JP4863863B2 - Repeater, communication network system - Google Patents

Description

The present invention is a relay device for relaying communication between different communication media, to a communication network system having Re and child.

Conventionally, “a wireless network capable of setting a relay route that is robust against interference by selecting a route having the smallest propagation loss in the entire relay route is provided. "A core node emits a relay route setting packet, and each node estimates a propagation loss between the node that emitted the packet and its own node by receiving the packet (step S2). . At the same time, referring to the metric included in the packet, the relay destination base station that minimizes the propagation loss is selected based on the sum of the propagation loss and the metric (steps S1 to S7). Here, the metric represents the total propagation loss from the core node to the node that released the relay route packet. Each base station autonomously performs the above work. Is proposed (Patent Document 1).
JP 2005-33815 A (summary)

In a network based on wireless communication, propagation loss varies greatly depending on the path due to the influence of interference and the like. In this case, the route with the minimum number of hops is not necessarily a route with stable quality and good communication.
In particular, when trying to minimize the number of hops, wireless communication terminals located far away try to communicate with weak radio waves, and therefore, a situation occurs in which communication is repeatedly interrupted due to changes in radio wave conditions over time.

In this regard, the technique described in Patent Document 1 proposes a method of estimating a propagation loss between nodes and selecting a communication path that minimizes the sum, instead of determining by the number of hops. .
However, this method is effective when the communication media are all the same, but in a network including a plurality of different communication media such as a network in which power lines and radios are mixed, each propagation loss is unified. There is a problem that it is difficult to handle.
The present invention has been made to solve the above-described problems, and in the network including a plurality of different communication media, when selecting a communication path, the qualitative or quantitative characteristics of each communication medium are reflected. relay device among that can, and to obtain a communication network system having Re and child.

The repeater according to the present invention is
A repeater for relaying communication between different communication media,
For each communication medium to be relayed, a communication means corresponding to the communication medium is provided.
A path information table that holds communication path information for specifying a packet relay destination, a communication cost table that holds an accumulated communication cost for each communication path specified by the packet transmission source, destination, and relay source , for each communication medium Storage means for storing the weight value defined in the above and the relay cost value when the communication packet is relayed by the relay,
Based on the packet received by the communication means, a communication cost calculation means for calculating an integrated communication cost of a communication path through which the packet has passed;
With
The communication means includes
Receiving a route search packet in which information of the integrated communication cost is stored,
The communication cost calculation means includes
When the communication means receives the route search packet, and calculates the communication cost from the relay source to the relay device of the route search packet, the weight value of the communication medium from the relay source of the route search packet to the repeater Multiplied by
If the route search packet is not addressed to the relay, add the relay cost value,
Add the accumulated communication cost from the first transmission source of the route search packet to reach the relay source and store it in the communication cost table,
The communication means includes
When the route search packet is not addressed to the repeater, it is characterized in that the broadcasting transmits the route search packet to each of the different communication medium.

The repeater according to the present invention reflects the qualitative or quantitative characteristics of each communication medium and determines the packet communication path in an autonomous and distributed manner, so that the communication path can be interrupted by an interference source. A new communication path can be found.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a network according to Embodiment 1 of the present invention.
In FIG. 1, a home network is formed in a house 101 for general households, and wireless communication paths 103, 109, and 110 that perform communication using radio, and a power line communication path 106 that performs communication using a power line. It is mixed.
Communication terminals that perform wireless communication are home appliances such as a microwave oven 102 and a washing machine 111.
In addition, the wireless power line repeaters 104 and 108 have a relay function for receiving communication via the wireless communication path and transferring it to the power line communication path 106.
The microwave oven 102 is connected to the wireless power line repeater 104 via the wireless communication path 103. The washing machine 111 is connected to the wireless power line repeater 108 via the wireless communication path 109. Furthermore, the microwave oven 102 and the washing machine 111 are directly connected through a wireless communication path 110.
The wireless power line repeater 104 is connected to the power line communication path 106 via the power supply terminal 105, and the wireless power line repeater 104 is connected to the power line communication path 106 via the power supply terminal 107.

In the network configuration as shown in FIG. 1, there is a possibility of being affected by an obstacle only by communication using a wireless communication path.
For example, consider a case where data is transmitted from the microwave oven 102 to the washing machine 111.
When data is transmitted via the wireless communication path 110, communication radio waves pass through members such as a floor and a wall, and there is a concern that communication quality may be deteriorated. The decrease in communication quality includes a decrease in throughput, an increase in packet error rate, and an increase in the risk of communication disconnection due to a subtle change in radio wave environment.
Therefore, the microwave oven 102 transmits the packet to the wireless power line repeater 104 via the wireless communication path 103, and the wireless power line repeater 104 transmits the packet received from the microwave oven 102 to the power line communication via the power supply terminal 105. It relays to the wireless power line repeater 108 downstairs via the route 106.
The repeater 108 receives a packet that has passed through the power line communication path 106 via the power terminal 107 and transmits the packet to the destination washing machine 111 via the wireless communication path 109.
Thus, by transmitting a packet via the power line communication path 106, more stable communication can be performed than when wirelessly transmitting through a member such as a floor or a wall.

FIG. 2 illustrates a method for determining a packet communication path.
In FIG. 2, communication terminals 2001, 2002, 2003, and 2004 are connected by communication paths 2006, 2007, 2008, and 2009, respectively.
Here, a procedure in the case of determining a communication path from the communication terminal 2001 to the communication terminal 2003 will be described.

(Step 1)
In the initial state, it is assumed that the communication terminal 2001 does not know the communication path to the communication terminal 2003.
The communication terminal 2001 broadcasts a route search packet to confirm whether there is a communication terminal that knows the communication route to the communication terminal 2003.
The route search packet 2005 is transmitted toward the communication terminal 2004, and the route search packet 2010 is transmitted toward the communication terminal 2002.
(Step 2)
When communication terminal 2004 receives route search packet 2005 and finds that the destination of the packet is not its own, communication terminal 2004 further transmits route search packet 2105 to another communication terminal by broadcast transmission. Similarly, the communication terminal 2002 receives the route search packet 2010 and transmits the route search packet 2106 to another communication terminal by broadcast transmission.
When transmitting a route search packet, the accumulated communication cost information of the communication route up to that point is included in the packet.
For example, when the communication terminal 2002 transmits the route search packet 2106, the communication cost of the communication route 2008 is calculated from the physical measurement amount such as the radio wave state of the packet received from the communication terminal 2001, and the information is routed. It is included in the search packet 2106 and transmitted. The communication terminal 2004 performs the same process.
(Step 3)
The communication terminal 2003 receives the route search packets 2105 and 2106. At this time, communication costs of the communication paths 2006 and 2007 are calculated and determined from a physical measurement amount such as a radio wave state of the received packet.
(Step 4)
The route search packets 2105 and 2106 also include communication cost information for the communication routes 2008 and 2009. Therefore, the communication terminal 2003 can also determine the communication costs of the communication paths 2008 and 2009.
(Step 5)
The communication terminal 2003 can determine the integrated communication cost of the communication path 2405 including the communication path 2009-> 2006 and the integrated communication cost of the communication path 2406 including the communication path 2008-> 2007 through the processing so far.
(Step 6)
The communication terminal 2003 selects the minimum communication cost from the communication paths 2405 and 2406.
After the communication route is determined, the communication terminal 2003 returns a route search response packet to the communication terminal 2001.
The route search response packet is delivered to the communication terminal 2001 via the communication terminal 2002.

  By determining the packet communication path in an autonomous and distributed manner as described above, a new communication path can be found even if the communication path is blocked by the interference source. Further, by performing route search in an autonomous and distributed manner, the number of communication terminals increases, and even if the number of routes increases, an increase in load per device can be suppressed.

Embodiment 2. FIG.
In the first embodiment, the outline of the method for determining the communication path in the present invention has been described.
In the second embodiment of the present invention, the configuration and operation of the wireless communication terminal according to the present invention will be described more specifically.

FIG. 3 is a block diagram showing a configuration of radio communication terminal 301 according to the second embodiment.
The wireless communication terminal 301 includes a wireless communication unit 302, a communication cost calculation unit 303, a data relay unit 304, and a storage unit 305.
The wireless communication unit 302 includes an interface for wireless communication, and transmits and receives communication packets by wireless communication.
The communication cost calculation unit 303 calculates a communication cost representing the communication quality of the communication path through which the packet has passed from a physical quantity such as the radio wave intensity of the received packet.
The data relay unit 304 has a function of instructing the wireless communication unit 302 to relay the received packet to another terminal when the received packet is not addressed to the own terminal. The instruction may be given directly to the wireless communication means 302 or may be given via the communication cost calculation means 303.
The storage unit 305 stores a communication cost weight 306, a route information table 307, and a communication cost table 308.

The communication cost weight 306 is a value that determines a relative cost ratio between wireless communication and power line communication.
The route information table 307 holds information indicating to which terminal the communication packet should be relayed when a communication packet other than that addressed to the own terminal is received. A specific configuration will be described later with reference to FIG.
The communication cost table 308 holds accumulated communication cost information for each communication path. A specific configuration will be described later with reference to FIG.
Note that the wireless communication unit 302 may have a function of performing communication using a power line.

The storage unit 305 can be configured by a writable storage device such as a RAM (Random Access Memory) or an HDD (Hard Disk Drive).
The communication cost calculation unit 303 and the data relay unit 304 can be configured by hardware such as a circuit device, or can be configured as software executed by an arithmetic device such as a microcomputer or CPU.

FIG. 4 shows the configuration and data example of the communication cost table 308.
The communication cost table 308 includes a “transmission source” column, a “destination” column, a “relay source” column, and an “accumulated cost” column.
The “source” column stores the address of the terminal that first broadcast-transmitted the route search packet.
The “destination” column stores the address of the final destination terminal that is going to determine the communication route by the route search packet.
The “relay source” column stores the address of the terminal immediately before transmitting the route search packet to the own terminal. The route search packet propagates through the communication terminals to the final destination terminal in order, but the address of the terminal immediately before transmitting the route search packet to the own terminal can be found by referring to the value in this column.
The “integrated cost” column stores the accumulated communication cost of the communication path through which the route search packet has reached the terminal itself.
For example, according to the data in the first row, the packet transmitted from the terminal “0” to the terminal “4” is relayed by the terminal “1” and reaches the terminal, and the accumulated communication cost until then is “14”. "
Further, according to the data in the second and third lines, among the packets transmitted from the terminal “0” to the terminal “4”, there are two types of packets that are relayed by the terminal “3” and reach the terminal. It can be seen that the accumulated communication cost of the communication path through which each packet exists is “18” and “13”.

FIG. 5 shows the configuration and data example of the route information table 307.
The route information table 307 has a “destination” column and a “relay destination” column.
The “destination” column stores the address of the destination terminal of the communication packet.
In the “relay destination” column, when a communication packet is transmitted to the terminal specified by the value of the “destination” column, a destination to which the communication packet is to be relayed next is stored. In a multi-hop network, a communication packet propagates to a final destination terminal via a communication terminal, but it can be understood by referring to the value in this column to which terminal the packet should be relayed next.
According to the data in the first row, when a packet addressed to the terminal “4” is received, it is understood that the packet should be relayed to the terminal “3” next.
Further, according to the data in the second row, it is understood that the packet addressed to the terminal “1” can be directly transmitted to the terminal “1”.

FIG. 6 illustrates a route search packet transmission procedure in the communication route determination procedure.
In FIG. 6, five terminals from communication terminals 600 to 604 form a wireless communication network. In the initial state, it is assumed that the route information table 307 and the communication cost table 308 of each communication terminal are empty, and the value of the communication cost weight 306 has been set.
Hereinafter, each step will be described.

(Step 1)
Communication terminal 600 is connected to communication terminals 601, 602, and 603.
Communication terminal 601 is connected to communication terminals 600 and 604.
Communication terminal 602 is connected to communication terminals 600 and 603.
Communication terminal 603 is connected to communication terminals 600, 602, and 604.
The communication terminal 604 is connected to the communication terminals 601 and 603.
Moreover, the communication cost of the communication path between each communication terminal is as shown in (step 1) of FIG. These communication costs are not known in advance, but when each communication terminal receives a packet, the communication cost of the communication path through which the packet has passed can be calculated based on received power or the like. To do.
For simplification of explanation, it is assumed that the communication cost values shown in FIG.
(Step 2)
The communication terminal 600 needs to determine a communication path addressed to the communication terminal 604 in order to transmit data to the communication terminal 604. Therefore, the route search packet is broadcast to the communication terminal 604.
The route search packet transmitted from the communication terminal 600 reaches the communication terminals 601, 602, and 603. Further, the communication terminal 602 broadcasts the received route search packet , and the route search packet reaches the communication terminal 603.
(Step 3)
Each communication terminal that receives the route search packet calculates the communication cost of the communication route through which the packet has passed from the received power or the like. Here, it is assumed that each value shown in (Step 1) has been calculated.
The calculated communication cost is stored in the communication cost table 308 for each communication path.
In the “transmission source” column, the address of the communication terminal 600 is stored.
In the “destination” column, the address of the communication terminal 604 is stored.
The “relay source” column stores the address of the terminal immediately before transmitting the route search packet to the own terminal. For example, in the case of the communication terminal 603, since a packet transmitted from the communication terminal 600 and a packet transmitted from the communication terminal 602 arrive, values corresponding to the two are stored.
The “integrated cost” column stores the accumulated communication cost of the communication path through which the route search packet has reached the terminal itself. In the case of the communication terminal 603, values corresponding to the above-described two communication paths are stored.
(Step 4)
Communication terminal 601 and 603, a route search packet received by broadcast transmission, the route search packet reaches the communication terminal 60 4. Upon receiving the first route search packet addressed to the own terminal, the communication terminal 604 accepts the route search packet addressed to the own terminal for a certain period of time.
Since the destination of the route search packet is its own terminal, the communication terminal 604 determines the accumulated communication cost of each communication route at this stage and stores it in the communication cost table 308.
The communication cost table 308 of the communication terminal 604 stores the accumulated communication costs of the following three communication paths.
(1) Route of communication terminal 600->601-> 604 (accumulated cost = 14)
(2) Route of communication terminal 600->602->603-> 604 (accumulated cost = 18)
(3) Route of communication terminal 600->603-> 604 (accumulated cost = 13)

  Next, a procedure for transmitting a route search response packet will be described.

  FIG. 7 illustrates a procedure in which the communication terminal 604 transmits a route search response packet after step 4 in FIG. Hereinafter, each step will be described.

(Step 1)
The communication terminal 604 waits for a route search packet addressed to itself for a certain period of time, and then determines an entry having the smallest value in the “accumulated cost” column of the communication cost table 308. Here, it can be seen that the route (integrated cost = 13) of the communication terminals 600->603-> 604 has the lowest accumulated cost.
Next, the communication terminal 604 reads the value in the “relay source” column of the confirmed entry, and transmits a route search response packet to the communication terminal. Here, the data is transmitted to the communication terminal 603.
(Step 2)
The communication terminal 603 receives the route search response packet transmitted from the communication terminal 604.
At this time, since the communication path between the communication terminals 603 and 604 is determined, the communication terminal 603 stores the information in the path information table 307.
In the “destination” column, the address of the communication terminal 604 is stored.
In the “relay destination” column, the address of the communication terminal 604 is stored.
(Step 3)
After storing the entry in the route information table 307, the communication terminal 603 determines the entry having the smallest value in the “integrated cost” column of the communication cost table 308. Here, it can be seen that the route to the communication terminal 600 (accumulated cost = 5) has the smallest accumulated cost.
Next, the communication terminal 603 reads the value in the “relay source” column of the confirmed entry, and transmits a route search response packet to the communication terminal. Here, the data is transmitted to the communication terminal 600.
(Step 4)
Communication terminal 600 receives the route search response packet transmitted from communication terminal 603.
At this time, since the communication path between the communication terminals 600 and 603 is determined, the communication terminal 600 stores the information in the path information table 307.
Here, the address of communication terminal 604 is stored in the “destination” column, and the address of communication terminal 603 is stored in the “relay destination” column.

The communication terminal 600 can determine the communication path addressed to the communication terminal 604 by the procedure illustrated in FIGS.
When route search packets and route search response packets regarding a plurality of destination terminals flow through the network, each packet may be identified by the value in the “transmission source” column of the communication cost table 308.

  As described above, the procedure for determining the communication path in the communication network has been outlined. Next, the operation of the communication terminal alone will be described with reference to a packet configuration and a flowchart.

FIG. 8 shows the configuration of the route search packet.
The route search packet includes a destination address 801, a transmission source address 802, a relay destination address 803, a relay source address 804, packet ID information 805, and accumulated cost information 806.
The destination address 801 stores the address of the destination terminal that is the target of the route search. The route search packet represents a packet for determining a communication route to the terminal specified by this value.
The source address 802 stores the address of the terminal that first transmitted the route search packet.
The relay destination address 803 stores the address of the destination terminal that transmits the route search packet next. In the case of broadcast transmission, a broadcast address or the like may be stored.
The relay source address 804 stores the address of the terminal that transmitted the route search packet immediately before.
The packet ID information 805 stores a unique ID number for identifying the route search packet. With this value, it is possible to prevent the route search packet having the same ID from being broadcasted many times.
The accumulated cost information 806 stores the accumulated communication cost from the terminal that first transmitted the route search packet to the terminal that transmitted the route search packet immediately before.

FIG. 9 shows the configuration of the route search response packet.
The route search response packet has a source address 901 and packet ID information 902.
The source address 901 stores the address of the terminal that first transmitted the route search packet.
The packet ID information 902 stores a unique ID number for identifying a route search response packet.

  FIG. 10 is an example showing the operation of the communication terminal 301 when a route search packet is received. Hereinafter, each step will be described.

(S1001)
The wireless communication unit 302 receives the route search packet.
(S1002)
The communication cost calculation unit 303 calculates the communication cost of the communication path with the communication terminal immediately before relaying the route search packet. This can be calculated by, for example, radio wave intensity, packet error rate, and throughput.
(S1003)
The communication cost calculation unit 303 multiplies the communication cost calculated in step S1002 by a communication cost weight 306 determined in advance for each communication medium being used.
The value of the communication cost weight 306 takes a value of 0 to 1, and a small value is set for a communication medium with a good communication state, and a large value is set for a communication medium with a bad communication state.
In the second embodiment, only an example of wireless communication is shown for simplification of description. However, in a communication network in which wired and wireless are mixed, the value of the communication cost weight 306 in the wired communication path is reduced, and wireless communication is performed. A rule of increasing the value in the communication path may be used.
In this way, by changing the weight for each communication medium, it becomes easy to select a communication path with a low communication cost, so it is possible to indirectly specify a communication medium to be preferentially used.
(S1004)
The communication cost calculation unit 303 updates the communication cost table 308 according to the procedure described in Step 3 to Step 4 of FIG.
The value in the “transmission source” column is the transmission source address 802 of the received route search packet.
The value in the “destination” column is the destination address 801 of the received route search packet.
The value of the “relay source” column is the relay source address 804 of the received route search packet.
The value in the “accumulated cost” column is a value obtained by adding the value of the accumulated cost information 806 of the received route search packet to the communication cost obtained in step S1003.
(S1005)
The data relay unit 304 confirms the destination address 801 of the received route search packet and confirms whether it is addressed to its own terminal.
If it is addressed to the own terminal, the route search packet reception process is terminated, and the process proceeds to the route search response packet transmission process described in FIG. If not addressed to the own terminal, the process proceeds to step S1006.
(S1006)
The data relay unit 304 instructs the wireless communication unit 302 to broadcast the route search packet. The instruction may be given via the communication cost calculation means 303 or the direct wireless communication means 302 may be controlled.

  By relaying such autonomously distributed route search packets, the effort of each communication terminal for performing route search can be distributed to the terminals of the entire network.

  FIG. 11 is an example showing the operation of the communication terminal 301 when a route search response packet is received. Hereinafter, each step will be described.

(S1101)
The wireless communication unit 302 receives the route search response packet.
(S1102)
The communication cost calculation unit 303 updates the route information table 307 according to the procedure described in steps 2 to 4 in FIG.
The value in the “destination” column is the source address 901 of the route search response packet.
The value in the “relay destination” column is the address of the terminal that transmitted the route search response packet.
(S1103)
The communication cost calculation unit 303 refers to the communication cost table 308 and determines the destination of the route search response packet according to the procedure described in step 1 to step 3 of FIG.
(S1104)
The communication cost calculation unit 303 instructs the wireless communication unit 302 to transmit the route search response packet to the destination of the route search response packet determined in step S1103.

As described above in the second embodiment, the communication terminal 301 transmits the route search packet to the destination terminal when determining the communication route, and determines the route by the route search response packet that is the response. A route with a better communication state can be determined regardless of the type of communication medium and also in a network in which a plurality of communication media are mixed.
Also, in the process where the route search packet and route search response packet are relayed by each terminal in the middle of the communication route, the packet is relayed while adding the accumulated communication cost of each communication route, so the latest communication status of the communication route The route can be determined based on the above, and a good communication state can be maintained.

Embodiment 3 FIG.
In the first and second embodiments, the configuration and operation of a communication terminal that mainly operates as a communication client have been described.
In the third embodiment of the present invention, the configuration and operation of a repeater that is mainly installed at a relay point of a communication network and relays between a wired communication path and a wireless communication path will be described. The repeater according to the third embodiment corresponds to the wireless power line repeaters 104 and 108 in FIG.

FIG. 12 is a block diagram showing a configuration of repeater 1201 according to the third embodiment.
The repeater 1201 includes a wireless communication unit 1202, a communication cost calculation unit 1203, a data relay unit 1204, a storage unit 1205, and a wired communication unit 1209.
The wireless communication unit 1202 includes an interface for wireless communication, and transmits and receives communication packets by wireless communication.
The wired communication unit 1209 includes an interface for wired communication, and transmits and receives communication packets by wired communication.
The communication cost calculation unit 1203 calculates a communication cost representing the communication quality of the communication path through which the packet has passed from the physical quantity such as the radio wave intensity of the packet received by the wireless communication unit 1202 and the wired communication unit 1209.
The data relay unit 1204 has a function of instructing the wireless communication unit 1202 or the wired communication unit 1209 to relay the packet to another terminal when the received packet is not addressed to the own relay unit . The instruction may be given directly to each communication means, or may be given via the communication cost calculation means 1203.
The storage unit 1205 stores a communication cost weight 1206, a route information table 1207, a communication cost table 1208, and relay cost information 1210.

The contents of the communication cost weight 1206, the route information table 1207, and the communication cost table 1208 are the same as the communication cost weight 306, the route information table 307, and the communication cost table 308 in FIG.
The relay cost information 1210 represents a value added to the communication cost when the repeater 1201 relays the route search packet. Although the communication cost is originally determined by the state of the communication path, the relay 1201 intentionally adds or subtracts the communication cost when relaying the route search packet. Thereby, a communication path can be specified indirectly.
That is, when relaying a packet toward a communication path that you do not want to go through, set the relay cost intentionally high, and when relaying a packet toward a preferred communication path, set the relay cost low. For example, since the setting is reflected when the communication route is determined by the route search packet, the communication route is determined so as to pass through a preferable communication route as a result.

  Next, the operation of the repeater 1201 alone will be described using a packet configuration and a flowchart.

FIG. 13 shows the configuration of the relay cost information 1210.
The relay cost information 1210 includes (1) a wireless-wireless cost 1301 representing a cost when a packet is received from a wireless communication path and transmitted to the wireless communication path, and (2) a packet is received from the wireless communication path and a wired communication path. Wireless-wired cost 1302 representing the cost when transmitting to the wireless communication, (3) wired-wireless cost 1303 representing the cost when receiving the packet from the wired communication path and transmitting it to the wireless communication path, (4) wired communication with the packet There are four types of cost information of wired-wired cost 1304 representing the cost when receiving from the path and transmitting to the wired communication path.
These relay cost values may be positive or negative. In addition, the relay cost information may be held for each combination of the reception-side communication medium and the transmission-side communication medium, not limited to the combination of wireless and wired communication. These cost values may be the same value.
Here, a value when relaying a packet from the wired communication medium to the wireless communication medium is set as a positive value, and a value when relaying a packet from the wireless communication medium to the wired communication medium is set as a negative value. . Thereby, when the repeater 1201 relays the route search packet, the route toward the wired communication medium is easily selected.

  FIG. 14 shows the operation when the repeater 1201 receives a route search packet. Hereinafter, each step will be described.

(S1401) to (S1405)
Since this is the same as steps S1001 to S1005 in FIG.
(S1406)
The communication cost calculation unit 1203 reads the relay cost information 1210 and adds the read value to the accumulated cost information 806 of the route search packet.
(S1407)
Since this is the same as step S1006 in FIG. 10, a description thereof will be omitted.

FIG. 15 shows the procedure of the relay cost addition method in step S1406 of FIG.
When the communication cost calculation unit 1203 starts step S1406 (S1501), first, it is determined whether the receiving side is wireless (S1502), and then it is determined whether transmission is wireless (S1503) (S1504). This determines the cost to be added.
By detecting the communication medium on the reception side and the communication medium on the transmission side, classifying the packets for each combination, and adding the relay cost, for example, by setting the wireless-wired cost 1302 to a negative number, It is possible to prioritize the communication path that passes through.

  The repeater 1201 itself may be configured to transmit a route search packet and receive a route search response packet as a response. The update procedure of the route information table 1207 and the communication cost table 1208 in this case is the same as that described in the second embodiment.

  As described above, according to relay 1201 according to the third embodiment, by having relay cost information 1210, packets that pass through an arbitrary communication medium or that are relayed from a certain communication medium to a certain communication medium. Costs can be adjusted and packets can avoid the use of specific communication media or can be directed back.

Embodiment 4 FIG.
FIG. 16 is a block diagram showing a configuration of repeater 1201 according to Embodiment 4 of the present invention.
The repeater 1201 according to the fourth embodiment includes a relay cost determination unit 1211 and an input unit 1212 in addition to the configuration of FIG. 12 described in the third embodiment.

  The relay cost determining unit 1211 automatically detects wireless and wired communication quality, determines a communication medium to be used preferentially, and determines the value of the relay cost information 1210. The determined cost is notified to the communication cost calculation means 1203.

The input unit 1212 is for the user to arbitrarily set the communication cost weight 1206 or the relay cost information 1210.
When the user inputs a value of the communication cost weight 1206 or the relay cost 1210, the value is notified to the communication cost calculation unit 1203.

  The communication cost calculation unit 1203 updates the communication cost weight 1206 or the relay cost information 1210 stored in the storage unit 1205, issues an instruction to the wireless communication unit 1202 and the wired communication unit 1209, and broadcasts the value. To notify other terminals.

As described above, according to the fourth embodiment, since the communication cost weight 1206 and the relay cost 1210 are automatically determined or can be input by the user, the communication cost depends on the communication state of the communication medium, the network configuration, and the like. You can change the settings flexibly.
Therefore, it is not necessary to change the factory setting according to the individual network in which the repeater 1201 is installed, which is advantageous from the viewpoint of manufacturing cost. Further, since the user can freely change the setting, it is not necessary for a specialized worker or the like to perform the maintenance work every time the setting is changed, which is advantageous from the viewpoint of maintenance cost.
Further, when the communication cost weight 1206 or the relay cost information 1210 is updated, the value is broadcast, so that the value can be automatically shared with other communication terminals and repeaters, and maintenance work is troublesome. Can be omitted.

1 is a configuration diagram of a network in Embodiment 1. FIG. A method for determining a packet communication path will be described. 6 is a block diagram showing a configuration of a wireless communication terminal 301 according to Embodiment 2. FIG. The structure of the communication cost table 308 and an example of data are shown. The structure of the route information table 307 and an example of data are shown. Of the communication route determination procedure, the route search packet transmission procedure will be described. The procedure in which the communication terminal 604 transmits a route search response packet after step 4 in FIG. 6 will be described. It shows a configuration of a route search packet. It shows about the structure of the route search response packet. It is an operation example of the communication terminal 301 when a route search packet is received. It is an operation example of the communication terminal 301 when a route search response packet is received. It is a block diagram which shows the structure of the repeater 1201 which concerns on Embodiment 3. FIG. The structure of the relay cost information 1210 is shown. The operation when the repeater 1201 receives a route search packet is shown. The procedure for adding the relay cost in step S1406 in FIG. 14 is shown. It is a block diagram which shows the structure of the repeater 1201 which concerns on Embodiment 4. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 101 Housing, 102 Microwave oven, 103 Wireless communication path, 104 Wireless power line repeater, 105 Power supply terminal, 106 Power line communication path, 107 Power supply terminal, 108 Wireless power line repeater, 109 Wireless communication path, 110 Wireless communication path, 111 Washing machine , 2001-2004 communication terminal, 2006-2009 communication route, 2005 route search packet, 2010 route search packet, 2405 communication route, 2406 communication route, 301 wireless communication terminal, 302 wireless communication means, 303 communication cost calculation means, 304 data relay Means, 305 storage means, 306 communication cost weight, 307 route information table, 308 communication cost table, 600 to 604 communication terminal, 800 route search packet, 801 destination address, 802 source address, 803 relay destination address 804 relay source address, 805 packet ID information, 806 accumulated cost information, 900 route search response packet, 901 source address, 902 packet ID information, 1201 relay, 1202 wireless communication means, 1203 communication cost calculation means, 1204 data relay Means, 1205 Storage means, 1206 Communication cost weight, 1207 Route information table, 1208 Communication cost table, 1209 Wired communication means, 1210 Relay cost information, 1301 Wireless-wireless cost, 1302 Wireless-wired cost, 1303 Wired-wireless cost, 1304 Wired-wired cost, 1211 relay cost determining means, 1212 input means.

Claims (12)

A repeater for relaying communication between different communication media,
For each communication medium to be relayed, a communication means corresponding to the communication medium is provided.
A path information table that holds communication path information for specifying a packet relay destination, a communication cost table that holds an accumulated communication cost for each communication path specified by the packet transmission source, destination, and relay source , for each communication medium Storage means for storing the weight value defined in the above and the relay cost value when the communication packet is relayed by the relay,
Based on the packet received by the communication means, a communication cost calculation means for calculating an integrated communication cost of a communication path through which the packet has passed;
With
The communication means includes
Receiving a route search packet in which information of the integrated communication cost is stored,
The communication cost calculation means includes
When the communication means receives the route search packet, and calculates the communication cost from the relay source to the relay device of the route search packet, the weight value of the communication medium from the relay source of the route search packet to the repeater Multiplied by
If the route search packet is not addressed to the relay, add the relay cost value,
Add the accumulated communication cost from the first transmission source of the route search packet to reach the relay source and store it in the communication cost table,
The communication means includes
When the route search packet is not addressed to the repeater, repeater, characterized by multi-address transmission to the route search packet to each of the different communication medium. The communication means is
When receiving the route search packet, if the route search packet is addressed to the repeater,
The communication means includes
Wait for a predetermined route search packet for a predetermined time,
The communication cost calculation means includes
Referring to the communication cost table, identify the communication path with the lowest accumulated communication cost,
The communication means includes
The repeater according to claim 1, wherein a route search response packet destined for an initial transmission source of the route search packet is transmitted toward a relay source of the communication route. The communication means includes
Receiving the route search response packet addressed to the other person the repeater,
The communication cost calculation means includes
When the communication means receives the route search response packet, the route information table stores an entry whose relay destination is the relay source of the route search response packet;
Referring to the communication cost table, identify the communication path with the lowest accumulated communication cost,
The communication means includes
The repeater according to claim 2, wherein the route search response packet is transmitted toward a relay source of the communication route. The storage means
The repeater according to any one of claims 1 to 3, wherein a cost value for relaying communication between a wired communication medium and a wireless communication medium is stored as the relay cost value. The relay cost value is
The value when relaying a packet from a wired communication medium to a wireless communication medium is a positive value.
The repeater according to claim 4, wherein a negative value is used for relaying a packet from a wireless communication medium to a wired communication medium. The relay cost determining means for determining the relay cost value based on a physical quantity detectable when the communication means receives a communication packet or a parameter representing the communication quality of a communication medium. The repeater in any one of Claim 5 thru | or 5. The repeater according to any one of claims 1 to 6, further comprising input means for inputting the weight value or the relay cost value and storing it in the storage means. The repeater according to any one of claims 1 to 7, wherein when the relay cost value is updated, the communication unit broadcasts the value. A wireless communication terminal having a multi-hop communication function;
A communication network system comprising one or more repeaters according to any one of claims 1 to 8. The wireless communication terminal is
Wireless communication means for transmitting and receiving wireless signals;
A path information table that holds communication path information for specifying a packet relay destination, a communication cost table that holds an accumulated communication cost for each communication path, and a storage unit that stores a weight value determined for each communication medium ;
Based on the packet received by the wireless communication means, a communication cost calculation means for calculating an integrated communication cost of a communication path through which the packet has passed;
With
The wireless communication means includes
Sending or receiving a route search packet in which information of the integrated communication cost is stored,
The communication cost calculation means includes
When the wireless communication unit receives the route search packet, the weight of the communication medium from the relay source of the route search packet to calculate the communication cost to the communication terminal until the communication terminal from the relay source of the route search packet After multiplying by the value,
Add the accumulated communication cost from the first transmission source of the route search packet to reach the relay source and store it in the communication cost table,
The wireless communication means includes
The communication network system according to claim 9, wherein when the route search packet is not addressed to the communication terminal, the route search packet is broadcast. The wireless communication means is
When the route search packet is received and the route search packet is addressed to the communication terminal,
The wireless communication means includes
Wait for a predetermined route search packet for a predetermined time,
The communication cost calculation means includes
Referring to the communication cost table, identify the communication path with the lowest accumulated communication cost,
The wireless communication means includes
The communication network system according to claim 10, wherein a route search response packet destined for an initial transmission source of the route search packet is transmitted toward the communication route. The wireless communication means includes
Receiving the route search response packet addressed to the other person the communication terminal,
The communication cost calculation means includes
When the wireless communication means receives the route search response packet, the route information table stores an entry whose relay destination is the relay source of the route search response packet;
Referring to the communication cost table, identify the communication path with the lowest accumulated communication cost,
The wireless communication means includes
The communication network system according to claim 11, wherein the route search response packet is transmitted toward the communication route.

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