JP2008244792A - Wireless network system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication system which can perform route retrieval with a communication-enabled range (radio wave coverage) of radio wave taken into consideration in an ad hoc communication network, the route retrieval also actualizing efficient relay. <P>SOLUTION: A wireless terminal selects a plurality of wireless terminals having many wireless terminals which can not directly communicate with itself from a wireless terminal list of wireless terminals existing in the surroundings and classifies nearby wireless terminals in the predetermined number of groups. After judging relative positions of the groups by a communication-enabled common station, each one candidate of wireless terminals to which the communication is relayed is selected for original and duplicate and when transmission and relay become necessary, transmission is performed to the preselected wireless terminals. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for establishing a path of an ad hoc communication network of a mobile portable terminal that can be moved.

  Well-known mobile phone terminals that employ wireless communication technology include mobile phones and automobile phones. In addition, indoor communication using a notebook personal computer or PDA (Personal Digital Assistants) using a wireless LAN (Local Area Network) is well known. The communication system described above has a fixed network infrastructure having a fixed radio base station. However, in recent years, there has been proposed an ad hoc communication network in which wireless terminals are able to relay and communicate with each other in an autonomous distributed type in which no fixed network infrastructure exists.

Ad-hoc communication networks are used for temporary communications during disasters, used for communication between mobile objects such as cars, and used for communication between personal computers used for meetings indoors. I can do it. Since it does not have a fixed network infrastructure, it is economical and suitable for performing wireless communication on an ad hoc basis on the spot. See Patent Document 1 as an example of an ad hoc communication network.
JP 2004-48478 A

  The ad hoc communication network has a plurality of problems such as a security problem for preventing information from leaking to others, and one of them is a route search method (also called a routing protocol). Since a fixed network infrastructure does not exist and a communication form (also referred to as a network topology) frequently changes, searching for a communication path is an important issue. In the Internet Engineering Task Force (IETF), which is an organization that promotes the standardization of Internet technology, the standardization of routing protocols for ad hoc communication networks is under study.

  A number of routing protocols have been proposed, but they are classified into several types according to the search method, and a reactive type that searches for a route when a communication request occurs, or a proactive type that always searches for a communication route and has a route table, It is classified into a hybrid type combining a reactive type and a proactive type, a location information type in which wireless terminals have location information using GPS (Global Positioning System), a hierarchical type in which route zones are hierarchical, and the like. . The Reactive type is advantageous in terms of battery life in wireless terminals with many battery-powered devices because radio waves are always transmitted when a communication is required, and radio waves are not always transmitted. It has the disadvantage that it takes time to start. On the other hand, the Proactive type is disadvantageous in terms of battery life because it always searches for a route before a communication request occurs, but it is disadvantageous in terms of battery life. Suitable when necessary.

  Many of the proposed routing protocols are based on the premise that neighboring wireless terminals can communicate with each other as if a wired communication network has been established. In the communication relay (path), wireless terminals communicate with each other as relay stations like a wired communication network according to a determined rule. However, since radio waves are actually used, there are cases where communication cannot be performed without reaching radio waves, or communication can be performed far away if radio wave transmission power is sufficient. Even if the radio wave reaches a distant radio terminal, it is relayed in detail according to the rules, so the transmission efficiency is constant regardless of the strength of the radio wave. See Japanese Patent Application Laid-Open No. 2004-228561 as an example of detailed relay. The proposal of patent document 1 is a proposal which selects an optimal path | route according to communication capability, when there exists a some communication path | route. It is an object of the present invention to provide a communication method that can perform a route search that takes into consideration a communicable range (radio wave coverage) of radio waves and that can be relayed efficiently.

  In a system in which a plurality of wireless terminals establish a wireless network in an autonomous and distributed manner, the wireless terminals transmit and receive themselves to other wireless terminals in the vicinity of the wireless terminal by constantly repeating communication that indicates the presence of the wireless terminal in a constant cycle or randomly. A means for sending a list of possible wireless terminals is provided.

  A wireless terminal that has received communication indicating presence from another wireless terminal includes means for responding with a list of wireless terminals that can transmit and receive itself.

  The wireless terminal that has received the response includes means for storing a wireless terminal list of a plurality of wireless terminals existing in the vicinity. The wireless terminal includes means for selecting a predetermined number of wireless terminals from the top in the order of the number of wireless terminals having many wireless terminals that cannot communicate directly with the wireless terminal from the stored wireless terminal list.

  The wireless terminals determine that the wireless terminals having more common wireless terminals that can be transmitted / received from the wireless terminal list among the predetermined number of selected wireless terminals are close to each other, and a predetermined number of wireless terminals that are close to each other. Means for classifying into groups.

The wireless terminal determines whether it is a group that is geographically distant or a close group based on the number of wireless terminals that can be transmitted / received to each group after classifying the selected wireless terminals into groups. Means for determining the target position. Wireless terminals common to each group are connected by lines, and if the number of lines is not biased, it is assumed that the group classification and the relative position of the group are correct.
If the number of lines is biased between specific groups, the grouping is not correct and the group classification is redone.

After determining the relative position of the group, the wireless terminal includes means for selecting, from the respective groups, wireless terminal candidates for relaying communication one by one, primary and secondary stations. The secondary station is a spare when the primary station cannot relay.
The relay station candidate primary and secondary stations may be periodically changed within the same group without being fixed.

  A wireless terminal having a transmission request (referred to as a transmitting station) is a positive terminal preselected from the address of the wireless terminal (referred to as a receiving station) desired to be received and a group of wireless terminals existing around the transmitting station. Means for designating and transmitting the address of the relay station are provided. If the positive relay station does not relay within a predetermined time after transmission, the transmitting station designates and transmits the sub relay station.

  The wireless terminal that receives the relay request (referred to as a relay station) checks whether the receiving station exists in the stored wireless terminal list, and if there is a receiving station, specifies the address of the next relay station And means for relay transmission to the receiving station. If there is no receiving station in the wireless terminal list, the address of the positive relay station selected in advance in the group of wireless terminals existing in the vicinity, excluding the group to which the preceding relay station belongs or the closest group that does not belong Means for designating and transmitting. Further, the relay station includes means for adding the address of its own next to the address of the relay station written to indicate the relayed route and designating the address of the next relay station for transmission.

  The relay station monitors whether or not the relay is performed within a predetermined time after specifying and transmitting the address of the positive relay station existing in each group. Includes means for designating the address of a secondary relay station previously selected in the group and attempting transmission again. In addition, the relay station includes means for not relaying again when communication having the same content is relayed through another communication path or the same communication path within a predetermined time.

  The receiving station includes means for performing response communication by determining the address of the relay station by going back the reception response to the transmitting station and the relayed communication path.

  When the transmission station continues to communicate with the reception station after receiving the reception response, the transmission station includes means for performing communication by specifying the communication path receiving the response from the reception station in reverse.

  According to the present invention, before wireless terminals constituting an ad hoc communication network generate a transmission request or a relay request, wireless terminals existing in a boundary area where radio waves reach are grouped in position and a representative thereof is selected. High-speed and efficient communication considering radio wave coverage becomes possible. There is no fear that communication will not be possible even if the propagation state of radio waves changes or the communication form (network topology) changes.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining a communication path search method according to the present invention. Alphanumeric characters indicate the arrangement of wireless terminals existing there. An area 100 that can be transmitted and received from the wireless terminal A1 (station address is temporarily set as A1) is indicated by a broken circle, and an area 101 that can be transmitted and received from the wireless terminal B3 (station address is temporarily set as B3) is indicated by a circle. Indicated by the solid line. Wireless terminals that can be transmitted and received from the wireless terminal A1 are indicated by B1, B2, B3... B22, and wireless terminals that cannot be directly transmitted and received from the wireless terminal A1 are indicated by C1, C2, C3. When transmitting from the wireless terminal A1, it is more efficient to select a wireless terminal that exists in the boundary region of the region 100 as a relay station as much as possible. Moreover, the possibility that the blank area of the relay is generated is smaller when the orientations are evenly distributed without overlapping. The present invention is a wireless network system capable of finding a wireless terminal existing near the boundary of an area where a certain wireless terminal can transmit and receive, and relaying it while distributing its orientation.

  Assume that the wireless terminal A1 preselects relay station candidates as B3, B5, B7, and B10. It is assumed that the wireless terminal B3 has previously selected relay station candidates as B14, C6, C23, and C48. If the wireless terminal A1 designates and transmits a relay station candidate (an arrow from A1 in FIG. 1), the wireless terminal B3 further relays to C6, C23, and C48. The wireless terminals B5, B7, B10, C6, C23, and C48 are also relayed, but are omitted because the figure becomes complicated. Although the relay is shown in four directions, it does not necessarily have to be four directions, and it may be selected from 2 to 16 directions depending on the system. Further, although the communicable range is a non-directional circle for explanation, it is not necessarily a circle due to the directivity of an ellipse or due to the radio wave environment and obstacles. The reason why the wireless terminal B3 does not relay to B14 is because B14 is in the same direction as A1 with which it communicated.

  As can be seen from FIG. 1, by selecting a relay station that exists at the boundary of the communicable area, it is possible to reduce the number of relays and perform efficient relay. This is more advantageous as the transmission power of radio waves increases.

  FIG. 2 shows a conventional relay according to a certain routing protocol with the same arrangement of wireless terminals as FIG. The range of radio wave communication is not particularly considered, and relaying is performed according to the routing rules as if there is a wired communication network. The communication text transmitted from the wireless terminal A1 is relayed as B18, B19, B12, B20, B3, C48,. Although it is not necessarily the same routing according to the routing protocol, it can be seen that the number of relays is large compared to FIG. In FIG. 1, A1 to C48 are 2 hops (relay), but in FIG. 2, 6 hops are required.

  Next, the search for the communication path of the present invention will be specifically described. FIG. 3 shows that wireless terminals are arranged around the wireless terminal A1, and alphanumeric characters indicate that there are wireless terminals having alphanumeric station addresses. A region 100 that can be transmitted and received from the wireless terminal A1 is indicated by a circular broken line. Wireless terminals that can be transmitted and received from the wireless terminal A1 are indicated by B1, B2, B3... B22, and wireless terminals that cannot be directly transmitted and received from the wireless terminal A1 are indicated by C1, C2, C3.

  Communication is performed by transmitting a radio wave from the wireless terminal A1 and indicating the presence of itself in the vicinity. In the MANET WG, this corresponds to communication called a Hello message. The communication indicating the presence of the user is always executed periodically after entering the wireless network, or at random time intervals, using free time during which communication is not performed. A response is requested to a wireless terminal existing in the vicinity with the local station address and a wireless terminal list that can be transmitted and received as viewed from the local station attached. Other wireless terminals existing around the wireless terminal A1 that has received this request respond with the wireless terminal list held by each wireless terminal attached.

  A wireless terminal list of the wireless terminal A1 obtained in this way is shown in FIG. Stations (wireless terminals) to which the wireless terminal A1 can transmit and receive are B1 to B22, but are not shown in FIG. In addition, stations that can be transmitted and received by each station are also partially shown. Since the wireless terminal is assumed to be a mobile object, the wireless terminal list needs to be constantly updated. The faster the movement speed, the more frequently the update is required. However, in a system with a slow movement, the update frequency may be lowered in order to reduce the power consumption of the wireless terminal. The way of viewing the wireless terminal list in FIG. 4 will be described. For example, the B3 station row in the third row from the top indicates a station where the B3 station itself that has received a response from the B3 station can transmit and receive. According to this, the stations that the B3 station can transmit and receive are B1, B2, B4, B12,... B20, B21, C2, C3, C4,.

  The wireless terminal A1 stores the obtained wireless terminal list in the storage unit and performs the subsequent processing. From the wireless terminal list, select the top several stations that have a large number of C stations (that is, stations that have many stations that cannot communicate from the A1 station). The number of top stations to select depends on the conditions of each system. If there are many directions to relay, select more. However, if more selections are made than necessary, not only stations that exist at the boundary of the communicable range (radio coverage) but also stations that are close to the wireless terminal A1 are selected. In FIG. 5, the top 12 stations with many C stations with the azimuth set to 4 are selected. The wireless terminals having 11 C stations are B1, B10, and B11. A station that has a lot of stations that cannot communicate from the A1 station is not necessarily far away from the A1 station, but may be regarded as far away if the wireless terminals are not arranged extremely biased.

Next, the azimuth is set to 4, and the stations selected in FIG. 5 are grouped into four groups. As a grouping method, the number of common stations that can be transmitted / received between the stations is counted, and stations having more common stations are set as the same group. It can be said that a station with many common stations is a geographically close station.
FIG. 6 shows an example of grouping.

  Next, the relative position of each group is determined. For this purpose, a common station that can transmit and receive in common between the groups is connected by a line. FIG. 7 shows a diagram in which common stations are connected by a line. If there is a bias in the number of lines in each group, grouping is not appropriate and grouping is performed again. In FIG. 7, the number of lines is group 1 and 2, group 3 and 4 are 4, group 1 and 3, group 2 and 4 are 3, group 1 and 4, and group 2 and 3 are 0. The relative position of each group can be determined as shown in FIG. That is, groups 1 and 2 are close, and groups 3 and 4 are close. Since groups 1 and 4 and groups 2 and 3 do not have a common station, the distance is long. FIG. 8 shows relative positions, and the groups 2 and 3 may be arranged at opposite positions. The radio terminal A1 does not know which position is the correct position, but the absolute position is not necessary.

  Once the relative positions of the groups are determined, the next candidate for the relay station is selected from each group. In FIG. 9, one primary and secondary station is selected in each group, but it is not limited to one station. As a selection criterion, a station with few adjacent stations and common stations is selected. This is because a station with many common stations is likely to exist in a position close to an adjacent group. The station thus selected is selected as the next relay station of the A1 station when there is a transmission request in the wireless terminal A1 or when there is a relay request from the other station in the A1 station. FIG. 1 shows that relay stations B3, B5, B7, and B10 selected from A1 are designated.

  A process (route search) for obtaining a wireless terminal list from “communication indicating presence of self” and further searching for a candidate for a relay station from the wireless terminal list is performed by a control unit of the wireless terminal. FIG. 14 shows an example of the internal structure of the wireless terminal (211). The control unit (204) includes a processing processor, a microcomputer, and the like, and operates according to instructions from a program stored in the storage unit (206). In the route search processing, the control unit (204) reads the route search processing program and the wireless terminal list from the storage unit (206) and executes the search processing.

  FIG. 10 shows a flow of route search processing. When the control unit (204) activates a timer for notifying the clock unit (205) of a certain cycle and an interrupt of the cycle occurs (step S2 in FIG. 10), it transmits “communication indicating the existence of itself” to neighboring wireless terminals. To (step S3). In transmitting a radio wave, it is executed after the collision detection unit (203) confirms that no other radio terminal is transmitting a radio wave. In the flow of FIG. 10, communication indicating the existence of itself is performed at a constant cycle. However, random time may be generated and executed not at regular intervals but at random times.

  When a nearby wireless terminal receives “communication indicating its presence” and responds with a list of stations that can be transmitted and received held by that station (step S4), the control unit (204) stores it. The station responding to the wireless terminal list of the unit (206) is registered as a station that can transmit and receive together with the list of stations that can be transmitted and received held by the station (step S5).

  When another wireless terminal transmits “communication indicating its presence” (step S6), it responds with a list of stations that can be transmitted / received currently held by itself (step S7).

  If the predetermined time has elapsed since the transmission of “communication indicating self-existence” (step S8), and if the predetermined time has elapsed, the “communication indicating self-existence” can be received. It is assumed that all wireless terminals have responded, and the process proceeds to a process for searching for a route (from step S9 to step S12).

  From the obtained wireless terminal list, N stations that are considered to exist at the boundary of the radio wave coverage are selected. The optimum number of N is determined for each system from the number of directions to relay and the number of peripheral wireless terminals. A station having many stations that cannot directly communicate with its own station selects the top N stations with the number of stations that cannot communicate directly as a station that seems to exist at the boundary of the radio wave coverage (step S9).

  Next, the selected top N stations are grouped with each other at a short distance (step S10). The number of groups corresponds to the number of directions in which communication is relayed. If the relay orientation is too small, a blank area of the relay is likely to be generated, and if there are too many orientations, the relay is overlapped, so that the transmission efficiency is lowered. Whether or not the station is near is determined by whether or not there are many common stations that can communicate.

  If grouping is possible, then the relative positional relationship between the groups is clarified (step S11). A group having a large number of common stations communicable between the groups is considered to be close in distance, and if it is small, it is considered to be far away, and the relative arrangement (position) of each group is determined.

  When the relative position of each group is determined, one or two stations having few common stations with the adjacent group are selected from each group to be candidates for relay stations (step S12).

  Since these processes are executed at regular intervals, relay station candidates are not always the same. In other words, there is a possibility that peripheral stations are moving, and there are stations that newly enter the wireless network, and there are stations that exit from the network. In a system in which station movement is frequent and fast, updating of relay station candidates must be frequently performed quickly.

  FIG. 11 shows a flow of actual transmission or relay using the relay station candidate obtained by the above route search processing. 14, various instructions such as a transmission instruction and information search request in the operation unit (207) of the wireless terminal (211) in FIG. 14, a call request in the voice input / output unit (209), or a fixed period or calendar generated from the clock unit (205). When communication with another wireless terminal is required due to generation of a communication request according to a schedule determined by a clock or transmission / reception of an external signal at the external input / output unit (210), the control unit (204) activates a transmission request program. To do. When a transmission request is generated or communication is relayed from another station (step S2 in FIG. 11), it is checked whether there is a receiving station that the transmitting station wants to send information to in the wireless terminal list held by the own station. (Step S3 in FIG. 11).

  If there is a receiving station in the communicable area of the own station, it is not necessary to designate a relay station, so that only the address of the receiving station (hereinafter sometimes abbreviated as ADR) is designated for transmission (or relay transmission) ( Step S4 in FIG.

  If there is no receiving station in the communicable area of the own station, it must be relayed to the next. Since there is no need to relay in the relayed or transmitted direction, it is determined in which group the relayed or transmitted station is located or close to which group. The determination method is based on whether or not there are many common stations (common stations that can transmit and receive) with each group in the wireless terminal list (step S5 in FIG. 11).

  When the direction (group) in which relaying or transmission has been performed is determined, a positive relay station is designated and transmitted from the primary and secondary relay stations selected in advance excluding the group (step S6 in FIG. 11).

  Since the radio wave from the positive relay station can be intercepted, whether or not the radio wave is transmitted to the next relay station is monitored by monitoring for a predetermined time (step S7 in FIG. 11).

  If there is no transmission to the next relay station as a result of the time monitoring, the ADR of the secondary relay station is designated and relay transmission is performed again (step S8 in FIG. 11).

  Whether the next relay station relays next is also monitored (step S9 in FIG. 11).

  When both the primary and secondary relay stations cannot relay, the relay in that direction is aborted. Alternatively, since the relay station may move and radio waves may not reach, the relay station candidate may be reselected to prepare for the next transmission request, or communication may be performed again (step S10 in FIG. 11). ).

  FIG. 12 shows a state of communication from the transmitting station (102) to the receiving station (106). Communication from the transmitting station (102) is directed not only in one direction but also in a plurality of directions, and a relay 1 station, a relay 2 station, a relay 3 station,... The communication path from the station to the receiving station (106) is shown. Further, although up to three relays are shown, the number of relays is not limited to three.

  When information from the transmitting station (102) is relayed to the receiving station (106), the receiving station (106) returns a response sentence to the transmitting station (102) using the reverse path.

  FIG. 13 shows an example of a communication format. A synchronization signal for synchronizing communication and a precarrier for detecting a communication collision are provided at the head. Next, the header part and control statements necessary for communication are continued, including a transmission source address (ADR), a reception destination ADR, a relay 1 station ADR, a relay 2 station ADR ... a communication sentence (text), an error check code, a post carrier, Continue. The relay route information (107) is information indicating the relay route by adding the ADR of the own station after the route information of the relay station that the relayed station has relayed before.

  The receiving station (106) replies to the transmitting station (102) by designating the route in the reverse direction based on the relay route information (107). The receiving station (106) may receive from a plurality of routes, and a rule is programmed in advance to use the route received fastest or select the route with the smallest number of routes.

  Upon receiving the response, the transmitting station (102) performs subsequent communication with the receiving station (106) using the route information obtained by the response as necessary.

A diagram for explaining a search method of a communication route of a wireless network Illustration of a relay method according to a conventional routing protocol Wireless terminal layout with the wireless terminal A1 as the center Wireless terminal list stored in wireless terminal A1 List of top 12 stations with many stations that wireless terminal A1 cannot communicate with Grouped list of top 12 stations with many stations that wireless terminal A1 cannot communicate with Distance related diagram of wireless terminal groups existing around wireless terminal A1 The relative position of the wireless terminal group existing around the wireless terminal A1 Relay station candidates for the wireless terminal group existing around the wireless terminal A1 Wireless terminal route search processing flow Flow that the wireless terminal transmits or relays Route from the transmitting station to the receiving station Example of communication format of wireless terminal Wireless terminal internal configuration diagram

Explanation of symbols

100 Transmission / reception area of wireless terminal A1 101 Transmission / reception area of wireless terminal B3 102 Transmitting station 103 Relay 1 station 104 Relay 2 station 105 Relay 3 station 106 Receiving station 107 Communication path information 201 Antenna 202 Wireless transmission / reception unit 203 Collision detection unit 204 Control unit 205 Clock unit 206 Storage unit 207 Operation unit 208 Display unit 209 Audio input / output unit 210 External input / output unit 211 Wireless terminal

Claims (10)

In a system in which a plurality of wireless terminals construct a wireless network in an autonomous and distributed manner,
Means for sending a wireless terminal list that can be transmitted and received by itself to other wireless terminals in the vicinity of the wireless terminal, in which communication indicating the presence of the wireless terminal is always repeated at regular intervals or randomly;
Means for responding by attaching a wireless terminal list that can be transmitted / received by the other wireless terminal that has received communication indicating the presence of the wireless terminal (hereinafter referred to as a wireless terminal list that can be transmitted / received);
Means for storing a list of wireless terminals of the plurality of wireless terminals existing around the wireless terminal that has received the response;
Means for counting the number of wireless terminals that the wireless terminal that has received the response cannot directly communicate with itself from the wireless terminal list and selecting a predetermined number of wireless terminals in order from the higher wireless terminal;
Means for classifying selected wireless terminals having a large number of wireless terminals in common that the wireless terminals receiving the response can be transmitted and received from the wireless terminal list into a predetermined number of groups;
The wireless terminal that received the response determines whether it is a group that is geographically distant or close from the number of wireless terminals that can be transmitted / received to each group after classifying the selected wireless terminal into a group Means for determining the relative position of the group;
Means for selecting at least one primary and secondary station candidate wireless terminals (hereinafter referred to as relay stations or stations) that relay communication from each group after the wireless terminal receiving the response determines the relative position of the group When,
A wireless network system comprising: A wireless terminal having information to be transmitted (hereinafter referred to as a transmitting station) includes an address of a wireless terminal (hereinafter referred to as a receiving station) from which information is to be received and a group of the wireless terminals existing around the transmitting station. The wireless network system according to claim 1, further comprising means for designating and transmitting an address of a positive relay station selected in advance. When the transmitting station specifies the address of the receiving station and the address of the positive relay station, and then transmits it, it monitors whether the relay is performed within a predetermined time. 2. The radio network system according to claim 1, further comprising means for attempting transmission again by designating an address of the sub-relay station previously selected in the group. The relay station designated by the address checks whether or not there is a receiving station in the held wireless terminal list. If the receiving station exists, the relay station does not specify the address of the next relay station, Means for relay transmission;
Means for designating and transmitting the address of a positive relay station preselected in a group of wireless terminals existing around the relay station if the receiving station is not present in the wireless terminal list;
The wireless network system according to claim 1, further comprising: The relay station designated by the address has means for adding the address of its own next to the address of the relay station written in order to indicate the route that has been relayed and specifying the address of the next relay station to transmit. The wireless network system according to claim 1, wherein: The relay station designated by the address is applicable if the previous transmitting station that requested the relay or the previous relay station is included in the group of wireless terminals existing around the relay station designated by the address Search for the group with the most wireless terminals that can be transmitted / received even if not included in the group and the address of the positive relay station previously selected in other groups except the corresponding group 2. The wireless network system according to claim 1, further comprising means for designating and transmitting. The relay station monitors whether or not the relay is performed within a predetermined time after specifying and transmitting the address of the positive relay station existing in each group. 2. The wireless network system according to claim 1, further comprising means for attempting transmission again by designating an address of a sub relay station preselected in the group. The wireless network system according to claim 1, wherein the relay station includes means for not relaying again when communication of the same content is relayed through another communication path or the same communication path within a predetermined time. 2. The wireless network according to claim 1, wherein the receiving station includes means for performing response communication by deciding the address of the relay station by going back the reception response to the transmission station and the relayed communication path. system. When the transmitting station continues communication with the receiving station after receiving the receiving response, the transmitting station includes means for performing communication by specifying the communication path receiving the response from the receiving station in reverse. The wireless network system according to claim 1.

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