JP4796427B2 - Wireless communication system - Google Patents

Description

  The present invention relates to a wireless communication system that supports communication in a wireless terminal device, and more particularly to a system including a wireless relay station.

FIG. 8 shows a communication system 100 that supports communication in a wireless terminal device in a conventional example. The communication system 100 includes an information transfer device 10, a backbone communication network (core network) 12, base station devices 14-1 to 14-n, communication lines 16L-1 to 16L-n, and wireless terminal devices 18-1-1-1. -N- _mn (n is a positive integer indicating the number of base station apparatuses connected to the information transfer apparatus 10, and _mn is an arbitrary positive integer corresponding to n). The information transfer apparatus 10 includes communication ports 16-0 to 16-n. The information transfer apparatus 10 is connected to the backbone communication network 12 via an upstream communication port (trunk port) 16-0 and a communication line 16L-0. Base station apparatuses 14-1 to 14-n are connected to communication ports (access ports) 16-1 to 16-n via communication lines 16L-1 to 16L-n, respectively.

The information transfer apparatus 10 transmits / receives information to / from the backbone communication network 12 via the communication port 16-0 and the communication line 16L-0. The information transfer apparatus 10 transmits / receives information to / from the base station apparatus 14-i via the communication port 16-i and the communication line 16L-i (i is an integer of 1 to n). The base station device 14-i performs transmission / reception of information by wireless communication with the wireless terminal devices 18-i-1 to 18-i-m _i (m and i are arbitrary positive integers). Area in which radio terminal apparatuses 18-i-1 to 18-i-m _i (m _i is an arbitrary positive integer corresponding to i) can transmit / receive information to / from base station apparatus 14-i Is the base station area 20-i. Further, the entire area including the base station areas 20-1 to 20-n is defined as a service area.

The communication ports 16-0 to 16-n and the wireless terminal apparatuses 18-1-1-1 to 18-n- _mn are the basic communication network 12 or other communication networks (not shown) connected to the basic communication network 12. A unique IP address is assigned that can be identified at. In general, an IP address is a 32-bit binary number divided into 8 bits and expressed by four decimal numbers such as “X1.X2.X3.X4”. When the IP address is expressed in binary, a binary number consisting of a predetermined number of upper digits is a network address, and a binary number consisting of the remaining lower digits is a host address. In the following description, the lower 8 bits are a host address.

The radio terminal device 18-i-1~18-i- m you, with assigned a common network address, different host addresses are allocated, respectively. For example, the wireless terminal apparatuses 18-1-1 to 18-1-m ₁ in FIG. 8 have IP addresses “10.1.1.1”, “10.1.1.2”,. 10.1.1.m ₁ ”is assigned to the wireless terminal apparatuses 18-2-1 to 18-2-m ₂ as IP addresses“ 10.1.2.1 ”and“ 10.1.2 ”, respectively. .2 ”,...“ 10.1.2.m ₂ ”are allocated. Similarly, until the i becomes n, the wireless terminal devices 18-i-1 to 18-i-m _i have IP addresses of “10.1.i.1” and “10.1.i.2”, respectively. ,... "10.1.i.m _i " is assigned.

The communication port 16-i has the same network address as that assigned to the wireless terminal devices 18-i-1 to 18 -i-m _i and the wireless communication terminals 18-i-1 to 18 -i-m _i. A host address different from the host address assigned to each is assigned. For example, “10.1.1.254” to “10.1.n.254” are assigned as IP addresses to the communication ports 16-1 to 16-n in FIG.

The information transfer device 10 receives packet information from the backbone communication network 12. The packet information includes an IP address that identifies one of the wireless communication terminals 18-i-1 to 18-i- _mn and data that the packet information is to be transmitted. Then, the data in the wireless terminal device 18-i-1~18-i- m radio terminal apparatus identified by the IP address of the _n 18-i-j (j is any integer of 1 to m _i) Packet information is transmitted from the communication port 16-i so as to be acquired. The base station device 14-i receives the packet information, converts it into a radio signal, and transmits it. The wireless terminal device 18-ij acquires packet information addressed to itself.

Japanese Patent Laid-Open No. 2005-21677 JP 2003-188911 A

  Here, in a wireless communication system that uses a wireless system that assumes communication between a transmission point and a reception point in wireless communication and that does not have a blocking object and is in a line-of-sight environment, there are blocking objects in areas where radio waves do not reach. In order to provide a wireless connection or extend the distance for wireless communication, it is considered preferable to provide a wireless relay station between the wireless base station and the terminal. Therefore, efficient packet path control is desired in a system having this wireless relay station. If the same thing is realized only by the radio base station without using the radio relay station, there arises a restriction that a wiring cost is required for wired connection between the radio base stations. Therefore, it is desired to construct a low-cost system while supporting communication over a wide range using a radio relay station.

  Furthermore, when a wireless terminal device moves in a system having a wireless relay station, it is necessary to cope with this in the information transfer device and the wireless relay station.

  The present invention is a wireless communication system that supports communication in a wireless terminal device, and includes a backbone communication network that transfers information based on a layer 3 address, an upstream communication port connected to the backbone communication network, and a plurality of downstream Transfer device that has a communication port and controls the transfer of information between its own upstream communication port and a plurality of downstream communication ports, and the upstream communication port is a plurality of downstream sides of the information transfer device A plurality of first radio base stations that are connected to any one of the communication ports, have a downstream radio communication port, and control transfer of information between the upstream communication port and the radio communication port thereof; The upstream communication port is wirelessly connected to the wireless communication port of the first wireless base station, and has at least one downstream communication port. Between the first wireless base station and its own communication port A wireless relay station for controlling the transfer of information, and an upstream communication port connected to a downstream communication port of the wireless relay station, a downstream wireless communication port, and the wireless relay station and its own wireless communication port A second wireless base station that controls transfer of information between the wireless terminal device and a wireless terminal device that is wirelessly connected to a wireless communication port of the first or second wireless base station, the information transfer device comprising: A path control table for storing a relationship between a layer 3 address of the wireless terminal device used in the communication network and a communication port of the wireless terminal device that reaches the first or second wireless base station to which the wireless terminal device is connected; The information received from the backbone communication network is transferred only to the communication port determined according to the layer 3 address, and the wireless terminal device connected to the first or second wireless base station is changed. Is when there is a routing table the change is transmitted to the information transfer apparatus is characterized in that it is updated about the change.

  The information transfer apparatus has a function of assigning and transferring a layer 2 address on the downstream side of the layer 3 address to the layer 3 address. The radio relay station has a plurality of communication ports, and the radio relay station A relay station path control table that stores a relationship between a layer 2 address that identifies a wireless terminal device connected downstream thereof and a communication port of its own reaching a second wireless base station to which the wireless terminal device is connected; When the information received from the first radio base station is transferred only to its own communication port determined according to the destination address, and the radio terminal device connected to the second radio base station is changed The change is transmitted to the radio relay station, and the relay station routing control table is updated for the change.

  According to the present invention, by using a wireless relay station, communication can be ensured even when the wireless terminal device moves to a place where the line of sight cannot be seen, and no wired wiring is required, thereby reducing wiring costs. . The information transfer device stores, in the routing table, the relationship between the layer 3 address of the wireless terminal device existing under its control and the communication port of its own reaching the wireless base station to which they are connected. Therefore, it is possible to determine a communication port to be output according to the destination address of the information layer 3 and output information from the communication port. Further, for the wireless terminal device in which the wireless relay station exists on the downstream side, the relationship between the layer 2 address and its own communication port reaching the wireless base station to which they are connected is stored in the route control table. Therefore, a communication port to be output can be determined according to the layer 2 address of information, and information can be output from the communication port. For this reason, it is possible to perform communication between a terminal of a backbone network, a wireless terminal, and wireless terminals without generating unnecessary traffic such as broadcast communication. Further, when the wireless terminal device moves, the route control table can be updated, so that the wireless terminal device can also be moved.

"Basic system"
FIG. 1 shows a configuration of a communication system 102 according to the basic form of the present invention. The same components as those of the communication system 100 shown in FIG. 8 are denoted by the same reference numerals and description thereof is omitted.

  The communication system 102 includes a backbone communication network 12, an information transfer device 22, base station devices 24-1 to 24-n, wireless terminal devices 26-1 to 26-m, and communication lines 28L-1 to 28L-n. (N is a positive integer indicating the number of base station devices 24 connected to the information transfer device 22, and m is a positive integer indicating the number of wireless terminal devices).

  The information transfer device 22 includes an upstream communication port (trunk port) 28-0, downstream communication ports (access ports) 28-1 to 28-n, and a table storage unit 22a. The information transfer device 22 is connected to the backbone communication network 12 from the upstream communication port 28-0 via the communication line 28L-0. Base station apparatuses 24-1 to 24-n are connected to communication ports 28-1 to 28-n via communication lines 28L-1 to 28L-n, respectively.

  The communication port 28-0 and the communication ports 28-1 to 28-n respectively have Mac addresses MacPx and MacP1 to MacPn, which are identification codes unique to hardware. The wireless terminal devices 26-1 to 26-m have Mac addresses Mac1 to Macm, respectively. The Mac address is a permanent identification code that is not changed by the counterpart device that performs communication.

  Further, the communication port 28-0 and the communication ports 28-1 to 28-n have port numbers Px and P1 to Pn, respectively, in addition to the MAC address. The port number is a number for identifying a communication port in processing executed by the information transfer apparatus 22 and is a number uniquely assigned in the information transfer apparatus 22.

  The base station device 24-i (i is an integer of 1 to n) communicates with a specific wireless terminal device among the wireless terminal devices 26-1 to 26-m in accordance with a predetermined wireless communication protocol to which a Mac address is applied. Packet information is transmitted and received by wireless communication. As the wireless communication protocol, it is preferable to apply IEEE 802.16 or the like.

  Between the wireless terminal device 26-j (j is an integer of 1 to m) and at least one of the base station devices 24-1 to 24-n, the predetermined wireless communication protocol is established before the wireless communication network is established. The following processing is executed according to the above.

  The wireless terminal device 26-j performs preliminary wireless communication with the base station device 24-i, and the base station device 24-i is different from the wireless terminal device 26-j. (K is an integer from 1 to m different from j), the frequency of communication with the base station device 24-i, the goodness of the propagation status of electromagnetic waves transmitted to and received from the base station device 24-i, and up to the base station device 24-i Measure the communication goodness defined by distance and so on. Then, based on the communication goodness, one that performs wireless communication is selected from the base station devices 24-1 to 24-n. The wireless terminal device 26-j transmits information including the Mac address Macj to the selected base station device 24-i. The base station device 24-i that has received the information recognizes the Mac address Macj.

  Through such processing, the base station device 24-i recognizes the Mac address Macj of the wireless terminal device 26-j with which the base station device 24-i communicates. For example, in the communication system 102 of FIG. 1, the base station device 24-1 recognizes Mac addresses Mac1, Mac3, and Mac7, the base station device 24-2 recognizes Mac addresses Mac2, Mac6, and Mac8, and the base station device 24 -N recognizes Mac addresses Mac4, Mac5 and Macm. The base station devices 24-1 to 24-n transmit and receive packet information by wireless communication with the wireless terminal device 24-j specified by the recognized Mac address Macj. A region where the wireless terminal device 26-j can transmit / receive information to / from the base station device 24-i is defined as a base station area 30-i.

  A unique IP address defined in the backbone communication network 12 is assigned to each of the communication ports 28-0 to 28-n. A common network address and different host addresses are assigned to the communication ports 28-1 to 28-n. In the information transfer apparatus 22 of FIG. 1, “10.1.3.3.1” is assigned to the communication port 28-0 as an IP address, and “10.1.2.1” is assigned to the communication ports 28-1 to 28-n as IP addresses. 1 "to" 10.1.2.n "are assigned. However, the upper 24 bits of the IP address are the network address and the lower 8 bits are the host address.

  The IP addresses of the communication ports 28-0 to 28-n are assigned in advance when the information transfer device 22 and the base station devices 24-1 to 24-n are installed, whereas the wireless terminal devices 26-1 to 26- The IP address of m is assigned later by the wireless terminal registration process described below, which is executed between the information transfer apparatus 22 and the base station apparatuses 24-1 to 24-n.

  The wireless terminal registration process will be described with reference to the sequence diagram of FIG. Here, a description will be given together with a specific example in which when the base station device 24-1 newly recognizes the Mac address Mac7 of the wireless terminal device 26-7, the IP address of the wireless terminal device 26-7 is newly assigned. In this example, before an IP address is assigned to the wireless terminal device 26-7, the wireless terminal devices 26-1 to 26-3 are assigned IP addresses “10.1.2.n + 1” to “10.1. 2.n + 3 "has already been assigned, and the assignment of IP addresses to other wireless terminal devices 26-4 to 26-m has not been completed.

  When the base station device 24-i newly recognizes the Mac address Macj, the base station device 24-i sends the connection notification packet information including the connection notification packet identifier in the header portion and the new Mac address Macj in the data portion to the communication line 28L-i. And it transmits to the information transfer apparatus 22 via the communication port 28-i (S1). In the example of FIG. 1, connection notification packet information including a new Mac address Mac7 in the data portion is transmitted to the information transfer device 22 via the communication line 28L-1 and the communication port 28-1.

  When the information transfer device 22 determines that the connection notification packet identifier is included in the header portion of the packet information received from the communication port 28-i, the information transfer device 22 extracts the Mac address Macj included in the data portion (S2). In the example of FIG. 1, the Mac address extracted from the data part is Mac7.

  The information transfer device 22 determines an IP address corresponding to the extracted Mac address Macj (S3). The network address of the IP address to be determined is the same as the common network address assigned to the communication ports 28-1 to 28-n. The host address of the IP address to be determined is different from any of the host addresses assigned to the communication ports 28-1 to 28-n, and is already assigned to the wireless terminal device 26-k other than the wireless terminal device 26-j. It shall be different from any of the already assigned host addresses. In the example of FIG. 1, the information transfer apparatus 22 determines that the IP address corresponding to the Mac address Mac7 is “10.1.2.n + 7”. The assigned host address is different from any of the host addresses “n + 1” to “n + 3” already assigned to the wireless terminal devices 26-1 to 26-3.

  If the wireless terminal devices 26-1 to 26-m existing in the base station areas 30-1 to 30-n are constant, IP addresses are associated with the Mac addresses Mac1 to Macm in advance. The information may be stored in advance in storage means (not shown) of the information transfer device 22. In this case, the same network address as the common network address assigned to the communication ports 28-1 to 28-n is associated with the Mac addresses Mac1 to Macm, and assigned to the communication ports 28-1 to 28-n. A different host address is associated with each of the Mac addresses Mac1 to Macm. In step S3, the information transfer device 22 may determine an IP address corresponding to the extracted Mac address Macj based on the information stored in the storage unit.

  The information transfer device 22 adds the contents of the address correspondence table TB stored in the table storage unit 22a based on the determined IP address (S4). As shown in FIG. 3A, the address correspondence table TB includes the determined IP address, the port number Pi of the communication port 28-i from which the connection notification packet information is received, and the data portion of the connection notification packet information. It is a table in which the included Mac address Macj is associated.

  In the communication system 102, the address correspondence table TB is connected to an IP address determined as an IP address to be assigned to the wireless terminal device 26-j and a base station device 24-i that transmits / receives information to / from the wireless terminal device 26-j. It has a meaning as a table in which the port number Pi of the communication port 28-i is associated with the Mac address Macj of the wireless terminal device 26-j.

  In the address correspondence table TB of FIG. 3A, “10.1.2.n + 1” is determined as the IP address for the wireless terminal device 26-1 having the Mac address Mac1, and the port number of the communication port 28-1 P1 is associated. Further, “10.1.2.n + 2” is determined as the IP address for the wireless terminal device 26-2 having the Mac address Mac2, and the port number P2 of the communication port 28-2 is associated therewith. Further, “10.1.2.n + 3” is determined as the IP address for the wireless terminal device 26-3 having the Mac address Mac3, and the port number P1 of the communication port 28-1 is associated.

  The information transfer device 22 determines the IP address determined for the Mac address Macj included in the data portion of the connection notification packet information, the port number Pi of the communication port 28-i that has received the connection notification packet information, and the connection notification. Information associated with the Mac address Macj included in the data part of the packet information is added to the address correspondence table TB and stored in the table storage unit 22a. In the example of FIG. 1, the information transfer device 22 has the IP address “10.1.2.n + 7” determined for the Mac address Mac7, and the port number P1 of the communication port 26-1 that has received the connection notification packet information. The MAC address Mac7 included in the data part of the connection notification packet information is associated, the address correspondence table TB is updated as shown in FIG. 3B, and stored in the table storage unit 22a.

  When the information transfer device 22 updates the address correspondence table TB, the header portion includes the address assignment packet identifier, the data portion includes the Mac address Macj, the IP address corresponding to the Mac address Macj, and the Mac address of the communication port 28-i. The address assignment packet information including MacPi is transmitted to the base station apparatus 24-i via the communication port 28-i and the communication line 28L-i (S5). In the example of FIG. 1, the information transfer device 22 includes the MAC address Mac7 in the data portion, the IP address “10.1.2.n + 7” corresponding to the Mac address Mac7, and the Mac address MacP1 of the communication port 28-1. The address assignment packet information is transmitted to the base station device 24-1 via the communication port 28-1 and the communication line 28L-1.

  If the base station device 24-i determines that the header of the received packet information includes the address assignment packet identifier, the base station device 24-i extracts the Mac address Macj, the IP address, and the Mac address MacPi from the data portion. Then, packet information including the IP address and the Mac address MacPi is transmitted to the wireless terminal device 26-j having the Mac address Macj (S6). The wireless terminal device 26-j extracts and stores the IP address and Mac address MacPi from the received packet information (S7). In the example of FIG. 1, if the base station apparatus 24-1 determines that the address-added packet identifier is included in the header portion of the received packet information, the MAC address Mac7 and the IP address “10.1.2” from the data portion. .N + 7 ”and the Mac address MacP1 is extracted. Then, information including the IP address “10.1.2.n + 7” and the Mac address MacP1 is transmitted to the wireless terminal device 26-7 having the Mac address Mac7. The wireless terminal device 26-7 extracts and stores the IP address “10.1.2.n + 7” and the Mac address MacP1 from the received information.

  The process in which the wireless terminal device 26-j obtains the IP address and the Mac address MacPi from the information transfer device 22 can also be performed by a widely known ARP (Address Resolution Protocol).

  Here, an example in which IP addresses have already been assigned to the wireless terminal devices 26-1 to 26-3 has been described, but an IP address is assigned to any of the wireless terminal devices 26-1 to 26-m. Even if not, the process in which the information transfer device 22 updates the address correspondence table TB is performed in the same manner. In this case, the contents of the table are added from the top column of the address correspondence table TB.

  In the above description, the wireless terminal registration process is started when the base station device 24-i recognizes a new Mac address Macj. However, the wireless terminal registration process is started at a predetermined time interval. Also good.

  According to the wireless terminal registration process, the same network address as the common network address assigned to the communication ports 28-1 to 28-n is assigned to the wireless terminal devices 26-1 to 26-m. Further, different host addresses from the host addresses assigned to the communication ports 28-1 to 28-n are assigned to the wireless terminal devices 26-1 to 26-m, respectively. In addition, the wireless communication terminals 26-1 to 26-m can acquire and store the Mac address Pi of the communication port 28-i to which the base station device 24-i that transmits and receives information to and from the wireless communication terminals 26-1 to 26-m is connected. .

  Processing in which the wireless terminal devices 26-1 to 26-m of the communication system 102 acquire packet information from the backbone communication network 12, and the wireless terminal device 26-j of the communication system 102 is transferred to another wireless terminal device 26-k. Processing for transmitting packet information will be described. It is assumed that IP addresses have already been assigned to the wireless terminal devices 26-1 to 26-m by the wireless terminal registration process. In addition, the wireless terminal devices 26-1 to 26-m acquire and store the Mac address Pi of the communication port 28-i to which the base station device 24-i that transmits / receives information to / from itself is connected by wireless terminal registration processing. Suppose you are.

  Packet information Pck transmitted / received between the backbone communication network 12 and the information transfer device 22, packet information Pck transmitted / received between the information transfer device 22 and the base station devices 24-1 to 24-n, and a base station device The packet information Pck transmitted / received between the 24-i and the wireless terminal device 26-j includes a first header part H1, a second header part H2, and a data part DA as shown in FIG. Consists of. The first header portion H1 includes a destination address D1 and a source address S1, and the second header portion H2 includes a destination address D2 and a source address S2. The destination address D1 is set with the mac address of the device that transfers the packet information to the device that is the destination of the packet information Pck or the device that is the destination of the packet information Pck. In the destination address D2, the IP address of the device that is the destination of the packet information Pck is set. The MAC address of the device that is the transmission source or transfer source of the packet information Pck is set in the transmission source address S1, and the IP address of the device that is the transmission source of the packet information Pck is set in the transmission source address S2. The data part DA includes data to be transmitted by the packet information Pck.

  The processing executed by the information transfer device 22 will be described with reference to the flowchart of FIG. The information transfer device 22 receives the information packet Pck via any one of the communication ports 28-0 to 28-n (S11).

  If the destination address D1 of the packet information Pck matches the MAC address assigned to the communication port that received the packet information Pck, the information transfer device 22 refers to the network address assigned to the communication port. It is determined that the packet information Pck is addressed to a device that performs communication via a communication port to which a different network address is assigned. In that case, the information transfer device 22 refers to the address correspondence table TB based on the IP address set in the destination address D2, and acquires the MAC address and the corresponding port number of the corresponding wireless terminal device (S12, S13). . Hereinafter, the corresponding wireless communication terminal MAC address and the corresponding port number are used.

  The information transfer device 22 generates packet information PckC in which the setting of the destination address D1 of the packet information Pck is changed to the corresponding wireless communication terminal mac address (S14). The information transfer device 22 transmits the packet information PckC as the downstream packet information PckL from the communication port 28-i having the corresponding port number (S15).

  On the other hand, if the destination address D1 of the packet information Pck does not match the MAC address assigned to the communication port that received the packet information Pck, the same network address as the network address assigned to the communication port is set. It is determined that the packet information Pck is addressed to a device that performs communication via the assigned communication port. In this case, the information transfer device 22 refers to the address correspondence table TB based on the Mac address set in the destination address D1, and acquires the corresponding port number (S12, S16). The information transfer device 22 transmits the packet information Pck as the downstream packet information PckL from the communication port 28-i having the corresponding port number (S17).

  In step S16, instead of referring to the address correspondence table TB based on the MAC address set in the destination address D1 and obtaining the corresponding port number, the address is based on the IP address set in the destination address D2. The corresponding port number may be acquired by referring to the correspondence table TB.

  The base station device 24-i receives the downstream packet information PckL from the information transfer device 22, converts it into a radio signal, and transmits it. Based on the setting of the destination address D1 of the received downstream packet information PckL, the wireless terminal device 26-j determines that the packet information is addressed to the wireless terminal device 26-j, and acquires the downstream packet information PckL. To do.

  As a first processing example, the information transfer device 22 receives the information packet Pck from the backbone communication network 12 via the communication line 28L-0 and the communication port 28-0, and wirelessly transmits the data part DA included in the information packet Pck. The case where it transmits to the terminal device 26-7 is demonstrated. It is assumed that “10.1.2.1” to “10.1.2.m” are assigned to the wireless terminal devices 26-1 to 26 -m as IP addresses by the wireless terminal registration process, respectively. At this time, the address correspondence table TB stored in the table storage unit 22a of the information transfer device 22 is as shown in FIG. In addition, the wireless terminal devices 26-1 to 26-m acquire and store the Mac address MacPi of the communication port 28-i to which the base station device 24-i that transmits / receives information to / from itself is connected by wireless terminal registration processing. Suppose you are.

  As shown in FIG. 4B, the communication port 28-0 communicates packet information Pck in which the Mac address MacPx and the IP address “10.1.2.n + 7” are set in the destination address part D1 and the destination address D2, respectively. Receive from port 28-0.

  In this case, the Mac address MacPx of the communication port 28-0 is set in the destination address D1 of the packet information Pck received by the information transfer apparatus 22 from the communication port 28-0. Therefore, the Mac address set as the destination address D1 matches the Mac address MacPx of the communication port 28-0 that has received the packet. Therefore, the information transfer device 22 refers to the address correspondence table TB based on the IP address set in the destination address D2, and acquires the corresponding port number and the corresponding wireless communication terminal MAC address.

  In the packet information Pck of FIG. 4B, the IP address set in the destination address part D2 is “10.1.2.n + 7”, and according to the address correspondence table TB of FIG. The MAC addresses of the wireless terminal devices are P1 and Mac7, respectively.

  The information transfer device 22 generates packet information PckC as shown in FIG. 4C in which the setting of the destination address part D1 of the packet information Pck is changed to the corresponding wireless communication terminal Mac address Mac7. The information transfer device 22 transmits the packet information PckC as the downstream packet information PckL from the communication port 28-1 having the corresponding port number P1.

  The base station device 24-1 receives the downstream packet information PckL from the information transfer device 22, converts it into a radio signal, and transmits it. Based on the setting of the destination address part D1 of the received downstream packet information PckL, the wireless terminal device 26-7 determines that the downstream packet information PckL is addressed to the wireless terminal device 26-7, and the downstream packet information PckL To get.

  As a second processing example, a case will be described in which the wireless terminal device 26-7 of the communication system 102 transmits packet information Pck to the wireless terminal device 26-3.

  The wireless terminal device 26-7 transmits packet information Pck in which the MAC address Mac3 of the wireless terminal device 26-3 is set to the destination address D1 as shown in FIG. The base station device 24-1 that has received the packet information Pck transmits the packet information Pck to the information transfer device 22.

  The information transfer device 22 receives the packet information Pck from the communication port 28-1. Then, the address correspondence table TB stored in the table storage unit 22a is referred to.

  In this case, the MAC address Mac3 of the wireless terminal device 26-3 is set as the destination address D1 of the packet information Pck received by the information transfer device 22 from the communication port 28-1. Therefore, the Mac address set as the destination address D1 does not match the Mac address Mac1 of the communication port 28-1 that has received the packet. Therefore, the information transfer device 22 refers to the address correspondence table TB based on the destination address D1 and acquires the corresponding port number. In the packet information Pck of FIG. 4D, the Mac address set in the destination address part D1 is Mac3, and according to the address correspondence table TB of FIG. 6, the corresponding port number is P1.

  The information transfer device 22 transmits the packet information Pck as the downstream packet information PckL from the communication port 28-1 having the corresponding port number P1.

  The base station device 24-1 receives the downstream packet information PckL from the information transfer device 22, converts it into a radio signal, and transmits it. Based on the setting of the destination address part D1 of the received downstream packet information PckL, the wireless terminal device 26-3 determines that the downstream packet information PckL is addressed to the wireless terminal device 26-3, and the downstream packet information PckL To get.

  According to the communication system 102 according to the basic form of the present invention, the same network address as the common network address assigned to the communication ports 28-1 to 28-n for the wireless terminal devices 26-1 to 26-m. Is assigned. Thus, even if the total number n of the base station devices 24-1 to 14-n is increased under the condition that the total number of the wireless terminal devices 26-1 to 26-m is constant, the information transfer device 22 The IP address occupied by the IP address does not increase, and the IP address can be used effectively. As a result, the number n of the base station areas 30-1 to 30-n can be increased without increasing the IP address occupied by the information transfer device 22, and the shape of the service area can be set flexibly.

  Further, when the network addresses are assigned to the wireless terminal devices 26-1 to 26-m in this way, when the wireless terminal devices 26-1 to 26-m transmit / receive information to / from the information transfer device 22, It becomes impossible to specify the intervening communication port only with the assigned network address. Therefore, the information transfer device 22 according to the present basic form is configured such that the port numbers Pi of the communication ports 28-i interposed when the wireless terminal devices 26-1 to 26-m transmit and receive information to and from the information transfer device 22. Are associated with the determined IP address and added to the address correspondence table TB. As a result, in the process in which the wireless terminal device 26-j acquires packet information from the backbone communication network 12 and the process in which the wireless terminal device 26-j transmits packet information to another wireless terminal device 26-k, the information Based on the address correspondence table TB, the transfer device 22 can specify a communication port to which the downstream packet information PckL is to be transmitted from among the communication ports 28-1 to 28-n to which the same network address is assigned. .

  Note that the wireless terminal registration process described above can be executed by applying a widely used DHCP (Dynamic Host Configuration Protocol) server. FIG. 7 shows a configuration of a communication system 104 to which the DHCP server 32 is applied. The DHCP server 32 is connected to the communication port 28- (n-1) via the communication line 28L- (n-1). The same components as those of the communication system 102 are denoted by the same reference numerals, and description thereof is omitted.

  When the wireless terminal device 26-j establishes a wireless communication connection with the base station device 24-i, the wireless terminal device 26-j transmits packet information including predetermined control information via the information transfer device 22, thereby the wireless terminal device 26-j. The DHCP server 32 is caused to execute the numbering process of the IP address assigned to j. The base station device 24-i acquires packet information including the issued IP address from the DHCP server 32 via the information transfer device 22, and transmits packet information including the IP address to the wireless terminal device 26-j. To do.

  The information transfer device 22 extracts the information included in the packet information transmitted / received between the base station device 24-i and the DHCP server 32, and thereby the IP address issued by the DHCP server 32 and the communication port 28- Information that associates the port number Pi of i with the MAC address Macj of the wireless terminal device 26-j is acquired, added to the address correspondence table TB, and stored in the address storage unit 22a.

  By applying the DHCP server, the information transfer device 22 can be easily configured, so that the design and manufacturing cost of the information transfer device 22 can be reduced.

"System including wireless relay station"
Here, the present applicant has filed an application in Japanese Patent Application No. 2006-9672 for the system of the above basic form. However, this basic system does not have the radio relay station 40. The present embodiment is based on the basic system and is provided with a wireless relay station 40 added thereto, and is based on WiMAX / IEEE802.16. The present embodiment is based on the use of ARP and DHCP, and is different from the basic form in this respect. However, as in the basic form, a system that does not use them can be used.

  A communication system 106 according to the embodiment including the wireless relay station 40 will be described with reference to FIG. In the present embodiment, as in the basic configuration described above, the information transfer device 22 includes an upstream communication port (trunk port) 28-0 for connection to the backbone communication network (core network) 12, and a base station device. 24 have downstream communication ports (access ports) 28-1 to 28-n (referred to as ports 28 as appropriate). The communication port 28-0 is referred to as Port0, and the illustrated communication ports 28-1 to 28-3 are referred to as Ports 1, 2, and 3, respectively.

  One network address (for example, 10.1.1.1) is assigned to one port in the upstream communication port Port0 as in a normal router. On the other hand, one network address can be assigned to a plurality of downstream communication ports Port1 to Port3.

  Here, the normal router routing control table only describes the interface of the router as the output destination with respect to the destination network address. In the information transfer apparatus 22, in addition to this, individual wireless terminals are described. A path control table in which the communication port 28 serving as an output destination is described for the addresses of the devices 26-1 to 26-m (referred to as 26 as appropriate) is stored in the table storage unit 22a.

  In this way, the information transfer device 22 can assign one network address to a plurality of communication ports 28 (Ports 1 to 3), and has a correspondence relationship between the communication port 28 and the destination address in the routing table, This is a router that can transfer a packet to the communication port 28 corresponding to the base station device 24 to which the wireless terminal device 26 is connected.

  In addition, the information transfer device 22 registers the layer 3 addresses (IP addresses in this example) of all the wireless terminal devices 26, the base station devices 24, and the wireless relay stations 40 in communication in the route control table. That is, as shown in FIG. 10, the relationship between the communication ports Port 1 to 3 connected to the layer 3 addresses of the wireless terminal device 26, the wireless base station 24, and the wireless relay station 40 connected to the information transfer device 22. Is described.

  The information transfer device 22 has means for communicating with the base station device 24 and the wireless relay station 40, and when the wireless terminal device 26 is connected (and disconnected) to the network, the information is transferred from the base station device 24 and the wireless relay station 40. The routing control table is updated by receiving notification.

  The radio relay station 40 has a path control table 40a therein, and all the radio terminal apparatuses 26, base station apparatuses 24, and radio relay stations 40 that are connected to and communicate with the path control table 40a. The correspondence relationship between the layer 2 address (MAC address in this example) and its own downstream communication port is registered. FIG. 11 shows a path control table of the radio relay station 40-1, and FIG. 12 shows a path control table of the radio relay station 40-2.

  The radio relay station 40 has means for communicating with the information transfer device 22 and all the base station devices 24 and radio relay stations 40 connected to the subordinate. When the radio terminal device 26 is connected (and disconnected) to the network, the radio relay station 40 The routing control table is updated by receiving notification from the base station device 24 and the radio relay station 40.

  Packets transmitted from the backbone communication network 12 to the wireless terminal device 26, the base station device 24, or the wireless relay station 40 are addressed based on the route control table of the information transfer device 22 and the route control table of the wireless relay station 40. To the communication port to which the wireless terminal device 26, the base station device 24, or the wireless relay station 40 is connected.

  A packet transmitted from the wireless terminal device 26 to another wireless terminal device 26 that is a destination is transmitted by the destination wireless terminal device 26 based on the route control table of the information transfer device 22 and the route control table of the wireless relay station 40. Forwarded to the connected port. Here, if a packet received from the downstream has an address that is not in the routing control table, it is transferred upstream.

  FIG. 13 shows the internal configuration of the information transfer device 22 and the radio relay station 40. Thus, both have basically the same configuration, and the protocol control unit 50 and the packet transfer processing unit 52 are included as the main configuration. That is, the protocol control unit 50 configured by a CPU or the like is connected to the system bus, and the memory 54 is connected via the system bus. A packet transfer control unit 52 is connected to the system bus via the PCI bus. The packet transfer control unit 52 is formed by a network processing device, and a memory 56 is connected thereto. In addition, a packet input / output processing unit 60 that forms a communication port on the upstream side and a packet input / output processing unit 62 on the downstream side are provided.

  In the case of the information transfer device 22, the packet transfer control unit 52 is connected to the backbone communication network 12 by the upstream packet input / output processing unit 60 and connected to the base station device 24 by the downstream packet input / output processing unit 62. Is done.

"Protocol control unit 50"
The protocol control unit 50 processes a control message exchanged between the information transfer device 22 and the radio relay station 40 or the base station device 24. That is, the control message received through the packet transfer processing unit 52 is analyzed and a corresponding process is performed. Further, the control message is generated and transmitted through the packet transfer processing unit 52.

  In particular, the protocol control unit 50 of the information transfer device 22 holds information about the wireless terminal device 26 and the wireless relay station 40 connected to the base station device 24 and grasps the connection relationship between them. Also, the continuity with the base station device 24 and the wireless relay station 40 and the available wireless communication band of the base station device 24 are grasped. These pieces of information are stored in the memory 54. For example, as shown in FIG. 14, information such as the layer 3 address and connection source / conductivity for each base station device 24 and radio relay station 40 is stored as a BS / RS management table. For example, in the case of the radio relay station 40-1, the relationship between the base station devices 24-4 and 24-5 connected as shown in FIG. 15 and the communication port to which it is connected is stored. FIG. 16 shows a table of the radio relay station 40-2.

"Packet transfer processing unit 52"
The packet transfer processing unit 52 performs packet transfer processing. When the packet input from the packet input / output processing unit 60 is a normal packet (for example, in the case of a data packet to the wireless terminal device 26), the corresponding output is referred to with reference to the path control table placed in the memory 56. Transfer to port (packet input / output processor 62). When the input packet is a control message packet with the base station device 24 or the radio relay station 40, the packet is transferred to the protocol control unit 50.

"Detailed Implementation Procedure"
Next, a bootstrap procedure of the communication system will be described. Here, the bootstrap procedure is a procedure for constructing a network system before providing network connection and communication service to the wireless terminal device 26. This bootstrap procedure will be described in three stages. FIG. 17 shows bootstrap procedures 1 and 2, and FIG.

  The terminal connection procedure is a procedure for enabling the wireless terminal device 26 to connect to the network and communicate with another terminal on the backbone communication network upstream from the information transfer device 22 or with another terminal connected downstream. It is. The terminal connection procedure is shown in FIG.

(A) Bootstrap procedure 1
1. When the information transfer device 22 and the base station device 24, and the wireless relay station 40 and the base station device 24 are connected by wire, the protocol control units 50 of the information transfer device 22 and the wireless relay station 40 manage the BS / RS in the memory 54, respectively. Information (IP address and connection port) of the base station device 24 connected to the table is registered. The information transfer apparatus 22 and the radio relay station 40 are assumed to know the IP address and MAC address of the base station apparatus 24 to be connected in advance, and the base station apparatus 24 is connected to the IP of the information transfer apparatus 22 and the radio relay station 40 to be connected. Assume that you know the address in advance. That is, these are set in advance by the network administrator and stored in the memory 54.

  The protocol control unit 50 of the information transfer device 22 registers the communication port 28 connected to the IP address of the connected base station device 24, that is, the output destination port, in the route control table in the memory 56 of the packet transfer processing unit 52. Order to do.

  The protocol control unit 50 of the radio relay station 40 registers the communication port connected to the MAC address of the connected base station device 24, that is, the output destination port, in the path control table in the memory 56 of the packet transfer processing unit 52. To order.

(B) Bootstrap procedure 2
2. When the radio relay station 40-1 is wirelessly connected to the base station apparatus 24-1, the base station apparatus 24-1 executes ARP with the information transfer apparatus 22.
3. When the ARP is completed, the base station device 24-1 notifies the information transfer device 22 of the MAC address of the wireless relay station 40-1. The protocol control unit 50 of the information transfer device 22 registers information (IP address and communication port that received the notification) of the radio relay station 40-1 connected to the BS / RS management table in the memory 54, and a packet transfer processing unit An instruction is issued to register the IP address of the wireless relay station 40-1 connected to the routing control table in the memory 56 of 52 and the port that received the notification, that is, the output destination port. At this time, it is assumed that the protocol control unit 50 can obtain the IP address from the notified MAC address (set by the network administrator and stored in the memory 54).
4). The protocol control unit 50 of the information transfer apparatus 22 requests the base station apparatus 24-1 to set a service flow (SF) to the radio relay station 40-1, and assigns the SF to the radio base station 24. -1. Here, SF is a unit for managing a communication band or the like used for wireless communication between the base station device 24-1 and the wireless relay station 40-1, and is preset in the information transfer device 22 by the network administrator. Stored in the memory 54.
5. The base station device 24-1 establishes SF with the radio relay station 40-1.

When SF is established on the radio, ARP is executed between the radio relay station 40-1 and the information transfer apparatus 22.
6). When the ARP is completed, the protocol control unit 50 of the wireless relay station 40-1 provides information (IP address and available information) of the base station device 24-5 that is wired to the information transfer device 22 under its own control. Bandwidth etc.). Upon receiving this, the protocol control unit 50 of the information transfer apparatus 22 registers the contents in the BS / RS management table in the memory 54. Further, it instructs the route control table in the memory 56 of the packet transfer processing unit 52 to register the IP address of the base station device 24-5 and the port that received the notification, that is, the output destination port.

(C) Bootstrap procedure 3
7). When the radio relay station 40-2 is wirelessly connected to the base station device 24-5, ARP is executed between the base station device 24-5 and the radio relay station 40-1.
8). When the ARP is completed, the base station device 24-5 notifies the wireless relay station 40-1 of the MAC address of the wireless relay station 40-2. The protocol control unit 50 of the radio relay station 40-1 registers the information (IP address and the port that received the notification) of the connected radio relay station 40-2 in the BS / RS management table in the memory 54, and transfers the packet. The path control table in the memory 56 of the processing unit 52 is instructed to register the MAC address of the connected radio relay station 40-2 and the port that received the notification, that is, the output destination port.
9. The radio relay station 40-1 notifies the information transfer apparatus 22 of the MAC address of the radio relay station 40-2. The protocol control unit 50 of the information transfer apparatus 22 registers the information (IP address and port that received the notification) of the radio relay station 40-2 in the BS / RS management table in the memory 54, and the memory 56 of the packet transfer processing unit 52. An instruction is issued to register the IP address of the wireless relay station 40-2 connected to the internal routing control table and the port that received the notification, that is, the output destination port. At this time, it is assumed that the protocol control unit 50 can obtain the IP address from the notified MAC address (set by the network administrator and stored in the memory 54). And ARP is performed between the information transfer apparatus 22 and the base station apparatus 24-5.
10. When the ARP is completed, the protocol control unit 50 of the information transfer apparatus 22 requests the base station apparatus 24-5 to set a service flow (SF) to the radio relay station 40-2.
11. When the SFs of the base station device 24-5 and the radio relay station 40-2 are established on the radio, the ARP is executed between the radio relay stations 40-1 and 40-2.
12 When the ARP is completed, the radio relay station 40-2 notifies information (such as an IP address and an available bandwidth) of the base station device 24-7 that is wiredly connected to the radio relay station 40-2. Receiving this, the radio relay station 40-1 registers the contents in the BS / RS management table in the memory 54 of the protocol control unit 50. Further, it instructs the route control table in the memory 56 of the packet transfer processing unit 52 to register the IP address of the base station device 24-7 and the port that received the notification, that is, the output destination port.
13. The radio relay station 40-1 notifies the information transfer apparatus 22 of the information (IP address, usable bandwidth, etc.) of the base station apparatus 24-7. Upon receiving this, the protocol control unit 50 of the information transfer apparatus 22 registers the contents in the BS / RS management table in the memory 54. Further, it instructs the route control table in the memory 56 of the packet transfer processing unit 52 to register the IP address of the base station device 24-7 and the port that received the notification, that is, the output destination port.

(D) Terminal connection procedure When the wireless terminal device 26 is wirelessly connected to the base station device 24-7, the base station device 24-7 executes ARP with the wireless relay station 40-2.
2. When the ARP is completed, the base station device 24-7 notifies the wireless relay station 40-2 of the MAC address of the wireless terminal device 26. The protocol control unit 50 of the wireless relay station 40-2 sets the MAC address of the connected wireless terminal device 26 and the port that received the notification, that is, the output destination port, in the route control table in the memory 56 of the packet transfer processing unit 52. Order to register. Then, the radio relay station 40-2 executes ARP with the radio relay station 40-1.
3. When the ARP is completed, the wireless relay station 40-2 notifies the wireless relay station 40-1 of the MAC address of the wireless terminal device 26. The protocol control unit 50 of the wireless relay station 40-1 registers the MAC address of the wireless terminal device 26 connected to the route control table in the memory 56 of the packet transfer processing unit 52 and the port that received the notification, that is, the output destination port. Order to do. The wireless relay station 40-1 executes ARP with the information transfer device 22.
4). When the ARP is completed, the radio relay station 40-1 notifies the information transfer apparatus 22 of the MAC address of the radio terminal apparatus 26. Here, the relationship between the MAC address of the wireless terminal device 26 and the communication port (output port) that received the notification is stored. If the protocol control unit 50 of the information transfer device 22 knows the IP address of the wireless terminal device 26 in advance (for example, the network administrator previously displays the correspondence table between the MAC address and the IP address of the wireless terminal device 26). 22), the protocol control unit 50 receives the IP address and notification of the wireless terminal device 26 in the route control table in the memory 56 of the packet transfer processing unit 52. That is, it instructs to register the output destination port.

  Here, if the protocol control unit of the information transfer device 22 does not know the IP address of the wireless terminal device 26 in advance (that is, the IP address of the wireless terminal device 26 is dynamically assigned by DHCP (Dynamic Host Configuration Protocol)). ), The protocol control unit has either a DHCP server (function to assign an IP address) or a DHCP relay agent (function to act as an intermediary with the DHCP server).

  The DHCP relay agent is a function for enabling the exchange of the DHCP server with the wireless terminal device 26 when the DHCP server is arranged on the core network side. The wireless terminal device 26 broadcasts DHCPDISCOVER in order to search for a DHCP server. However, since the broadcast can be used only on the same LAN, the DHCP relay agent relays the DHCP message to the DHCP server. When the relay agent is set in the protocol control unit 50 and the address of the DHCP server of the backbone communication network 12 is registered, the router converts the DHCP message received by broadcast into unicast and relays it to the DHCP server. The DHCP server that has received the DHCP message returns a DHCPOFFER message to the information transfer apparatus 22 using unicast. The protocol control unit 50 transfers this to the wireless terminal device 26.

  The protocol control unit can know the IP address of the wireless terminal device 26 in the process of exchanging the DHCP control message with the wireless terminal device 26. At this point, the protocol control unit 50 requests to register the IP address of the wireless terminal device 26 in the route control table in the memory 56 of the packet transfer processing unit 52. In the transmission of the DHCP control message until the IP address of the wireless terminal device 26 is set in the route control table, the packet transfer processing unit 52 already obtains the correspondence information between the MAC address of the wireless terminal device 26 and the communication port. To send to the output port.

In this way, in the information transfer device 22, when the registration for the wireless terminal device 26 is completed, the information transfer device 22 executes ARP with the wireless base station 24-7.
5. When ARP ends, the protocol control unit 50 of the information transfer apparatus 22 requests the base station apparatus 24-7 to set a service flow (SF) to the wireless terminal apparatus 26. The SF is a unit for managing a communication band and the like used for wireless communication between the base station device 24 and the wireless terminal device 26. The SF is set in the information transfer device 22 in advance by the network administrator, and is stored in the memory 54. Stored in
6). When SF is established on the radio, the radio terminal device 26 can communicate with other terminals.

(D) Processing Procedure of Packet Transfer Processing Unit 52 Hereinafter, the processing procedure of the packet transfer processing unit 52 in the information transfer device 22 and the radio relay station 40 will be described.

<Packet Transfer Procedure in Information Transfer Device 22>
(When a packet is input to the communication port on the backbone network 12 side)
When a packet is received from the upstream packet input / output processing unit 60, the packet transfer processing unit 52 confirms whether or not the MAC address of the received packet is addressed to the information transfer device 22.

  As a result of the confirmation, if the MAC address is addressed to the information transfer device 22, it is confirmed whether the IP address is addressed to the transfer device. On the other hand, if the MAC address and the IP address are addressed to the information transfer device 22, the packet is transferred to the protocol control unit 50.

  If the MAC address is not addressed to the information transfer device 22 and the IP address is not addressed to the information transfer device 22, the corresponding output port is obtained by referring to the path control table in the memory 56 (in this case, the communication port 28-1). To the corresponding packet input / output processing unit 62 on the downstream side.

<Packet Transfer Procedure at Radio Relay Station 40>
(When a packet is input to the upstream port)
When a packet is received from the upstream packet input / output processing unit 60, the packet transfer processing unit 52 checks whether or not the MAC address of the received packet is addressed to the radio relay station 40 itself.

  As a result of the confirmation, if the MAC address and the IP address are addressed to the radio relay station 40 itself, the packet is transferred to the protocol control unit 50. On the other hand, if the MAC address is not addressed to the radio relay station 40 itself, the routing control table in the memory 56 is referred to find the corresponding output port (in this case, the downstream output port), and the corresponding packet input is entered. The data is transferred to the output processing unit 62.

<Packet Transfer Procedure at Radio Relay Station 40>
(When a packet is input to a downstream port)
When a packet is received from the downstream packet input / output processing unit 62, the packet transfer processing unit 52 checks whether the MAC address of the received packet is addressed to the radio relay station 40 itself.

  As a result of the confirmation, if the MAC address and the IP address are addressed to the radio relay station 40 itself, the packet is transferred to the protocol control unit 50. On the other hand, if the MAC address is not addressed to the radio relay station 40 itself, the routing control table in the memory 56 is referred to find the corresponding output port and transferred to the corresponding packet input / output unit 62 on the downstream side. On the other hand, if there is no corresponding route control table in the memory 56, the packet is transferred to the upstream packet input / output processing unit 60.

<Packet Transfer Procedure in Information Transfer Device 22>
(When a packet is input to the downstream communication port on the base station device 24 side)
When receiving a packet from the packet input / output processing unit 62, the packet transfer processing unit 52 confirms whether or not the MAC address of the received packet is addressed to the information transfer device 22.

  As a result of this confirmation, if the MAC address is addressed to the information transfer device 22, it is confirmed whether the IP address is addressed to the information transfer device 22. If the MAC address and the IP address are addressed to the information transfer device 22, the packet is transferred to the protocol control unit 50.

  If the MAC address is addressed to the information transfer apparatus 22 and the IP address is not addressed to the information transfer apparatus 22, the corresponding output port is obtained by referring to the routing control table in the memory 56 (in this case, the main communication network side Transfer to the corresponding packet input / output processing unit 60.

  If the MAC address is not addressed to the information transfer device 22, but the IP address is the same as the IP address of another wireless terminal device 26 registered in the routing table in the memory 56, the registered wireless terminal device The packet is transferred to 26 output ports, that is, the corresponding packet input / output processing unit 62.

  In this way, packet transfer is performed using the routing table.

"Process when moving wireless terminal device"
In the communication system of the present embodiment, there is a possibility that the wireless terminal device 26 in communication moves, and it is preferable that the system can cope with this. Therefore, control for allowing movement of the wireless terminal device 26 during communication will be described below. By this control, the wireless terminal device 26 can switch the connection to the base station device 24 that can perform better wireless communication while communicating.

  The information transfer device 22 and the wireless relay device hold the same routing control table and management table as described above. The boot slap procedure and the terminal connection procedure are executed in the same manner.

  When the wireless terminal device 26 moves, the information transfer device 22, the wireless relay station 40, and the base station device 24 have means for communicating, and the route to the base station device 24 to which the wireless terminal device 26 is newly connected is provided. In response, the information transfer device 22 and the radio relay station 40 update their route control tables. That is, the protocol control unit 50 in FIG. 13 instructs to rewrite the table in the memory 56 of the packet transfer processing unit 52.

"Configuration example 1"
As shown in FIG. 20, the procedure (part 1) when the wireless terminal device 26 (10.1.2.5) moves from the base station device 24-7 to the base station device 24-2 is based on FIG. I will explain.
1. When the wireless terminal device 26 connected to the base station device 24-7 receives a better radio wave from the other base station device 24-2, the base station device 24-7 receives a handover request (HO request). ).
2. The base station device 24-7 transmits the request (HO request) to the information transfer device 22.
3. The information transfer device 22 transfers the HO request to the base station device 24-2, and informs that the wireless terminal device 26 will move.
4). The base station device 24-2 notifies the information transfer device 22 that it can accept the movement of the wireless terminal device 26 (transmits a HO acceptance response).
5. The information transfer device 22 informs the base station device 24-7 that it can move to the base station device 24-2 (transfers the HO acceptance response).
6). The base station device 24-7 informs the wireless terminal device 26 that it can move to the base station device 24-2 (transfers the HO acceptance response).
7). The wireless terminal device 26 notifies the base station device 24-7 of switching to the base station device 24-2. Further, the connection with the base station device 24-7 is disconnected.
8). The base station device 24-7 transfers the switching notification to the radio relay station 40-2. The protocol control unit 50 of the wireless relay station 40-2 deletes the item of the wireless terminal device 26 in the route control table in the memory 56 of the packet transfer processing unit 52.
9. The radio relay station 40-2 transfers the switching notification (movement to the base station device 24-2) to the radio relay station 40-1. The protocol control unit 50 of the wireless relay station 40-1 deletes the item of the wireless terminal device 26 in the route control table in the memory 56 of the packet transfer processing unit 52.
10. The wireless relay station 40-1 transfers the switching notification (movement to the base station device 24-2) to the information transfer device 22. Further, the protocol control unit 50 of the information transfer device 22 deletes the item of the wireless terminal device 26 in the route control table in the memory 56 of the packet transfer processing unit 52.
11. The information transfer device 22 sets information related to the wireless terminal device 26 (information such as service flow settings) in the base station device 24-2.
12 Wireless connection between the wireless terminal device 26 and the base station device 24-2 is completed.
13. The base station device 24-2 transmits a connection notification (HO completion notification) to the information transfer device 22. The protocol control unit 50 of the information transfer device 22 adds the item of the wireless terminal device 26 to the route control table in the memory 56 of the packet transfer processing unit 52.

"Configuration example 2"
Based on FIG. 22, a procedure (part 2) when the wireless terminal device 26 (10.1.2.1) moves from the base station device 24-1 to the base station device 24-6 will be described.
1. When the wireless terminal device 26 connected to the base station device 24-1 receives a better radio wave from the other base station device 24-6, the base station device 24-1 receives a handover request (HO request). ).
2. The base station device 24-1 transmits the request (HO request) to the information transfer device 22.
3. The information transfer device 22 transfers the HO request to the base station device 24-6 and informs that the wireless terminal device 26 will move.
4). The base station device 24-6 informs the information transfer device 22 that it can accept the movement of the wireless terminal device 26 (transmits a HO acceptance response).
5. The information transfer device 22 notifies the base station device 24-1 that it can move to the base station device 24-6 (transfers the HO acceptance response).
6). The base station device 24-1 informs the wireless terminal device 26 that it can move to the base station device 24-6 (transfers a HO acceptance response).
7). The wireless terminal device 26 notifies the base station device 24-1 of switching to the base station device 24-6. The connection with the base station device 24-1 is disconnected.
8). The base station device 24-1 transfers the switching notification to the information transfer device 22. The protocol control unit 50 of the information transfer apparatus 22 deletes the item of the mobile terminal in the route control table in the memory 56 of the packet transfer processing unit 52.
9. The information transfer device 22 sets information related to the wireless terminal device 26 (information such as service flow settings) in the base station device 24-6.
10. Wireless connection between the wireless terminal device 26 and the base station device 24-6 is completed.
11. The base station device 24-6 transmits a connection notification (HO completion notification) to the radio relay station 40-2. The protocol control unit 50 of the radio relay station 40-2 adds the item of the mobile terminal to the route control table in the memory 56 of the packet transfer processing unit 52.
12 The wireless relay station 40-2 transmits a connection notification (HO completion notification) to the wireless relay station 40-1. The protocol control unit 50 of the radio relay station 40-1 adds the item of the mobile terminal to the route control table in the memory 56 of the packet transfer processing unit 52.
13. The wireless relay station 40-1 transmits a connection notification (HO completion notification) to the information transfer device 22. The protocol control unit 50 of the information transfer device 22 adds the item of the wireless terminal device 26 to the route control table in the memory 56 of the packet transfer processing unit 52.

  In this way, the information transfer device 22 and the wireless relay stations 40-1 and 40- updated when the two wireless terminal devices 26 in communication shown in FIGS. 20, 21, and 22 are moved. FIG. 23, FIG. 24, and FIG. 25 show the path control tables in FIG. As described above, in the route control table of the information transfer device 22, the communication port of the wireless terminal device 26 (10.1.2.5) is changed from Port 1 to Port 2, and in the route control table of the wireless relay station 40-1. Data indicating that the wireless terminal device 26 (0: 0: 0: 0: 0: 5) is connected to Port 2 is deleted, and the wireless terminal device 26 (0: 0: 0: 0: 0: 1) is Port 2. That the wireless terminal device 26 (0: 0: 0: 0: 0: 5) is connected to Port 2 in the routing control table of the wireless relay station 40-2. Data is deleted, and data indicating that the wireless terminal device 26 (0: 0: 0: 0: 0: 1) is connected to Port 1 is added.

It is a figure which shows the structure of the communication system which concerns on the basic composition of this invention. It is a figure explaining a wireless terminal registration process. It is a figure which shows an address corresponding table. It is a figure which shows the structure of packet information. It is a flowchart of the process which an information transfer apparatus performs. It is a figure which shows the address corresponding table after a radio | wireless terminal registration process is performed. It is a figure which shows the structure of the communication system which applied the DHCP server. It is a figure which shows the structure of a communication system. It is a figure which shows the structure of the communication system which concerns on embodiment of this invention. It is a figure which shows the route control table in an information transfer apparatus. It is a figure which shows the route control table in a radio relay station. It is a figure which shows the route control table in a radio relay station. It is a figure which shows the internal structure of an information transfer apparatus and a radio relay station. It is a figure which shows the structure of the management table of an information transfer apparatus. It is a figure which shows the management table in a radio relay station. It is a figure which shows the management table in a radio relay station. It is a figure which shows the bootstrap procedures 1 and 2 of a system. It is a figure which shows the bootstrap procedure 3 of a system. It is a figure which shows a terminal connection procedure. It is a figure which shows the mode of a movement of a wireless terminal device. It is a figure which shows the procedure 1 in the case of a movement of a wireless terminal device. It is a figure which shows the procedure 2 in the case of a movement of a radio | wireless terminal apparatus. It is a figure which shows the route control table after the update in an information transfer apparatus. It is a figure which shows the route control table after the update in a radio relay station. It is a figure which shows the route control table after the update in a radio relay station.

Explanation of symbols

100, 102 Communication system, 10, 22 Information transfer device, 12 backbone communication network, 14-1 to 14-n, 24-1 to 24-n base station device, 16-0 to 16-n communication port, 16L-0 -16L-n, 28L-0 to 28L-n communication line, 18-1-1 to 18-n- _n wireless terminal device, 20-1 to 20-n, 22a table storage unit, 30-1 to 30n base Station area, 26-1 to 26-m wireless terminal device, 32 DHCP server, 40 wireless relay station.

Claims (2)

A wireless communication system that supports communication in a wireless terminal device,
A backbone communication network for transferring information based on a layer 3 address;
Information transfer for controlling the transfer of information between the upstream communication port and the plurality of downstream communication ports, the upstream communication port being connected to the backbone communication network and having a plurality of downstream communication ports Equipment,
An upstream communication port is connected to one of the plurality of downstream communication ports of the information transfer apparatus, and has a downstream wireless communication port, and information between the upstream communication port and the wireless communication port of the own information transfer device A plurality of first radio base stations that control the transfer of
The upstream communication port is wirelessly connected to the wireless communication port of the first wireless base station, and has at least one downstream communication port. Information between the first wireless base station and its own communication port A wireless relay station that controls the transfer of
An upstream communication port is connected to the downstream communication port of the wireless relay station, and has a downstream wireless communication port, and controls the transfer of information between the wireless relay station and its own wireless communication port. Two radio base stations;
A wireless terminal device wirelessly connected to the wireless communication port of the first or second wireless base station;
Including
The information transfer device has the a layer 3 address of the wireless terminal device, the routing control table for storing in correspondence a self downstream communication port to reach the wireless terminal equipment used in the backbone network The information received from the backbone communication network is transferred only to the downstream communication port determined as the downstream communication port corresponding to the layer 3 address using the routing table , and
When there is a change in the radio terminal apparatus connected to the first or second radio base station, the change is transmitted to the information transfer apparatus, and the routing table is updated with the change. Wireless communication system. The wireless communication system according to claim 1, wherein
The information transfer apparatus has a function of assigning and transferring a layer 2 address on its downstream side to a layer 3 address,
The radio relay station has a plurality of communication ports, and reaches a second radio base station to which the radio relay station is connected and a layer 2 address for identifying the radio terminal equipment to which the radio relay station is connected downstream. It has a relay station routing control table that stores the relationship of its own communication port, and transfers information received from the first radio base station only to its own communication port determined according to its destination address,
When there is a change in the radio terminal apparatus connected to the second radio base station, the change is transmitted to the radio relay station, and the relay station routing control table is updated with the change. Wireless communication system.

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