JP2006129381A - Network participation method, repeater and repeating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a communication terminal to be more surely participated in a wireless network. <P>SOLUTION: A server device 1 is connected to a repeater 5a via a wired LAN 4, and other repeaters 5b and 5c including this repeater 5a are disposed at predetermined positions. When a communication terminal 6 communicates with the server device 1 on a wireless ad hoc network 3 via the plurality of repeaters 5a-5c, the communication terminal 6 accesses the specific repeater 5c to transmits its own IP address U, and the repeater 5c which receives the IP address U of the communication terminal 6 through this transmission, notifies the other neighboring repeater 5b of the IP address U to establish a communication path between the communication terminal 6 and the server device 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a network participation method, and more particularly to a network participation method suitable for participation in a wireless network.

In recent years, with the development of wireless technology, a technology for building a wireless network that does not require an access point has attracted attention. For example, the Internet Engineering Task Force (IETF), an organization that promotes standardization of Internet technology, is a routing protocol that implements a wireless network that is autonomously configured with communication terminals in the MANET WG (Mobile Ad-hoc Networks Working Group). Is being discussed.
The ad hoc network (Ad-hoc Network) technology is a technology for constructing a wireless network that is autonomously composed of communication terminals. In this technology, all communication terminals have a function as a router. Then, these communication terminals sequentially transfer packets to neighboring nodes. For example, when using the OLSR (The Optimized Link State Routing) protocol, which is one of the ad hoc network technologies, the source communication terminal dynamically changes the transfer destination after grasping the topology of the entire network. Thus, it is possible to communicate with the communication terminal of the other party (for example, Non-Patent Document 1).
"OLSR (The Optimized Link State Routing Protocol)", [online], [searched on August 1, 2004], Internet <URL: HYPERLINK "http://hipercom.inria.fr/olsr/" http: // hipercom.inria.fr/olsr/ ＞

  However, for example, when a mobile terminal such as PHS (Personal Handyphone System) or PDA (Personal Digital Assistant) is used as a communication terminal, the communication terminal does not function as a router due to restrictions on memory capacity, and the communication terminal is wireless. There were cases where the network could not be accessed.

  Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a network participation method that enables a communication terminal to more reliably participate in a wireless network, and a relay device and a relay method used therefor. Is to provide.

  In order to solve the above-mentioned problem, the present invention is a wireless network participation method of a wireless terminal that performs wireless network communication with a service providing apparatus via a plurality of relay devices, and the wireless terminal performs the wireless network communication In this case, the specific relay device is accessed to transmit its own address, and the relay device that has received the address of the wireless terminal by this transmission notifies the other adjacent relay device of the address, and A communication path between the wireless terminal and the service providing apparatus is established.

  According to the present invention, a communication terminal can more reliably participate in a wireless network.

FIG. 1 is a block diagram showing an entire system including a relay device according to an embodiment of the present invention. Here, a case where a wireless ad hoc network is constructed by installing three relay devices in a special venue (for example, a concert venue) will be described as an example.
In FIG. 1, a server device (service providing device) 1 is connected to a communication network 2 such as the Internet and a wired LAN (Local Area Network) 4. One wired relay device 5 a is connected to the wired LAN 4, and the relay device 5 a can communicate with the server device 1. The server device 1 uses a web server, for example, but may use a DHCP (Dynamic Host Configuration Protocol) server or the like.
The relay device 5a has a bidirectional relationship with the relay device 5b, and the relay device 5b has a bidirectional relationship with the relay device 5c. Note that the relay devices 5a to 5c are installed at fixed positions, respectively.

The communication terminal (wireless terminal) 6 communicates with the server device 1 by accessing any of the relay devices 5a to 5c described above. The communication terminal 6 is, for example, a mobile terminal such as a PHS, a PDA, or a mobile phone. Here, the communication terminal 6 is provided to a user in a special venue. With this configuration, a wireless ad hoc network (wireless network) 3 is constructed.
In addition, although the IP address and the MAC address are assigned to each of the devices 1, 5a to 5c, 6 shown in FIG. 1, details will be described later. Hereinafter, the relay devices 5a to 5c and the communication terminal 6 will be described in order.

FIG. 2 is a block diagram illustrating a configuration of the relay apparatus. Although the relay device 5c will be described here, the relay devices 5a and 5b have the same configuration.
In FIG. 2, the relay device 5c is a personal computer, for example, and includes a communication interface 51, a storage device 52, and a processing device 53 for controlling them. The communication interface 51 is a wireless interface or the like, and the storage device 52 is a memory, a hard disk, or the like.

The storage device 52 includes a routing table 521C and an ARP table 522C. ARP is an abbreviation for Address Resolution Protocol, and is a protocol for obtaining a MAC address from an IP address.
The routing table 521C stores associations between destination IP addresses and transfer destination IP addresses, and the ARP table 522C stores associations between IP addresses and MAC addresses. These tables 521C and 522C are updated according to the access status from the communication terminal 6.
The processing device 53 is a CPU or the like, and operates according to a relay program incorporated in the relay device 5c. The relay program described above may be stored in a predetermined area of the storage device 52 in advance, or may be read from a computer-readable recording medium such as a CD-ROM.

  FIG. 3 is a block diagram showing the configuration of the communication terminal 6. In FIG. 3, the communication terminal 6 includes a communication interface 61, a storage device 62, an input device 63, a display device 64, and a processing device (CPU) 65 that controls them. The communication interface 61 is a wireless interface, and the storage device 62 is a memory, a hard disk, or the like. The input device 63 is an operation button or the like, and the display device 64 is a computer display or the like.

  The storage device 52 includes a routing table 621 and an ARP table 622. The routing table 621 stores associations between destination IP addresses and transfer destination IP addresses, and the ARP table 622 stores associations between IP addresses and MAC addresses. “U” in the routing table 621 represents the IP address of the communication terminal 6, and “R” represents the representative address of the default gateway. The communication terminal 6 can access any relay device 5a to 5c using the representative address R. The ARP table 622 stores the association between the representative address R and the MAC address c, which will be described in detail later. The MAC address c is the MAC address of the relay device 5c.

[Communication terminal joining process]
Next, a process in which the communication terminal 6 participates in the ad hoc network 3 shown in FIG. 1 will be described based on FIGS. 4 and 5. Here, a case where a user at a special venue operates the communication terminal 6 to check a web page from the server device 1 will be described as an example.
FIG. 4 is a diagram illustrating a processing procedure in which the communication terminal 6 participates in the wireless ad hoc network 3.
First, the user operates the communication terminal 6 shown in FIG. 3 to transmit an ARP request packet. The ARP request packet is a packet for acquiring a MAC address from an IP address, and here, the representative address R described above is used as the IP address. Then, the relay device close to the communication terminal 6, for example, the processing device 53 of the relay device 5c shown in FIG. 2, receives the ARP request packet from the communication terminal 6 (S10).
Subsequently, the processing device 53 transmits an ARP response packet corresponding to the ARP request packet to the communication terminal 6 (S11). The transmitted ARP response packet is added with its own MAC address, that is, the MAC address c of the relay device 5c. As a result, the communication terminal 6 receives the ARP response packet and sets the association between the MAC address c of the relay device 5c and the representative address R in the ARP table 622 (see FIG. 3).
Then, the communication terminal 6 transmits the web request of the server device 1 to the relay device 5c using the MAC address c of the relay device 5c set in the ARP table 622. The IP address U of the communication terminal 6 is added to the web request.

  Then, the processing device 53 of the relay device 5c shown in FIG. 2 receives the web request from the communication terminal 6 (S12). Subsequently, the processing device 53 registers the IP address U of the communication terminal 6 added to the web request received in S12 in the routing table 621 in FIG. 2, and sets the MAC address u of the communication terminal 6 in the ARP in FIG. Register in the table 622 (S13). Then, the processing device 53 transmits the web request received in S12 to the other relay device 5b (S14). The IP address U of the communication terminal 6 is added to the transmitted web request. In this way, the relay device 5c notifies the IP address U of the communication terminal 6 to the other adjacent relay device 5b. Then, the relay device 5b also transmits a web request with the IP address U of the communication terminal 6 added to the relay device 5a. Finally, the relay device 5a sends the web request from the communication terminal 6 to the server device. Will be sent to 1. FIG. 5 shows the setting states of the routing tables 521A to 521C and 621 and the ARP tables 522A to 522C and 622 for the communication terminal 6 and the relay devices 5a to 5c at this time.

  According to FIG. 5, the IP address “U” of the communication terminal 6 is set as the destination IP address in the routing tables 521A to 521C of all the relay devices 5a to 5c (see the inside of the thick frame). The IP addresses “B”, “C”, and “U” of the adjacent devices 5b, 5c, and 6 are respectively set in the transfer destination IP addresses of the routing tables 521A to 521C (inside the thick frames) reference). That is, the transfer address matches the communication path between the communication terminal 6 and the server device 1 described above. As a result, it is possible to establish a communication path between the communication terminal 6 and the server device 1. Assume that on the tables 521A to 521C and 522A to 522C shown in FIG. 5, associations other than those relating to the communication terminal 6 (that is, those other than those within the thick frame in FIG. 5) are set in advance.

  Thereafter, the server device 1 transmits a web response corresponding to the web request from the communication terminal 6 to the relay device 5a. Then, the relay device 5a refers to the routing table 521A and the ARP table 522A illustrated in FIG. 5 and transfers the web response to the transfer destination relay device 5b. Similarly, the relay device 5b also transfers the web response to the transfer destination relay device 5c. And by this transfer, the relay apparatus 5c receives a web response from the other relay apparatus 5b, and transmits the received web response to the communication terminal 6 (S15 in FIG. 4). As a result, the web data indicating the web response is displayed on the communication terminal 6, and the user confirms the content. Therefore, when the user operates the communication terminal 6 to access any one of the relay devices 5a to 5c, the communication terminal 6 can surely participate in the wireless ad hoc network 3 without functioning as a router. Can do. Moreover, since the communication terminal 6 does not need to function as a router, memory resources and battery consumption can be saved. Therefore, a mobile terminal with limited memory resources can be used as the communication terminal 6, which is beneficial.

[Continuation confirmation process of communication terminal in relay device]
Thereafter, the relay device 5 c illustrated in FIG. 5 performs processing for confirming a bidirectional relationship with the communication terminal 6. Here, this is called “communication terminal participation continuation confirmation processing”.
FIG. 6 is a diagram illustrating a procedure relating to a communication terminal participation continuation confirmation process in the relay device.
The processing device 53 of the relay device 5c transmits a survival confirmation packet to the communication terminal 6 of FIG. 5 (S21). This survival confirmation packet is a packet for maintaining a bidirectional relationship with the communication terminal 6.

In this case, for example, if the communication terminal 6 of FIG. 5 exists in the communication area of the relay device 5c, the communication terminal 6 receives the survival confirmation packet and returns it to the relay device 5c. The MAC address u of the communication terminal 6 is added to the returned survival confirmation packet. Then, the processing device 53 of the relay device 5c receives a survival confirmation packet from the communication terminal 6 within a valid period (for example, a predetermined time set in advance) (in the case of “Yes” in S22), The ARP table 522C in FIG. 5 is updated using the added MAC address u of the communication terminal 6 (S23), and the process returns to S21. In the update of S23, the setting state of the ARP table 522C illustrated in FIG. 5 is maintained. The valid period is stored in a predetermined area of the storage device 52 of the relay device 5c shown in FIG.
In this way, the relay device 5c continues to transmit the survival confirmation packet to the communication terminal 6 at regular intervals, and performs confirmation for maintaining the bidirectional relationship with the communication terminal 6. Thereby, the communication terminal 6 can maintain a bidirectional relationship with the relay device 5c.

  On the other hand, when the communication terminal 6 cannot communicate with the relay device 5c of FIG. 5 because the user using the communication terminal 6 of FIG. 5 has moved in S22, for example, the relay device 5c The survival confirmation packet cannot be received from the communication terminal 6 within the effective period (in the case of “No” in S22), and the transmission of the survival confirmation packet is stopped (S24). Thereby, the communication terminal 6 can stop the bidirectional relationship with the relay device 5c.

[Communication terminal participation continuation / removal processing in relay device]
Next, a process in which the communication terminal 6 in FIG. 5 that maintains the bidirectional relationship with the relay device 5c in FIG. 5 continues to participate in or leaves the wireless ad hoc network 3 will be described. Here, the processing of the relay device 5c in FIG. 5 will be mainly described. This process is referred to as “communication terminal participation continuation / leaving process”.
FIG. 7 is a diagram illustrating a procedure relating to a communication terminal participation continuation confirmation process in the relay device.
When the processing device 53 of the relay device 5c shown in FIG. 2 receives a web request from the communication terminal 6 of FIG. 5 within a preset valid period (in the case of “Yes” in S31), the processing device 53 of FIG. The routing table 521C is updated similarly to the processing from S15 to S15 (S32). Here, the routing table 521C is the same as the association shown in FIG. The processing device 53 transmits a web request from the communication terminal 6 to another relay device 5b (S33), and then transmits a web response from the relay device 5b to the communication terminal 6 (S34). The valid period is stored in a predetermined area of the storage device 52 shown in FIG.

  On the other hand, when the processing device 53 does not receive a web request from the communication terminal 6 of FIG. 5 within the preset effective period (in the case of “No” in S31), the routing shown in FIG. The IP address of the communication terminal 6 is deleted from the table 521C (see inside the thick frame), and the IP address U of the communication terminal 6 is deleted from the ARP table 522C (see inside the thick frame) shown in FIG. 5 (S35). . Then, the processing device 53 notifies the other adjacent relay device 5b of the fact that the bidirectional relationship with the communication terminal 6 has been disconnected due to the deletion of S35, that is, the information that the link has been disconnected (S36). The notified information includes the IP address U of the communication terminal 6.

  Then, similarly to the relay device 5c, the relay device 5b also deletes the IP address U of the communication terminal 6 from the routing table 521B (see the thick frame) shown in FIG. 5, and the ARP table 522B shown in FIG. The IP address U of the communication terminal 6 is deleted from (refer to the inside of the thick frame). Then, the relay device 5b also notifies the other adjacent relay device 5a of information that the bidirectional relationship with the communication terminal 6 has been disconnected. As a result, the relay device 5a also deletes the IP address U of the communication terminal 6 from the routing table 521A (see the bold frame) shown in FIG. 5, and also the ARP table 522A (see the bold frame) shown in FIG. ) To delete the IP address U of the communication terminal 6. As a result, the communication path between the communication terminal 6 and the server device 1 is released. In this way, the communication terminal 6 can continue to participate in the wireless ad hoc network 3 or leave the wireless ad hoc network 3.

The present invention is not limited to the embodiment described above. Although the case where the communication terminal 6 accesses the relay device 5c has been described in the present embodiment, for example, the case where the communication terminal 6 accesses another relay device 5a, 5b can also be applied.
The number of communication terminals 6, relay devices 5a to 5c, and server device 1 may be changed. For example, another server device may be connected to the communication network 2 shown in FIG. 1 and communication may be performed between this server device and the communication terminal 6.
Furthermore, the configuration (including the data structure) of the relay devices 5a to 5c and the program processing procedure can be variously changed by a known technique.

It is a block diagram which shows the whole system containing the relay apparatus which concerns on embodiment of this invention. It is a block diagram which shows the structure of the relay apparatus of FIG. It is a block diagram which shows the structure of the communication terminal of FIG. It is a process procedure of the relay apparatus of FIG. 1 and is a diagram showing a procedure related to a process for a communication terminal to join a wireless ad hoc network. It is a figure which shows the setting state of the routing table and ARP table about a communication terminal and each relay apparatus when the communication terminal of FIG. 1 participates in a wireless ad hoc network. It is a figure which shows the procedure regarding the participation continuation confirmation process of the communication terminal in the relay apparatus of FIG. It is a figure which shows the procedure regarding the joining continuation / detachment process of the communication terminal in the relay apparatus of FIG.

Explanation of symbols

1 Server device (service providing device)
5a, 5b, 5c Relay device 6 Communication terminal (wireless terminal)

Claims (9)

A wireless network participation method of a wireless terminal that performs wireless network communication with a service providing device via a plurality of relay devices,
When the wireless terminal performs the wireless network communication, the wireless terminal accesses the specific relay device and transmits its own address, and the relay device that has received the address of the wireless terminal by this transmission transmits the address to the other relay device. A wireless network joining method, characterized in that a communication path between the wireless terminal and the service providing apparatus is established by notifying the adjacent relay apparatus. A relay device that relays wireless network communication between a service providing device and a wireless terminal,
A storage device and a processing device for controlling the storage device, the storage device storing an address for communicating with the service providing device and the other relay device;
The processor is
If a request for wireless network communication with the service providing apparatus is received from the wireless terminal, the address assigned to the wireless terminal is received from the wireless terminal and registered in the storage device,
Notifying the other relay device of the address of the wireless terminal read from the storage device and registering the address, and the service corresponding to the request from the wireless terminal from the other relay device that has been registered A relay device that receives a response from a providing device and transmits the received response to the address of the wireless terminal read from the storage device. A representative address of a default gateway is set in the storage device,
The relay device according to claim 2, wherein the processing device receives the request for the wireless network communication after obtaining the representative address set in the storage device from the wireless terminal. The processor is
When the address of the wireless terminal is registered in the storage device, it continues to transmit a survival confirmation packet for maintaining a bidirectional relationship with the wireless terminal to the wireless terminal at regular intervals, and the wireless The relay apparatus according to claim 2, wherein when the existence confirmation packet is not received from a terminal for a predetermined period, transmission of the existence confirmation packet to the wireless terminal is stopped. The processor is
When the address of the wireless terminal is registered in the storage device, if the request from the wireless terminal is not within the preset effective period, the address of the wireless terminal is stored in the storage device. As well as deleting
Informing the other adjacent relay device of information indicating that the two-way relationship with the communication terminal has been disconnected due to the deletion, and releasing the communication path between the wireless terminal and the service providing device. The relay apparatus according to claim 2. A relay method of a relay device that relays wireless network communication between a service providing device and a wireless terminal,
The relay device includes a storage device and a processing device that controls the storage device, and the storage device stores an address for communicating with the service providing device and the other relay device,
The processor is
When receiving a request for wireless network communication with the service providing apparatus from the wireless terminal, receiving an address assigned to the wireless terminal from the wireless terminal and registering it in the storage device;
Notifying the other relay device of the address of the wireless terminal read from the storage device and registering the address; and the service corresponding to a request from the wireless terminal from the other relay device registered Receiving the response of the providing device, and transmitting the received response to the address of the wireless terminal read from the storage device. A representative address of a default gateway is set in the storage device,
The relay method according to claim 6, wherein the processing device receives the request for wireless network communication after obtaining the representative address set in the storage device from the wireless terminal. The processor is
When registering the address of the wireless terminal in the storage device, continuing to transmit to the wireless terminal a survival confirmation packet for maintaining a bidirectional relationship with the wireless terminal;
The method further comprises the step of: stopping the transmission of the survival confirmation packet to the wireless terminal when the survival confirmation packet is not received from the wireless terminal that has continued to transmit for a predetermined period of time. The relay method described. The processor is
When the address of the wireless terminal is registered in the storage device, if the request from the wireless terminal is not within the preset effective period, the address of the wireless terminal is stored in the storage device. A step to delete,
Notifying the other neighboring relay device of information indicating that the two-way relationship with the communication terminal has been disconnected due to the deletion, and releasing the communication path between the wireless terminal and the service providing device The relay method according to claim 6, further comprising:

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