. Fig. 15 shows a format of the route response message. In Fig. 15, type field (8 bits) stores a number for indicating a route response message. Flag field (2 bits) stores a flag representative of a mode, e.g. requesting for a delivery acknowledgement as to the route response message. Prefix length field (5 bits), when designating the next hop wireless communication device identifier on a sub-net basis, stores the number of mask bits. The number-of-relays field (8 bits) represents the number of relays of from the source wireless communication device to the destination wireless communication device. Respective values are stored in destination-wireless- communication device identifier field (32 bits), destination-wireless- communication device sequence number field (32 bits) and source-wireless- communication device identifier field (32 bits). Lifetime field (32 bits) stores a value representative of an effective time of the route. Furthermore, looking up the route recording section 109 for IP header source address, wireless-communication device-concerned identifier and destination address, transmission is made by storing the next hop wireless communication identifier in the source wireless communication device of within the route response message (step S1307). In this example, wireless communication device identifier was based on IPv4 address. However, in the case of using IPv6 address, the field storing a wireless communication device identifier has a 128-bit length wherein prefix length field has 7 bits. Fig. 16 shows a route response message to be transmitted at the wireless communication device N5 upon receiving the route request message shown in Fig. 7. The route-control-message generation processing section 106 makes such a route response message while the route-control-message transmission processing section 105 requests the network controller 103 to transmit it. Thus, transmission data is sent out of the network controller 103 through the data link control section 102 and physical interface 101 (step S1308). Using Fig. 19, explanation is now made on the transfer operation of upon receiving a route response message in the case the own device is not a transmission source nor a target of route search. At first, when receiving a route response message, the route-control- message reception processing section 108 records, in the route recording section 109, {destination wireless communication device identifier 1001 = destination wireless communication device identifier within the route request message, next hop wireless communication device identifier 1002 = identifier of immediately-preceding neighbor wireless communication device transmitted the received route response message, immediately-preceding hop wireless communication device identifier 1003 = next hop wireless communication device identifier to source wireless communication device of within route response message, recorded in the route recording section 109} wherein, otherwise, update is made when there is already an entry (step S1901). Meanwhile, where the number of relays and sequence numbers are also managed, recorded (updated) is the number of relays and source-wireless-communication device sequence number in the received route request message. Furthermore, the information as to entry effective time, valid/invalid flags, etc. can be recorded (updated) additionally. Then, the route-control-message generation processing section 106 is instructed by the route-control-process deciding section 110 to provide the IP- header source address with an own wireless communication device identifier, the destination address with a next hop wireless communication device identifier to source wireless communication device and the limit-number-of-relays field subtracted by 1 about a route response message, thereby relay-transmitting the route response message (step S1902). There is shown in Fig. 20 the manner the route request message propagates as in the above. The route request message A2001 generated at wireless communication device N1 contains {source wireless communication device identifier = N1 , destination wireless communication device identifier = N5, N10, N11}, to be broadcast. This message is received at wireless communication devices N2, N3, N6. Wireless communication device N2, N3, N6, because not a destination wireless communication device, sets the IP-header source address with N2, N3, N6, to relay-broadcast the route request message A2001 to the neighbor wireless communication device. At this time, wireless communication device N4, N5 N7 receives the route request message A2001. However, wireless communication device N1 does not carry out a relay-processing because the route request message relayed from wireless communication device N2, N3, N6 is the one transmitted by itself. When the route request message A2001 is received at wireless communication device N5, the own device is contained in the destined wireless communication devices. Accordingly, it makes a route request message C2003 excluding the own device by setting the IP-header source address with an wireless-communication device-concerned identifier, thereby relay-broadcasting the same. The route request message C2003 is given a configuration as {source wireless communication device identifier = N1 , destination wireless communication device identifier = . N10, N11}. Accordingly, wireless communication device N3 is to receive a route request message having a different destination-wireless-communication device field value because not having a destination wireless communication device identifier = N5 existed in the route request message relayed by the own device. However, wireless communication device N3 does not relay-process the route request message because {source wireless communication device identifier = N1 , route-request identifier = 1} already exists in the route-request table 202 and hence is decided as a route request message received earlier. Wireless communication device N5, after relay-broadcasting the route request message C2003, transmits the route request message containing {source wireless communication device identifier = N1 , destination wireless communication device identifier = N5} to wireless communication device N3 in order for delivery to wireless communication device N1 by way of a route the route request message has been delivered, i.e. wireless communication device N3. Wireless communication device N7, because of not a destination wireless communication device, relay-broadcasts a route request message A2001 further to the neighbor wireless communication device. At this time, wireless communication device N6 receives a route request message already received, hence not effecting a relay processing. The route request message C2003 broadcast-relayed from wireless communication device N5 is received at wireless communication device N11. Wireless communication device N11 carries out a similar process to the foregoing wireless communication device N5, to relay-broadcast a route request message D2004 excluding the own device by setting the IP-header source address with an wireless-communication device-concerned identifier. The route request message D2004 is configured as {source wireless communication device identifier = N1 , destination wireless communication device identifier = N10}. Thereafter, a route response message containing {source wireless communication device identifier = N1 , destination wireless communication device identifier = N11} is transmitted to wireless communication device N5 in order for ' delivery to wireless communication device N1 via the route the route-request message has been delivered, i.e. wireless communication devices N5, N3. The route request message A2001 , broadcast-relayed from wireless communication device N9, is received at wireless communication device N10. Wireless communication device N10 also performs a similar process to the foregoing wireless communication device N5, N11 , to relay-broadcast a route request message B2002 excluding the own device by setting the IP-header source address with a wireless-communication device-concerned identifier and the destination address with a broadcast address. The route request message B2002 is configured as {source wireless communication device identifier = N1, N5, destination wireless communication device identifier = N11}. Thereafter, the route response message containing {source wireless communication device identifier = N1, destination wireless communication device identifier = N10} is transmitted to wireless communication device N9 in order for delivery to wireless communication device N1 by way of the route the route request message has been delivered, i.e. wireless communication devices N9, N6. Thereafter, wireless communication device N10 receives the route request message D2004. However, because of {source wireless communication device identifier = N1, route-request identifier = 1} exists in the route-request table 202 and hence is decided as a route request message received earlier, no route response message is sent. This is true for wireless communication device N11. Even when receiving a route request message B2002, no route response message is sent because already responded. Incidentally, the tables and message formats are mere one examples, which form may be given different provided that having similar information. Meanwhile, in this embodiment, the process proceeds branching depending upon whether or not the wireless-communication device-concerned identifier is included within a destination wireless communication device identifier field of the route request message. This condition may be given that the wireless-communication device-concerned identifier is included in a destination wireless communication device identifier field of within a route request message or that the effective route information to the destination wireless communication device identifier is possessed in the route recording section 109. In this case, even where the destination is not the own device, a route response message is sent to the source depending upon the possessed route information, to delete the address of destination wireless communication device being possessed from the destination of a route request message to be transferred. This allows the source wireless communication device under route search to know a route to a target rapidly. Incidentally, the embodiment realized the routing control section 111 on discrete hardware. However, this is not limitative but it can be realized on software by use of a computer comprising a central processing unit (CPU) and a main memory. Namely, it is possible to provide a wireless communication program for causing a computer to function, in order to route-search wireless communication devices over an ad-hoc network, as: a route request information recording section for recording identifiers specifying wireless communication devices as targets of route search; a route control message generation processing section for generating a route request message containing the identifiers of one or a plurality of the wireless communication devices recorded; a transmitting section for broadcasting the route request message generated; and a route control message reception processing section for receiving a route response message transmitted from the wireless communication device as a target of search received the route request message and deleting relevant one of the identifiers of the wireless communication devices as^ targets of route search from the route request information recording section. Meanwhile, it is possible to provide a wireless communication program for causing a computer to function, in order to route-search wireless communication devices over an ad-hoc network, as: a receiving section for receiving a route request message containing one to a plurality of identifiers specifying wireless communication devices as targets of route search; a target- of-route deciding section for deciding whether or not the targets of route search in the route request message received include the own device; a route control message generation processing section for generating a route response message to the wireless communication device as a transmission source of route search and a route request message removed of the own identifier of the wireless communication device from the wireless communication device identifiers described in the route request message, in the case the target-of-route deciding section decided the own device as a target of route search; and a transmitting section for making a transmission of a route response message generated by the route control message generation processing section and a broadcast-transfer of a route request message generated. Also, it is possible to provide a computer-readable recording medium recording the wireless communication program. As described above, according to the present embodiment, because a route to a plurality of destinations can be acquired by once route search even upon the occurrence of data destined for a plurality of wireless communication devices, the burden can be greatly reduced over the network.

Embodiment 2 Figs. 21 to 30 show an embodiment of a wireless communication device and route search method in embodiment 2 of the invention. The route search method of this embodiment is different from the method of embodiment 1 in that the route request message is added with, as an identifier, an alias having a 32-bit length corresponding to a destination wireless communication device identifier while the route response message uses the alias without using a destination wireless communication device identifier 605. Here, Fig. 22 shows the route request message. In Fig. 22, there is a difference from the route request message in embodiment 1 shown in Fig. 6 in that an alias option is provided to store the alias values of the destination wireless communication devices requested in the route request message. Fig. 23 shows a format of the alias option. In Fig. 23, option type field (8 bits) stores a number indicative of an alias option. Option length field (8 bits) stores a value indicative of a data length of the alias option on a 32-bit basis. Alias length field (8 bits) stores a value indicative of a bit length of each alias. The alias field stores an alias value effective only in the duration the information about the route request message is recorded in the wireless communication devices, as to the wireless communication devices stored in the destination wireless communication device identifier. Incidentally, in the case the source wireless communication device records the sequence numbers of the relevant destination wireless communication device identifiers, the destination wireless communication device identifiers may store the values thereof by addition. Meanwhile, in this example, wireless communication device identifier was based on IPv6 address. However, in the case of using IPv4 address, the field storing the wireless communication device identifier requires 32-bit length. Next, Fig. 26 shows a format of the routing response message in this embodiment. In Fig. 26, there is a difference from the routing response message shown in Fig. 15 in that having an alias field 2601 and a route request identifier field 2602. The areas field (7 bits) 2601 stores a conversion in 7 bit of the alias value of the own device indicated in the received route request message. The route-request identifier is to unambiguously identify the route request message. The route response message is to identify the corresponding route request message. Meanwhile, in order to realize communication of those messages, the source route-request table 201 and route-request table 202 in the route-request- information recording section 107 is different in organization from that of embodiment 1 , as shown in Figs. 21 and 25. Fig. 21 shows an example of source route-request table in wireless communication device N1 in the invention. This is different from the source route-request table in embodiment 1 shown in Fig. 5 in that there is further provided an alias field 2101 for the destination wireless communication device identifiers. The alias field has a value assigned by adding from 1 , in order, to the wireless communication devices as destinations respectively for route-request identifiers, in the source wireless communication device on the route request message. Accordingly, destination wireless communication device N5 is assigned with alias 1 , destination wireless communication device N10 is with alias 2, and destination wireless communication device N11 is with alias 3. Fig. 25 shows the content of the route-request table 202 in the wireless communication device for relay. This is different from the route-request table in embodiment 1 in that alias 2501 is recorded for destination wireless communication devices. Explanation is made on the communicating operation to be made by the wireless communication device having the source route-request table and route- request table as in the above. This embodiment is for the case that wireless communication device N1 searches a route to wireless communication devices N5, N10, N11 similarly to embodiment 1 , wherein the wireless communication devices has the same configuration as embodiment 1. Fig. 24 shows an example of a route request message to be transmitted from wireless communication device N1. Alias option field stores an option length = 1 and an alias length = 2. The alias option is shown having a data length of 32 bits while the alias has two bits in the number of bits. Wireless communication device N5 stores an alias value of 1 , N10 an alias value of 2 and N11 an alias value of 3. The alias field has the remaining 26 bits in 0 padding. Each wireless communication device, when receiving a route request message, operates similarly to embodiment 1 shown in Fig. 13. At step S1303, the alias information about destination wireless communication devices are also recorded together. Fig. 25 shows the content of the route-request table 202 in a relaying wireless communication device. There are included a destination wireless communication device identifier of the own device and further another wireless communication device identifier. When receiving a route request message to be relayed, the received route request message is deleted of the wireless-communication device-concerned identifier and alias. The route request message is made set again with a number-of-destination-nodes field and in-alias-option option length field, and then relay-broadcast with IP-header source address rendered as a wireless communication identifier of relevant apparatus (step S1306). Meanwhile, when receiving a route request message containing an own destination wireless communication device identifier, a route-response message is made in a format shown in Fig. 26. This is transmitted with an IP-header source address using an wireless-communication device-concerned identifier, the destination address looking up the route recording section (109) and the next hop wireless communication device identifier stored in source wireless communication device in the route-response message (step S1308). In this example, wireless communication device identifier used IPv6 address. However, where using IPv4 address, the field storing a wireless communication device identifier requires a 32-bit length while prefix length field is given 5 bits. Fig. 27 is an example of a route-response message to be sent at wireless communication device N5 in the case of receiving the route request message shown in Fig. 24. The alias field is set with 0000001. Meanwhile, when wireless communication device N5 receives the route request message shown in Fig. 24, it contains a destination wireless communication device identifier other than the own identifier. Accordingly, when the limit-number-of-relays field of the IP header is greater than 1 , the route request message is again made and transmitted. Fig. 28 shows an example of the route request message to be relayed. By omitting the wireless communication device N5 identifier in the destination wireless communication device identifier field 605 in the route request message, identifiers of wireless communication devices N10, N11 are set up. Number-of- destination-nodes field 608 is set with 2, number-of-relays field 603 with 2 and source wireless communication device identifier field 606 with N1 , respectively. By deleting 01 relevant to N5 in the alias-option alias field 2201 , an alias option is again made and added to the route request message in order for transmission. Using Fig. 29, explanation is now made on the relay operation in the case of receiving a route response message that the own device is not a source. At first, search is made through the route request table 22 for an entry matched to the combination of {source wireless communication device identifier, route request identifier, alias} in the route request message (step S2901). It is decided whether the entry exists or not (step S2902). When there is no entry, the process is ended as it is. Meanwhile, when the entry exists, recoded to the route recording section

(109) is {destination wireless communication device identifier = destination wireless communication device identifier of searched entry, next hop wireless communication device identifier = identifier of immediately-preceding neighbor wireless communication device transmitted a received route response message, immediately-preceding hop wireless communication device identifier = next hop wireless communication device identifier to source wireless communication device of within the route response message recorded in the route recording section (109)} wherein, otherwise, update is made when the entry already exists (step S2903). Meanwhile, where the number of relays and sequence numbers are also managed, recorded (updated) is the number of relays and destination- wireless-communication device sequence number of within the received route response message. Furthermore, the information as to entry effective time, valid/invalid flags, etc. may be recorded (updated) additionally. Thereafter, the route response message is relay-transmitted by setting the IP-header source address with an wireless-communication device-concerned identifier and the destination address with a next hop wireless communication device identifier to source wireless communication device, and by subtracting the limit-number-of-relays field by 1 (step 2904). Using Fig. 30, explanation is now made on the operation in the case of receiving a route response message that the own device is a source. At first, when receiving a route response message to a route request message sent by the own device, search is made through the source route request table 21 for an entry represented by {source wireless communication device identifier, route request identifier, alias} contained in the route request message (step S3001). It is decided whether or not there is an entry fallen under (step S3002). When there is no entry, the process is ended as it is. Meanwhile, in case there is an entry fallen under, the route response field of the entry fallen under is set as "response present" (step S3003). Furthermore, in the route recording section (109) is made an entry of {destination wireless communication device identifier = destination wireless communication device identifier of retrieved entry, next hop wireless communication device identifier = neighbor wireless communication device transmitted the route response message, immediately-preceding hop wireless communication device identifier = not present}. Otherwise, update is made when it already exists (step S3004). Meanwhile, entry effective time, flags indicative of validity/invalidity, the number of relays to the destination wireless communication device, etc. may be recorded additionally. Incidentally, in the present embodiment, the route control section 111 was realized on the separated ones of hardware. However, this is not limitative, i.e. it can be realized on software by use of a computer comprising a central processing unit (CPU) and a main memory. Also, it is possible to provide a computer-readable recording medium recording the wireless communication program. As described above, in the case that the length of identifier of wireless communication device is increased by supporting IPv6, shorter identifiers can be temporarily assigned in each execution of route search so that route response can be made by using the identifier. In one route search, the control message can be reduced in the number of bits. This makes it possible to retrieve a route for a plurality of destinations and reduce the burden over a network. Embodiment 3 Figs. 31 and 32 show one embodiment of a wireless communication device and route search method in embodiment 3 of the invention. Fig. 31 is a block diagram showing a configuration of a wireless communication device in the present embodiment. This is different from embodiment 1 in that further having a route search-startup deciding section 312. The network controller 311 has a basic function similar to that shown in embodiments 1 and 2. However, this further has a function to inform, to the route-control-process deciding section 110, whether the data for starting up a route search, in kind, is synchronous data represented by voice and moving images to be transmitted real time or asynchronous data represented by file transfer, Web browsing, etc. A route-control-process deciding section 314 has a basic function similar to that shown in embodiment 1. However, when there is shown that the route search startup data in kind is synchronous data from the network controller 311 , route search is started up immediately. Meanwhile, when there is shown that it is asynchronous data, the route-search wait timer is started up which is within a route-search-startup deciding section 312. When the timer of the route-search- startup deciding section 312 expires, route search for non-synchronism is started up. Incidentally, the route-search-startup deciding section 312 corresponds to a route-request instructing section of the invention. A route-request-information recording section 313 has a source route- request table 201 that is for recording separately as entry for asynchronous data and entry for synchronous data. However, when a destination wireless communication device identifier exists in the synchronous-data entry, entry is not made for asynchronous data. Explanation is made below on the communicating operation to be carried out by the wireless communication device configured as in the above. Fig. 32 shows a flow of a route search in the wireless communication device. At first, where there is an occurrence of a communication request from the higher-layer processing section 104, the route-control-process deciding section 314 searches through the route recording section 109, to decide whether or not having an effective route to a destination wireless communication device of data. When not having an effective route, route search is started up. By starting up a route search, the route-control-process deciding section 314 decides whether the data occurred in kind is synchronous data or asynchronous data (step S3101). In the case of synchronous data, necessary information including a source wireless communication device identifier, i.e. wireless-communication device-concerned identifier, a route request identifier, destination wireless communication device identifiers and update time, is recorded to a synchronous- data source route request table of the route-request-information recording section 313 (step S3102). Thereafter, executed are the steps S403 - step S410 of the route search process shown in Fig. 4, similarly to embodiment 1 (step S3103). Meanwhile, when decided as asynchronous data in the decision at the step S3101 , it is decided whether or not the route-search wait timer in the route- search-startup deciding section 312 is in operation (step S3104). When the route-search wait timer is not in operation, the timer is started up (step S3107). When the route-search wait timer is in operation, timer count is continued to record the necessary information including a source wireless communication device identifier, i.e. relevant-wireless-communication device identifier, a route request identifier, destination wireless communication device identifiers and update time is recorded to a asynchronous-data source route request table of the route-request-information recording section 313_; (step S3105). Then, it is decided whether or not the route-search wait timer expired

(step S3106). In case expired, the steps S403 - S410 of the route search process shown in Fig. 4 are executed as to the entries, not yet searched for routes, described in the asynchronous data source route-request table (step

S3103). Meanwhile, when the route-search wait timer is not expired, the process returns to step S3 wireless communication device 101. Incidentally, in the present embodiment, the route control section 111 was realized on the separated ones of hardware. However, this is not limitative, i.e. it can be realized on software by use of a computer comprising a central processing unit (CPU) and a. main memory. Also, it is possible to provide a computer-readable recording medium recording the wireless communication program. As described above, route search is separated as those for asynchronous data and for synchronous data. As for asynchronous data, besides a route search for distributing the same data to a plurality of destinations, route search can be made to the respective destinations of a plurality of transmission data occurred in a predetermined time by use of one route control message. This can greatly reduce the burden over a network.

INDUSTRIAL APPLICABILITY The wireless communication device and route search method of the invention is useful for an ad-hoc network, an autonomous distributed network, a self-organized network or the like, and suited for implementing a route search over such a network.

Claims

CLAIMS 1. A wireless communication device comprising: a route request information recording section recording identifiers specifying wireless communication devices as targets of route search on an ad- hoc network; a route control message generation processing section for generating a route request message including the identifiers of the wireless communication devices one to a plurality in the number recorded in the route request information recording section; a transmitting section for broadcasting the route request message generated at the route control message generation processing section; and a route control message reception processing section for receiving a route response message transmitted from the wireless communication device on a target of route received the route request message and deleting the identifier of the wireless communication device as the target of route search fallen under from the route request information recording section.

2. A wireless communication device according to claim 1 , including a route request section for sequentially recording the identifiers of the wireless communication devices requiring route search to the route request information recording section, and a route request instructing section for instructing a timing generating a route request message to the route control message generation processing section, the route request instructing section counting a route search wait time of from a start of recording to the route request information recording section, to instruct the route control message generation processing section after elapsing a predetermined time.

3. A wireless communication device according to claim 2, wherein the route request instructing section decides whether or not the data requiring route search is synchronous data, and counts the route search wait time when the data is asynchronous data. 5 4. A wireless communication device according to claim 1 , further including a response time managing section for managing a route response wait time of from a transmission of a route request message that a transmission source is the own device to a reception of the route response message, and a transmission counter for counting the number of transmission o executions of route request messages effected before receiving route response messages from the wireless communication devices of all the targets of search contained in the route request message, whereby, the route control message generation processing section, at within a predetermined number of times as to the number of transmission5 executions, again generates a route request message to the wireless communication device as a target of search not responded despite elapsing the route response time so that the transmitting section broadcasts the route request message. 5. A wireless communication device according to claim 2, further 0 including a response time managing section for managing a route response wait time of from a transmission of a route request message that a transmission source is the own device to a reception of the route response message, and a transmission counter for counting the number of transmission executions of route request messages effected before receiving route response5 messages from the wireless communication devices of all the targets of search contained in the route request message, whereby, the route control message generation processing section, at within a predetermined number of times as to the ^number of transmission executions, again generates a route request message to the wireless communication device as a target of search not responded despite elapsing the route response time so that the transmitting section broadcasts the route request message. 6. A wireless communication device according to claim 3, further including a response time managing section for managing a route response wait time of from a transmission of a route request message that a transmission source is the own device to a reception of the route response message, and a transmission counter for counting the number of transmission executions of route request messages effected before receiving route response messages from the wireless communication devices of all the targets of search contained in the route request message, whereby, the route control message generation processing section, at within a predetermined number of times as to the number of transmission executions, again generates a route request message to the wireless communication device as a target of search not responded despite elapsing the route response time so that the transmitting section broadcasts the route request message. 7. A wireless communication device comprising: a receiving section for receiving a route request message containing one to a plurality of identifiers specifying wireless communication devices as targets of route search over an ad-hoc network; a target-of-route deciding section for deciding whether or not the targets of route search in the route request message received include the own device; a route control message generation processing section for generating a route response message to the wireless communication device as a transmission source of route search and a route request message deleted of an identifier of the wireless communication device concerned from wireless communication device identifiers described in the route request message, in the case the target- of-route deciding section decided the own device as a target of route search; a transmitting section for transmitting a route response message generated by the route control message generation processing section and broadcast-transferring a route request message generated. 8. A wireless communication device according to any one of claims 1 to 6, further including a target-of-route deciding section for deciding whether or not targets of route search in the route request message received include the own device, the route control message generation processing section, when the target-of-route deciding section decided the own device as a target of route search, generating a route response message to the wireless communication device as a transmission source of route search, and a route request message removed of an identifier of the own wireless communication device from wireless communication device identifiers described in the route request message, the transmitting section making a transmission of the route response message generated by the route control message generation processing section and a broadcast-transfer of the route request message generated. 9. A wireless communication device according to any one of claims 1 to 7, wherein the route control message generation processing section generates a route request message containing a route request identifier for identifying unambiguously a route request message and a new identification code corresponding to the wireless communication device as a target of search and less in data amount than the identifier of the relevant wireless communication device, or generating the route response message containing only the route request identifier and the own identification code. 10. A route search method comprising: a step for a first wireless communication device for searching a route over an ad-hoc network to store identifiers specifying wireless communication devices as targets of route search in a route request information recording section; a step for the first wireless communication device to generate and broadcast a route request message containing one to a plurality of wireless communication device identifiers recorded; a step for a second wireless communication device received the route request message, in a case a wireless communication device as a target of search, to transmit a route response message to the first wireless communication device as a transmission source; a step for the second wireless communication device to generate and broadcast-transfer a route request message removed of the own identifier of the wireless communication device from the wireless communication device identifiers described in the route request message; and a step for the first wireless communication device to receive the route response message from the second wireless communication device and delete the identifier of the second wireless communication device from the targets of route search stored in the route request information recording section. 11. A route search method according to claim 10, further including a step for the first wireless communication device to count route search wait time of from a start of recording to the route request information recording section, to generate and broadcast the route request message after elapsing a predetermined time. 12. A route search method according to one of claim 10 and claim 11 , having a step for the first wireless communication device to count a route response wait time of from a transmission of a route request message to a reception of a route response message, and generate again and broadcast a route request message when not received a route response message from the wireless communication device as a target of search within a predetermined time, which step is repeated until the number of transmission executions of the route request message exceeds a. predetermined number of times. 13. A wireless communication program for causing a computer to function, in order to route-search wireless communication devices over an ad-hoc network, as: a route request information recording section for recording identifiers specifying wireless communication devices as targets of route search; a route control message generation processing section for generating a route request message containing the identifiers of one or a plurality of the wireless communication devices recorded; a transmitting section for broadcasting the route request message generated; and a route control message reception processing section for receiving a route response message transmitted from the wireless communication device as a target of search received the route request message and deleting relevant one of the identifiers of the wireless communication devices as targets of route search from the route request information recording section. 14. A wireless communication program for causing a computer to function, in order to route-search wireless communication devices over an ad-hoc network, as: a receiving section for receiving a route request message containing one to a plurality of identifiers specifying wireless communication devices as targets of route search; a target-of-route deciding section for deciding whether or not the targets of route search in the route request message received include the own device; a route control message generation processing section for generating a route response message to the wireless communication device as a transmission source of route search and a route request message removed of the own identifier of the wireless communication device from the wireless communication device identifiers described in the route request message, in the case the target- of-route deciding section decided the own device as a target of route search; and a transmitting section for making a transmission of a route response message generated by the route control message generation processing section and a broadcast-transfer of a route request message generated. 15. A computer-readable recording medium recording a wireless communication program according to one of claim 13 and claim 14.