JP2000341323A - Ad hoc radio terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the use efficiency of radio resources from decreasing and to shorten the time needed to change a communication route by trying to change a current communication route through a communication between a repeater terminal and a destination terminal even when the current communication route is not cut off. SOLUTION: When a repeater terminal and a destination terminal, in a communication route which is currently used, become unable to communicate with each other as the destination terminal moves, a change of the current communication route is tried through the communication between the repeater terminal and destination terminal even if the current communication route is not cut off. This terminal has a communication route for transferring data packets controlled according to information held in a route storage part 55 and transmission source data 61, destination data 62, etc., and held in the route storage part 55. A communication route control part 58 repeats route control and changes the communication route at need according to the contents of a beacon packet received by a beacon reception part 57 and the respective data held in the route storage part 55.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless ad hoc terminal used as one of a plurality of wireless terminals constituting an ad hoc network (ad hoc network), and more particularly to a wireless ad hoc terminal adapted to movement of a destination terminal. The present invention relates to a wireless ad hoc terminal whose configuration is changed.

[0002]

2. Description of the Related Art In an ad hoc network, at least three wireless terminals each having all functions of transmitting, receiving and relaying data packets are used. , A destination terminal to which a data packet is to be transmitted, or a relay terminal that relays a data packet. When direct communication cannot be performed between the source terminal and the destination terminal, the data packet is relayed by at least one relay terminal, and the data packet is transferred from the source terminal to the destination terminal.

As a prior art of an ad hoc network in which a plurality of wireless terminals communicate with each other, for example, Japanese Patent Application Laid-Open No. Hei 8-97821 entitled "Wireless Data Communication Method and Apparatus and Wireless Data Communication System" is known. Each wireless terminal that constitutes an ad hoc network has a relay function, so that the source terminal that is the source of the data packet and the destination terminal that is the destination of the data packet cannot communicate directly due to the distance or the like. Also, data packets can be transferred by configuring an ad hoc network using a wireless terminal existing between a source terminal and a destination terminal as a relay terminal.

[0004] In this type of ad hoc network, each wireless terminal can move. But,
If a part of the wireless terminal that configures the ad hoc network moves far while transferring data packets from the source terminal to the destination terminal using the ad hoc network, the currently used communication route will not be used. May not be possible.

[0005] When a communication route is interrupted due to a movement of a wireless terminal or the like, it is necessary to search for a new route.
In such a case, a route search packet (referred to as a control packet) is generally transmitted from a wireless terminal performing a route search to an unspecified wireless terminal existing in the vicinity thereof. Then, the wireless terminal that has received the control packet repeats the broadcast transmission of the control packet again until it reaches the destination of the control packet. In this way, a search for a new communication route is performed. When the control packet reaches the destination, the result of the route search is notified from the destination to the wireless terminal performing the route search, and the update of the communication route is completed.

[0006] In the case of the ad hoc network disclosed in Japanese Patent Application Laid-Open No. Hei 8-97821, a terminal that transmits a control packet is a source terminal, and a destination of the control packet is a destination terminal. Therefore, the route search is started from the source terminal, and the result of the route search is delivered from the destination terminal to the source terminal.

[0007] Further, in the "ad hoc network packet routing method" (Japanese Patent Application No. 10-038667) filed by the present applicant, the terminal transmitting the control packet is the destination terminal, and the transmission destination of the control packet is The source terminal. Therefore, the route search is started from the destination terminal. For example, an ad hoc network as shown in FIG. 18 can be configured. In the example of FIG. 18, three relay terminals A, B, and C existing between the source terminal S and the destination terminal Z are used. That is, the source terminal S transmits the data packet to the relay terminal A. Relay terminal A relays the received data packet and transfers it to relay terminal B. Similarly, the relay terminal B transfers the data packet to the relay terminal C, and the relay terminal C transfers the data packet to the destination terminal.

When a relay terminal B moves as shown in FIG. 19A while transferring data packets in the ad hoc network of FIG. 18, relay terminals A and B
18 is interrupted, so that the communication route shown in FIG. 18 cannot be used. In this case, for example, as shown in FIG. 19A, the relay terminal A detects the interruption of the communication route, and sends a route update request from the relay terminal A to the transmission source terminal S.

When the source terminal S receives the route update request from the relay terminal A, as shown in FIG. 19B, the source terminal S sends a control packet to an unspecified wireless terminal in the vicinity to search for a route. Broadcast transmission. The wireless terminal receiving the control packet repeats the broadcast transmission of the control packet until the wireless terminal reaches the destination terminal Z to search for a route.

In the example of FIG. 19B, the control packet transmitted by the transmission source terminal S reaches the destination terminal Z via the relay terminal D, the relay terminal E, and the relay terminal F. Destination terminal Z
Receives the control packet and notifies the source terminal S of the result of the route search via the relay terminals F, E and D as shown in FIG. When receiving the result of the route search, the source terminal S transmits a data packet to the destination terminal Z using the new communication route.

Further, a route search can be performed as shown in FIG. In FIG. 20A, since the relay terminal B has moved to a position away from the relay terminal C, the communication path between the relay terminal B and the relay terminal C is cut off. In this example,
The relay terminal C has given a route update request to the destination terminal Z. Upon receiving the route update request from the relay terminal C, the destination terminal Z broadcasts a control packet to neighboring unspecified wireless terminals for route search. The wireless terminal that has received the control packet from the destination terminal Z repeats the broadcast transmission of the control packet until it reaches the source terminal.

In the example of FIG. 20B, the control packet from the destination terminal Z reaches the transmission source terminal S via the relay terminals F, E, and D. When the control packet reaches the source terminal S, the update of the communication route is completed. That is, FIG.
As shown in (c), the data packet from the transmission source terminal S is delivered to the destination terminal Z via the relay terminals D, E, and F.

On the other hand, when a data packet is transferred from a source terminal S to a destination terminal Z in an ad hoc network as shown in FIG. 21A, the destination terminal Z moves as shown in FIG. 21B. There is a possibility. In the case of a conventional wireless ad hoc terminal, if the destination terminal Z is within the wireless communication range of the relay terminal C, even if the destination terminal Z moves into the wireless communication range of the relay terminal A,
The transfer of the data packet is continued using the current communication route, that is, the communication route that relays the relay terminals A, B, and C. However, direct transfer from the relay terminal A to the destination terminal Z is more efficient because the number of relays is reduced.

In the case of the ad hoc network disclosed in Japanese Patent Application Laid-Open No. Hei 8-97821, the destination terminal Z in FIG. 21 moves out of the wireless communication range of the relay terminal C, and the destination terminal Z moves to the wireless communication range of the relay terminal A. When it moves inside, the route search is performed in the same procedure as in FIG. That is, relay terminal C relays relay terminals B and A to notify transmission source terminal S that the communication route needs to be updated. In that case,
The source terminal S broadcasts a control packet and starts searching for a route. The relay terminal that has received the control packet transmits the control packet again by broadcast transmission until it reaches the destination terminal Z.

In the case of FIG. 21, the control packet transmitted from the source terminal S reaches the destination terminal Z via the relay terminal A. When the destination terminal Z receives the control packet, the result of the route search is relayed to the relay terminal A and notified to the transmission source terminal S. As a result, the data packet transmitted by the destination terminal S is received by the relay terminal A, and the data packet relayed by the relay terminal A is transferred to the destination terminal Z.

When a route search is performed from the destination terminal Z to the source terminal S, the destination terminal Z shown in FIG. When moving within the wireless communication range of FIG.
A route search is performed in the same procedure as described above. That is, the destination terminal Z determines that the communication route needs to be updated, starts broadcast transmission of a control packet from the destination terminal Z, and searches for a route. The relay terminal that has received the control packet transmits the control packet again by broadcast transmission until it reaches the source terminal S. When the source terminal S receives the control packet, the source terminal S transmits the data packet using the communication route through which the control packet has passed.

On the other hand, when a data packet is transferred from a source terminal S to a plurality of destination terminals Z1 and Z2 in an ad hoc network as shown in FIG.
There is a possibility that the destination terminal Z1 moves as shown in FIG.

In the case of the conventional wireless ad hoc terminal, if the destination terminal Z1 is within the wireless communication range of the relay terminal E as shown in FIG. , The data packet is transferred from the source terminal S to the destination terminal Z1 using the current communication route, that is, the communication route relaying the relay terminals C, D, and E. However, in the case of FIG. 22, the number of relays is smaller when the transfer is performed from the relay terminal B to the destination terminal Z1.

In the case of the ad hoc network disclosed in Japanese Patent Application Laid-Open No. Hei 8-97821, the destination terminal Z1 shown in FIG.
Moves into the wireless communication range of the relay terminal B,
A route search is performed in the same procedure as in step 9. That is, the relay terminal E determines that the communication route needs to be updated, and relays the relay terminals D and C to notify the transmission source terminal S to that effect. In that case, the source terminal broadcasts a control packet and starts searching for a route. The relay terminal that has received the control packet transmits the control bucket again by broadcast transmission until reaching the destination terminal Z1.

Upon receiving the control packet, the destination terminal Z1 uses the communication route through which the control packet has passed to inform the source terminal of the result of the communication route search. Source terminal S
Uses the result of the communication route search to secure a new communication route. In the example of FIG. 22B, the relay terminal A relays the two relay terminals A and B from the source terminal S and transfers the relay terminal A to the destination terminal Z1 with the least number of relays. To transmit data packets to the two destination terminals Z1 and Z2.

When a route is searched from the destination terminal Z1 toward the transmission source terminal S, the destination terminal Z1 shown in FIG.
Moves out of the wireless communication range of the relay terminal E, and the destination terminal Z1 moves into the wireless communication range of the relay terminal B,
A route search is performed in the same procedure as in FIG.

That is, the destination terminal Z1 determines that the communication route needs to be updated, and starts broadcast transmission of a control packet from the destination terminal Z1 to search for a route. The relay terminal that has received the control packet transmits the control packet again by broadcast transmission until it reaches the source terminal S. When the source terminal S receives the control packet, a new communication route is secured according to the communication route through which the control packet has passed. In the example of FIG. 22B, the relay terminal A relays the two relay terminals A and B from the source terminal S and transfers the relay terminal A to the destination terminal Z1 with the least number of relays. To transmit data packets to the two destination terminals Z1 and Z2.

[0023]

In the case of using a conventional wireless ad hoc terminal, unless a relay terminal relaying a data packet to a destination terminal recognizes that communication with the destination terminal has become impossible, communication is not performed. Do not change the route. Therefore, for example, even if the destination terminal Z moves from the state (a) to the state (b) shown in FIG. 21 and moves within the wireless communication range of the relay terminal A, the relay terminals B and C are still relayed. Then, the data packet is transferred to the destination terminal Z.

That is, although the destination terminal Z receives the data packet transmitted from the relay terminal A, the destination terminal Z further receives the data packet relayed from the relay terminal C to receive the same data packet. Will receive it. There is a problem in that the use efficiency of the radio resources deteriorates with the transfer of such useless data packets.

In FIG. 21B, the destination terminal Z
Is moved out of the wireless communication range of the relay terminal C, the relaying of the data packet from the relay terminal A to the destination terminal Z is possible. Since the broadcast transmission of the control packet and the notification processing of the route search result are performed, there is a problem that it takes time until the data packet is transmitted.

Further, as shown in FIG. 22, for example, when the same data packet is received by a plurality of destination terminals Z1 and Z2, the same data packet is set within the radio communication range of the radio terminal B relaying the same data packet. Even if the destination terminal Z1 moves, the existing communication route is used as it is, unless the conventional wireless ad hoc terminal recognizes that the route needs to be updated. Therefore, the use efficiency of the radio resource is deteriorated due to the useless transfer of the data packet.

Further, even when it is recognized that the route needs to be updated, the source terminal S and the destination terminal Z1 are in spite of being able to receive the same data packet.
Since broadcast processing of a control packet and notification processing of a route search result are performed between them, it takes a long time until a data packet is transmitted.

According to the present invention, in a wireless ad hoc terminal as described above, it is possible to prevent the use efficiency of wireless resources from being reduced due to the transfer of useless data packets and to shorten the time required for changing the communication route. Aim.

[0029]

According to the first aspect of the present invention, there is provided a wireless terminal serving as a source of a data packet using at least three wireless terminals each having all functions of transmitting, receiving and relaying a data packet. When the wireless terminal that is the destination of the data packet and the wireless terminal that relays the data packet are respectively defined as a source terminal, a destination terminal, and a relay terminal, and when direct communication cannot be performed between the source terminal and the destination terminal, A wireless ad hoc terminal used as one of the wireless terminals in an ad hoc network that relays a data packet at at least one of the relay terminals and forwards the data packet from the source terminal to the destination terminal. Regarding a communication route from a source terminal to a destination terminal, first identification information for specifying the destination terminal and the communication route Second identification information for identifying a wireless terminal closer to the source terminal among two wireless terminals located adjacent to itself on the route, and a wireless terminal closer to the destination terminal among the two wireless terminals Communication route information holding means for holding third identification information for identifying the communication path, beacon transmission means for periodically transmitting a signal including fourth identification information for identifying itself to surrounding wireless terminals, A beacon receiving means for receiving the fourth identification information transmitted from a peripheral wireless terminal, and a beacon receiving means for transmitting the data packet to the destination terminal when the terminal itself is not the last relay terminal. Identification information comparing means for comparing the first identification information held by the communication route information holding means with the fourth identification information received by the beacon receiving means from another wireless terminal; A route update requesting unit for transmitting a route update request signal from the relay terminal detecting the match to the destination terminal when the result of the comparison by the information comparing unit matches, and when the relay terminal itself is the destination terminal, When receiving the route update request signal from another wireless terminal, the second identification information held by the communication route information holding unit of the wireless terminal corresponds to the relay terminal that transmitted the route update request signal. A first route change unit that changes the identification information and transmits a route update response signal to the relay terminal that has transmitted the route update request signal, and a relay terminal that has itself transmitted the route update request signal. In this case, when the route update response signal is received, the third identification information held by its own communication route information holding means is replaced with the route update response signal. Second route changing means for changing to identification information corresponding to the destination terminal which has transmitted the signal, and transmitting, receiving and relaying the data packet using a communication route determined by the information held by the communication route information holding means. It is characterized by performing.

In the first aspect, each wireless terminal, that is, a wireless ad hoc terminal, transmits, receives, and relays a data packet so as to use a communication route corresponding to information held by the communication route information holding means. Each wireless ad hoc terminal is used as one of a source terminal, a destination terminal, and a relay terminal. The communication route information holding means includes, for a communication route from a source terminal currently being used to a destination terminal, a first route specifying the destination terminal.
Identification information for identifying a wireless terminal that is closer to the source terminal among two wireless terminals located adjacent to itself on the communication route; and destination information for the two wireless terminals. Third identification information for specifying a wireless terminal closer to the terminal is held.

The beacon transmitting means of each wireless terminal periodically transmits a signal (beacon packet) including fourth identification information for specifying the terminal to peripheral wireless terminals. Therefore, the beacon receiving means of each wireless terminal can receive the fourth identification information included in the beacon packet transmitted from the wireless terminals in the vicinity. That is, each wireless terminal can identify the presence or absence of another wireless terminal that can wirelessly communicate with the wireless terminal based on whether or not the wireless terminal has received the beacon packet. Further, from the fourth identification information of the received beacon packet, the communicable wireless terminal that transmitted the beacon packet can be specified.

If the identification information comparison means itself is not the last relay terminal transmitting the data packet to the destination terminal (the next relay terminal is itself the destination terminal), the identification information comparison means has its own communication route information holding means. Is compared with the fourth identification information received by the beacon receiving unit from another wireless terminal. Route update request means,
When the result of the comparison by the identification information comparing means matches,
The relay terminal that has detected the coincidence transmits a route update request signal to the destination terminal.

For example, in the ad hoc network of FIG. 8, when the destination terminal 10 (Z) moves to the communicable range of the relay terminal 10 (B) as shown in FIG.
(B) is not the final relay terminal, and the relay terminal 10
Since (B) relays the data packet of the destination terminal 10 (Z), the comparison result of the identification information comparison means of the relay terminal 10 (B) matches, and the relay terminal 10 (B) sends the destination terminal 10 (Z). Z)
Sends a route update request signal to the.

When the first route change means receives a route update request signal from another wireless terminal when the first route change means itself is the destination terminal, the first route change means holds the second route information held by its own communication route information holding means. The identification information is changed to identification information corresponding to the relay terminal that has transmitted the route update request signal, and a route update response signal is transmitted to the relay terminal that has transmitted the route update request signal.

If the second route change means itself is the relay terminal which has transmitted the route update request signal, and receives the route update response signal, the second route change means retains its own communication route information holding means. The third identification information is changed to identification information corresponding to the destination terminal that transmitted the route update response signal. For example, in the ad hoc network shown in FIG. 8, the destination terminal 10 (Z) moves to the communicable range of the relay terminal 10 (B) as shown in FIG.
(B), when the route update request signal is transmitted to the destination terminal 10 (Z), in the destination terminal 10 (Z), the first route changing means transmits the second identification information to the relay terminal 10 (B). In the relay terminal 10 (B), the second route change unit associates the third identification information with the destination terminal 10 (Z).

As a result, the communication route is changed so that the data packet is transmitted directly from the relay terminal 10 (B) to the destination terminal 10 (Z). This change of the communication route is realized by the transfer of the beacon packet from the destination terminal 10 (Z) to the relay terminal 10 (B).
This is executed even when a communication route between 0 (Z) and the relay terminal 10 (D) is available.

When the communication route is changed as described above, the relay at the relay terminals 10 (C) and 10 (D) is omitted in FIG. 9, so that the number of relays is reduced and unnecessary data packet transfer occurs. Since there is no radio resource utilization efficiency, radio resource utilization efficiency is improved. Further, when the communication route is changed, it is not necessary to perform control packet broadcast transmission or route search result notification processing between the source terminal and the destination terminal, so that the time required for changing the communication route is short.

[0038] The second aspect of the present invention provides at least three sections each having all functions of transmitting, receiving and relaying data packets.
A wireless terminal that is a source of a data packet, a wireless terminal that is a destination of a data packet, and a wireless terminal that relays a data packet are defined as a source terminal, a destination terminal, and a relay terminal, respectively, When direct communication between the source terminal and the destination terminal is not possible, at least one of the relay terminals relays a data packet and transfers the data packet from the source terminal to the destination terminal. In the wireless ad hoc terminal used as one of the wireless terminals, regarding the currently used communication route from one source terminal to a plurality of destination terminals including a first destination terminal and a second destination terminal, First identification information for respectively identifying a destination terminal, and two adjacent wireless terminals at positions adjacent to itself on the communication route Second identification information for identifying a wireless terminal closer to the source terminal among the wireless communication terminals; third identification information for identifying a wireless terminal closer to the destination terminal among the two adjacent wireless terminals; Communication route information holding means for holding relay number information corresponding to the number of relays from the terminal to the wireless terminal; and periodically transmitting a signal including fourth identification information identifying itself to surrounding wireless terminals. Beacon transmitting means for transmitting, beacon receiving means for receiving the fourth identification information transmitted from a peripheral wireless terminal, and, if itself is any destination terminal, its own communication route information The first identification information held by the holding unit is compared with the fourth identification information received from the other wireless terminal by the beacon receiving unit, and the source terminal having the same fourth identification information is compared. Communication from An identification information comparison unit that detects a match when the identification information is included in the first identification information as another destination terminal that belongs to the first identification information; Route update request means for transmitting a route update request signal including the relay number information to a second destination terminal that has transmitted the fourth identification information to one destination terminal; In the case of the second destination terminal that has received the communication route information, a plurality of communication routes based on the number of relays held by its own communication route information holding means and the number of relays included in the route update request signal. The number of relays comparing the number of relays, and if the relay destination itself is the second destination terminal, as a result of the comparison by the number of relays comparing, when the communication route is changed, the number of relays becomes smaller. Is it The second communication route information held by its own communication route information holding means;
A route update response unit that transmits a route update response signal to the first destination terminal while changing the identification information of the first destination terminal to identification information that specifies the first destination terminal; If the route update response signal is received from the second destination terminal in the case of the destination terminal, the third identification information held by its own communication route information holding means is replaced with the second destination information. Communication route changing means for changing to identification information for identifying a terminal, wherein transmission, reception and relay of a data packet are performed using a communication route determined by information held by the communication route information holding means.

In the present invention, each wireless terminal, that is, a wireless ad hoc terminal transmits, receives and relays a data packet so as to use a communication route corresponding to the information held by the communication route information holding means. Each wireless ad hoc terminal is used as at least one of a source terminal, a destination terminal, and a relay terminal. In some cases, the destination terminal performs the function of a relay terminal. Claim 2 assumes that a communication route for transferring a data packet from the same source terminal to a plurality of destination terminals is formed.

The communication route information holding means includes first identification information for specifying each of the plurality of destination terminals, and the one of the two adjacent wireless terminals adjacent to itself on the communication route, which is closer to the source terminal. The second identification information for identifying the wireless terminal of the second, the third identification information for identifying the wireless terminal closer to the destination terminal among the two adjacent wireless terminals, and the number of relays from the source terminal to the wireless terminal. The corresponding relay number information is held.

The beacon transmitting means of each wireless terminal periodically transmits a signal (beacon packet) including the fourth identification information for specifying the terminal to peripheral wireless terminals. Therefore, the beacon receiving means of each wireless terminal can receive the fourth identification information included in the beacon packet transmitted from the wireless terminals in the vicinity. That is, each wireless terminal can identify the presence or absence of another wireless terminal that can wirelessly communicate with the wireless terminal based on whether or not the wireless terminal has received the beacon packet. Further, from the fourth identification information of the received beacon packet, the communicable wireless terminal that transmitted the beacon packet can be specified.

If the identification information comparison means itself is any of the destination terminals, the identification information comparison means holds the first information held by itself.
And the fourth identification information received by the beacon receiving unit from another wireless terminal. Then, a match is detected when the fourth identification information is included in the first identification information as another destination terminal belonging to a communication route from the same source terminal.

The route update requesting means transmits the fourth destination terminal from the first destination terminal which has detected the match by the identification information comparing means to the fourth destination terminal.
A route update request signal including the number of relay information is transmitted to the second destination terminal that has transmitted the identification information. For example, in the ad hoc network shown in FIG. 11, two destination terminals 10 (Z1) and 1 (Z1) are sent from the same source terminal 10 (S).
Data packets are transferred to routes 0 (Z2) by different routes. When the destination terminal 10 (Z2) moves from the state of FIG. 11 as shown in FIG. 12 and the destination terminal 10 (Z2) enters the communicable range of the destination terminal 10 (Z1), for example, the destination terminal 10 (Z1) ) Receives the beacon packet from the destination terminal 10 (Z2).

In this case, the destination terminal 10 (Z1) has the same fourth identification information as that of the source terminal 10 (Z2).
As the other destination terminal belonging to the communication route from (S), the first
, The identification information comparison means of the destination terminal 10 (Z1) detects a match, and the destination terminal 10 (Z1)
The route update requesting means transmits a route update request signal from the destination terminal 10 (Z1) to the destination terminal 10 (Z2).

If the relay number comparison means is itself the second destination terminal that has received the route update request signal, the relay number comparison means compares the relay number information held by its own communication route information holding means with the route update request. The relay number of a plurality of communication routes is compared based on the relay number information included in the signal.

The route update responding means, when itself is the second destination terminal, as a result of the comparison by the relay number comparing means, if the number of relays becomes smaller when the communication route is changed, The second identification information held by the communication route information holding means is changed to the identification information for specifying the first destination terminal, and a route update response signal is transmitted to the first destination terminal.

When the communication route changing means receives the route update response signal from the second destination terminal when the communication route changing means itself is the first destination terminal, the communication route changing means owns the communication route information holding means. Associated third identification information with the second destination terminal. The communication route from the source terminal to the second destination terminal is changed by the change of the second identification information at the second destination terminal and the change of the third identification information at the first destination terminal. You.

For example, the destination terminal 10 (Z2) moves from the state of FIG. 11 as shown in FIG.
2) is within the communicable range of the destination terminal 10 (Z1), and a route update request signal is transmitted from the destination terminal 10 (Z1) to the destination terminal 10 (Z2) as follows. In the example of FIG. 12, the source terminal 10 (S)
(B), 10 (C) and 10 (D) are relayed to the destination terminal 10 (Z
The number of relays when transferring the data packet in 2) is four. On the other hand, the number of relays when the data packet is transferred from the source terminal 10 (S) to the destination terminal 10 (Z2) by relaying the relay terminal 10 (A) and the destination terminal 10 (Z1) is three.

Therefore, when the communication route is changed, the number of relays becomes smaller, so that in the destination terminal 10 (Z2) that has received the route update request signal, the route update responding means transmits the second identification information to the destination terminal 10 (Z1). ). Then, from the destination terminal 10 (Z2) to the destination terminal 10 (Z
A route update response signal is transmitted to 1). The destination terminal 10 (Z1) that has received the route update response signal associates the third identification information with the destination terminal 10 (Z2).

The change of the second identification information at the destination terminal 10 (Z2) and the change of the third identification information at the destination terminal 10 (Z1) cause the source terminal 10 (S) to change the destination terminal 1 (S2).
The communication route up to 0 (Z2) is changed. That is, the data packet transmitted from the source terminal 10 (S) is transferred to the destination terminal 10 (Z2) via the relay terminal 10 (A) and the destination terminal 10 (Z1).

The change of the communication route is performed by the destination terminal 10.
Since this is realized by transferring a beacon packet from (Z2) to the destination terminal 10 (Z1), it is executed even when a communication route between the destination terminal 10 (Z2) and the relay terminal 10 (D) is available. In addition, when the communication route is changed as described above, the number of relays is reduced and unnecessary data packet transfer is not performed, so that the utilization efficiency of wireless resources is improved.

When the communication route is changed, it is not necessary to perform a broadcast transmission of a control packet and a notification process of a route search result between the source terminal and the destination terminal, so that the time required for changing the communication route is eliminated. Is short. Claim 3 is the wireless ad-hoc terminal according to claim 2, wherein the relay destination itself is the second destination terminal, and as a result of the comparison by the relay number comparing means, when the communication route is changed, the number of relays increases. In a state where the second destination terminal is receiving the data packet, reverse route update request means for transmitting a reverse route update request signal from the second destination terminal to the first destination terminal; The first destination terminal, when receiving a reverse route update request signal from the second destination terminal, stores the second identification information held by its own communication route information holding unit in the second destination terminal. First reverse route update means for changing to identification information for specifying the second destination terminal, and itself when the second destination terminal is at least the reverse route update request signal, Communication route Information holding means is characterized by providing the said third identification information is further a second reverse route updating means for changing the identification information identifying the first destination terminal retention.

The reverse route update requesting means, if itself is the second destination terminal and the number of relays increases when the communication route is changed as a result of the comparison by the relay number comparing means, the second destination terminal While the terminal is receiving the data packet, the second destination terminal transmits a reverse route update request signal to the first destination terminal. The first reverse route update means, if it is the first destination terminal itself and at least receives a reverse route update request signal from the second destination terminal, retains its own communication route information. The second identification information held by the means is changed to identification information for specifying the second destination terminal.

When the second reverse route update means is itself the second destination terminal and transmits the reverse route update request signal, the second reverse route update means holds its own communication route information holding means. The third identification information is changed to identification information for specifying the first destination terminal. For example, when the destination terminal 10 (Z2) moves from the state of FIG. 11 to the destination terminal 10 (Z2) as shown in FIG. (Z2) receives the beacon packet from the destination terminal 10 (Z1).

In this case, in the destination terminal 10 (Z2), the fourth identification information of the destination terminal 10 (Z1) is the same as the source terminal 10 (Z2).
As the other destination terminal belonging to the communication route from (S), the first
, The identification information comparison means of the destination terminal 10 (Z2) detects a match, and the destination terminal 10 (Z2)
The route update requesting means transmits a route update request signal from the destination terminal 10 (Z2) to the destination terminal 10 (Z1).

In the example of FIG. 12, a case where a data packet is transferred from the source terminal 10 (S) to the destination terminal 10 (Z2) by relaying the relay terminals 10 (B), 10 (C) and 10 (D). Is four, and the source terminal 10 (S) transmits
(A) and the destination terminal 10 (Z1).
The number of relays when transferring the data packet to (Z2) is three.

Therefore, when the communication route is changed, the number of relays increases, so that even if the destination terminal 10 (Z1) receives the route update request signal, the route update response means does not perform the operation of claim 2. However, when the destination terminal 10 (Z1) is receiving a data packet from another wireless terminal (relay terminal 10 (A)), in order to change the communication route on the destination terminal 10 (Z2) side, The reverse route update requesting means of the destination terminal 10 (Z1) is configured to switch from the destination terminal 10 (Z1) to the destination terminal 10 (Z2).
Sends a reverse route update request signal to the server.

Upon receiving the reverse route update request signal, the first reverse route update means of the destination terminal 10 (Z2) associates the second identification information of the destination terminal 10 (Z2) with the destination terminal 10 (Z1). . In the destination terminal 10 (Z1) that has transmitted the reverse route update request signal, the second reverse route update unit associates the third identification information with the destination terminal 10 (Z2).

The change of the second identification information at the destination terminal 10 (Z2) and the change of the third identification information at the destination terminal 10 (Z1) cause the source terminal 10 (S) to change the destination terminal 1 (S2).
The communication route up to 0 (Z2) is changed. That is, the data packet transmitted from the source terminal 10 (S) is transferred to the destination terminal 10 (Z2) via the relay terminal 10 (A) and the destination terminal 10 (Z1).

A fourth aspect of the present invention is the wireless ad hoc terminal of the third aspect, wherein the wireless ad hoc terminal itself is the first destination terminal,
Update completion notifying the second destination terminal of the completion of the route update when the first reverse route update means changes the second identification information to identification information specifying the second destination terminal. A notification means is further provided. In claim 4, the update completion notifying means is itself the first destination terminal, and the first reverse route updating means converts the second identification information to the identification information for specifying the second destination terminal. When it has been changed, the completion of the route update is notified to the second destination terminal. This allows the second destination terminal to identify whether the first destination terminal has successfully updated the route.

Claim 5 provides at least three units each having all the functions of transmitting, receiving and relaying data packets.
A wireless terminal that is a source of a data packet, a wireless terminal that is a destination of a data packet, and a wireless terminal that relays a data packet are defined as a source terminal, a destination terminal, and a relay terminal, respectively, When direct communication between the source terminal and the destination terminal is not possible, at least one of the relay terminals relays a data packet and transfers the data packet from the source terminal to the destination terminal. In a wireless ad hoc terminal used as one of the wireless terminals, regarding a currently used communication route from one source terminal to a plurality of destination terminals, first identification information for specifying each of the plurality of destination terminals, The wireless terminal that is closer to the source terminal among the two adjacent wireless terminals located adjacent to itself on the communication route Second identification information to be specified, third identification information to specify a wireless terminal closer to a destination terminal among the two adjacent wireless terminals, and a number of relays from the source terminal to the wireless terminal. Communication route information holding means for holding relay number information, beacon transmission means for periodically transmitting a signal including fourth identification information for identifying itself to surrounding wireless terminals, A beacon receiving means for receiving the transmitted fourth identification information, and, when the communication terminal itself is a relay terminal, the fourth identification information received by the beacon receiving means, The identification information comparing means for comparing the identification information with the first identification information held by the first identification information, and the relay terminal itself, and as a result of the comparison by the identification information comparing means, the received fourth identification information is the first identification information. Identification If it corresponds to the destination terminal included in the information, the route update request signal including the relay number information held by the communication route information holding means of the communication device itself is transmitted to the destination corresponding to the received fourth identification information. Route update requesting means for transmitting to the terminal, and itself is a destination terminal, when the route update request signal is received from a relay terminal, the relay number information held by the destination terminal, Relay number comparing means for comparing the number of relays of a plurality of communication routes based on the relay number information included in the received route update request signal; and As a result, if the number of relays becomes smaller when the communication route is changed, the second identification information held by the own communication route information holding unit is replaced with the relay terminal that sent the route update request signal. A route update response means for changing the identification information to be specified and transmitting a route update response signal to the relay terminal, and when itself is a relay terminal and receives a route update response signal from the destination terminal; A route changing means for adding identification information for specifying a destination terminal that has transmitted the route update response signal to the third identification information held by its own communication route information holding means,
Data packets are transmitted, received and relayed using a communication route determined by information held by the communication route information holding means.

According to the fifth aspect, each wireless terminal, that is, a wireless ad hoc terminal, transmits, receives and relays a data packet so as to use a communication route corresponding to the information held by the communication route information holding means. Each wireless ad hoc terminal is used as at least one of a source terminal, a destination terminal, and a relay terminal. In addition, one relay terminal may perform a function of relaying a data packet to a plurality of different destination terminals. Claim 5 assumes that a communication route for transferring a data packet from the same source terminal to a plurality of destination terminals is formed.

The communication route information holding means firstly specifies the plurality of destination terminals with respect to the currently used communication route from one source terminal to a plurality of destination terminals.
Identification information, and second identification information for identifying a wireless terminal that is closer to the source terminal among two adjacent wireless terminals located adjacent to itself on the communication route; and identification information of the two adjacent wireless terminals. The third identification information for identifying the wireless terminal closer to the destination terminal, and relay number information corresponding to the number of relays from the source terminal to the wireless terminal are held.

The beacon transmitting means of each wireless terminal periodically transmits a signal (beacon packet) including the fourth identification information for specifying the terminal to peripheral wireless terminals. Therefore, the beacon receiving means of each wireless terminal can receive the fourth identification information included in the beacon packet transmitted from the wireless terminals in the vicinity.

That is, each wireless terminal can identify the presence or absence of another wireless terminal capable of wireless communication with the wireless terminal based on whether or not a beacon packet has been received. Further, from the fourth identification information of the received beacon packet, the communicable wireless terminal that transmitted the beacon packet can be specified. The identification information comparing means includes:
When the terminal itself is a relay terminal, the fourth identification information received by the beacon receiving unit is compared with the first identification information held by the communication route information holding unit of the terminal itself.

The route update requesting means is itself a relay terminal, and as a result of the comparison by the identification information comparing means, the received fourth identification information corresponds to the destination terminal included in the first identification information. In this case, a route update request signal including the number-of-relays information held by the communication route information holding unit itself is transmitted to the destination terminal corresponding to the received fourth identification information.

For example, in the ad hoc network shown in FIG. 15, data packets are transferred from the same source terminal 10 (S) to two destination terminals 10 (Z1) and 10 (Z2) by different routes. I have. When the destination terminal 10 (Z2) moves from the state of FIG. 15 as shown in FIG. 16 and the destination terminal 10 (Z2) enters the communicable range of the relay terminal 10 (B), for example, the relay terminal 10 (B) ) Is destination terminal 1
A beacon packet from 0 (Z2) is received.

In this case, in the relay terminal 10 (B), the fourth identification information for specifying the destination terminal 10 (Z2) has the first identification information as one destination terminal belonging to the communication route from the same source terminal 10 (S). Of the relay terminal 10
As a result of the comparison by the identification information comparing means (B), a match is detected. In this case, the route update requesting means of the relay terminal 10 (B) transmits a route update request signal including the relay number information held by itself to the destination terminal 10 (Z2).

When the relay number comparison means itself is the destination terminal and receives the route update request signal from the relay terminal, the relay number comparison means compares the relay number information held by the destination terminal with the received route update request signal. The relay number of a plurality of communication routes is compared based on the relay number information included in the signal. The route update responding means is itself a destination terminal, and as a result of comparison by the relay number comparing means, if the number of relays becomes smaller when the communication route is changed, the communication route information holding means of the own means holds the information. The second identification information is changed to identification information for identifying the relay terminal that has transmitted the route update request signal, and a route update response signal is transmitted to the relay terminal.

When the route change means is itself a relay terminal and receives a route update response signal from the destination terminal, the third identification information held by its own communication route information holding means is provided. The identification information for identifying the destination terminal that has transmitted the route update response signal is added to the information. For example, as shown in FIG. 16, the destination terminal 10 (Z2) moves, the destination terminal 10 (Z2) enters the communicable range of the relay terminal 10 (B), and the destination terminal 10 (Z) moves from the relay terminal 10 (B). (Z
When the route update request signal is transmitted to 2),
It works as follows.

In the case of FIG. 16, the data packet is transferred from the source terminal 10 (S) to the destination terminal 10 (Z2) via the relay terminals 10 (C), 10 (D), 10 (E). The number of relays is 4, and the source terminal 10 (S)
The number of relays when transferring a data packet to the destination terminal 10 (Z2) via (A) and 10 (B) is three. That is,
Changing the communication route reduces the number of relays.

Therefore, the route update responding unit recognizes that the communication route should be changed from the result of the comparison by the relay number comparing unit of the destination terminal 10 (Z2). Then, the route update response means transmits the second identification information of the destination terminal 10 (Z2) to the relay terminal 1 (Z2).
0 (B), and transmits a route update response signal to the relay terminal 10 (B).

Upon receiving the route update response signal, the relay terminal 10 (B) adds identification information for specifying the destination terminal 10 (Z2) to the third identification information of the relay terminal 10 (B). The change of the second identification information in the destination terminal 10 (Z2) and the change of the destination terminal 1 to the third identification information in the relay terminal 10 (B).
By adding 0 (Z2), the communication route from the source terminal 10 (S) to the destination terminal 10 (Z2) is changed. That is, from the source terminal 10 (S) to the relay terminals 10 (A), 10
The communication route is changed so that the data packet is transferred to the destination terminal 10 (Z2) via (B).

The change of the communication route is performed by the destination terminal 10.
Since this is realized by transferring a beacon packet from (Z2) to the relay terminal 10 (B), it is executed even when a communication route between the destination terminal 10 (Z2) and the relay terminal 10 (E) is available. When the communication route is changed as described above, the number of relays decreases, and unnecessary data packet transfer does not occur, so that the utilization efficiency of radio resources is improved.

Further, when the communication route is changed, it is not necessary to perform control packet broadcast transmission or notification processing of the route search result between the source terminal and the destination terminal. Is short. Claim 6 is the wireless ad hoc terminal according to claim 5, wherein the terminal itself is a destination terminal, and when the route update request signal is received from a relay terminal, the destination terminal becomes unable to receive a data packet. The route update responding means transmits the second identification information held by its own communication route information holding means to the route update request signal, irrespective of the result of the comparison by the relay number comparing means. Change to the identification information that identifies the sending relay terminal,
A route update response signal is transmitted to the relay terminal.

According to a sixth aspect of the present invention, the route update response means is a destination terminal itself, and when the route update request signal is received from the relay terminal, the destination terminal cannot receive the data packet. Irrespective of the result of the comparison by the relay number comparing means, the second identification information held by its own communication route information holding means is identified by an identification for specifying the relay terminal which transmitted the route update request signal. Information and transmitting a route update response signal to the relay terminal.

Therefore, when the communication route is interrupted,
The communication route can be changed between the source terminal and the destination terminal without performing control packet broadcast transmission or route search result notification processing, so that the time required to change the communication route is reduced. 8. A wireless terminal serving as a source of a data packet and a wireless terminal serving as a destination of a data packet using at least three wireless terminals each having all functions of transmitting, receiving and relaying a data packet. And a wireless terminal that relays a data packet is defined as a source terminal, a destination terminal, and a relay terminal, respectively, and when direct communication cannot be performed between the source terminal and the destination terminal, at least one of the relay terminals In a wireless ad hoc terminal used as one of the wireless terminals in an ad hoc network for transferring a data packet from the source terminal to the destination terminal by relaying a packet, the current usage from one source terminal to a plurality of destination terminals A first identification information for specifying each of the plurality of destination terminals, Second identification information for identifying a wireless terminal that is closer to the source terminal among two adjacent wireless terminals at positions adjacent to itself on the port, and one that is closer to the destination terminal among the two adjacent wireless terminals. Communication route information holding means for holding third identification information for specifying the wireless terminal, and beacon transmission for periodically transmitting a signal including fourth identification information for specifying itself to surrounding wireless terminals Means, beacon receiving means for receiving the fourth identification information transmitted from a peripheral wireless terminal,
An identification information comparing unit that compares the fourth identification information received by the beacon receiving unit with the first identification information held by the communication route information holding unit of itself when the relay terminal itself is a relay terminal; Means and the relay terminal itself, and as a result of the comparison by the identification information comparing means, when the received fourth identification information corresponds to the destination terminal included in the first identification information, Route update requesting means for transmitting to the destination terminal corresponding to the fourth identification information having received the route update request signal;
When the route update request signal is received from the relay terminal, the destination terminal identifies whether or not the destination terminal can receive the data packet. Said second
And the root update responding means for transmitting a route update response signal to the relay terminal, while changing the identification information of the relay terminal to the identification information for specifying the relay terminal that has transmitted the route update request signal, When a route update response signal is received from the destination terminal, the third communication route information holding unit holds the third route update response signal.
Route change means for adding identification information for specifying the destination terminal that transmitted the route update response signal to the identification information of the data packet, using a communication route determined by the information held by the communication route information holding means. Send,
It is characterized by receiving and relaying.

In the present invention, each wireless terminal, that is, a wireless ad hoc terminal transmits, receives and relays a data packet so as to use a communication route corresponding to the information held by the communication route information holding means. Each wireless ad hoc terminal is used as at least one of a source terminal, a destination terminal, and a relay terminal. In addition, one relay terminal may perform a function of relaying a data packet to a plurality of different destination terminals. Claim 7 assumes that a communication route for transferring a data packet from the same source terminal to a plurality of destination terminals is formed.

The communication route information holding means firstly specifies the plurality of destination terminals with respect to the currently used communication route from one source terminal to a plurality of destination terminals.
Identification information, and second identification information for identifying a wireless terminal that is closer to the source terminal among two adjacent wireless terminals located adjacent to itself on the communication route; and identification information of the two adjacent wireless terminals. And third identification information for identifying the wireless terminal closer to the destination terminal.

The beacon transmitting means of each wireless terminal periodically transmits a signal (beacon packet) including the fourth identification information for specifying the terminal to peripheral wireless terminals. Therefore, the beacon receiving means of each wireless terminal can receive the fourth identification information included in the beacon packet transmitted from the wireless terminals in the vicinity.

That is, each wireless terminal can identify the presence or absence of another wireless terminal capable of wireless communication with the wireless terminal based on the presence or absence of the reception of the beacon packet. Further, from the fourth identification information of the received beacon packet, the communicable wireless terminal that transmitted the beacon packet can be specified. The identification information comparing means includes:
When the relay terminal itself is a relay terminal, the fourth identification information received by the beacon receiving unit is compared with the first identification information held by the communication route information holding unit of the terminal itself.

The route update request means itself is a relay terminal, and as a result of the comparison by the identification information comparing means, the received fourth identification information corresponds to the destination terminal included in the first identification information. If there is, the route update request signal is transmitted to the destination terminal corresponding to the received fourth identification information. The route update responding means is itself a destination terminal, and when receiving the route update request signal from the relay terminal, identifies whether or not the destination terminal can receive the data packet, and cannot receive the data packet. In that case, the second identification information of the relay terminal itself is changed to identification information for specifying the relay terminal that has transmitted the route update request signal, and a route update response signal is transmitted to the relay terminal.

When the route change unit itself is the relay terminal and receives the route update response signal from the destination terminal, the route change unit adds the route update response to the third identification information held by itself. Add identification information that identifies the destination terminal that transmitted the signal. Therefore, for example, as shown in FIG. 16, the movement of the destination terminal 10 (Z2) causes the relay terminal 10 (Z2) to move.
(B) can communicate with the destination terminal 10 (Z2), and when the communication path between the destination terminal 10 (Z2) and the relay terminal 10 (E) is interrupted, the source terminal 10 (S) And destination terminal 10
The communication route can be changed so as to relay to the destination terminal 10 (Z2) using the relay terminal 10 (B) without performing control packet broadcast transmission or route search result notification processing between (Z2). Therefore, the time required for changing the communication route is reduced.

[0084]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) One embodiment of a wireless ad hoc terminal according to the present invention will be described with reference to FIGS.
This will be described with reference to FIGS. 2, 8, 9 and 10. This embodiment corresponds to claim 1. FIG. 1 is a block diagram showing a configuration of a wireless ad hoc terminal of this embodiment. FIG. 2 is a flowchart showing the operation of the communication route control unit of this embodiment. FIG. 8 is a block diagram showing a configuration and an arrangement example (1) of the ad hoc network. FIG. 9 is a block diagram showing a configuration and an arrangement example (2) of the ad hoc network. FIG. 10 is a block diagram showing an operation example of each terminal of this embodiment.

In this embodiment, the first identification information, the second identification information, the third identification information, the communication route information holding means, the beacon transmitting means and the beacon receiving means in claim 1 are:
These correspond to the destination data 62, the immediately preceding data 63, the immediately succeeding data 64, the route storage unit 55, the beacon transmitting unit 56, and the beacon receiving unit 57, respectively. Further, the identification information comparison means of claim 1 corresponds to steps S10 to S13 of FIG. 2, the route update request means of claim 1 corresponds to step S14, and the first route change means of step 1 corresponds to step S20.
The second route changing means in claim 1 corresponds to steps S15 and S16.

The wireless ad hoc terminal shown in FIG. 1 includes a wireless transceiver 51, a data packet transmitting unit 52, a data packet relaying unit 53, a data packet receiving unit 54, a route storage unit 55, a beacon transmitting unit 56, a beacon receiving unit 57, A communication route control unit 58 is provided. The wireless ad hoc terminal performs wireless communication with another wireless ad hoc terminal via the wireless transceiver 51. When the wireless ad hoc terminal is a source terminal, the data packet transmitting unit 52 transmits a data packet to be transmitted to another wireless ad hoc terminal via the wireless transceiver 51.

When the wireless ad hoc terminal is a relay terminal, the data packet relay unit 53 relays a data packet input from another wireless ad hoc terminal, and transmits the data packet to another wireless ad hoc terminal via the wireless transceiver 51. Forward. When the wireless ad hoc terminal is the destination terminal, the data packet receiving unit 54 receives a data packet input from another wireless ad hoc terminal.

In this example, the communication route for transferring the data packet is controlled according to the information held in the route storage unit 55. The route storage unit 55 stores transmission source data 61,
Destination data 62, immediately preceding data 63, and immediately following data 64 are held. When there are a plurality of communication routes with different transmission sources, a plurality of sets of data distinguished for each transmission source are stored in the route storage unit 55. Each data will be described later.

The beacon transmitting section 56 holds identification information for specifying the wireless ad hoc terminal, and repeatedly transmits the identification information as a beacon packet via the wireless transceiver 51 at a constant cycle. Beacon receiver 57
Receives a beacon packet transmitted as a wireless signal by another wireless ad hoc terminal. If another wireless ad hoc terminal exists within a range in which the wireless ad hoc terminal can wirelessly communicate with the wireless ad hoc terminal, the beacon receiving unit 57 receives a beacon packet, so that the presence of the other wireless ad hoc terminal can be known. Further, each of the other wireless ad hoc terminals can be specified from the identification information included in the beacon packet.

The communication route control unit 58 repeatedly executes the route controls (1) and (2) shown in FIG. 2 to determine the contents of the beacon packet received by the beacon receiving unit 57 and the data stored in the route storage unit 55. Based on the above, the communication route is changed as necessary. By using a plurality of wireless ad hoc terminals in FIG. 1, an ad hoc network as shown in FIG. 8, for example, can be configured. In FIG. 8, each wireless terminal 10 corresponds to a wireless ad hoc terminal. In the example of FIG. 8, the wireless terminal 10 (S) is assigned to the source terminal, and the wireless terminals 10 (A), 10 (B),
(C) and 10 (D) are assigned to the relay terminal, and the wireless terminal 1
0 (Z) is assigned to the destination terminal. Since this is an ad hoc network, such assignments are changed as needed.

When direct communication can be performed between the wireless terminal 10 (S) as the source terminal and the wireless terminal 10 (Z) as the destination terminal, there is no need to use a relay terminal. When the distance to the terminal is long or there is some communication failure, the relay terminal is used to form an ad hoc network as shown in FIG. 8, so that communication can be performed between the source terminal and the destination terminal.

Source data 61 held in the route storage unit 55 of the wireless ad hoc terminal of FIG. 1 is identification information for specifying the source terminal. In the example of FIG. 8, all the wireless terminals 10 (S), 10 (A), 10 (B), 10 (C),
(D) and 10 (Z) are 1 from one source terminal (10 (S)).
Since the wireless terminal 10 exists on the communication route to one destination terminal (10 (Z)), the identification information “S” for identifying the source terminal (10 (S)) is included in the source data 61 for any wireless terminal 10. (Same as the identification information held by the beacon transmission unit 56 of the transmission source terminal).

The destination data 62 held in the route storage unit 55 of the wireless ad hoc terminal in FIG. 1 is identification information for specifying the destination terminal. In the example of FIG. 8, all the wireless terminals 10 (S), 10 (A), 10 (B), 10 (C),
(D) and 10 (Z) are 1 from one source terminal (10 (S)).
Since there is a communication route to one destination terminal (10 (Z)), the destination data 6
2 includes identification information "Z" for specifying the destination terminal (10 (Z)).
(Same as the identification information held by the beacon transmission unit 56 of the destination terminal).

The immediately preceding data 63 held in the route storage unit 55 of the wireless ad hoc terminal shown in FIG. 1 is located on the near side of the position adjacent to each wireless ad hoc terminal on the currently used communication route (close to the transmission source). ) Is identification information for specifying the wireless ad hoc terminal of the first method. For example, in FIG. 8, the relay terminal (1) is located on the upstream side of the relay terminal (10 (B)).
0 (A)), the route storage unit 55 of the relay terminal (10 (B)) stores the relay terminal (10
(A)) (same as the identification information held by the beacon transmitting unit 56 of the relay terminal 10 (A)).

Immediately after the data 64 held in the route storage unit 55 of the wireless ad hoc terminal shown in FIG. 1 is located on the rear side of the position adjacent to each wireless ad hoc terminal on the currently used communication route (the one closer to the destination). ) Is identification information for specifying the wireless ad hoc terminal. For example, in FIG. 8, the relay terminal (10 (B)) is behind (downstream) the relay terminal (10 (B)).
(C)), the route storage unit 55 of the relay terminal (10 (B)) stores the relay terminal (10
(C)) (the same as the identification information held by the beacon transmitting unit 56 of the relay terminal 10 (C)).

Each wireless terminal 10 shown in FIG. 8 can identify the communication route of the data packet by referring to each data in the route storage unit 55. When relaying a data packet, it is possible to know to which wireless terminal 10 the received data packet is to be transmitted next by referring to the immediate data 64. Route storage unit 5 of each wireless terminal 10
In 5, when a communication route between the transmission source terminal and the destination terminal is first secured, data corresponding to the communication route is set. When first securing a communication route,
As before, a control packet for route search is transmitted by broadcast transmission from a source terminal to a destination terminal, and the wireless terminal 10 receiving the control packet repeats the transmission of the control packet, thereby transmitting the control packet. The communication route from to the destination terminal can be searched.

Each step in FIG. 2 will be described below. In step S10, it is determined whether or not itself is a relay terminal. If the identification information held by the beacon transmission unit 56 does not correspond to any of the transmission source data 61 and the destination data 62 held in the route storage unit 55, the beacon itself can be regarded as a relay terminal. If it is a relay terminal, the process proceeds to step S11.

In step S 11, the wireless terminal 1 immediately after corresponding to the immediately following data 64 held in the route storage 55
Identify whether 0 is the destination terminal. If the wireless terminal 10 immediately after is not the destination terminal, the process proceeds to step S12. In step S12, it is determined whether or not the beacon receiving unit 57 has received a beacon packet from another wireless terminal 10. If a beacon packet has been received, the process proceeds to step S13.

In step S13, the identification information included in the beacon packet received in step S12 is compared with the contents of destination data 62 held in route storage unit 55. If they match, the process proceeds to step S14. In step S14, a route update request signal is transmitted to the destination terminal for which a match has been detected in step S13.

In step S15, it is determined whether or not a route update completion signal has been received from the destination terminal as a response to the route update request signal sent in step S14. Upon receiving the route update completion signal, the process proceeds to step S16. For example, if the route update completion signal cannot be received within a predetermined time after the transmission of the route update request signal, the process of step S16 is not executed.

In step S16, the data immediately after the route storage unit 55 is changed to the identification information of the destination terminal that has transmitted the route update completion signal. In step S20, it is determined whether or not the terminal itself is a destination terminal. If it is the destination terminal, the process proceeds to step S21. In step S21, it is determined whether or not the relay terminal has received the route update request signal transmitted in step S14. If a route update request signal has been received, the process proceeds to step S22.

In step S22, the contents of the immediately preceding data 63 held in the route storage unit 55 are changed to the identification information of the relay terminal that transmitted the route update request signal. In step S23, a route update completion signal is sent to the relay terminal that has sent the route update request signal. For example, in the ad hoc network shown in FIG.
(Z)) moves to the destination terminal (10) as shown in FIG.
When (Z)) approaches the relay terminal (10 (B)) (enters the communicable range), the relay terminal (10 (B)) moves to the destination terminal (10 (B)).
(Z)) can be received.

In this case, when the communication route control unit 58 of the relay terminal (10 (B)) executes the route control (1) of FIG. 2, the relay terminal itself is the relay terminal, and the terminal immediately after is not the destination terminal. Upon receiving a beacon packet from the destination terminal (10 (Z)), the process proceeds to step S13. As shown in FIG. 8, the communication route control unit 58 of the relay terminal (10 (B))
Holds "Z" as the destination data 62, the identification information "Z" included in the beacon packet transmitted by the destination terminal (10 (Z)) matches. Therefore, the process proceeds to step S14.

In this case, the relay terminal (10 (B)) sends a route update request signal to the destination terminal (10 (Z)) in step S14. The route update request signal may be transmitted as a packet addressed to the destination terminal. On the other hand, the destination terminal (10
When (Z)) executes the route control (2) in FIG. 2, the process proceeds from step S20 to S21 because the terminal itself is the destination terminal. When the route update request signal transmitted by the relay terminal (10 (B)) is received in step S21, step S2 is performed.
Proceed to step 2.

The destination terminal (10 (Z)) determines in step S22
Changes the immediately preceding data 63 of its own communication route control unit 58 to the identification information "B" of the relay terminal (10 (B)). Thereafter, the destination terminal (10 (Z)) changes the relay terminal (1).
0 (B)).

When the destination terminal (10 (Z)) sends a route update completion signal in step S23, the relay terminal (10 (Z))
(B)) detects this in step S15. Then, in the next step S16, the content of the data 64 immediately after being held in the communication route control unit 58 on the relay terminal (10 (B)) is changed to the identification information “Z” of the destination terminal (10 (Z)). Thereafter, the relay terminal (10 (B)) sends the relayed data packet directly to the destination terminal (10 (Z)).

Therefore, the relay terminal (10 (B)) and the destination terminal (10 (Z)) operate as shown in FIG. Before the communication route is changed, the number of relays from the source terminal (10 (S)) to the destination terminal (10 (Z)) is 5, but the number of relays from the relay terminal (10 (B)) to the destination terminal (10 (Z)). If the communication route is changed so that the data packet is directly transmitted to Z)), the number of relays becomes three. Such a change in the communication route minimizes the number of relays of packet transfer, thereby suppressing consumption of communication resources.

Further, since the procedure for updating the communication route is started in response to the detection of the beacon packet in the relay terminal, the destination terminal (10 (Z)) in FIG.
The communication route is automatically changed to an optimal communication route even before the communication range of (D)) is exceeded. Further, since the communication route is changed based on the data held in the communication route control unit 58, it is not necessary to broadcast a control packet for searching the communication route, and the change of the communication route is completed in a short time.

(Second Embodiment) One embodiment of the wireless ad hoc terminal of the present invention will be described with reference to FIGS. 3 to 6 and FIGS. This form is claimed in claim 2
To claim 4. FIG. 3 is a block diagram showing a configuration of the wireless ad hoc terminal of this embodiment. FIG. 4 is a flowchart showing the operation (1) of the communication route control unit of this embodiment. FIG. 5 is a flowchart showing the operation (2) of the communication route control unit of this embodiment. FIG. 6 is a sequence diagram showing an operation example (1) of each destination terminal of this embodiment.

FIG. 11 is a block diagram showing a configuration and arrangement example (3) of the ad hoc network. FIG.
It is a block diagram which shows the structure and arrangement example (4) of an ad hoc network. FIG. 13 is a block diagram showing an operation example (2) of each destination terminal of this embodiment. FIG. 14 is a block diagram showing an operation example (3) of each destination terminal of this embodiment.

This embodiment is a modification of the first embodiment. In each of the drawings, elements corresponding to those of the first embodiment are denoted by the same reference numerals. The following description is omitted for the same parts. In this embodiment, claim 2
First identification information, second identification information, third identification information,
The relay number information, the communication route information holding means, the beacon transmitting means, and the beacon receiving means respectively include destination data 62,
Immediately preceding data 63, immediately following data 64, relay number data 65,
It corresponds to the route storage unit 55B, the beacon transmission unit 56, and the beacon reception unit 57.

Further, the identification information comparing means of the present invention is arranged as shown in FIG.
The route update request means of claim 2 corresponds to step S35, the relay number comparison means of claim 2 corresponds to steps S38 and S39, and the route update response means of claim 2 corresponds to The communication route changing means according to claim 2 corresponds to steps S40 and S41.
6, S37.

The reverse route update request means in claim 3 corresponds to steps S47 and S48 in FIG. 5, and the first reverse route update means in claim 3 corresponds to steps S43 and S44. The second reverse route updating means performs step S5.
Corresponds to 0. The update completion notifying means in claim 4 corresponds to step S45. The wireless ad hoc terminal shown in FIG. 3 includes a wireless transceiver 51, a data packet transmission unit 52, a data packet relay unit 53, a data packet reception unit 54, a route storage unit 55B, and a beacon transmission unit 5 as in FIG.
6, a beacon receiving unit 57 and a communication route control unit 58B.

In this example, the communication route for transferring the data packet is controlled according to the information held in the route storage unit 55B. The route storage unit 55B stores the source data 6
1, destination data 62, immediately preceding data 63, immediately following data 64
And the number-of-relays data 65 are held. When there are a plurality of communication routes with different transmission sources, a plurality of sets of data distinguished for each transmission source are stored in the route storage unit 55. Each data will be described later.

The communication route control section 58B repeatedly executes the control shown in FIGS. 4 and 5, and performs necessary control based on the contents of the beacon packet received by the beacon receiving section 57 and each data held in the route storage section 55B. The communication route is changed according to. By using a plurality of wireless ad hoc terminals in FIG. 3, an ad hoc network as shown in FIG. 11, for example, can be configured. In FIG.
Each wireless terminal 10 corresponds to a wireless ad hoc terminal. In the example of FIG. 11, the wireless terminal 10 (S) is allocated to the source terminal, and the wireless terminals 10 (A), 10 (B),
(C) and 10 (D) are assigned to relay terminals, and two wireless terminals 10 (Z1) and 10 (Z2) are assigned to destination terminals, respectively. Since this is an ad hoc network, such assignments are changed as needed.

The source data 61 held in the route storage unit 55B of the wireless ad hoc terminal shown in FIG. 3 is identification information for specifying the source terminal. In the example of FIG. 11, all the wireless terminals 10 (S), 10 (A), 10 (B), 10 (C),
Since 10 (D), 10 (Z1) and 10 (Z2) exist on the communication route from the same source terminal (10 (S)) to the destination terminal, the source data 61 stores identification information “S” (same as the identification information held by the beacon transmission unit 56 of the transmission source terminal) that specifies the transmission source terminal (10 (S)).

The destination data 62 stored in the route storage unit 55B of the wireless ad hoc terminal shown in FIG. 3 is identification information for specifying the destination terminal. In the example of FIG. 11, since there are two destination terminals (10 (Z1), 10 (Z2)), identification information for specifying each of the two destination terminals is included in one destination data 62 of all the terminals. “Z1, Z2” (the same as the identification information held by the beacon transmitting unit 56 of each destination terminal) is stored.

The immediately preceding data 63 held in the route storage unit 55B of the wireless ad hoc terminal shown in FIG. 3 is located on the near side of the position adjacent to each wireless ad hoc terminal on the currently used communication route (close to the transmission source). ) Is identification information for specifying the wireless ad hoc terminal of the first method. For example, in FIG. 11, since the relay terminal (10 (B)) exists on the near side (upstream side) of the relay terminal (10 (C)), the route storage unit 55B of the relay terminal (10 (C)) has As the immediately preceding data 63, the identification information “B” (relay terminal 10 (B)) for specifying the relay terminal (10 (B))
(B) (the same as the identification information held by the beacon transmission unit 56).

Immediately after the data 64 held in the route storage unit 55B of the wireless ad hoc terminal in FIG. 3 is located on the rear side of the position adjacent to each wireless ad hoc terminal on the currently used communication route (the one closer to the destination). ) Is identification information for specifying the wireless ad hoc terminal. For example, in FIG. 11, the relay terminal (10 (D)) exists behind (downstream side) the relay terminal (10 (C)). Therefore, the route storage unit 55B of the relay terminal (10 (C)) has Immediately after, as the data 64, identification information “D” (relay terminal 10 (D)) for specifying the relay terminal (10 (D))
(D) same as the identification information held by the beacon transmission unit 56).

The number-of-relays data 65 held in the route storage unit 55B of the wireless ad hoc terminal in FIG. 3 indicates the number of relays from the source terminal to the wireless terminal 10. For example, FIG.
In step 1, the transmission source terminal (10 (S)) switches to the relay terminal (10 (S)).
Since the number of relays up to (C)) is 2, the relay terminal (10 (C))
"2" is held as the relay number data 65 in the route storage unit 55B.

Each radio terminal 10 shown in FIG. 11 can identify the communication route of the data packet by referring to each data in the route storage unit 55B. When relaying a data packet, it is possible to know to which wireless terminal 10 the received data packet is to be transmitted next by referring to the immediate data 64. When a communication route between a source terminal and a destination terminal is first secured, data corresponding to the communication route is set in the route storage unit 55B of each wireless terminal 10. When a communication route is initially secured, a control packet for route search is transmitted by broadcast transmission from a source terminal to a destination terminal as in the related art, and the wireless terminal 10 receiving the control packet performs control. By repeating packet transmission, a communication route from the source terminal to the destination terminal can be searched.

Each step of FIGS. 4 and 5 will be described below. In step S30, it is determined whether there are a plurality of destination terminals. In practice, each wireless terminal 10 can identify whether there are a plurality of destination terminals by referring to the destination data 62 held in the route storage unit 55B. If there are a plurality of destination terminals, the process proceeds to step S31.

In step S31, it is determined whether or not the terminal itself is a destination terminal. Actually, whether or not the beacon transmitting unit 56 itself is a destination terminal can be identified by checking whether or not the identification information held by the beacon transmitting unit 56 matches any of the destination data 62 held in the route storage unit 55B. If the terminal itself is the destination terminal, the process proceeds to step S32. In step S32,
It identifies whether or not a beacon packet transmitted by another wireless terminal 10 has been received. If a beacon packet has been received, the process proceeds to step S33; otherwise, the process proceeds to step S38.

In step S33, the identification information included in the received beacon packet is compared with the destination data 62 in the route storage unit 55B. If the identification information included in the beacon packet is included in the destination data 62, it is determined that they match, and the process proceeds to step S34. Step S34
Then, the relay number data 65 held in its own route storage unit 55B is input.

In step S35, a route update request signal (1) is transmitted to the destination terminal (the terminal that transmitted the beacon packet) that has detected a match in step S33. The route update request signal (1) includes the relay number data 65 held by itself input in step S34. The route update request signal (1) is transmitted as a packet addressed to the destination terminal.

In step S36, a route update completion signal from another wireless terminal 10 (destination terminal), which is a response to the route update request signal (1) transmitted in step S35, is sent.
Identify whether (1) has been received. For example, if the route update completion signal (1) is received within a predetermined time after the transmission of the route update request signal (1), the process proceeds to step S37; otherwise, the process proceeds to step S42 in FIG.

In the step S37, the route storage section 55B
Immediately after the above, the content of the data 64 is changed to the identification information of the destination terminal that has transmitted the route update completion signal (1). That is, the communication route is changed so that the terminal becomes a relay terminal that sends a data packet to the destination terminal. In step S38, the other wireless terminal 10 performs the processing in step S35
To determine whether or not the route update request signal (1) sent out in step (1) has been received. If it has been received, the process proceeds to step S39.

In step S39, in order to determine whether the number of relays becomes smaller when the communication route is changed, the relay of another wireless terminal 10 included in the route update request signal (1) received in step S38 is determined. Numerical data 65 (Hop (1))
Is compared with the relay number data 65 (Hop (2)) held in the route storage unit 55B. Actually, when the communication route is changed, the number of relays increases by one.
The value obtained by adding 1 to Hop (1) is compared with the number of relays Hop (2). If the number of relays becomes smaller when the communication route is changed, the process proceeds to step S40, and if not, the process proceeds to step S46 in FIG.

In the step S40, the route storage section 55B
Is changed to the identification information of the destination terminal that transmitted the route update request signal (1). That is, the communication route is changed so that the relay terminal that inputs the data packet to itself becomes the destination terminal that has transmitted the route update request signal (1). Step S4
In step 1, a route update completion signal (1) is sent to the destination terminal that sent the route update request signal (1).

In step S46 of FIG. 5, since the number of relays does not decrease even if the communication route is changed, a route update completion signal is sent to the destination terminal that has sent the route update request signal (1). In step S47, it is determined whether or not the wireless terminal 10 (destination terminal) is receiving a data packet. For example, if a communication route used so far is cut off, it becomes impossible to receive a data packet. If a data packet has been received, the process proceeds to step S48.

In step S48, a route update request signal
Conversely, a route update request signal (2) is sent to the destination terminal of the other party that sent (1). In step S49, it is determined whether or not a route update completion signal (2), which is a response to the route update request signal (2) transmitted in step S48, has been received. For example, if the route update completion signal (2) is received within a predetermined time after the transmission of the route update request signal (2), the process proceeds to step S50.

At step S50, the route storage unit 55B
Immediately after this, the contents of the data 64 are changed to the identification information of the destination terminal of the other party that has sent the route update completion signal (2). That is, the communication route is changed so that it becomes a relay terminal that sends a data packet to the destination terminal that itself sends the route update request signal (1). Note that the process of step S50 may be performed between steps S46 and S47. However, if no data packet has been received in step S47, there is no need to change the communication route, and the change must be canceled.

In step S42, it is determined whether or not another wireless terminal 10 has received the route update unnecessary signal transmitted in step S46. If the route update unnecessary signal has been received, the process proceeds to step S43. In step S43, it is determined whether or not another wireless terminal 10 has received the route update request signal (2) transmitted in step S48. For example, when the route update request signal (2) is received within a predetermined time after the transmission of the route update request signal (1), step S44 is performed.
Proceed to.

In the step S44, the route storage section 55B
Is changed to the identification information of the destination terminal of the other party that sent the route update request signal (2). That is, the communication route is changed such that the relay terminal that inputs the data packet to itself becomes the destination terminal that has transmitted the route update request signal (2). For example, in the ad hoc network shown in FIG.
2)) moves and the destination terminal (10 (Z
When 2)) approaches the destination terminal (10 (Z1)) (enters the communicable range), the destination terminal (10 (Z1)) can receive a beacon packet from the destination terminal (10 (Z2)). .

In this case, when the communication route control unit 58B of the destination terminal (10 (Z1)) executes the processing of FIG. 4, it is one of a plurality of destination terminals for the same transmission source. 10 (Z2)), the process proceeds to step S33. As shown in FIG. 11, the destination terminal (10 (Z1)) holds the identification information "Z1, Z2" of the two destinations as the destination data 62. And the identification information “Z2” included in the beacon packet to be transmitted.
Therefore, the process proceeds to step S34.

In this case, the destination terminal (10 (Z1)) sends a route update request signal (1) including the relay number information (Hop (1)) to the destination terminal (10 (Z2)) in step S35. .
On the other hand, when the destination terminal (10 (Z2)) executes the processing of FIG. 4, the process proceeds to step S38 because the destination terminal itself is the destination terminal.
When the route update request signal (1) transmitted by the destination terminal (10 (Z1)) is received in step S38, step S38 is performed.
Proceed to 39.

In the example of FIG. 11, the number of relays (Hop (1)) of the destination terminal (10 (Z1)) is two, and the number of relays (Hop (2)) of the destination terminal (10 (Z2)) is four. Therefore, as a result of the comparison in step S39, it is recognized that the number of relays becomes smaller when the route is changed, and the process of the destination terminal (10 (Z2)) proceeds to step S40. The destination terminal (10 (Z2)) changes the immediately preceding data 63 of its own communication route control unit 58B to the identification information “Z1” of the destination terminal (10 (Z1)) in step S40. (10 (Z2)) is the destination terminal (1
0 (Z1)).

The destination terminal (10 (Z2)) determines in step S41
Sends a route update completion signal (1) at the destination terminal (1).
0 (Z1)) is detected in step S36. Then, in the next step S37, the content of the data 64 immediately after being held in the communication route control unit 58B on the destination terminal (10 (Z1)) is changed to the identification information “Z2” of the destination terminal (10 (Z2)). Thereafter, the destination terminal (10 (Z1)) sends the relayed data packet to the destination terminal (10 (Z2)).

Therefore, the destination terminal (10 (Z1)) and the destination terminal (10 (Z2)) operate as shown in FIG.
Before changing the communication route, the number of relays from the source terminal (10 (S)) to the destination terminal (10 (Z2)) is 4,
When the communication route is changed so that the data packet is transmitted from the destination terminal (10 (Z1)) to the destination terminal (10 (Z2)), the number of relays becomes three. Such a change in the communication route minimizes the number of relays of packet transfer, thereby suppressing consumption of communication resources.

Since the communication route update procedure is started in response to the detection of the beacon packet in the destination terminal (10 (Z1)), the destination terminal (10 (Z2)) in FIG. The communication route is automatically changed to the optimal communication route even before the communication range of)) is exceeded. Further, since the communication route is changed based on the data held in the communication route control unit 58B, it is not necessary to broadcast a control packet for searching for the communication route, and the change of the communication route is completed in a short time.

Conversely, when the destination terminal (10 (Z1)) moves and enters the communicable range of the destination terminal (10 (Z2)) in the ad hoc network of FIG. Is assumed. In that case, as shown in FIG. 14, the destination terminal (10 (Z2)) is replaced with the destination terminal (10 (Z1)).
Receiving the beacon packet from the destination terminal (10
The processing of the communication route control unit 58B of (Z2)) proceeds from step S32 to S33 in FIG.

As shown in FIGS. 11 and 14, the destination terminal (10 (Z2)) holds the identification information “Z1, Z2” of the two destinations as the destination data 62. The identification information “Z1” included in the beacon packet transmitted by (Z1)) matches. Therefore, the process proceeds to step S34. In this case, the destination terminal (10 (Z2))
Sends a route update request signal (1) including relay number information (Hop (1)) to the destination terminal (10 (Z1)) in step S35.

Here, when the destination terminal (10 (Z1)) executes the process of FIG. 4, the process proceeds to step S38 because the destination terminal itself is the destination terminal. When the route update request signal (1) transmitted by the destination terminal (10 (Z2)) is received in step S38, the process proceeds to step S39. 11 and 14, the number of relays (Hop (1)) of the destination terminal (10 (Z2)) is four, and the number of relays (Hop (2)) of the destination terminal (10 (Z1)) is two. Therefore, as a result of the comparison in step S39, it is recognized that the number of relays does not decrease even if the route is changed, and the destination terminal (10
The process of (Z1)) proceeds to step S46.

In this case, the destination terminal (10 (Z1)) sends a route update unnecessary signal in step S46, and
Go to 47. The destination terminal (10 (Z1)) is
(A)), assuming that it is not out of the communicable range, the process of the destination terminal (10 (Z1)) proceeds from step S47 to S48, so that the destination terminal (10 (Z1)) transfers the destination terminal (10 (Z1)). Z2)), a route update request signal (2) is transmitted.

When receiving the route update request signal (2), the destination terminal (10 (Z2)) transmits the immediately preceding data 63 of the communication route control unit 58B to the destination terminal (10 (Z2)) in step S44.
(Z1)) is changed to the identification information “Z1”, and step S45 is performed.
Route update completion signal to the destination terminal (10 (Z1))
Send out (2). When the destination terminal (10 (Z1)) receives the route update completion signal (2) from the destination terminal (10 (Z2)), the content of the data 64 immediately after the destination terminal (10 (Z1)) holds in step S50. Is changed to “Z2” which is identification information of the destination terminal (10 (Z2)). As a result, the communication route is changed so that the destination terminal (10 (Z1)) relays the data packet to the destination terminal (10 (Z2)).

Therefore, the destination terminal (10 (Z
1)) and the destination terminal (10 (Z2)) operate as shown in FIG. 13 and 14, the communication route is changed to the same communication route with a smaller number of relays. Also, two destination terminals (10 (Z1), 10 (Z
FIG. 6 summarizes each operation of 2)).

(Third Embodiment) One embodiment of a wireless ad hoc terminal according to the present invention will be described with reference to FIGS.
This will be described with reference to FIG. This embodiment corresponds to claims 5 to 7. FIG. 7 is a flowchart showing the operation of the communication route control unit of this embodiment. FIG. 15 is a block diagram showing a configuration and arrangement example (5) of the ad hoc network. FIG. 16 is a block diagram showing a configuration and an arrangement example (6) of the ad hoc network. FIG. 17 is a block diagram showing an operation example of each terminal of this embodiment.

This embodiment is a modification of the second embodiment, and the configuration of the wireless ad hoc terminal is the same as that of FIG. However, the content of the processing executed by the communication route control unit 58B has been changed as shown in FIG. The following description of the same parts as those of the second embodiment is omitted. In this embodiment, the first identification information, the second identification information, the third identification information, the number of relays, the communication route information holding means, the beacon transmitting means, and the beacon receiving means according to claim 5 and claim 7, respectively, Destination data 62, immediately preceding data 63, immediately following data 6
4, the relay number data 65, the route storage unit 55B, the beacon transmission unit 56, and the beacon reception unit 57.

Further, the identification information comparison means of claim 5 and claim 7 corresponds to steps S70 to S73, the route update request means of claim 5 and claim 7 corresponds to step S75, and the relay of claim 5 The number comparing means performs steps S78 and S7.
9 and S81, the route update response means of claims 5 and 7 correspond to steps S82 and S83, and the route change means of claims 5 and 7 correspond to steps S76 and S7.
Corresponds to 7. The route update response means of claim 6 corresponds to steps S80, S82, S83.

In this embodiment, the communication route control unit 58B periodically and repeatedly executes the route control (1) and the route control (2) shown in FIG. 7, and stores the contents of the beacon packet received by the beacon receiving unit 57 and the route. The communication route is changed as necessary based on the data held in the unit 55B.

By using a plurality of wireless ad hoc terminals of this embodiment, an ad hoc network as shown in FIG. 15, for example, can be constructed. In FIG. 15, each wireless terminal 10 corresponds to a wireless ad hoc terminal. In the example of FIG. 15, the wireless terminal 10 (S) is assigned to the source terminal, and the wireless terminals 10 (A), 10 (B),
(C), 10 (D), and 10 (E) are assigned to the relay terminals,
Two wireless terminals 10 (Z1) and 10 (Z2) are respectively assigned to destination terminals. Since this is an ad hoc network, such assignments are changed as needed.

Also in this embodiment, the route storage unit 55B of each wireless ad hoc terminal holds transmission source data 61, destination data 62, immediately preceding data 63, immediately following data 64, and relay number data 65. In the example of FIG. 15, all the wireless terminals 10 (S), 10 (A), 10 (B), 10 (C),
Since (D), 10 (E), 10 (Z1) and 10 (Z2) exist on the communication route from the same source terminal (10 (S)) to the destination terminal, any wireless terminal 10 The transmission source data 61 holds identification information “S” (same as the identification information held by the beacon transmission unit 56 of the transmission source terminal) for specifying the transmission source terminal (10 (S)).

In this embodiment, one immediate data 64
Can hold the identification information of a plurality of destination terminals. When a communication route between a source terminal and a destination terminal is first secured, data corresponding to the communication route is set in the route storage unit 55B of each wireless terminal 10.
When first securing a communication route, as before,
A control packet for route search is transmitted by broadcast transmission from the source terminal to the destination terminal,
The wireless terminal 10 that has received the control packet repeats the transmission of the control packet, so that a communication route from the source terminal to the destination terminal can be searched.

The steps in FIG. 7 will be described below. In step S70, it is determined whether there are a plurality of destination terminals. Actually, each wireless terminal 10 is stored in the route storage 55B.
By referring to the destination data 62 stored in the destination terminal, it is possible to identify whether or not there are a plurality of destination terminals. If there are a plurality of destination terminals, the process proceeds to step S71.

In the step S71, it is determined whether or not the terminal itself is a relay terminal. Actually, when the identification information held by the beacon transmission unit 56 is different from the destination data 62 and the transmission source data 61 held in the route storage unit 55B, it is sufficient to identify itself as a relay terminal. If it is a relay terminal, the process proceeds to step S72. Step S72
Then, it is determined whether or not a beacon packet transmitted by another wireless terminal 10 has been received. If a beacon packet has been received, the process proceeds to step S73.

In the step S73, the identification information included in the received beacon packet is compared with the destination data 62 in the route storage section 55B. If the identification information included in the beacon packet is included in the destination data 62, it is determined that they match, and the process proceeds to step S74. Step S74
Then, the relay number data 65 held in its own route storage unit 55B is input.

In step S75, a route update request signal is transmitted to the destination terminal (the terminal that transmitted the beacon packet) that has detected a match in step S73. This route update request signal includes the number-of-relays data 65 held by itself input in step S74. The route update request signal is transmitted as a packet addressed to the destination terminal.

In step S76, it is determined whether or not a route update completion signal has been received from another wireless terminal 10 (destination terminal), which is a response to the route update request signal transmitted in step S75. For example, if a route update completion signal is received within a predetermined time after the transmission of the route update request signal, the process proceeds to step S77. In step S77, the contents of the data 64 immediately after the route storage unit 55B are changed to the identification information of the destination terminal that has transmitted the route update completion signal.
That is, the communication route is changed so that the terminal becomes a relay terminal that sends a data packet to the destination terminal.

At step S78, it is determined whether or not the terminal itself is a destination terminal. Actually, by comparing the identification information held by the beacon transmission unit 56 with the destination data 62 held in the route storage unit 55B, it is possible to identify whether or not the terminal itself is the destination terminal. If it is the destination terminal, the process proceeds to step S79. In step S79, it is determined whether or not another wireless terminal 10 (relay terminal) has received the route update request signal transmitted in step S75. If a route update request signal has been received, the process proceeds to step S80.

In step S80, it is determined whether or not the data packet itself has been received. If so, the process proceeds to step S81; otherwise, the process proceeds to step S82. In step S81, in order to identify whether or not the number of relays is reduced by the route change, the number of relays Hop (1) included in the route update request received in step S79 and the number of relays data 65 held by itself are determined.
(Hop (2)). Actually, changing the communication route increases the number of relays by one.
Is compared with the current number of relays (Hop (2)).
If the number of relays decreases due to the route change, step S8
Proceed to 2.

In the step S82, the route storage section 55B
Is changed to the identification information of the relay terminal that transmitted the route update request signal. That is, the communication route is changed so that the relay terminal that has transmitted the route update request signal is used as the relay terminal.

In step S83, a route update completion signal is sent to the relay terminal that sent the route update request signal. For example, in the ad hoc network shown in FIG. 15, the destination terminal (10 (Z2)) moves, and as shown in FIG.
When approaching (B)) (entering the communicable range), the relay terminal (10 (B)) can receive the beacon packet from the destination terminal (10 (Z2)).

In this case, when the communication route control unit 58B of the relay terminal (10 (B)) executes the route control (1) of FIG. 7, the relay terminal belonging to the relay terminal belonging to a plurality of communication routes from the same transmission source itself. Since there is one, the destination terminal (10 (Z
When the beacon packet from 2)) is received, the process proceeds to step S73. As shown in FIG. 15, the relay terminal (10
Since (B)) holds the identification information “Z1, Z2” of the two destinations as the destination data 62, the identification information “Z2” included in the beacon packet transmitted by the destination terminal (10 (Z2)) is stored. Matches. Therefore, step S7
Proceed to 4.

In this case, the relay terminal (10 (B)) transmits the relay number information to the destination terminal (10 (Z2)) in step S75.
A route update request signal including (Hop (1)) is transmitted. on the other hand,
When the destination terminal (10 (Z2)) executes the route control (2) in FIG. 7, the process proceeds to step S79 since the destination terminal itself is the destination terminal. When the route update request signal transmitted by the relay terminal (10 (B)) is received in step S79, step S8 is performed.
Proceed to process 0.

If the destination terminal (10 (Z2)) has not yet deviated from the communicable range of the relay terminal (10 (E)),
The destination terminal (10 (Z2)) can receive the data packet relayed from the relay terminal (10 (E)). In that case, the process proceeds from step S80 to S81.

If the destination terminal (10 (Z2)) is already out of the communicable range of the relay terminal (10 (E)), the destination terminal (10 (Z2)) switches to the relay terminal (10 (E)). Since the data packet relayed from)) cannot be received, the process immediately proceeds to step S82 in that case. In the example of FIG. 15, the number of relays (Hop (1)) of the relay terminal (10 (B)) is two, and the number of relays (Hop (2)) of the destination terminal (10 (Z2)) is four. As a result of the comparison in step S81, it is recognized that the number of relays becomes smaller when the route is changed, and the destination terminal (10 (Z2))
The process proceeds to step S82.

The destination terminal (10 (Z2)) executes step S8
2, the previous data 6 of its own communication route control unit 58B.
3 is changed to the identification information "B" of the relay terminal (10 (B)), and thereafter, the destination terminal (10 (Z2)) receives the data packet from the relay terminal (10 (B)). On the other hand, when the relay terminal (10 (B)) receives the route update completion signal transmitted by the destination terminal (10 (Z2)) in step S83,
In step S77, the identification information “Z2” of the destination terminal (10 (Z2)) is added to the data 64 immediately after the communication route control unit 58B itself, and thereafter, the relay terminal (10
(B)) changes the communication route so as to relay the data packet addressed to the destination terminal (10 (Z2)).

Therefore, the relay terminal in this case (10 (B))
The destination terminal (10 (Z2)) performs an operation as shown in FIG. As shown in FIG. 17, the route storage unit 5 after the change
The data 64 immediately after 5 holds identification information “Z1, Z2” of each of the two destination terminals. That is, the relay terminal (10 (B)) has two destination terminals (10 (Z1), 1 (1)).
0 (Z2)).

Before the communication route is changed, the number of relays from the source terminal (10 (S)) to the destination terminal (10 (Z2)) is four, but the number of relays from the relay terminal (10 (B)) to the destination terminal (1
When the communication route is changed so that the data packet is transmitted to 0 (Z2)), the number of relays becomes three. Such a change in the communication route minimizes the number of relays of packet transfer, thereby suppressing consumption of communication resources.

Further, since the relay terminal (10 (B)) starts the procedure for updating the communication route in response to the detection of the beacon packet, the destination terminal (10 (Z2)) in FIG. The communication route is automatically changed to the optimal communication route even before the communication range of)) is exceeded. Further, since the communication route is changed based on the data held in the communication route control unit 58B, it is not necessary to broadcast a control packet for searching for the communication route, and the change of the communication route is completed in a short time.

If the communication route is interrupted due to the movement of the destination terminal, steps S80 to S8 in FIG.
Since the process proceeds to step 2 and changes the communication route irrespective of the number of relays, even if the communication route is interrupted, it is not necessary to search for the communication route again from the beginning.

[0172]

According to the first aspect of the present invention, when an ad hoc network is configured using the wireless ad hoc terminal, the relay terminal on the currently used communication route communicates with the destination terminal as the destination terminal moves. When it becomes possible, even if the current communication route is not interrupted, the communication route between the relay terminal and the destination terminal is changed, so that the communication route with a smaller number of relays can be automatically selected. In addition, since there is no need to restart the search for the communication route from the beginning, the communication route can be changed in a short time.

When an ad hoc network is configured using the wireless ad hoc terminals of claims 2 to 4,
If there are a plurality of destination terminals that receive the same data packet from the same source terminal and the plurality of destination terminals can communicate with each other as at least one of the destination terminals moves, the current communication route is interrupted. Even if there is no communication route, the communication route is tried to be changed by communication between the plurality of destination terminals, so that a communication route with a smaller number of relays can be automatically selected. In addition, since there is no need to restart the search for the communication route from the beginning, the communication route can be changed in a short time. Further, since the number of communication routes to be used and the number of relay terminals for relaying data packets are reduced, the traffic of the entire network is reduced.

When an ad hoc network is configured using the wireless ad hoc terminals of claims 5 to 7,
If there is a plurality of destination terminals receiving the same data packet from the same source terminal and communication becomes possible between the destination terminal and the relay terminal with the movement of one destination terminal, the current communication Even if the route is not blocked, the communication route between the destination terminal and the relay terminal is attempted to be changed, so that a communication route with a smaller number of relays can be automatically selected. In addition, since there is no need to restart the search for the communication route from the beginning, the communication route can be changed in a short time. Further, since the number of communication routes to be used and the number of relay terminals for relaying data packets are reduced, the traffic of the entire network is reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a wireless ad hoc terminal according to a first embodiment.

FIG. 2 is a flowchart illustrating an operation of a communication route control unit according to the first embodiment.

FIG. 3 is a block diagram illustrating a configuration of a wireless ad hoc terminal according to a second embodiment.

FIG. 4 is a flowchart illustrating an operation (1) of a communication route control unit according to the second embodiment.

FIG. 5 is a flowchart illustrating an operation (2) of the communication route control unit according to the second embodiment.

FIG. 6 shows an operation example (1) of each destination terminal according to the second embodiment.
FIG.

FIG. 7 is a flowchart illustrating an operation of a communication route control unit according to the third embodiment.

FIG. 8 is a block diagram showing a configuration and an arrangement example (1) of an ad hoc network.

FIG. 9 is a block diagram illustrating a configuration and an arrangement example (2) of an ad hoc network.

FIG. 10 is a block diagram illustrating an operation example of each terminal according to the first embodiment.

FIG. 11 is a block diagram illustrating a configuration and an arrangement example (3) of an ad hoc network.

FIG. 12 is a block diagram showing a configuration and arrangement example (4) of an ad hoc network.

FIG. 13 is a block diagram illustrating an operation example (2) of each destination terminal according to the second embodiment.

FIG. 14 is a block diagram illustrating an operation example (3) of each destination terminal according to the second embodiment.

FIG. 15 is a block diagram showing a configuration and an arrangement example (5) of an ad hoc network.

FIG. 16 is a block diagram showing a configuration and an arrangement example (6) of an ad hoc network.

FIG. 17 is a block diagram illustrating an operation example of each terminal according to the third embodiment.

FIG. 18 is a block diagram illustrating a configuration and an arrangement example (7) of an ad hoc network.

FIG. 19 shows an operation example (1) when a communication route is interrupted.
FIG.

FIG. 20 shows an operation example (2) when a communication route is interrupted.
FIG.

FIG. 21 is a block diagram illustrating a configuration and an arrangement example (8) of an ad hoc network.

FIG. 22 is a block diagram illustrating a configuration and an arrangement example (9) of an ad hoc network.

[Explanation of symbols]

 Reference Signs List 10 wireless terminal 51 wireless transceiver 52 data packet transmitting unit 53 data packet relay unit 54 data packet receiving unit 55, 55B route storage unit 56 beacon transmitting unit 57 beacon receiving unit 58 communication route control unit 61 source data 62 destination data 63 immediately before Data 64 Immediate data 65 Relay count data

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masahiro Morikura 3-19-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Japan Telegraph and Telephone Corporation F-term (reference) 5K030 HA08 JL01 JT09 KA05 KA08 LB05 LE17 MD07 5K033 DA19 DB12 DB18 5K067 AA11 AA14 BB21 CC08 DD17 DD24 DD51 EE02 EE06 EE25 FF02 HH22 HH23 KK15 5K072 AA15 AA23 BB02 BB13 BB25 BB27 CC02 CC35 DD11 EE04 EE13 FF03 FF04 9A001 BB03 BB04 CC05 CC06 DD06

Claims (7)

[Claims] 1. A wireless terminal serving as a source of a data packet using at least three wireless terminals each having all functions of transmitting, receiving and relaying a data packet.
When the wireless terminal that is the destination of the data packet and the wireless terminal that relays the data packet are respectively defined as a source terminal, a destination terminal, and a relay terminal, and when direct communication cannot be performed between the source terminal and the destination terminal, A wireless ad hoc terminal used as one of the wireless terminals in an ad hoc network for relaying a data packet at at least one of the relay terminals and transferring the data packet from the source terminal to the destination terminal, Regarding a communication route from a source terminal to a destination terminal, first identification information for specifying the destination terminal, and a wireless terminal closer to the source terminal among two wireless terminals located adjacent to itself on the communication route. Second identification information for identifying a wireless terminal; and third identification information for identifying a wireless terminal closer to a destination terminal among the two wireless terminals. Communication route information holding means for holding identification information of the same; beacon transmission means for periodically transmitting a signal including fourth identification information identifying itself to surrounding wireless terminals; Beacon receiving means for receiving the transmitted fourth identification information, and holding the communication route information of its own if it is not the last relay terminal transmitting a data packet to the destination terminal Means for comparing the first identification information held by the means with the fourth identification information received by the beacon receiving means from another wireless terminal; and a comparison between the identification information comparing means. If the results match,
Route update request means for transmitting a route update request signal from the relay terminal detecting the match to the destination terminal; and receiving the route update request signal from another wireless terminal when the relay terminal itself is the destination terminal. Then, while changing the second identification information held by the communication route information holding means of itself to identification information corresponding to the relay terminal that transmitted the route update request signal, the route update request signal is First route changing means for transmitting a route update response signal to the transmitting relay terminal; and when the relay terminal itself transmits the route update request signal, receiving the route update response signal; The third identification information held by its own communication route information holding means is changed to the identification information corresponding to the destination terminal that transmitted the route update response signal. A second rerouting means for further provided, a wireless ad-hoc terminal, which comprises carrying out the transmission of data packets, the reception and relay using the communication route determined by the information held in the communication route information holding means. 2. A wireless terminal serving as a data packet source, comprising at least three wireless terminals each having all functions of transmitting, receiving and relaying data packets,
When the wireless terminal that is the destination of the data packet and the wireless terminal that relays the data packet are respectively defined as a source terminal, a destination terminal, and a relay terminal, and when direct communication cannot be performed between the source terminal and the destination terminal, A wireless ad-hoc terminal used as one of the wireless terminals in an ad-hoc network for relaying a data packet by at least one of the relay terminals and transferring the data packet from the source terminal to the destination terminal; A first identification information for specifying each of the plurality of destination terminals with respect to a currently used communication route from a plurality of destination terminals including a first destination terminal and a second destination terminal; Second identification information for identifying a wireless terminal closer to the source terminal among two adjacent wireless terminals located adjacent to itself And third identification information for specifying a wireless terminal closer to the destination terminal among the two adjacent wireless terminals, and relay number information corresponding to the number of relays from the source terminal to the wireless terminal. Communication route information holding means; beacon transmission means for periodically transmitting a signal including fourth identification information identifying itself to a nearby wireless terminal; Beacon receiving means for receiving the identification information; if the communication terminal is itself a destination terminal, the first identification information held by the communication route information holding means of the beacon receiving means; Is compared with the fourth identification information received from the other wireless terminal, and the fourth identification information is included in the first identification information as another destination terminal belonging to a communication route from the same transmission source terminal. Be Identification information comparing means for detecting a match when the identification information comparison means detects a match, and a second destination for transmitting the fourth identification information to the first destination terminal from the first destination terminal having detected the match. Route update request means for transmitting a route update request signal including the relay number information to a terminal;
In the case of the destination terminal, the number of relays of a plurality of communication routes is compared based on the number of relays held by its own communication route information holding unit and the number of relays included in the route update request signal. When the number of relays is smaller than the number of relays as a result of the comparison between the number of relays and the relay number comparing means when the relay destination itself is the second destination terminal, if the number of relays is smaller, The second identification information held by the route information holding means is stored in the first
Route update response means for transmitting a route update response signal to the first destination terminal, while changing the identification information to identify the destination terminal of the first destination terminal; The second
Receiving the route update response signal from the destination terminal of the third communication terminal, the third identification information held by its own communication route information holding means is changed to identification information for specifying the second destination terminal. A wireless ad hoc terminal, comprising: a route changing unit for transmitting, receiving, and relaying a data packet using a communication route determined by information held by the communication route information holding unit. 3. The wireless ad-hoc terminal according to claim 2, wherein the relay destination itself is the second destination terminal, and as a result of the comparison by the relay number comparing means, if the communication route is changed, the number of relays increases. When the second destination terminal is receiving the data packet, reverse route update request means for transmitting a reverse route update request signal from the second destination terminal to the first destination terminal; The first destination terminal, when receiving a reverse route update request signal from the second destination terminal, stores the second identification information held by its own communication route information holding unit in the second destination terminal. First reverse route update means for changing to identification information for specifying the second destination terminal, and itself when the second destination terminal is at least transmitting the reverse route update request signal, The communication le Wireless ad hoc, further comprising second reverse route updating means for changing the third identification information held by the port information holding means to identification information for specifying the first destination terminal. Terminal. 4. The wireless ad hoc terminal according to claim 3, wherein the wireless ad hoc terminal itself is the first destination terminal, and first reverse route update means identifies the second identification information and identifies the second destination terminal. Wireless ad hoc terminals, further comprising update completion notifying means for notifying the second destination terminal of the completion of the route update when the identification information is changed to the identification information to be updated. 5. A wireless terminal serving as a source of a data packet using at least three wireless terminals each having all functions of transmitting, receiving and relaying a data packet,
When the wireless terminal that is the destination of the data packet and the wireless terminal that relays the data packet are respectively defined as a source terminal, a destination terminal, and a relay terminal, and when direct communication cannot be performed between the source terminal and the destination terminal, A wireless ad-hoc terminal used as one of the wireless terminals in an ad-hoc network for relaying a data packet by at least one of the relay terminals and transferring the data packet from the source terminal to the destination terminal; And a plurality of destination terminals, the first identification information for specifying the plurality of destination terminals respectively, and two adjacent wireless terminals located adjacent to itself on the communication route. Second identification information for identifying a wireless terminal closer to the source terminal,
A communication route that holds third identification information for specifying a wireless terminal closer to a destination terminal among the two adjacent wireless terminals and relay number information corresponding to the number of relays from the source terminal to the wireless terminal. Information holding means, beacon transmitting means for periodically transmitting a signal including fourth identification information identifying itself to a nearby wireless terminal, and the fourth identification information transmitted from the surrounding wireless terminal Receiving the beacon receiving means, when the relay terminal itself, the first identification information received by the beacon receiving means, the first communication route information holding means of its own holding the first Identification information comparing means for comparing the identification information with the destination terminal which itself is a relay terminal and the fourth identification information received as a result of the comparison by the identification information comparing means is included in the first identification information; If it is, a route for transmitting a route update request signal containing the relay number information held by the communication route information holding means of itself to the destination terminal corresponding to the received fourth identification information Update request means, itself being a destination terminal, if the route update request signal is received from a relay terminal, the relay number information held by the destination terminal, and the received route update request signal The number of relays of the plurality of communication routes based on the number of relays included in the relay number comparing means, and the destination terminal itself, and as a result of the comparison by the number of relays comparing means, the communication route is changed. If the number of relays is smaller, the second identification information held by the communication route information holding means of the communication device itself is changed to identification information for specifying the relay terminal that transmitted the route update request signal. And a route update response means for transmitting a route update response signal to the relay terminal; and if the route update response means itself is a relay terminal and receives a route update response signal from the destination terminal, Route changing means for adding, to the third identification information held by the communication route information holding means, identification information for specifying a destination terminal which has transmitted the route update response signal; A wireless ad-hoc terminal for transmitting, receiving, and relaying a data packet using a communication route determined by information held. 6. The wireless ad-hoc terminal according to claim 5, wherein when the terminal itself is a destination terminal and receives the route update request signal from a relay terminal, the destination terminal becomes unable to receive a data packet. The route update responding means transmits the second identification information held by its own communication route information holding means to the route update request signal, irrespective of the result of the comparison by the relay number comparing means. A wireless ad-hoc terminal, which changes the transmitted relay terminal to identification information for identifying the relay terminal, and transmits a route update response signal to the relay terminal. 7. A wireless terminal serving as a source of a data packet using at least three wireless terminals each having all functions of transmitting, receiving and relaying a data packet.
When the wireless terminal that is the destination of the data packet and the wireless terminal that relays the data packet are respectively defined as a source terminal, a destination terminal, and a relay terminal, and when direct communication cannot be performed between the source terminal and the destination terminal, A wireless ad-hoc terminal used as one of the wireless terminals in an ad-hoc network for relaying a data packet by at least one of the relay terminals and transferring the data packet from the source terminal to the destination terminal; And a plurality of destination terminals, the first identification information for specifying the plurality of destination terminals respectively, and two adjacent wireless terminals located adjacent to itself on the communication route. Second identification information for identifying a wireless terminal closer to the source terminal,
Communication route information holding means for holding third identification information for identifying a wireless terminal closer to the destination terminal of the two adjacent wireless terminals; and a signal containing fourth identification information for identifying itself. A beacon transmitting means for periodically transmitting to the wireless terminal; a beacon receiving means for receiving the fourth identification information transmitted from a peripheral wireless terminal; Identification information comparing means for comparing the fourth identification information received by the receiving means with the first identification information held by the communication route information holding means of the receiving means, and the relay terminal itself, As a result of the comparison by the identification information comparing means, if the received fourth identification information corresponds to the destination terminal included in the first identification information, the fourth identification information having received the route update request signal To Route update request means for transmitting to a corresponding destination terminal, and whether or not the destination terminal itself can receive a data packet when the route update request signal is received from the relay terminal. And when the data packet cannot be received, the second identification information held by the communication route information holding means of itself is used as identification information for specifying the relay terminal that transmitted the route update request signal. A route update response means for changing and transmitting a route update response signal to the relay terminal; if the route update response means is a relay terminal itself and receives a route update response signal from the destination terminal, A route for adding identification information for specifying the destination terminal that has transmitted the route update response signal to the third identification information held by the communication route information holding means of And changing means is provided, the wireless ad-hoc terminal, which comprises carrying out the transmission of data packets, the reception and relay using the communication route determined by the information held in the communication route information holding means.