JP2008193407A - Radio terminal and radio communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio terminal capable of changing a transfer route or a network configuration without changing the transfer information or address of a peripheral terminal or without performing processing to hold information of a substitute route, and to provide a radio communication system. <P>SOLUTION: The radio terminal includes: a transmission control means for simultaneously transmitting adjacent terminal information, including information for identifying at least the self radio terminal and information for identifying the radio terminals being communicable with the self radio terminal; and a reception control means for receiving the adjacent terminal information of the radio terminal other than the self radio terminal from the radio terminal. The reception control means selects the paired terminals or the group terminals, on the basis of the received adjacent terminal information and the adjacent terminal information of the self radio terminal, and acquires an address for transfer processing where the radio terminal to be communicable respectively with the paired terminals or the group terminals, and the self radio terminal as a transfer destination. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wireless terminal and a wireless communication system, and more particularly to a change of a transfer route.

  Conventionally, a technology that uses an address that can be changed depending on the situation mainly for transfer, apart from an address that physically identifies a terminal (hereinafter referred to as a “physical address”), regardless of whether it is wired or wireless. There are many. In these systems, when a terminal joins a network, an address is assigned by some means (for example, DHCP: Dynamic Host Configuration Protocol), and basically the same address is used until the terminal leaves the network. Each terminal exchanges information necessary for transferring a packet with other peripheral terminals (hereinafter, also referred to as “peripheral terminals”) that can communicate with each other according to the assigned address. The actual transfer is performed using “address”). Thus, by using an address unrelated to the physical address, it is possible to assign an address according to the structure of the network, and the amount of information for packet transfer such as a routing table can be compressed. For example, in the Internet, by making the upper bits of the addresses of a plurality of terminals connected to the outside via the same terminal the same, it becomes possible to process the plurality of terminals as if they were one. ing.

  In ZigBee (registered trademark of Koninklijke Philips Electronics NV), a tree structure with the coordinator as the apex (hereinafter also referred to as “tree”) is formed. The addresses assigned at this time are based on the tree structure. Allocation is performed after being calculated. As a result, by using parameters indicating the characteristics of the entire tree shared by each terminal with its own address, data can be obtained from a plurality of terminals connected to itself without exchanging information with peripheral terminals. Can be selected (for example, see Non-Patent Document 1).

  In addition, in a wireless network, there is a multi-hop network that realizes communication between two distant terminals by relaying other terminals. In such a wireless multi-hop network, the network configuration frequently changes as the wireless link is frequently disconnected. Further, when the density of terminals is high, it is not necessary for all terminals constituting the network to relay communication between other nodes. Therefore, there is a method of configuring a network so that some terminals perform relay processing and other terminals do not perform communication other than that related to themselves.

  Further, as a communication system that realizes quick path switching by preparing an alternative path in advance in preparation for a situation in which communication is disconnected, for example, “the corresponding path at the time of data communication request 10 must be set. For example, the route discovery process 20 finds and sets the route, and the link state management process 40 monitors the state of the link 30 on the route set by the route discovery process 20 and links in the route table of each wireless terminal. The alternative route discovery process 50 sets alternative route candidates when the link quality deteriorates.The route switching process 60 switches the alternative route candidates as regular routes. (For example, refer to Patent Document 1).

JP 2004-282270 A (summary) ZigBee Specification, ZigBee Alliance, 2005 (p222-225)

  However, in the conventional method in which an address is assigned by some means (for example, DHCP) at the time when the terminal joins the network as described above, when the network configuration is changed, transfer information of the peripheral terminal is stored. Need to change. Furthermore, when the addresses are collected, it is necessary to cancel the address and change the transfer information to be managed for each terminal. Further, when the network structure and the address are closely related as in ZigBee and the peripheral terminal does not have the transfer information, it is necessary to change the address itself.

  Also, in a wireless multi-hop network, when configuring a network so that some terminals perform relay processing and other terminals do not perform communication other than their own, the receiver power supply is used to perform relay processing. Therefore, the power consumption of a terminal that performs relay processing is larger than that of a terminal that does not perform relay processing. In such a case, in order to equalize the power consumption, it is possible to equalize the power consumption of both terminals by switching between a terminal that performs relay processing and a terminal that does not perform relaying as needed. However, in the existing method, it is necessary to change transfer information of many peripheral terminals when changing the terminal that performs the relay process.

  Since such address change processing needs to confirm that the terminals before and after the change are the same, address change can be performed on all terminals that may transmit data to the terminal (in many cases, network All terminals participating in the network). In addition, it is necessary to consider address reuse, processing of remaining packets addressed to the old address, and there is a problem that address change requires a large amount of calculation resources and communication resources.

  As a solution that does not involve an address change, for example, in Patent Document 1, since stable communication cannot be ensured only by a combination of a destination and a transfer destination set in advance, an alternative route different from a normal transfer route is used. A method has been proposed in which an alternative route is used when a normal route cannot be used for some reason after it is set in advance. However, since such a method needs to store alternative routes in many peripheral terminals, the amount of data to be held by each terminal increases and is difficult to adapt in a large-scale network.

  Accordingly, there has been a demand for a wireless terminal and a wireless communication system that can change a transfer route or a network configuration without performing processing such as changing transfer information or addresses of peripheral terminals or holding alternative route information. .

  A wireless terminal according to the present invention includes a plurality of wireless terminals having a function of transmitting and receiving communication information, and is used for a wireless communication system that relays communication information between the plurality of wireless terminals based on a transfer processing address. A transmission control means for broadcasting adjacent terminal information including at least information for identifying the own wireless terminal and information for identifying the wireless terminal capable of communicating with the own wireless terminal; and the wireless terminal other than the own wireless terminal Receiving control means for receiving neighboring terminal information of the wireless terminal, and the receiving control means is capable of communicating with the own wireless terminal based on the received neighboring terminal information and the neighboring terminal information of the own wireless terminal. An arbitrary terminal (hereinafter referred to as “pair terminal”) or an arbitrary plurality of wireless terminals (hereinafter referred to as “set terminal”), and the pair terminal or set terminal, Beauty of its own radio terminal capable of communicating wireless terminals respectively and acquires the transfer processing for the address to the transfer destination.

  A radio communication system according to the present invention includes a plurality of the radio terminals.

  The present invention selects a pair terminal or a combination terminal from among the wireless terminals that can communicate with the own wireless terminal based on the received adjacent terminal information and the adjacent terminal information of the own wireless terminal, the pair terminal or the combination terminal, and Perform processing such as changing transfer information or addresses of peripheral terminals, or holding alternative route information by acquiring transfer processing addresses with transfer destinations being wireless terminals that can communicate with their own wireless terminals. Without changing the transfer path or network configuration.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a configuration of a wireless communication system according to the first embodiment. As shown in the figure, the wireless communication system is composed of a plurality of wireless terminals 101 having a function of transmitting and receiving communication information, and a transfer processing address is assigned when the wireless terminal 101 joins a network, and this transfer processing Communication information is relayed between a plurality of wireless terminals 101 based on an address. In FIG. 1, a solid line and a dotted line connecting the wireless terminals 101 indicate that the two wireless terminals 101 connected by the solid line and the dotted line can communicate with each other, and the solid line is used for packet transfer. A route is shown, and a dotted line shows a route that is not used for packet transfer. Further, the numbers shown in the wireless terminal 101 indicate transfer processing addresses (hereinafter simply referred to as “addresses”) assigned to transfer packets during network configuration. Indicates an invariant address (hereinafter referred to as “physical address”) that physically identifies each wireless terminal 101 (hereinafter, the same applies to the diagrams showing the configuration of the wireless communication system).
In the following description, among the plurality of wireless terminals 101, when the wireless terminal 101 is identified using an address, it is indicated by a terminal (address). For example, when the address of the wireless terminal 101 is 1, it is referred to as “terminal 1”. Further, among the plurality of wireless terminals 101, when the wireless terminal 101 is identified using a physical address, it is indicated by a terminal (physical address). For example, when the physical address of the wireless terminal 101 is A, it is referred to as “terminal A”. Further, when not particularly identified, it is simply referred to as “terminal”.

  FIG. 2 is a diagram showing the configuration of the wireless terminal according to Embodiment 1. In FIG. As shown in FIG. 2, the wireless terminal 101 includes an antenna 201, a receiving circuit 202, a transmitting circuit 203, a received data processing unit 204, a transmission data generating unit 205, and an adjacent terminal managing unit 206. Yes. The reception circuit 202 and the reception data processing unit 204 correspond to the reception control unit of the present invention, and the transmission circuit 203 and the transmission data generation unit 205 correspond to the transmission control unit of the present invention. Further, the operation (described later) of the adjacent terminal management unit 206 may be performed by the reception data processing unit 204 or the transmission data generation unit 205, and the adjacent terminal management unit 206 may not be provided.

  The antenna 201 is an antenna for transmitting and receiving radio signals. The reception circuit 202 processes the radio signal input from the antenna 201, converts it into digital information, and sends it to the reception data processing unit 204 as reception data. The reception data processing unit 204 performs necessary processing on the reception data received from the reception circuit 202, and then transmits necessary data (information about the adjacent terminal) to the adjacent terminal management unit 206. If the received data is a data communication signal (packet) addressed to the terminal itself, a reception process is performed. If the received data is a data communication signal (packet) addressed to another terminal, the adjacent terminal management unit 206 is inquired about the transfer destination in order to transfer the packet. Further, when the received data is a signal addressed to all terminals transmitted from the peripheral terminal, the information of the received signal is transmitted to the adjacent terminal management unit 206. Using the information from the adjacent terminal management unit 206 obtained in this way, the transfer destination is determined and sent to the transmission data generation unit 205 as transfer data. Details of the transfer operation will be described later.

  The transmission data generation unit 205 uses the adjacent terminal information (described later) obtained from the adjacent terminal management unit 206 to add necessary control information to the data generated by the own terminal to create a transmission signal. Further, a transmission signal is created from the transfer data received from the reception data processing unit 204. The transmission circuit 203 converts the transmission signal generated by the transmission data generation unit 205 into a radio signal and outputs it to the antenna 201.

  The adjacent terminal management unit 206 has storage means for storing information such as an adjacent terminal list (described later), and a list of terminals that can directly communicate with the own terminal using data received from the received data processing unit 204 (Hereinafter referred to as “neighboring terminal list”). Manage the correspondence between addresses and physical addresses as needed. Also, in response to a transfer destination inquiry from the reception data processing unit 204, the transfer destination is instructed. For example, when the destination is included in the adjacent terminal list, the destination itself is returned as the transfer destination, and when the destination is not included in the adjacent terminal list, the routing protocol included in the adjacent terminal management unit 206 is followed. Answer. If necessary, a routing packet is transmitted to make an inquiry to an adjacent terminal. Further, the adjacent terminal management unit 206 collects information obtained from peripheral terminals, determines a pair (described later), and determines a packet relay destination.

  The reception data processing unit 204, the transmission data generation unit 205, and the adjacent terminal management unit 206 store a program for realizing the function of each unit in, for example, an HDD (Hard Disk Drive) or the like, and a microcomputer, a CPU, or the like stores the program. The functions of each unit may be realized according to the instructions of the program, or the functions of each unit may be realized using hardware such as a circuit device.

  The operation of the present embodiment having such a configuration will be described below. The operation in the present embodiment will be described below using cluster tree routing in ZigBee, but the present invention is not limited to this, and an arbitrary address assignment method may be used. The present invention is applicable to a wireless network that includes a plurality of terminals and performs transfer processing using a code that identifies each terminal.

  The cluster tree routing in ZigBee differs greatly from a normal IP network in that the normal network uses three layers of the OSI reference model, that is, the routing uses an address different from the physical address of the IP address to specify the destination. In the second layer, that is, in the data link layer, an address unique to a physical device called a MAC address is used as a destination, whereas in the ZigBee network, an address used as a destination in the network layer is also used for specifying a destination in the data link layer. In ZigBee, there is one terminal called coordinator in the network, and this terminal generates an address by itself to create a network. Other terminals communicate with other directly communicable terminals to participate in the network and acquire addresses. At this time, a parent-child relationship is created in which the terminal that directly communicates when joining the network is “parent” and the terminal is “child”.

The adjacent terminal management unit 206 of the wireless terminal 101 in this embodiment uses the data received from the reception data processing unit 204 described above, and the address of the terminal with which the terminal can communicate is the parent, child, other (transfer (Not used for) and stored.
An example will be described below with reference to FIG. Since the terminal A is a coordinator, the address “0” is allocated and used by itself when the network is started. Next, terminal B connects to terminal A and joins the network. At this time, terminal A assigns address “1” to terminal B. Terminal C to terminal K participate in the network in the same manner and receive an address assignment. After receiving the address assignment, when a signal is received from a peripheral terminal, the information in the adjacent terminal management unit 206 is updated. For example, in the terminal K, the parent is “A”, the child is “C, J”, and the others are “B, F, G”.

  In ZigBee, in principle, packets are transferred using a parent-child relationship. For example, the terminal K and the terminal G can directly communicate with each other, but the terminals A and B are relayed and transferred from the terminal K → the terminal A → the terminal B → the terminal G. In ZigBee, the parent-child relationship of the terminal can be calculated from the address at the time of address assignment, and the transfer destination address can be determined without using information other than the address of itself and the destination. That is, when a packet is transferred from the terminal K to the terminal G, in the terminal K, the transfer destination address is determined only from the information that the destination address is “12” and the information that the own address is “23”. Can be calculated to be “0” (this calculation is performed by the adjacent terminal management unit 206). In order to use such a transfer method, links that do not form a parent-child relationship (links indicated by dotted lines in FIG. 1) are not used in principle. Up to this point, this is the normal operation of ZigBee.

  FIG. 3 is a diagram illustrating a configuration of the information management table and a data example according to the first embodiment. The data example of FIG. 3 shows information collected by the adjacent terminal management unit 206 of the terminal F. 4 is a diagram for explaining tree reconfiguration according to the first embodiment, FIG. 5 is a diagram for explaining tree degeneration according to the first embodiment, and FIGS. 6 and 7 are router replacements by address exchange according to the first embodiment. FIG.

Hereinafter, the operation of the wireless terminal 101 according to the first embodiment will be described with reference to FIGS. 3 to 7, taking the network configuration in FIG. 1 as an example, and (1) creating a pair, (2) reconfiguring a tree, (3) The description will be divided into tree degeneration and (4) router replacement by address exchange.
4 to 7, a thick line connecting the wireless terminals 101 is a route used for packet transfer, and indicates that the two wireless terminals 101 connected are “pairs” (hereinafter referred to as wireless). This is the same in the diagram showing the configuration of the communication system). Here, the “pair” includes one wireless terminal 101 that needs to perform relay (hereinafter referred to as “router”) and one wireless terminal 101 that does not need to perform relay (hereinafter referred to as “end”). The packet relaying performed by the router is defined as a relationship connected between two wireless terminals 101 that can be completely replaced by the end. That is, the end is a terminal that can directly communicate with all the wireless terminals 101 connected by a link (solid line in the figure) used by the paired routers for packet transfer.

(1) Creation of Pair When configuring the network as described above, the information exchanged between the terminals includes information on the physical address of the own terminal, and the adjacent terminal management unit 206 determines the physical address contained in the received signal. Collect information. As a result, information on physical addresses of terminals that can communicate with the own terminal is collected. For example, in the case of the terminal F, as shown in FIG. 3A, the physical addresses of the terminals B, C, D, E, and K are collected as adjacent terminal information.
When the network is configured, each terminal transmits the neighboring terminal information collected in the neighboring terminal management unit 206 of the terminal itself to all peripheral terminals (broadcast transmission). As shown in FIG. 3B, the terminal that has received the neighboring terminal information includes information on the physical address of the terminal that has transmitted the neighboring terminal information, and information on the physical address of the neighboring terminal of the terminal that has transmitted the neighboring terminal information. Is recorded and a pair is determined by the following operation.

An example of the pair determination method will be described below, but the following method is not the only method, and any method for selecting a specific terminal from surrounding terminals can be used.
First, each terminal compares the adjacent terminal information of the own terminal recorded in the adjacent terminal management unit 206 of the own terminal with the adjacent terminal information received from the adjacent terminal, and calculates the duplication rate obtained by the following (Equation 1). Calculate for all neighboring terminals.

  (Number of overlapping terminals) / (number of adjacent terminals of own terminal + number of terminals included in adjacent terminal information−number of overlapping terminals) = duplication rate (Expression 1)

  Here, the “number of overlapping terminals” is the number of terminals included in the adjacent terminals of the own terminal among the terminals included in the adjacent terminal information. Note that the value of the duplication rate obtained by this calculation is the same value regardless of which terminal the duplication rate between specific terminals is calculated when adjacent terminal information is completely exchanged between the terminals. . An example of the terminal F in FIG. 1 is shown below using FIG.

The adjacent terminals of the terminal F are five terminals (B, C, D, E, K).
Information on the physical address of the adjacent terminal obtained from each terminal is as follows. In addition, * was added to the terminal which overlapped with the adjacent terminal of the terminal F. FIG.
Terminal B: A, C *, F, G, K *, J
Terminal C: B *, D *, E *, F, K *
Terminal D: C *, E *, F
Terminal E: C *, D *, F
Terminal K: A, B *, C *, F, G, J *

From the above (Equation 1), the respective overlap rates are as follows.
Terminal B: 2 / (5 + 6-2) = 0.22
Terminal C: 4 / (5 + 5-4) = 0.66
Terminal D: 2 / (5 + 3-2) = 0.33
Terminal E: 2 / (5 + 3-2) = 0.33
Terminal K: 3 / (5 + 6-2) = 0.38

  Next, each terminal transmits a pair request signal to the terminal (in this case, terminal C) having the highest duplication rate among the adjacent terminals of the terminal itself. The terminal that has received the pair request signal determines whether to accept the request. As a judgment here, for example, when it is judged to accept except when already paired with another terminal, or when the duplication rate is below a certain value, it is not accepted, or the duplication rate is below the upper fixed rank If so, make a decision not to accept it.

When it is determined that the pair request is accepted, an acceptance signal is sent to the terminal that has transmitted the pair request signal to establish a pair relationship. Further, when forming a pair relationship, at the time of tree reconfiguration to be described later, one terminal of the pair becomes a router and the other terminal becomes an end. Which terminal becomes which is decided when the pair is established. These are hereinafter referred to as “provisional router” and “provisional end”.
In addition, there is a possibility that a terminal that cannot form a pair relationship may appear if there is no suitable terminal that is a pair terminal in the vicinity, or if all peripheral terminals are paired with other terminals and left behind. There is. Such a terminal (hereinafter referred to as an “isolated terminal”) operates differently from other terminals at the time of tree reconstruction as will be described later.

  After the pair relationship is established, each terminal again transmits neighboring terminal information to all peripheral terminals (broadcast transmission). At this time, a special identification code is added to the physical address information of the paired terminals in the adjacent terminal information, and the pair relationship is notified to the peripheral terminals. The terminal that has received the adjacent terminal information updates the previous adjacent terminal information recorded in the adjacent terminal management unit 206, and adds physical address information related to the paired terminals as shown in FIG.

(2) Tree reconfiguration After information has been exchanged between all terminals and sufficient time has elapsed for establishing a pair relationship, the coordinator (terminal A in the example of FIG. 4) instructs network reconfiguration for all terminals. Send. The terminal that has received the network reconfiguration instruction sends a network reconfiguration instruction to all the terminals that are children of the terminal itself. With this process, all terminals are temporarily disconnected from the network, and rejoin the network.
At this time, the terminal that has been provisionally ended by the above-described operation is forcibly connected to the pair partner, becomes a child of the pair partner, and ends without being connected to terminals other than the pair partner. In addition, the terminal that has become a temporary router by the above-described operation is recorded in the adjacent terminal management unit 206 as to whether or not the following three conditions are satisfied from among the peripheral terminals that have become routers. From the neighboring routers that satisfy the conditions, the router terminal to be connected is selected and connected. However, if the peripheral terminal to be connected is a coordinator, the determination is made only under condition 1. Further, when the own terminal is an isolated terminal, the determination is made only with Condition 2.
Thereby, the terminal that has become the router notifies the peripheral terminals that the terminal has become the router.

(Condition 1) Direct communication between the pair partner of the local terminal and the peripheral terminal (Condition 2) Direct communication between the pair partner of the local terminal and the peripheral terminal is possible (Condition 3) Can communicate directly

As shown in FIG. 4, the above-described pair is formed between the terminal BK, the terminal CF, the terminal DE, and the terminal GJ, and the terminals B, C, D, and G are temporary routers, terminals K, The network is configured with F, E, and J as temporary ends.
Taking the operation of the terminal C as an example, when the notification that the peripheral terminal B is a router is received, the terminal C (condition 1) between the terminals FB, (condition 2) between the terminals CK, (condition 3) ) It is determined whether or not the terminal F-K can communicate directly. In this case, since all the communication of the conditions 1 to 3 is possible, the terminal C is connected to the terminal B and becomes a router.
Taking the operation of the terminals H and I as isolated terminals as an example, when the terminals H and I receive a notification from the terminal G as a router, they can directly communicate with the terminal J as a pair of the terminals G. Whether or not the terminal H is capable of direct communication between the terminals H and J, and whether the terminal I is capable of direct communication between the terminals I and J (Condition 2). Determine whether or not. In this case, since the terminals H and I can communicate with the terminal J, the terminals H and I are connected to the terminal G and become the end.

(3) Tree Degeneration After performing the above-described tree reconfiguration, each router determines whether its own terminal satisfies the following conditions 4 and 5 from information recorded in the adjacent terminal management unit 206, and satisfies the condition. The router performs tree degeneration. Since the router is not worthy as a router, it transitions to the end.

(Condition 4) The router connected to the terminal itself is only the parent.
(Condition 5) The only child connected to the terminal is the pair partner.

The router satisfying the above conditions 4 and 5 notifies the pair partner of the cancellation of the pair relationship and requests network reconfiguration. Then, it determines whether there is a router that satisfies the above condition 2 from router terminals other than the currently connected router, and if there is a router that satisfies the above condition 2, selects that router To do. If the selected router is different from the currently connected router, the connected router is notified of network reconfiguration and connected to the newly selected router.
The end terminal notified of the destruction of the pair relationship connects to another peripheral router. The condition at this time is condition 2 described above.

FIG. 5 shows a structure after the tree structure shown in FIG. 4 is degenerated. As shown in FIG. 4, the terminal D is connected to the parent terminal C only, and the child terminal is only the paired terminal E. Therefore, the above-described conditions 4 and 5 are satisfied, and the terminal D notifies the pair partner terminal E of the cancellation of the pair relationship and requests tree degeneration. The terminal E, which is the end notified of the cancellation of the pair relationship, connects to the terminal C that satisfies the condition 2 among the routers of the peripheral terminals.
As a result of performing the tree degeneration by such an operation, as shown in FIG. 5, terminal E is connected to terminal C (and its paired terminal F), and terminal D is connected to terminal C unchanged from before. Become.
In FIG. 4, the other routers do not perform the tree degeneration because the conditions are not satisfied. However, if the terminal D is reconfigured and then connected to a router other than the terminal C, the terminal C also degenerates in the terminal D degeneration. Degeneration is performed to satisfy 4 and 5.

In this way, tree reduction is repeatedly performed until all router terminals do not satisfy the conditions 4 and 5. By executing tree degeneration, the number of router terminals that perform relaying can be reduced, and the power consumption of the entire network can be reduced.
In addition, it is possible to increase the number of router candidates that can be connected to each terminal by eliminating the pair and reselecting the connection router. As a result, it is possible to reduce the scale of the entire network and the number of relays.

(4) Router replacement by address exchange A tree network including a pair relationship created by following the above procedure can exchange addresses for transfer processing between paired terminals (hereinafter referred to as “address exchange”). Become. Here, there is a possibility that a problem may occur if the address of the terminal is changed in a situation where data to be communicated and relayed remains in the terminal, so the address exchange must be performed with the consent of both terminals. There is. For this reason, address exchange is performed by the following procedures 1-5.

(Procedure 1) When it is necessary to execute address exchange in one of the terminals (described later), an address exchange request signal is transmitted to the other terminal having a pair relationship.
(Procedure 2) The terminal that has received the address exchange request signal decides whether to accept the request based on the status of the terminal itself, information to be communicated / transferred, and either the address exchange acceptance signal or the address exchange rejection signal Reply.
(Procedure 3) When the terminal that has transmitted the address exchange request signal is a router terminal, it operates as a router terminal until it receives the address exchange acceptance signal after transmitting the address exchange request signal. That is, the operation as a router terminal is terminated only when an address exchange acceptance signal is received.
(Procedure 4) When the terminal that has transmitted the address exchange request signal is an end terminal, the terminal operates as a router terminal from the time when the address exchange request signal is transmitted. That is, it operates as a router terminal except when it receives an address exchange rejection signal.
(Procedure 5) If either the address exchange acceptance signal or the address exchange rejection signal is not received within a predetermined time, the address exchange request signal is transmitted again.

  Factors that make it necessary to perform the above-described exchange operation are determined by the remaining battery level of the terminal, the communication load, the elapsed time since the previous exchange operation, the communication interruption with the specific terminal, and the like. In the case of an exchange in an emergency or abnormality, the exchange is executed by transmitting an exchange execution signal without obtaining the consent of the pair partner terminal.

  The following transfer processes 1 to 3 show an example of the transfer process of each terminal that has executed address exchange by such a procedure. The packet received in this example is a packet whose destination in the data link layer matches the address at the time of reception, and is the same as the operation of a normal network system.

(Transfer process 1) When the destination of the network layer (final packet destination) is other than the local terminal and the pair terminal.
The adjacent terminal management unit 206 is inquired about the transfer destination, and after obtaining an appropriate transfer destination, normal transfer processing is performed.
(Transfer process 2) The destination of the network layer is the address of the pair partner before the address exchange, that is, the address of the own terminal after the address exchange.
Relay is performed for the address of the pair partner after the address exchange, that is, the own terminal address before the address exchange.
(Transfer process 3) When the destination of the network layer is the own terminal address before the address exchange, that is, the address of the pair partner after the address exchange.
Performs normal reception processing to pass received data to the application layer.

  Further, when a packet to be transmitted is delivered from the application layer during the address exchange operation, the address before the address exchange is given as the source address of the network layer. Thereafter, the same process as the transfer process 1 is performed. For this process, the transmission data generation unit 205 has a function for managing whether or not address exchange is performed and a function for recording an address before address exchange.

  The network configured as described above has the following characteristics (a) and (b) as compared with the conventional network by address exchange. The effect will be described with examples.

(A) Realizing equalization of power consumption between two terminals in a pair relationship.
One of the two terminals in a pair relationship is a router, and the other is an end. Since the router needs to relay packets between other terminals, the power consumption is considered to be larger than the end. Therefore, equalization of power consumption is realized by exchanging roles by exchanging addresses.

6 and 7 are diagrams for explaining router replacement by address exchange according to the first embodiment. In the example shown in FIG. 5, the terminal K does not transmit / receive other than the packet related to the terminal K. On the other hand, the terminal B needs to relay all communications related to the terminals A and K, and communications between the terminals C, D, E, and F and the terminals G, H, I, and J. Therefore, there is a large difference in power consumption between the terminal K and the terminal B.
Therefore, as shown in FIG. 6, when the terminal B and the terminal K exchange addresses, the network changes and the terminal K can be loaded. By periodically repeating the router replacement by address exchange, the power consumption of the terminals B and K can be equalized, and the network operation time can be extended.
In addition, as shown in FIG. 7, after a terminal B and a terminal K exchange addresses, a plurality of pairs exchange addresses at the same time, as in the case where terminals C and F exchange addresses. However, network connectivity is maintained.
In a network formed in this way, it is possible to determine whether or not a pair exchanges addresses regardless of neighboring pairs, and it is not necessary to perform any confirmation or notification.

(B) When one terminal fails, the other terminal substitutes the relay function to realize network redundancy.
When a failure occurs in a terminal, communication via the terminal becomes impossible and the transfer path is changed. In a normal network, it is necessary to change the routing table, and in the ZigBee tree network, change the address of the related terminal.
Therefore, by exchanging addresses between terminals in a pair relationship, the entire network can operate without changing any information except for the paired terminals. In addition, even if one of the two terminals in a pair relationship fails, it is possible to suppress the influence on the entire network by executing the relay function of the other terminal, so that a stable network can be constructed. Can be realized. In this case, in order to detect a failure between the paired terminals, for example, signals are periodically exchanged.

In the example of FIG. 5, when the terminal B fails, all communication between the terminal A and the terminals C to K is impossible. In the conventional ZigBee network, there is a method in which addresses assigned to the terminals C to K are once discarded and the network is reconfigured or a transfer path is independently set between each terminal and the terminal A. Changes the address, and the latter causes a dramatic increase in traffic.
In the first embodiment, when the terminal K detects the failure of the terminal B, the exchange execution signal is transmitted to the terminal B, and the terminal K receives and forwards the packet addressed to the terminal 1. Therefore, the terminals C to K do not need to change addresses and do not need to set their own detour route. This operation is performed not only when the terminal is broken, but also when the link used for transfer is disconnected due to an obstacle, etc., and the communication path is changed without affecting the entire network. Is possible. Therefore, the adjacent terminal management unit 206 has a function of always holding the address of the pair terminal.

  As described above, in the present embodiment, a pair relationship is formed in the network, the network tree is reconfigured and the tree is degenerated based on this relationship, the router is replaced by address exchange, and the packet transfer process By doing so, without causing the overhead caused by the address change when changing the network configuration, that is, without affecting the peripheral terminals, such as transfer information or address change, It is possible to achieve equalization of power consumption between terminals, reduction of total power consumption, and avoidance of communication interruption due to terminal failure.

  In the above description, the operation when a ZigBee tree network is used for routing has been described. However, the present invention is not limited to this, and a protocol different from the ZigBee tree network may be used for routing. For example, a protocol in which the data link layer address and the network layer address are completely different, such as an IP network, may be used.

Further, in the above description, the case where each terminal creates a pair in a distributed manner based on communication with peripheral terminals has been described. However, the present invention is not limited to this, and adjacent terminal information of each terminal is specified as a specific terminal. Alternatively, it is possible to perform centralized processing for performing necessary calculations by collecting them in a separately provided arithmetic device and notifying each terminal of the pair relationship. By performing such centralized processing, it is possible to create a pair using a wider range of information.
As an example of the necessary calculation, there is, for example, a method for obtaining an overlap rate between terminals. When a pair is generated by a specific terminal or an arithmetic device, it is possible to perform processing such as comparing the duplication rates obtained by each terminal and leveling the duplication rates obtained by all terminals.

  In addition, the creation of a pair is based on measuring the values that fluctuate according to the distance between terminals, such as the received signal strength and radio signal propagation delay, when collecting neighboring terminal information for each terminal. It is also possible to select a terminal with the shortest distance from its own terminal and create a pair. In this case, combined use with the above-described central processing by the specific terminal or the arithmetic unit is also possible.

As described above, in the present embodiment, the formed tree has many conditions that need to be satisfied as compared with a normal tree. That is, in connection between routers, it is necessary that any two terminals out of four terminals composed of two pairs can directly communicate (conditions 1 to 3).
Therefore, the formed tree may be in an inefficient form such as when the route is detoured or when the number of relays increases. Therefore, a network can be reconfigured, a network considering the pair is configured, the pair is changed, and the network is reconfigured again to form a more efficient tree.

  In the above description, the link between pairs is always used in the network, and the case where the router and end in a pair relationship form a parent-child network on the tree has been described. After the tree reconfiguration and degeneration, the router that configures the pair requests the network reconfiguration to the paired end terminal, and the end terminal connects to any router that satisfies the above-described condition 2 without taking the configuration. Also good. An example of such network reconfiguration will be described below with reference to FIGS.

  8 and 9 are diagrams for explaining network reconfiguration according to the first embodiment. For example, if the above-mentioned network reconfiguration is performed after the tree configuration as shown in FIG. 5, terminal K is connected as a child of terminal A (address is 45), not as a child of terminal B, as shown in FIG. Is possible. By operating in this way, it is possible to reduce the scale of the entire network, reduce the number of relays, and the like. However, in this case, after the address exchange operation is performed, the path may be redundant with respect to the packets addressed to the terminals constituting the pair. As illustrated in FIG. 9, taking as an example the case where terminal B and terminal K perform address exchange, a packet addressed to terminal B is transmitted as destination 1 in the network layer. Therefore, the packet is sent to address 1 after address exchange, that is, to terminal K. When it is determined that the original destination is the terminal B at the terminal K, the terminal B is transferred to the terminal B. If transfer according to the tree structure is performed in this transfer, the transfer is performed in the order of terminal K → terminal A → terminal B. Therefore, a function for directly using the link between pairs is added to each terminal in the pair-to-pair packet transfer after address exchange.

  As described above, the tree formed in this embodiment has many conditions that need to be satisfied as compared with a normal tree. Therefore, a shorter communication path can be used depending on the presence or absence of address exchange. It is. Such an example will be described next with reference to FIGS.

10 and 11 are diagrams for explaining path shortening by address exchange according to the first embodiment. As shown in FIG. 10, since direct communication between the terminals BD is impossible, communication between the address 1 and the address 3 needs to be via the address 2. In FIG. 10, after address exchange is performed between terminals BK and DE, address 1 and address 3 are between terminals KE and can communicate directly without terminal C. is there.
By changing the communication path by exchanging addresses in this way, it is possible to improve communication efficiency. In order to realize communication specifically, it is necessary that the peripheral terminal receives information related to address exchange such as an address exchange request and acceptance, and the adjacent terminal management unit 206 records the address change of the adjacent terminal. .

Embodiment 2. FIG.
In the second embodiment, an alternative to the router function is realized by exchanging a router address (described later) assigned to the router. Note that the configuration of the wireless terminal 101 is the same as that of the first embodiment.

  12 and 13 are diagrams illustrating the configuration of the wireless communication system according to the second embodiment. Hereinafter, with reference to FIGS. 12 and 13, the operations in the second embodiment are (1) creation of a pair, (2) tree reconfiguration, (3) tree degeneration, and (4) router replacement by address exchange. Separately described.

(1) Creation of Pair A pair relationship is established by the same operation as the creation of the pair in the first embodiment described above.

(2) Tree Reconfiguration A portion different from the first embodiment will be described. By the same operation as in the first embodiment, the terminal that has become a temporary router selects and connects the router terminal to be connected from the peripheral routers that satisfy the above-described conditions 1 to 3. The terminal that became the router notifies the peripheral terminals.
Next, in the second embodiment, the router further assigns another address as an end terminal to itself. In the example shown in FIG. 12, terminal B assigns address 1 as a router and address 23 as an end terminal. Hereinafter, the respective addresses are referred to as “router address” and “end address”. Similarly, terminal C assigns router address 2 and end address 24.

(3) Tree reduction Tree reduction is performed by the same operation as the tree reduction of the first embodiment described above.

(4) Router change by address exchange A tree network including a pair relationship created by following the above procedure can exchange addresses between paired terminals. Although the basic procedure is the same as the address exchange in the first embodiment, in the second embodiment, an alternative to the router function is realized by exchanging the router address assigned to the router.
An example of the network configuration after such address exchange is shown in FIG. As shown in FIG. 13, the router address 1 is exchanged between the terminal B and the terminal K, and the transfer path between the terminals A and C changes from the path via the terminal B to the path via the terminal K. Here, there is a possibility that problems may occur if the address held by the terminal is changed in a situation where data to be communicated and relayed remains in the terminal, so address exchange must be performed with the consent of both terminals. There is. For this reason, address exchange is performed by the following procedures 1-5.

(Procedure 1) When it becomes necessary to execute address transmission / reception in one of the terminals (described later), a transmission / reception request signal is transmitted to the other terminal having a pair relationship.
(Procedure 2) The terminal that has received the transmission / reception request signal determines whether to accept the request based on the status of the terminal itself and information to be communicated / transferred, and returns either the transmission / reception acceptance signal or the transmission / rejection rejection signal.
(Procedure 3) When the terminal that has transmitted the transfer request signal is a router terminal, after transmitting the transfer request signal, the operation as the router terminal is continued until the transfer acceptance signal is received. That is, the operation as a router terminal is terminated only when an acceptance / reception signal is received.
(Procedure 4) When the terminal that transmitted the transfer request signal is an end terminal, the communication addressed to the router address held by the paired router is started from the time when the transfer request signal is transmitted. In other words, the above operation is continued except when an exchange rejection signal is received.
(Procedure 5) If either the acceptance / rejection signal or the acceptance / rejection signal is not received within a certain time, the acceptance / reception request signal is transmitted again.

  Factors that make it necessary to perform the above-described transmission / reception operation are determined based on the remaining battery level of the terminal, the communication load, the elapsed time since the previous transmission / reception operation, the communication interruption with the specific terminal, and the like. In the case of giving and receiving in an emergency or abnormality, the sending and receiving signal is transmitted and the sending and receiving is executed without obtaining the consent of the pair partner terminal. In order to realize this operation, the adjacent terminal management unit 206 has a function of holding addresses that have been exchanged in the past.

  The following transfer processes 1 and 2 show an operation example of the transfer process of each terminal that has performed the transfer operation by such a procedure. The packet received in this example is a packet whose destination in the data link layer matches the address held at the time of reception, and is different from the operation of a normal network system in that a packet addressed to a plurality of addresses is received.

(Transfer process 1) When the destination of the network layer (final packet destination) is other than the address held by the terminal itself.
The adjacent terminal management unit 206 is inquired about the transfer destination, and after obtaining an appropriate transfer destination, normal transfer processing is performed.
(Transfer process 2) The destination of the network layer is an address held by the terminal itself.
Performs normal reception processing to pass received data to the application layer.

  Note that a terminal that becomes a router at the time of network reconfiguration is assigned two addresses, but the router terminal itself needs to use an end address when transmitting data.

  As described above, in the present embodiment, in addition to the effects of the first embodiment, the information (address before exchange) that each terminal should hold can be reduced, and the processing at the time of packet transmission / reception is simplified. Can be

Embodiment 3 FIG.
In the third embodiment, the pair relationship connected between the two wireless terminals 101 described in the first and second embodiments is changed to a group composed of three or more wireless terminals 101 (hereinafter simply referred to as “group”). Expand. Note that the configuration of the wireless terminal 101 is the same as that of the first embodiment.

  14 and 15 are diagrams illustrating the configuration of the wireless communication system according to the third embodiment. Hereinafter, with reference to FIGS. 14 and 15, the operations in the third embodiment are (1) creation of a set, (2) tree reconfiguration, (3) tree degeneration, and (4) router replacement by address exchange. Separately described. 14 and 15, a thick line connecting the wireless terminals 101 is a route used for packet transfer, and indicates that the two wireless terminals 101 connected are “sets”.

(1) Creation of a set As in the first embodiment, when configuring a network, a signal exchanged between terminals includes a physical address, and the adjacent terminal management unit 206 stores the physical address included in the received signal. Collect information. As a result, information on physical addresses of terminals that can communicate with the own terminal is collected as adjacent terminal information. When the network is configured, each terminal transmits information on the collected physical addresses of the adjacent terminals to the surrounding terminals (broadcast transmission). The terminal that has received the neighboring terminal information records the physical address information of the terminal that has transmitted the neighboring terminal information and the physical address information of the neighboring terminal of the terminal that has transmitted the neighboring terminal information, and determines a set.

An example of the group determination method will be described below. However, the following method is not the only method, and any method for selecting a specific terminal group from surrounding terminals can be used. In the following description, a case where the set is composed of three units will be described as an example. The number of terminals constituting the set may be two or more.
First, each terminal obtains the overlap rate for all adjacent terminals using (Equation 1) as in the first embodiment.
Next, each terminal transmits a set request signal to the two terminals in descending order of the overlapping rate among the adjacent terminals. The terminal that has received the pair request signal determines whether to accept the request. As a judgment here, for example, when it is judged that it is accepted except when it is already paired with another terminal, or when the duplication rate is below a certain value, it is not accepted, or the duplication rate is below the upper fixed rank If so, make a decision not to accept it. A pair is formed only when all the terminals that make up the group accept participation in the pair. When some terminals refuse to participate in the set, the set is not formed, and a signal indicating cancellation is transmitted to the terminal that accepted the participation.

If it is determined that the group request is accepted, an acceptance signal is sent to the terminal that has transmitted the group request signal to establish a group relationship. Also, when creating a pair relationship, at the time of tree reconfiguration to be described later, one specific terminal of the pair is a router and the other terminal is an end. Which terminal will be decided at the time of establishing the set. Hereinafter, these are referred to as “provisional router” and “provisional end”, respectively.
Note that there may be a terminal that cannot create a pair if there is no appropriate terminal in the vicinity, or if all the peripheral terminals form a pair with other terminals and are left behind. Such a terminal (hereinafter referred to as an “isolated terminal”) operates differently from other terminals at the time of tree reconstruction described later.

  After the group relationship is established, each terminal transmits the neighboring terminal information to all the surrounding terminals again (broadcast transmission). At this time, a special code is added to the terminals constituting the set in the adjacent terminal information, and the set relation is notified to the peripheral terminals. The terminal that has received the neighboring terminal information updates the previous neighboring terminal information recorded in the neighboring terminal management unit 206, and adds physical address information regarding the terminals that are in a pair relationship.

(2) Tree reconfiguration After information has been exchanged between all the terminals and a sufficient time has passed for establishing the group relationship, the coordinator (terminal A in the example of FIG. 14) instructs network reconfiguration to all the terminals. Send. The terminal that has received the network reconfiguration instruction sends a network reconfiguration instruction to all the terminals that are children of the terminal itself. With this process, all terminals are temporarily disconnected from the network, and rejoin the network.
At this time, a terminal that has become a temporary end by the above-described operation is forcibly connected to a temporary router that exists in the set, becomes a child of the router, and becomes an end without being connected to terminals other than the router. In addition, the terminal that has become a temporary router by the above-described operation is recorded in the adjacent terminal management unit 206 as to whether or not the following three conditions are satisfied from among the peripheral terminals that have become routers. From the neighboring routers that satisfy the conditions, the router terminal to be connected is selected and connected. However, if the peripheral terminal to be connected is a coordinator, the determination is made only under condition 1. Further, when the own terminal is an isolated terminal, the determination is made only with Condition 2.
Thereby, the terminal that has become the router notifies the peripheral terminals that the terminal has become the router.

(Condition 1) All temporary ends of the group to which the own terminal belongs and the peripheral terminal can directly communicate (Condition 2) All temporary ends of the group to which the own terminal and the peripheral terminal belong can directly communicate (Condition 3) The own terminal All temporary ends of the group to which the terminal belongs and all temporary ends of the group to which the peripheral terminal belongs can directly communicate with each other.

FIG. 14 shows an example of a tree structure after reconfiguration. The above-described set is formed between the terminals B, G, K and the terminals C, D, E, and the network is configured with the terminals B and C as temporary routers and the terminals G, K, D, E as temporary ends.
Taking terminal C as an example, upon receiving a notification that peripheral terminal B is a router, terminal C will connect between terminals EB and FB in (Condition 1) and terminal C- in (Condition 2). It is determined whether or not direct communication is possible between G, between terminals C and K, and between terminals E and G, between terminals EK, between terminals FG and between terminals F and K under (Condition 3). . In this case, since all the communication of the conditions 1 to 3 is possible, the terminal C is connected to the terminal B and becomes a router.
Further, taking the operation of terminal D, which is an isolated terminal, as an example, when terminal D receives a notification from terminal C, which is a router, direct communication with terminals E and F, which are the ends of the set to which terminal C belongs, is performed. It is determined whether or not it is possible, that is, the terminal D (condition 2) determines whether or not direct communication is possible between the terminals DE and DF. In this case, since the terminal D can communicate with the terminal E and the terminal F, it connects to the terminal C and becomes an end.

(3) Tree Degeneration After performing the above-described tree reconfiguration, each router determines whether its own terminal satisfies the following conditions 4 and 5 from information recorded in the adjacent terminal management unit 206, and satisfies the condition. The router performs tree degeneration. Since the router is not worthy as a router, it transitions to the end.

(Condition 4) The router connected to the terminal itself is only the parent.
(Condition 5) The child connected to the own terminal is only the end of the group to which the own terminal belongs.

The router satisfying the above conditions 4 and 5 notifies the terminal belonging to the set of the discard of the set and requests network reconfiguration. Then, it determines whether or not there is a router that satisfies the above condition 2 from router terminals other than the currently connected router, and if there is a router that satisfies the above condition 2, an appropriate router is selected. select. If the selected router is different from the currently connected router, the connected router is notified of network reconfiguration and connected to the newly selected router.
The end terminal notified of the destruction of the set connects to another peripheral router. The condition at this time is condition 2 described above.

In this way, tree reduction is repeatedly performed until all router terminals do not satisfy the conditions 4 and 5. By executing tree degeneration, the number of router terminals that perform relaying can be reduced, and the power consumption of the entire network can be reduced.
In addition, it is possible to increase the number of router candidates that can be connected to each terminal by eliminating the group and reselecting the connection router. As a result, it is possible to reduce the scale of the entire network and the number of relays.

(4) Router replacement by address exchange In a tree network including a pair relationship created by following the above-described procedure, addresses can be exchanged between terminals constituting the pair. Here, there is a possibility that a problem may occur if the address of the terminal is changed in a situation where data to be communicated and relayed remains in the terminal, so the address exchange must be performed with the consent of both terminals. There is. For this reason, address exchange is performed by the following procedures 1-5.

(Procedure 1) When it becomes necessary to execute address exchange (described later) in any of the terminals, an address exchange request signal is transmitted from the terminal having the pair relationship to the selected terminal. As a criterion for selection, for example, the remaining battery level of the terminal, the past address change history, the number of changes, and the like can be considered.
(Procedure 2) to (Procedure 4) are the same as (Procedure 2) to (Procedure 4) of (4) Router replacement by address exchange described in the first embodiment.
(Procedure 5) If either the address exchange acceptance signal or the address exchange rejection signal is not received within a predetermined time, the address exchange request signal is transmitted again. Alternatively, another terminal is selected from the set and the operation of the procedure 1 is executed again.

  Factors that make it necessary to perform the above-described exchange operation are determined by the remaining battery level of the terminal, the communication load, the elapsed time since the previous exchange operation, the communication interruption with the specific terminal, and the like. In the case of an exchange in an emergency or abnormality, the exchange is performed by transmitting an exchange execution signal without obtaining the consent of the address exchange partner terminal.

  The following transfer processes 1 to 3 show an example of the transfer process of each terminal that has executed address exchange by such a procedure. The packet received in this example is a packet whose destination in the data link layer matches the address at the time of reception, and is the same as the operation of a normal network system.

(Transfer process 1) When the destination of the network layer (final packet destination) is other than the address used by the own terminal and the partner terminal performing address exchange.
The adjacent terminal management unit 206 is inquired about the transfer destination, and after obtaining an appropriate transfer destination, normal transfer processing is performed.
(Transfer process 2) When the destination of the network layer is the own terminal address after the address exchange, that is, the address used by the exchange partner terminal before the address exchange.
Relay is performed for the address of the address exchange partner after the address exchange, that is, the own terminal address before the address exchange.
(Transfer process 3) The destination of the network layer is the address of the local terminal before address exchange, that is, the address of the address exchange partner after address exchange.
Performs normal reception processing to pass received data to the application layer.

  Further, when a packet to be transmitted is delivered from the application layer during the address exchange operation, the address before the address exchange is given as the source address of the network layer. Thereafter, the same process as the transfer process 1 is performed. For this processing, the transmission data generation unit 205 has a function for managing whether or not address exchange is being performed, a function for managing address exchange partners, and a function for recording addresses before address exchange.

  FIG. 15 shows an example in which address exchange is performed between terminal B and terminal K in the tree configuration shown in FIG. As shown in FIG. 15, for example, the relay path between the terminal A and the terminal D was terminal A → terminal B → terminal C → terminal D before the address exchange, but after the address exchange, the terminal A → terminal K → terminal C → terminal D. In this way, the terminal B does not need to perform relay processing, and power consumption can be greatly reduced.

  As described above, in the present embodiment, in addition to the effects of the first embodiment, more terminals can execute the router function, and further power consumption can be equalized and redundancy can be ensured. It becomes.

  In the third embodiment, an example is described in which all routers form a set with the same number of terminals. However, the present invention is not limited to this, and the operation is such that each terminal forms a set made up of a different number of terminals. It can also be done. For example, depending on the number of terminals that dynamically change the number of terminals belonging to a set according to the number of peripheral terminals, or the number of terminals that are already subtracted from the number of peripheral terminals that belong to a set that is configured by another terminal It is also possible to adopt a configuration in which the number of terminals to be changed is changed. In addition, it includes that the number of terminals belonging to the group is two.

  The operation of realizing the replacement of the router function by exchanging the router address described in the second embodiment is replaced with the pair in the operation in the third embodiment, thereby replacing the embodiment. As in the case of 2, it is possible to realize an alternative to the router function.

1 is a diagram showing a configuration of a radio communication system according to Embodiment 1. FIG. 2 is a diagram illustrating a configuration of a wireless terminal according to Embodiment 1. FIG. FIG. 3 is a diagram illustrating a configuration of an information management table and a data example according to Embodiment 1. 6 is a diagram for explaining tree reconstruction according to Embodiment 1. FIG. 6 is a diagram for explaining tree degeneration according to Embodiment 1. FIG. 6 is a diagram for explaining router replacement by address exchange according to Embodiment 1. FIG. 6 is a diagram for explaining router replacement by address exchange according to Embodiment 1. FIG. 2 is a diagram for explaining network reconfiguration according to Embodiment 1. FIG. 2 is a diagram for explaining network reconfiguration according to Embodiment 1. FIG. It is a figure explaining the path | route shortening by the address exchange which concerns on Embodiment 1. FIG. It is a figure explaining the path | route shortening by the address exchange which concerns on Embodiment 1. FIG. 6 is a diagram illustrating a configuration of a wireless communication system according to a second embodiment. FIG. 6 is a diagram illustrating a configuration of a wireless communication system according to a second embodiment. FIG. 6 is a diagram showing a configuration of a radio communication system according to Embodiment 3. FIG. 6 is a diagram showing a configuration of a radio communication system according to Embodiment 3. FIG.

Explanation of symbols

  101 wireless terminal, 201 antenna, 202 reception circuit, 203 transmission circuit, 204 reception data processing unit, 205 transmission data generation unit, 206 adjacent terminal management unit

Claims (25)

A wireless terminal configured by a plurality of wireless terminals having a function of transmitting and receiving communication information, and used in a wireless communication system that relays communication information between the plurality of wireless terminals based on a transfer processing address,
Transmission control means for broadcasting adjacent terminal information including at least information for identifying the own wireless terminal and information for identifying the wireless terminal capable of communicating with the own wireless terminal;
Receiving control means for receiving neighboring terminal information of the wireless terminal from the wireless terminal other than the own wireless terminal;
The reception control means includes
Based on the received neighboring terminal information and the neighboring terminal information of the own wireless terminal, among the wireless terminals that can communicate with the own wireless terminal, a pair terminal that is an arbitrary terminal or a group terminal that is an arbitrary plurality of wireless terminals A wireless terminal that selects and acquires a transfer processing address with a wireless terminal that can communicate with the paired terminal or the paired terminal and the own wireless terminal as a transfer destination. The transmission control means includes
Broadcast information including information identifying the paired terminal or the set terminal in the adjacent terminal information,
The reception control means includes
From the wireless terminal other than the own wireless terminal, neighboring terminal information including information for identifying the paired terminal or the assembled terminal of the wireless terminal is received, and based on the received neighboring terminal information, the paired terminal or the assembled terminal of the wireless terminal , And the wireless terminal, a pair terminal or a set terminal of the own wireless terminal, and the own wireless terminal can determine whether they can communicate with each other. The wireless terminal according to claim 1, wherein a wireless address is acquired. The reception control means includes
The wireless terminal according to claim 1 or 2, wherein the transfer processing address of the own wireless terminal is changed to a transfer processing address of either the pair terminal or the set terminal according to a predetermined condition. . The transmission control means includes
According to a predetermined condition, an address exchange request signal is transmitted to the pair terminal or the combination terminal,
4. The radio according to claim 3, wherein when an address exchange request signal is received by said reception control means, an address exchange permission signal is transmitted to said pair terminal or said group terminal in accordance with a predetermined condition. Terminal. The reception control means includes
When the address exchange permission signal is received from either the pair terminal or the set terminal, the transfer processing address of the own wireless terminal is changed to the transfer processing address of the wireless terminal that has transmitted the address exchange permission signal. The wireless terminal according to claim 3 or 4, characterized in that: The reception control means includes
When changing the transfer processing address of the own wireless terminal, the information of the transfer processing address before the change is held, and the destination of the received communication information is the transfer of the own wireless terminal before the change of the transfer processing address When it is a processing address, the communication information is received,
The transmission control means includes
When the destination of the received communication information is the transfer processing address of the own wireless terminal after the change of the transfer processing address, the communication information is transferred to the transfer processing address of the own wireless terminal before the change of the transfer processing address. Information is transmitted, The radio | wireless terminal in any one of Claims 3-5 characterized by the above-mentioned. The transmission control means includes
When the destination of the received communication information is other than the transfer processing address of the own wireless terminal before and after the change of the transfer processing address, the communication information is transmitted with the transfer processing address before the change as the transmission source. The wireless terminal according to claim 3, wherein the wireless terminal is a wireless terminal. The transmission control means includes
Regular information is transmitted to the paired terminal or the set terminal,
The reception control means includes
When the predetermined information is not received from the pair terminal or the set terminal for a certain period, the transfer processing address of the own wireless terminal is changed to the transfer processing address of the pair terminal or the set terminal. The radio | wireless terminal in any one of Claims 1-7. The reception control means includes
Based on the received neighboring terminal information and the neighboring terminal information of the own wireless terminal, for the number of wireless terminals included in the neighboring terminal information of the wireless terminal that can communicate with the own wireless terminal and the neighboring terminal information of the own wireless terminal, 9. The duplication rate which is a ratio of the number of radio terminals common to both adjacent terminal information is obtained, and the pair terminal or the set terminal of the own radio terminal is selected according to the duplication rate. A wireless terminal according to any one of the above. The reception control means includes
The wireless terminal according to any one of claims 1 to 9, wherein the pair terminal or the set terminal of the own wireless terminal is selected based on the reception strength of the received adjacent terminal information or communication information. The reception control means includes
When selecting the pair terminal or the set terminal, based on a predetermined condition, the own wireless terminal is a wireless terminal that relays communication information between the plurality of wireless terminals, or communicates between the plurality of wireless terminals. Select which end operation, which is a wireless terminal that does not relay information,
When the own wireless terminal operates as the router, obtain the transfer processing address with the wireless terminal that can communicate with the pair terminal or the set terminal of the own wireless terminal and the own wireless terminal as a transfer destination,
The wireless terminal according to claim 1, wherein when the wireless terminal operates as the end, a transfer processing address whose destination is the paired terminal or the combined terminal is acquired. The plurality of wireless terminals form a topology network based on a tree structure;
The reception control means includes
When the own wireless terminal operates as the router, it is determined whether the router connected to the own wireless terminal is only the parent terminal, and the child terminal is only the pair terminal or the combination terminal, and satisfies the condition 12. The wireless terminal according to claim 11, wherein the wireless terminal acquires a transfer processing address that operates as the end. The reception control means includes
Holding a plurality of addresses for transfer processing;
An end address that is a transfer processing address used for transmission / reception of the communication information that is the destination or transmission source of the own wireless terminal is different from a router address that is a transfer processing address used for relaying the communication information that is not addressed to the own wireless terminal. The wireless terminal according to claim 1, wherein a transfer processing address is used. The transmission control means includes
According to a predetermined condition, the router address information is transmitted to the pair terminal or the combination terminal,
The reception control means includes
Receiving information of the router address from the paired terminal or the set terminal of the own wireless terminal, and changing the forwarding processing address of the own wireless terminal to the router address according to a predetermined condition, The wireless terminal according to claim 13. The transmission control means includes
Regular information is transmitted to the paired terminal or the set terminal,
The reception control means includes
The wireless communication device according to claim 13 or 14, wherein when the predetermined information is not received from the pair terminal or the set terminal for a certain period, the forwarding processing address of the own wireless terminal is changed to the router address. Terminal. The reception control means includes
Holds the received router address,
16. The wireless terminal according to claim 15, wherein when a failure of the pair terminal or the combination terminal is detected, the forwarding processing address of the own wireless terminal is changed to the router address.   A wireless communication system comprising a plurality of wireless terminals according to claim 1. A plurality of wireless terminals according to any one of claims 1 to 12,
A wireless communication system characterized in that equalization of power consumption of each wireless terminal is realized by periodically changing a transfer processing address of each wireless terminal. A plurality of wireless terminals according to any one of claims 1 to 12,
A wireless communication system that realizes a transfer path change by changing a transfer processing address of the pair terminal or the set terminal of the wireless terminal against a failure of the wireless terminal or a disconnection of a communication path . A plurality of wireless terminals according to any one of claims 13 to 16,
A wireless communication system characterized by realizing equalization of power consumption of each wireless terminal by periodically changing the router address of each wireless terminal. A plurality of wireless terminals according to any one of claims 13 to 16,
A wireless communication system, wherein a transfer path is changed by changing a router address of the pair terminal or group terminal of the wireless terminal in response to a failure of the wireless terminal or a disconnection of a communication path. A plurality of wireless terminals according to any one of claims 1 to 16,
An arithmetic device that transmits and receives predetermined information to and from the plurality of wireless terminals;
The arithmetic unit is:
Receiving the neighboring terminal information transmitted from the plurality of wireless terminals, selecting the pair terminal or the set terminal for each wireless terminal based on at least the received neighboring terminal information, and selecting the selected pair terminal or the set Sending information about the terminal to the wireless terminal;
The wireless terminal is
A wireless communication system, wherein the transfer processing address is acquired based on the received pair terminal or information on the paired terminal. The arithmetic unit is:
Based on the received signal received from the wireless terminal, the distance between the wireless terminals is estimated, and based on the distance between the wireless terminals and the neighboring terminal information, the pair terminal or the set terminal for each wireless terminal is selected. The wireless communication system according to claim 22. A plurality of wireless terminals according to any one of claims 1 to 16,
Among the plurality of wireless terminals, a specific wireless terminal is:
Receiving the neighboring terminal information transmitted from a wireless terminal other than its own wireless terminal, and based on at least the received neighboring terminal information, select the pair terminal or the group terminal for each wireless terminal, and the selected pair terminal or Sending information about the set terminal to the wireless terminal;
The wireless terminal is
A wireless communication system, wherein the transfer processing address is acquired based on the received pair terminal or information on the paired terminal. The specific wireless terminal is
Based on a received signal received from a wireless terminal other than its own wireless terminal, a distance between the wireless terminals is estimated, and based on the distance between the wireless terminals and the adjacent terminal information, the pair terminal or the set for each wireless terminal The wireless communication system according to claim 24, wherein a terminal is selected.

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