JP2008245193A - Communication path setting device, communication terminal, and multihop network system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To set a communication path designed arbitrarily to each communication terminal without conflicting with a communication path set autonomously. <P>SOLUTION: A communication path setting device is used for setting a communication path of a communication terminal connected to a multihop network to the communication terminal. The device includes communication means 103 for performing communication via the multihop network and memory means 102 for storing communication path information of the multihop network. The communication means 103 transmits a setting packet including information for setting the communication path to each communication terminal constituting the communication path based on the communication path information. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to communication path setting of a multi-hop network.

  In general, each wireless terminal having a relay function constitutes a network, and even for terminals in a range where direct wireless communication is not possible, the relay functions are used to relay in order by terminals within the communication range. A network that indirectly transmits data to a destination communication terminal and realizes data communication between the terminals is called a multi-hop network.

  In this multi-hop network system, it is necessary to determine a communication path as to which terminal relays and transmits data before data transmission to a destination communication terminal.

  As a method for determining a communication path, for example, there is an AODV (Ad hoc On-Demand Distance Vector) protocol. In this protocol, when a request for data communication is made, a route search is performed to determine a route, and the route is determined by the following procedure.

(1) A terminal that starts a route search first transmits a route request packet including a destination address and a communication cost by broadcast.
(2) The terminal that has received the route request packet changes the communication cost and relays it by broadcast if it is not the destination communication terminal, and also relays the information of the route request packet and the relay source terminal that relays this packet to itself. Remember the address.
(3) When the destination communication terminal receives the route request packet, the destination communication terminal generates a route response packet and transmits it to the relay source address that relayed the route request packet.
(4) The terminal that has received the route response packet relays the stored route request packet to the relay source terminal, and stores the terminal that relayed the route response packet in the route table as a relay destination (next hop) address, Store the corresponding destination address.
(5) When the terminal that has started the route search receives the route response packet, the terminal that relayed the route response packet is stored in the route table as the relay destination address, the corresponding destination address is stored, and the route search is terminated.

When a route search is performed in this way, information on the destination communication terminal and the relay destination terminal is stored in each route table of the relay terminal from the data transmission source terminal to the destination communication terminal, and relaying is performed according to the relay destination address. By doing so, it becomes possible to transmit data from the transmission source terminal to the destination communication terminal.
Further, by transmitting a route request packet and a route response packet according to the communication cost, data can be communicated through a route having the lowest communication cost.

  On the other hand, regarding a route selection method of a multi-hop wireless communication system, “a multi-hop wireless communication system capable of establishing an optimum route in consideration of link quality and a route selection method thereof are provided. As a technique for the purpose, “the relay node receives the RREQ, obtains the link quality metric of the route from the transmission source node to the own node, registers this in the RREQ, and transfers it. The destination node receives the RREQ, obtains the link quality metric of the route from the transmission source node to the own node, registers this in the RREP, and returns it. The destination node that has received the same RREQ by another route returns an RREP in response to the RREQ having an excellent link quality metric. A source node that has received the same RREP via a different route generates route information based on the RREP having an excellent link quality metric. Is proposed (Patent Document 1).

  “The data packet is transferred through the network until it is received by the destination node. In response, the destination node generates a route response packet including route information. The route information can include a cost. The route response packet is forwarded through the network until it is received by the source node. During transfer, multiple path response packets can be generated that include different costs. The source node can then calculate the cost and select the best route based on the cost. Is also proposed (Patent Document 2).

JP 2005-33557 A (summary) JP 2005-65267 A (summary)

According to the conventional technology, even when a message cannot be reached on the route to the destination communication terminal due to a failure or the like, an alternative route can be found autonomously and distributedly.
On the other hand, when a terminal issues a route request packet, it is relayed by broadcast, and the route to the destination is set by all the terminals on the discovered route, so even a terminal that does not need to change the route, Each time a route request packet is issued due to a communication error due to a temporary failure in communication state or communication collision, the route to the destination communication terminal may change.

As described above, there is a possibility that the route is changed every time the route request packet is issued, and therefore it is difficult to estimate the currently used route when the system is operated.
For example, when a communication failure occurs, it is difficult to immediately identify the location where the failure occurred.

  Further, since the route search is performed by broadcasting, the communication cost for the network is high, and it is necessary to suppress the generation of route request packets as much as possible.

  Especially in network systems where there are many fixedly installed communication terminals, such as air conditioning and lighting control networks in building facilities, and the communicable area rarely changes due to movement, a small number of mobile terminals execute. It is not desirable for the route search to frequently generate route request packets with high communication costs or to change the route between fixed terminals that do not need to be changed.

  In addition, since there is no means for setting the route from the outside, it is not possible to perform operations such as temporarily setting a detour route for maintenance work such as terminal replacement, and returning the route to the original state after work. There was a problem that it took.

  The present invention has been made to solve the above-described problems, and sets an arbitrarily designed communication path in each communication terminal without competing with the communication path autonomously set by each communication terminal. It is aimed at.

  A communication path setting device according to the present invention is a device for setting a communication path of a communication terminal connected to a multi-hop network in the communication terminal, the communication means for performing communication via the multi-hop network, Storage means for storing communication path information of a multi-hop network, and the communication means is information for setting the communication path for each communication terminal constituting the communication path based on the communication path information. A configuration packet including the above is transmitted.

According to the communication path setting device according to the present invention, an arbitrary communication path can be set in each communication terminal independently of the communication path that each communication terminal sets autonomously.
In addition, for example, when performing a maintenance work or the like, it is possible to arbitrarily set a communication path convenient for the work, so that it is possible to easily grasp the communication path set in each communication terminal and to improve work efficiency. .

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of communication path setting apparatus 101 according to Embodiment 1 of the present invention.
The communication path setting device 101 includes a setting path storage unit 102 and a communication unit 103.
The setting path storage unit 102 stores communication path information described later with reference to FIG.
The communication means 103 communicates with other communication terminals via a network.

FIG. 2 is a block diagram showing a configuration of communication terminal 201 according to the first embodiment.
The communication terminal 201 includes a route storage unit 202 and a communication unit 203.
The path storage unit 202 stores a communication path table 401 described with reference to FIG.
The communication unit 203 communicates with other communication terminals and the communication path setting device 101 via a network.

The setting path storage unit 102 and the path storage unit 202 can be configured by a storage device such as an HDD (Hard Disk Drive) and a RAM (Random Access Memory).
The communication means 102 and the communication means 203 can be configured as means for performing communication using wired communication means such as EtherNet, USB, RS-232C, in addition to wireless communication means using radio waves and wireless communication means using infrared rays.
Further, the communication path setting device 101 and the communication terminal 201 appropriately include control means such as a CPU and a microcomputer for generating communication packets and controlling operations.

FIG. 3 is a configuration diagram of setting route information stored in the setting route storage unit 102 of the communication route setting device 101.
The setting route information is information used by the communication route setting device 101 to set the communication route of each communication terminal, and can be configured in a table format, for example, as shown in FIG. In the configuration example of FIG. 3, each row represents one communication path.
In the “route configuration terminal address list” column, the addresses of the communication terminals constituting the communication route represented by the row are stored in the order of the relayed communication terminals.
The “number of set terminals” column stores a value indicating how many communication terminals have been set among the communication terminals stored in the “route configuration terminal address list” column. Details will be described later with reference to FIGS.
In the data example of FIG. 3, for example, in a communication route transmitted by n relays from a transmission source terminal to a destination communication terminal, n + 1 address values are stored in the set route configuration terminal address list column.

  Note that the format of the set route information is not limited to the table format as shown in FIG. 3, but may be an arbitrary format. In addition, the value of each entry is set in advance or entered separately.

FIG. 4 shows a configuration and data example of the route information table 401 stored in the route storage unit 202 of the communication terminal 201.
The route information table 401 has a “destination address” column and a “relay destination address” column.
The “destination address” column stores the address of the final destination terminal to which the communication terminal transmits a communication packet.
In the “relay destination address” column, when the communication terminal transmits a communication packet addressed to the communication terminal corresponding to the “destination address” column, the address of the terminal to which the packet is to be transmitted next is stored.

In the data example of the first row, it is understood that when a communication packet is transmitted to the communication terminal n, the packet should first be transmitted to the communication terminal 1. The communication terminal 1 also holds the same communication route table, and the packet is delivered to the communication terminal n that is the final destination by repeating the relay of the packet.
Since the communication terminals 201 in the network have such a path information table 401 in a distributed manner, it is possible to relay and transmit a message from a certain source terminal to a destination communication terminal.

  Note that the format of the route information table 401 is not limited to the table format as shown in FIG. 4 and may be any format.

  Next, the route setting operation in the first embodiment will be described.

FIG. 5 illustrates an outline of an operation in which the communication path setting device 101 sets the communication path of each communication terminal. Here, a case where the setting route 510 addressed from the transmission source communication terminal 502 to the final destination communication terminal 506 is set as an example.
In FIG. 5, the subscripts of the communication terminals 502 to 506 represent the relay order of the communication paths. Hereinafter, each step will be described.

(1) The communication path setting device 101 reads the communication path information described with reference to FIG. 3 and acquires the addresses of the communication terminals constituting the communication path.
(2) The communication path setting device 101 transmits a setting packet including information for setting a communication path in order from the final destination terminal of the acquired communication path.
(3) The communication terminal that has received the setting packet sets an entry to be held in the communication path table 401 based on the content.

  FIG. 6 illustrates a detailed sequence of an operation in which the communication path setting device 101 sets the communication path of each communication terminal. Hereinafter, each step will be described.

(S601)
The communication path setting device 101 reads the communication path information described with reference to FIG. 3 from the communication path storage unit 102 and acquires the addresses of the constituent terminals constituting the setting path 510 from the “path constituent terminal address list” column. Also, the value in the “number of terminals set” column is set to 0.
Next, the communication path setting device 101 transmits a setting packet including information for setting a communication path to the (n−1) th communication terminal 505.
The setting packet includes information indicating that the address of the communication terminal 506 should be set in the “destination address” column of the route information table 401 and the address of the communication terminal 506 should be set in the “relay destination address” column.

(S602)
Upon receiving the setting packet, the communication terminal 505 sets the address of the communication terminal 506 in the “destination address” column of the route information table 401 and the address of the communication terminal 506 in the “relay destination address” column of the route information table 401.
(S603)
The communication terminal 505 transmits a route setting response to the communication route setting device 101.

(S604)
When the communication path setting device 101 receives the path setting response in step S603, the communication path setting apparatus 101 increments the value of the “number of set terminals” column in the communication path information by one. Further, the increased value is compared with the number of terminals in the “route configuration terminal address list” column, and it is determined whether or not to continue transmission of the setting packet.
Here, since there are still unset terminals, transmission of the set packet is continued.
(S605)
The communication path setting device 101 transmits a setting packet including information for setting a communication path to the (n-2) th communication terminal 504.
The setting packet includes information indicating that the address of the communication terminal 506 should be set in the “destination address” column of the route information table 401 and the address of the communication terminal 505 should be set in the “relay destination address” column.

(S606)
Upon receiving the setting packet, the communication terminal 504 sets the address of the communication terminal 506 in the “destination address” column of the route information table 401 and the address of the communication terminal 505 in the “relay destination address” column of the route information table 401.
(S607)
The communication terminal 504 transmits a route setting response to the communication route setting device 101.

  The communication path setting device 101 repeats transmission of the setting packet and reception of the path setting response until the value in the “number of terminals already set” column matches the number of terminals in the “path configuration terminal address list” column. Thereby, a setting route 510 from the transmission source communication terminal 502 to the destination communication terminal 506 is set.

  When transmitting a message from the transmission source communication terminal 502 to the destination communication terminal 506, each communication terminal refers to the route information table 401 held in its route storage means 202 by the following procedure, and acquires the relay destination of the message. To do.

(1) The communication terminal 502 refers to the value in the “relay destination address” column of the entry whose value in the “destination address” column matches the address of the destination communication terminal 506, and acquires the address of the relay destination communication terminal 503. The electronic message is transmitted to the communication terminal 503.
(2) When the communication terminal 503 receives the message to the destination communication terminal 506, the communication terminal 503 similarly refers to the route information table 401 held in its route storage unit 202 and sends the message to the second relay destination communication terminal 504. Send.
(3) By repeating this procedure, a message is relayed from the source communication terminal 502 to the destination communication terminal 506.

  Thus, the communication path setting device 101 can set an arbitrary communication path for each communication terminal. As a result, for example, when performing maintenance work, etc., it is possible to arbitrarily set a communication path convenient for the work, so that the communication path set in each communication terminal can be easily grasped and work efficiency is improved. is there.

  Further, when the communication path setting device 101 sets the communication path of each communication terminal, the setting packet is transmitted in order from the communication terminal closest to the final destination terminal in the “path configuration terminal address list” column. The communication path that has been set functions effectively even when the communication path setting device 101 is setting the path of each communication terminal.

  That is, for example, when a transmission request for a message from the communication terminal 504 to the communication terminal 506 occurs at the time when the route information table 401 from the communication terminals 506 to 504 is set, the route information table 401 that has already been set is displayed. Telegram relay is possible based on this.

Here, it is assumed that the communication path setting device 101 transmits setting packets in order from the transmission source communication terminal in the “path configuration terminal address list” column.
When a message transmission request from the communication terminal 504 to the communication terminal 506 is generated when the route information table 401 from the communication terminals 502 to 504 is set, the communication terminal 506 is addressed to the route information table 401 of the communication terminal 505. Therefore, there is a possibility that transmission to the destination communication terminal 506 cannot be performed correctly.
By transmitting the setting packets in order from the final destination terminal, data inconsistency in the route information table 401 does not occur.

As described above, according to the first embodiment, when setting a route from the communication route setting device 101, setting packets are sequentially transmitted from the communication terminal closest to the destination communication terminal in the “route configuration terminal address list” column. Since the transmission is performed, even if the communication path is being set for each communication terminal, the communication path that has been set functions effectively.
Therefore, even when other communication using a part of the route occurs, it is possible to relay a message to the destination communication terminal without causing data inconsistency in the route information table 401. Further, redundancy of the communication path can be ensured.

  Further, even when a setting packet cannot be correctly transmitted to any one of the route configuration terminals during the route setting procedure due to a communication error or the like, similarly, data inconsistency in the route information table 401 does not occur. It is possible to relay a message to a communication terminal.

If a relay error such as “There is no route information corresponding to the routing table” or “Communication to the corresponding relay destination address failed” occurs during operation of the communication terminal, the communication terminal searches for an alternative route by itself. Therefore, a route request packet is transmitted.
In general, since a route request packet is transmitted by broadcast transmission, the load on the network is high, and its transmission should be suppressed as much as possible. However, according to the first embodiment, the set route information table 401 is effective. Therefore, it is possible to effectively suppress the issue of a route request packet having a high communication load.

Embodiment 2. FIG.
FIG. 7 is a block diagram showing a configuration of communication path setting apparatus 701 according to Embodiment 2 of the present invention.
The communication path setting device 701 is additionally provided with a terminal return detection unit 704 in addition to the configuration described with reference to FIG.
The terminal return detection unit 704 detects whether or not the communication terminal 201 is communicable, and detects that the communication terminal 201 has returned to a communicable state from a state where communication is not possible, such as a power failure or failure.
Other configurations are the same as those in FIG.

  The terminal return detection unit 704 detects whether or not the communication terminal 201 can communicate using one of the following methods.

(1) The communication terminal 201 in the network is configured to periodically transmit a message notifying the communicable state to the communication path setting device 101. The message is received by the terminal return detection means 704 via the communication means 203.
The terminal return detection unit 704 determines that the communication terminal is in a communication disabled state when the periodic notification is interrupted, and determines that the communication is in a communicable state when the periodic notification is resumed. , Return can be detected.
(2) By periodically transmitting an operation confirmation packet from the terminal return detection means 704 to the communication terminal 201 and detecting a response thereof, the communication terminal 201 is in a communication disabled state or in a communication enabled state. Detects return.
(3) Other suitable detection methods may be used.

  Note that the terminal return detection unit 704 can be configured by hardware such as a circuit device that realizes the function, or can be configured as software executed on an arithmetic device such as a CPU or a microcomputer.

FIG. 8 illustrates the operation when the communication terminal configuring the communication path becomes in a communication disabled state while the communication path setting device 701 is setting the communication path to each communication terminal. Here, a case where a setting route 810 addressed from the transmission source communication terminal 802 to the final destination communication terminal 806 is set as an example.
Note that the subscripts assigned to the communication terminals 802 to 806 indicate the relay order of the communication paths as in FIG.

In FIG. 8, the communication path setting device 701 transmits a communication path setting packet to each communication terminal by the procedure described in the first embodiment.
Here, when the communication terminal 804 in the middle is in a state where communication is not possible due to a failure or the like, the setting packet cannot be transmitted, so that the route setting is interrupted there. At this time, the value in the “number of set terminals” column is smaller than the number of terminals configuring the setting route 810.

FIG. 9 illustrates the operation when the terminal return detection unit 704 of the communication path setting device 701 detects that the communication terminal 804 has returned to the communicable state after FIG.
The communication path setting device 701 immediately resumes the interrupted path setting, and sets from the interrupted path setting order shown in FIG. Hereinafter, the operation of resuming route setting will be described step by step.

(1) The terminal return detection unit 704 detects that the communication terminal 804 has returned to a communicable state.
(2) The communication route information described in FIG. 3 is read from the set route storage unit 702, and an entry whose value in the “number of set terminals” column is smaller than the number of terminals in the “route configuration terminal address list” column is specified. To do.
(3) With respect to the entry identified in step (2), the transmission of the setting packet is resumed from the communication terminal that previously interrupted the transmission of the setting packet.
(4) After that, as in the first embodiment, transmission of the setting packet is repeated until the value in the “number of set terminals” column matches the number of terminals in the “route configuration terminal address list” column.
(5) The setting route 810 is set by the above procedure.

  As described above, according to the second embodiment, when the terminal return detection unit 704 detects that the communication terminal has returned to the communicable state, the interrupted route setting is immediately resumed. Even if it is interrupted in step S1, the desired route can be set automatically and reliably. Further, it is possible to shorten the time from returning to setting a route.

Embodiment 3 FIG.
FIG. 10 is a block diagram showing a configuration of communication path setting apparatus 1001 according to Embodiment 3 of the present invention.
The communication route setting device 1001 newly includes route search permission flag setting means 1005 in addition to the configuration described in FIG. 1 of the first embodiment.
The route search permission flag setting unit 1005 generates a packet for instructing the communication terminal whether to autonomously set a communication route by transmitting a route request packet, and transmits the packet via the communication unit 1003. . Details will be described later.
Other configurations are the same as those in FIG.

  The route search permission flag setting unit 1005 can be configured by hardware such as a circuit device that realizes the function, or can be configured as software executed on an arithmetic device such as a CPU or a microcomputer. it can.

FIG. 11 is a functional block diagram of communication terminal 1101 according to Embodiment 3 of the present invention.
The communication terminal 1101 newly includes a route search unit 1104 and a route search permission flag storage unit 1105 in addition to the configuration described in FIG. 2 of the first embodiment.
Other configurations are the same as those in FIG.

The route search unit 1104 controls the issuance of route request packets, and performs route search when a route search request is generated due to an application instruction or a communication error in the communication unit.
The route search is performed when “permitted” is set in the value held in the route search permission flag storage unit 1105, but the route search is performed when “not permitted” is set. Do not do.

  The route searching means 1104 can be configured by hardware such as a circuit device that realizes the function, or can be configured as software executed on an arithmetic device such as a CPU or a microcomputer.

The route search permission flag storage unit 1105 stores a route search permission flag that takes two values “permitted” and “not permitted”. The value of the flag is set by an instruction packet generated by the route search permission flag setting unit 1005 of the communication route setting device 1001.
Note that the route search permission flag storage unit 1105 and the route storage unit 1102 may be configured integrally.

  Next, operations of communication path setting device 1001 and communication terminal 1101 in the third embodiment will be described.

(1) When the communication route setting device 1001 starts route setting, the route search permission flag setting unit 1005 generates an instruction packet indicating that “route search permission flag = not permitted” is set, and the communication unit 1003 To all terminals in the network.
(2) The communication terminal 1101 receives the above instruction packet, and stores the same value in the route search permission flag storage unit 1105. As a result, all communication terminals 1101 in the network do not autonomously transmit route request packets.

(3) When the route setting by the communication route setting device 1001 is completed, the route search permission flag setting unit 1005 generates an instruction packet indicating that “route search permission flag = permitted” is set, and via the communication unit 1003 Send to all devices in the network.
(4) The communication terminal 1101 receives the above instruction packet, and stores the same value in the route search permission flag storage unit 1105. As a result, each communication terminal autonomously transmits a route request packet again.

  When transmitting the above-described instruction packet to all terminals in the network, broadcast may be used or may be individually transmitted to each terminal.

As described above, according to the third embodiment, the value of the flag stored in the route search permission flag storage unit 1105 is set to the instruction packet from the communication route setting device 1001 before route setting from the communication route setting device 1001. By setting according to the above, each communication terminal can be prevented from transmitting a route request packet.
Therefore, when the communication path setting device 1001 sets a communication path, the value of the communication path table 401 held by each communication terminal 1101 is not autonomously updated, and an attempt is made to set from the path setting device. It is possible to reliably set a desired route.

In the above description, the route setting device 1001 sets the route search permission flag to “non-permitted” before setting the route, and returns the route search permission flag to “permitted” when the route setting is completed. It can also be like this.
(1) During operation, the route search permission flag is set to “not permitted”, and the route search permission flag is set to “permitted” only when the route search is necessary.
(2) When setting a short route, the route search permission flag is set to “permitted”, and the route search permission flag is set to “not permitted” only when the number of route constituting terminals is large.

  In the above description, the route search permission flag is set for all terminals in the network. However, only some of the communication terminals 1101 may set the route search permission flag.

  As described above, by setting the route search permission flag of each communication terminal 1101 from the communication route setting device 1001, the route information table 401 is not changed, and the route can be easily grasped in terms of operation and maintenance.

Embodiment 4 FIG.
In the third embodiment, the setting of the route search permission flag by the instruction packet from the communication route setting device 1001 has been described.
On the other hand, a battery remaining amount detecting means (not shown) is provided in the communication terminal 1101, and when the remaining battery level falls below a predetermined threshold, a route search permission flag held in the route search permission flag storage means 1105 is automatically set. It may be set to “not permitted”.
The setting operation may be performed by the battery remaining amount detecting means or may be performed via a control unit such as a CPU or a microcomputer.
By doing in this way, when the battery remaining amount becomes low, communication of a route request packet can be suppressed and the battery consumption can be reduced. In addition, since it does not respond to the route search, it does not become a relay terminal, the amount of communication for relay is reduced, and the battery consumption can be reduced as well.

Embodiment 5. FIG.
In Embodiment 3-4, the structure which sets a route search permission flag to the communication terminal 1101, and suppresses each communication terminal transmitting a route request packet was demonstrated.
In the fifth embodiment of the present invention, a configuration capable of setting whether or not autonomous updating can be performed for each entry in the communication path table will be described.
The configuration of the communication terminal according to the fifth embodiment is the same as that in FIG. 2 described in the first embodiment except for the route information table 1201 described in FIG.

FIG. 12 shows the configuration and data example of the route information table 1201 held by the communication terminal 201 in the fifth embodiment.
In the fifth embodiment, the route information table 1201 newly has an “autonomous update availability” column in addition to the configuration of FIG. This column takes two values, “permitted” and “impossible”.

When the communication terminal 201 receives the setting packet from the communication route setting device 101, the communication terminal 201 sets the route information in the “destination address” and “relay destination address” columns of the route information table 1201 stored in the route storage unit 202, and “autonomous update” Set “impossible” in the “permitted” column.
On the other hand, when an entry of the route information table 1201 is autonomously generated by the route request packet, the value of the “autonomous update availability” column in the entry is set to “permitted”.

(1) When the value of the “autonomous update availability” column is “impossible”, the entry is not updated even when the communication terminal 201 receives the route request packet and the route response packet.
Even if a route request to the communication terminal corresponding to the “destination address” column of the entry occurs in the communication terminal 201, the route request packet is not transmitted, and the “relay destination address” set at that time The message is relayed according to the column value.

(2) When the value of the “autonomous update availability” column is “enabled” The entry is updated according to the contents of the route request packet and the route response packet. When a route request to the communication terminal corresponding to the “destination address” column of the entry occurs in the communication terminal 201, a route request packet is issued to start the route search.

FIG. 13 explains the route setting operation of the communication terminal according to the fifth embodiment.
In FIG. 13, “1” to “4” are communication terminals according to the fifth embodiment.
Here, each step will be described by taking as an example a case where a communication path addressed from communication terminals “1” to “4” is set.

(1) Before route request packet transmission The communication terminal “2” holds entries “destination address = 4”, “relay destination address = 3”, and “autonomous update availability = impossible” in the route information table 1201.
The communication terminal “3” holds entries of “destination address = 4”, “relay destination address = 4”, and “autonomous update availability = impossible” in the route information table 1201.
That is, the communication path between the communication terminals “2” to “4” is set by the communication path setting device 101, and each communication terminal cannot autonomously update the path.
It is assumed that the route information table 1201 of the communication terminal “1” has not been set yet.

(2) Route Request Packet Transmission The communication terminal “1” transmits a route request packet for requesting a communication route addressed to the communication terminal “4” by broadcast transmission. The transmitted route request packet reaches the communication terminal “2”.

(3) Route response packet reply The communication terminal “2” receives the route request packet transmitted by the communication terminal “1”.
Next, the communication terminal “2” reads the content of the received route request packet and compares the requested destination address with the “destination address” of each entry in the route information table 1201.
Here, the entries “destination address = 4”, “relay destination address = 3”, and “autonomous update availability = impossible” match this. Therefore, it can be seen that the communication route addressed to the communication terminal “4” cannot be autonomously changed by the route request packet.
Next, the communication terminal “2” returns a route response packet indicating that “relay destination address = 2” should be set to the communication terminal “1”.

(4) Route Information Table Setting The communication terminal “1” sets an entry in the route information table 1201 based on the content of the received route response packet. Here, entries of “destination address = 4”, “relay destination address = 2”, and “autonomous update availability = allowed” are newly generated.

  By the operation as described above, even when a route request packet is transmitted, the route information entry set to “autonomous update availability = impossible” by the communication route setting device 101 is maintained without being overwritten. .

In the case of a normal route request packet, in step (3), the communication terminal “2” transfers the route request packet as it is to the communication terminal “4”. ”Column works effectively and returns a route response packet without forwarding.
Therefore, the route information entry is maintained without being overwritten and updated.

As described above, according to the fifth embodiment, the “autonomous update availability” column is provided in the route information table 1201, and the value in the same column is set to “impossible” for the route information entry set by the communication route setting device 101. ”And the value in the same column is set to“ Yes ”for the route information entry autonomously set by the route search. Therefore, the route set from the communication route setting device 101 is given priority, It can be prevented from being changed by route search.
Therefore, the route is not changed unnecessarily, and it is possible to easily check the communication route of each communication terminal when performing maintenance work or the like.

In the above description, whether or not the value of the “autonomous update availability” column is set by the communication route setting device 101 or autonomously by route search is set automatically. However, the value of the “autonomous update availability” column may be arbitrarily changed by an instruction packet from the communication path setting device 101.
By doing so, it becomes possible to finely control the route searched by route search and the route set from the communication route setting device 101 and used in a fixed manner.

Embodiment 6 FIG.
In Embodiment 6 of the present invention, when a communication terminal receives a plurality of route response packets, it is possible to determine which route should be selected according to the value of communication cost included in the packet. An example will be described.

FIG. 14 shows the configuration and data example of the route information table 1401 stored in the route storage means of the communication terminal in the sixth embodiment.
The route information table 1401 has a new “communication cost” column in addition to the configuration of FIG. 12 described in the fifth embodiment.
The “communication cost” column stores a value indicating the cost for communication from the communication terminal to the communication terminal corresponding to the “destination address”, for example, the number of relay hops.

FIG. 15 explains the route setting operation of the communication terminal according to the sixth embodiment.
In FIG. 15, “1” to “6” are communication terminals according to the sixth embodiment.
Here, each step will be described by taking as an example a case where a communication path addressed from communication terminals “5” to “4” is set.

(1) Before route request packet transmission The communication terminal “1” holds entries of “destination address = 4”, “relay destination address = 2”, “autonomous update availability = impossible” in the route information table 1401.
The communication terminal “2” holds entries of “destination address = 4”, “relay destination address = 3”, and “autonomous update availability = impossible” in the route information table 1401.
The communication terminal “3” holds entries of “destination address = 4”, “relay destination address = 4”, and “autonomous update availability = impossible” in the route information table 1401.
The communication terminal “6” holds entries of “destination address = 4”, “relay destination address = 4”, and “autonomous update availability = possible” in the route information table 1401.
That is, the communication path between the communication terminals “1” to “4” is set by the communication path setting device 101, and each communication terminal cannot autonomously update the path.
Further, the communication path between the communication terminals “6” to “4” is autonomously set by the path request packet, and each communication terminal can update the path autonomously.
It is assumed that the route information table 1401 of the communication terminal “5” has not been set yet.

(2) Route Request Packet Transmission The communication terminal “5” transmits a route request packet for requesting a communication route addressed to the communication terminal “4” by broadcast transmission. The transmitted route request packet reaches the communication terminals “2”, “3”, and “6”.

(3) Route response packet reply The communication terminals “2”, “3”, and “6” receive the route request packet transmitted by the communication terminal “5”.
Next, the communication terminals “2”, “3”, and “6” read the contents of the received route request packet and compare the requested destination address with the “destination address” of each entry in the route information table 1401. .
Since each terminal holds a route information entry addressed to the communication terminal “4”, a route response packet is returned to the communication terminal “5”. The route response packet includes the value of the “communication cost” column.
Here, for the communication terminal “3”, the value of the “communication cost” column is set to be lower than that of other communication terminals in advance. The lower setting may be appropriately designed according to the network environment, communication terminal specifications, and the like.

(4) Route Information Table Setting The communication terminal “5” sets an entry in the route information table 1401 based on the content of the received route response packet. In the example of FIG. 15, since a plurality of route response packets are received, the packet having the lowest “communication cost” value included in the packet is selected.
Here, regarding the communication terminal “3”, the value of the “communication cost” column is set to be lower than that of other communication terminals in advance, so that the communication terminal “3” is easily selected.
As a result, entries of “destination address = 4”, “relay destination address = 3”, and “autonomous update availability = possible” are newly generated.

As described above, according to the sixth embodiment, for a communication terminal with “autonomous update availability = impossible”, a route response is set by setting a low value in the “communication cost” column in advance. In a situation where a plurality of communication paths can be selected depending on the contents of the packet, it is possible to adjust so that the communication path that is “autonomous update availability = impossible” is preferentially selected.
Therefore, it is possible to more reliably prevent the route set by the communication route setting device 101 from being changed.

Embodiment 7 FIG.
FIG. 16 is a block diagram showing a configuration of communication path setting apparatus 1601 according to Embodiment 7 of the present invention.
The communication path setting device 1601 newly includes a terminal information acquisition unit 1604 and a path design unit 1605 in addition to the configuration described in FIG.

The terminal information acquisition unit 1604 acquires, for example, the following information about each communication terminal 201 via the communication unit 1603.
(1) List of surrounding terminals capable of communication (2) Information such as received radio wave intensity, path information table, remaining battery level, memory amount

  The route design unit 1605 uses the information acquired by the terminal information acquisition unit 1604 to design an optimal route from the transmission source terminal to the destination communication terminal. The designed route is stored in the setting route storage unit 1602 and set in each communication terminal 201 by the same setting packet as described in the first embodiment.

  The terminal information acquisition unit 1604 and the route design unit 1605 can be configured by hardware such as a circuit device that realizes these functions, or are configured as software executed on an arithmetic device such as a CPU or a microcomputer. You can also.

The route design unit 1605 designs a communication route according to the following procedure.
(1) List all possible routes from the source terminal to the destination communication terminal.
(2) Define an evaluation function consisting of the number of hops and the received radio wave intensity at each hop. An evaluation function may be determined in advance.
(3) A route is designed by selecting a route from which the evaluation value based on the evaluation function is optimal from the received radio wave intensity information obtained by the terminal information acquisition unit 1604.
(4) When the network has a plurality of communication media, and relaying is performed across the gateways and bridges, information on the communication media is acquired by the terminal information acquisition unit 1604, and the route design unit 1605 is evaluated. Information of the communication medium may be used as a function parameter.

  As described above, according to the seventh embodiment, since the route setting device 1601 is provided with the terminal information acquisition unit 1604 and the route design unit 1605, an optimum route is automatically designed and set in each communication terminal 201. It becomes possible to do.

Embodiment 8 FIG.
In the seventh embodiment, it has been described that the route design unit 1605 automatically designs a communication route using a predetermined evaluation function based on the information acquired by the terminal information acquisition unit 1604.
The route design unit 1605 refers to the current route information of each communication terminal obtained by the terminal information acquisition unit 1604, and more communication terminals 201 that are used in more communications, that is, more relay destination addresses are set. A route that passes through the terminal may be set with priority.

  In this way, since routes that pass through terminals that are set more frequently as relay destination addresses are prioritized and routes are not distributed, they pass through specific terminals. It is easy to check the communication path. In addition, the amount of route information can be reduced, and the amount of memory required for the communication terminal can be reduced to reduce the cost.

Embodiment 9 FIG.
The route design unit 1605 refers to the current route information of each communication terminal obtained by the terminal information acquisition unit 1604 so that the load on the communication terminal 201 used in more communications is reduced, that is, the relay destination The route may be set so that terminals set as addresses are dispersed as much as possible. In particular, a route may be set so that a communication terminal with a low battery level is not set as a relay destination address.

  In this way, by setting a route so that terminals set as relay destination addresses are distributed, the load of each communication terminal can be distributed and network traffic can be used effectively. Further, by preventing communication terminals with a low battery level from being set as relay destination addresses, the communication amount of communication terminals with a low battery level can be reduced, and the battery life can be extended.

Embodiment 10 FIG.
In the communication route setting apparatus according to Embodiment 10 of the present invention, the route design means 1605 sets a communication route according to the following procedure.

(1) The route design unit 1605 refers to the current route information of each communication terminal obtained by the terminal information acquisition unit 1604.
(2) The route design unit 1605 identifies a plurality of transmission source terminals that pass the same route with respect to the same destination address, that is, communication terminals that hold the same route information including the same destination address and relay destination address.
(3) The route design unit 1605 handles these communication terminals as a group passing through the same route. Further, a procedure for handling a plurality of communication terminals having the same route information as a group is applied hierarchically, and a plurality of communication terminals 201 that use a part of the route overlappingly for communication to the same destination are handled as a group. You may do it.
(4) The route design unit 1605 designs a route so that communication from a communication terminal handled as a group to a communication terminal outside the group is always transmitted via a common communication terminal. This terminal will function as an exit terminal for the group.

FIG. 17 shows the result of the route design means 1605 automatically designing the communication route.
In FIG. 17, “1” to “6” are communication terminals according to the tenth embodiment. The communication terminals “3” to “5” are common in that they all pass through the communication terminal “2” when transmitting a message to the communication terminals “1” and “6”.
Communication terminals “2” to “5” are a group of communication terminals set to be handled as a group in step (3).
The communication terminal “2” is the communication terminal set as the egress terminal in the above step (4).

  The exit terminal may be selected from terminals in the group, or a terminal outside the group may be set as the exit terminal.

As described above, according to the tenth embodiment, the communication terminals 201 are grouped according to the current route information, and communication from the group to the outside of the group is always relayed through a common communication terminal. , Making it easier to check the route.
In addition, since it can be assumed that the physical location of the communication terminal determined to be a group, as an index for determining the placement information, location information, and group information for application programs, setting workers, maintenance companies, etc. Can be used.

The route design means 1605 designs the route by combining the number of hops, received radio wave intensity, communication medium, current route information, battery remaining amount, memory amount, group, etc. described in the seventh to tenth embodiments. May be.
By doing so, the relay communication volume of the communication terminal with a small battery remaining amount or the communication terminal with a small amount of memory is decreased, and the relay communication volume of the communication terminal having a large memory amount or a communication terminal having a sufficient network traffic is increased. It is possible to design a route such as
The communication terminal may have the same configuration as the terminal information acquisition unit 1604 and the route design unit 1605 described above.

Embodiment 11 FIG.
FIG. 18 is a block diagram showing a configuration of communication path setting apparatus 1801 according to Embodiment 11 of the present invention.
The communication path setting device 1801 includes an input unit 1805. The input unit 1805 receives the set route information and stores the contents in the set route storage unit 1802.
In the seventh to tenth embodiments, it has been described that the route design unit 1605 automatically designs the communication route. However, as shown in FIG. 18, separately set route information may be supplied to the communication route setting device 1801. .

In the above first to eleventh embodiments, the communication route setting device and the communication terminal are described as different devices. However, the communication terminal in the network has the function of the communication route setting device and sets the route to other communication terminals. It may be.
Moreover, each structure from Embodiment 1-11 may be selected and comprised only in part, and can also be set as the structure containing all. Each effect can be acquired by setting it as the structure containing several embodiment.

2 is a functional block diagram of a communication path setting device 101 according to Embodiment 1. FIG. 2 is a block diagram showing a configuration of a communication terminal 201 according to Embodiment 1. FIG. 3 is a configuration diagram of setting route information stored in a setting route storage unit 102 of the communication route setting device 101. FIG. The configuration and data example of the route information table 401 stored in the route storage means 202 of the communication terminal 201 are shown. An outline of an operation in which the communication path setting device 101 sets a communication path of each communication terminal will be described. A detailed sequence of an operation in which the communication path setting device 101 sets the communication path of each communication terminal will be described. 6 is a functional block diagram of a communication path setting device 701 according to Embodiment 2. FIG. The operation when a communication terminal constituting the communication path becomes in a communication disabled state during setting of the communication path will be described. After FIG. 8, the operation when the terminal return detection unit 704 detects that the communication terminal 504 has returned to the communicable state will be described. 10 is a functional block diagram of a communication path setting device 1001 according to Embodiment 3. FIG. 6 is a functional block diagram of a communication terminal 1101 according to Embodiment 3. FIG. 10 shows a configuration and a data example of a route information table 1201 held by the communication terminal 201 in the fifth embodiment. The route setting operation | movement of the communication terminal which concerns on Embodiment 5 is demonstrated. The structure and data example of the route information table 1401 stored in the route storage means of the communication terminal in the sixth embodiment are shown. The route setting operation of the communication terminal according to the sixth embodiment will be described. FIG. 20 is a functional block diagram of a communication path setting device 1601 according to Embodiment 7. The route design means 1605 shows the result of automatically designing the communication route. It is a block diagram which shows the structure of the communication route setting apparatus 1801 which concerns on Embodiment 11. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 101 Communication path setting apparatus, 102 Setting path memory | storage means, 103 Communication means, 201 Communication terminal, 202 Path | route storage means, 203 Communication means, 401 Path | route information table, 502-506 Communication terminal, 510 Setting path | route, 701 Communication path setting apparatus, 702 setting route storage means, 703 communication means, 704 terminal return detection means, 802 to 806 communication terminal, 810 setting route, 1001 communication route setting device, 1002 setting route storage means, 1003 communication means, 1005 route search permission flag setting means, 1101 communication terminal, 1102 route storage means, 1103 communication means, 1104 route search means, 1105 route search permission flag storage means, 1201 route information table, 1401 route information table, 1601 communication route setting device, 1602 set route storage Stage, 1603 communication means, 1604 terminal information acquisition unit, 1605 route designing unit, 1801 a communication path setting apparatus, 1802 set the route storing means, 1803 communication means, 1804 terminal information acquisition unit, 1805 an input unit.

Claims (21)

An apparatus for setting a communication path of a communication terminal connected to a multi-hop network to the communication terminal,
Means for communicating via the multi-hop network;
Storage means for storing communication path information of the multi-hop network;
With
The communication means includes
Based on the communication path information, a setting packet including information for setting the communication path is transmitted to each communication terminal constituting the communication path. The communication means includes
When sending the configuration packet,
The communication path setting device according to claim 1, wherein the setting packet is transmitted in order from a final destination terminal to a transmission source terminal of the communication path set by the setting packet. Comprising a detecting means for detecting whether or not the communication terminal can communicate;
The communication means includes
When sending the configuration packet,
When the detection means detects that the destination communication terminal that transmits the setting packet cannot communicate,
Suspend the setting packet transmission,
After the detecting means detects that the communication terminal can communicate again,
The communication path setting device according to claim 1 or 2, wherein transmission of the temporarily interrupted setting packet is resumed. The communication means includes
Before sending the configuration packet,
For communication terminals that configure the communication path set by the setting packet,
Send a packet that prohibits the communication terminal from setting the communication path autonomously,
The communication path setting device according to any one of claims 1 to 3, wherein a packet for canceling the prohibition is transmitted after the transmission of the setting packet. Terminal information acquisition means for acquiring information about a communication terminal connected to the multi-hop network;
Communication path automatic design means for automatically designing the communication path of the multi-hop network based on the information acquired by the terminal information acquisition means;
With
The communication path automatic design means is:
The communication path setting device according to any one of claims 1 to 4, wherein a design result is stored in the storage unit as the communication path information. The terminal information acquisition means
List all communication paths that can be set by the communication path automatic design means, obtain the received radio wave intensity of each communication terminal constituting the communication path, and a list of terminals that can communicate,
The communication path automatic design means is:
Based on the received radio wave intensity of each communication terminal acquired by the terminal information acquisition means and a list of terminals that can communicate, evaluate each of the listed communication paths using a predetermined evaluation function,
The communication path setting device according to claim 5, wherein a communication path of the multi-hop network is designed based on the evaluation result. The terminal information acquisition means
Obtaining a communication route table held by a communication terminal connected to the multi-hop network;
The communication path automatic design means is:
The communication path setting device according to claim 5, wherein communication terminals that are set most frequently as communication paths in a communication path table held by each communication terminal are included in the designed communication path. The terminal information acquisition means
Obtaining a communication route table held by a communication terminal connected to the multi-hop network;
The communication path automatic design means is:
The communication path setting device according to claim 5, wherein the communication paths are designed so that communication terminals set as communication paths of the respective communication terminals are distributed. The terminal information acquisition means
Obtaining a communication route table held by a communication terminal connected to the multi-hop network;
The communication path automatic design means is:
Based on the acquisition result of the terminal information acquisition means, group communication terminals that share at least part of the communication path for the same destination,
The communication path setting device according to any one of claims 5 to 8, wherein a communication path is designed using a result of the grouping. The communication path automatic design means is:
When designing the communication path of each grouped communication terminal,
Set one communication terminal as the exit terminal of the group,
The communication path setting device according to claim 9, wherein a communication path is designed so that communication with a communication terminal outside the group passes through the egress terminal. A communication terminal that performs communication in a multi-hop network,
Storage means for storing a communication route table of the communication terminal;
Communication means for performing communication via the multi-hop network based on the communication path table;
With
The communication means includes
Receiving a setting packet including information for setting the communication path of the communication terminal;
A communication terminal, wherein a communication path based on information included in the setting packet is set in the communication path table. The storage means
Stores a flag indicating whether or not the communication terminal can autonomously set a communication path,
The communication means includes
Only when the flag is set to be acceptable, sends a predetermined route request packet to the multi-hop network,
The communication terminal according to claim 11, wherein the communication path table is set based on the response packet. A battery for supplying power to the communication terminal;
Battery remaining amount detecting means for detecting the remaining amount of the battery;
With
The battery remaining amount detecting means is
The communication terminal according to claim 12, wherein when the detected value is equal to or less than a predetermined value, the flag is set to be disabled. The communication path table is
For each entry in the communication path, the communication terminal has an update availability column that stores information indicating whether or not the entry can be autonomously updated.
The communication means includes
The route request packet for updating the entry is transmitted to the multi-hop network only when the value of the update availability column is set to be possible. The communication terminal according to any one of the above. The communication means includes
When a route request packet sent by another communication terminal is received,
In the entry of the route information table corresponding to the destination of the route request packet,
When it is stored in the update availability column that it is impossible,
The communication terminal according to claim 14, wherein a route response packet is generated based on the contents of the entry, and is returned to the transmission source terminal of the route packet. The communication path table is
It has a communication cost column that stores the communication cost from the communication terminal to the destination terminal,
The communication means includes
When a route request packet sent by another communication terminal is received,
In the entry of the route information table corresponding to the destination of the route request packet,
When it is stored in the update availability column that it is impossible,
The communication terminal according to claim 14, wherein a route response packet reflecting the value of the communication cost column is generated based on the content of the entry, and is returned to the transmission source terminal of the route request packet. Terminal information acquisition means for acquiring a communication route table held by a communication terminal connected to the multi-hop network;
Communication path automatic design means for automatically designing the communication path of the communication terminal based on the information acquired by the terminal information acquisition means;
With
The communication path automatic design means is:
Based on the acquisition result of the communication path table, group communication terminals that share at least part of the communication path for the same destination,
The communication terminal according to any one of claims 11 to 16, wherein a communication path is designed using a result of the grouping. The communication path automatic design means is:
When designing the communication path of each grouped communication terminal,
Set one communication terminal as the exit terminal of the group,
The communication terminal according to claim 17, wherein a communication path is designed so that communication with a communication terminal outside the group passes through the egress terminal. The communication path setting device according to any one of claims 1 to 10,
A communication terminal according to any one of claims 11 to 18,
Have
The communication path setting device includes:
Sending the configuration packet to the communication terminal;
The communication terminal is
A multi-hop network system, wherein a communication route based on information contained in the setting packet is set in the communication route table. The communication path setting device according to any one of claims 1 to 10,
A communication terminal according to any one of claims 14 to 18,
Have
The communication terminal is
Of the entries held in the communication path table, the entries set by the communication path setting device,
The multi-hop network system, wherein the update availability column is set to indicate that the update is impossible. The communication path setting device according to any one of claims 1 to 10,
A communication terminal according to any one of claims 16 to 18,
Have
The communication terminal is
Of the entries held in the communication path table, the entries set by the communication path setting device,
The multi-hop network system, wherein a value of the communication cost column is set smaller than other entries.

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