JP2005348246A - Wireless communication method, mobile ip terminal, access point, and intelligent switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless communication method for reducing a load of position registration processing, a mobile IP terminal, an access point, and an intelligent switch for the wireless communication method. <P>SOLUTION: A mobile IP terminal STA1 located in a cell provided by the access point AP1a receives a beacon signal including a paging identifier corresponding to the intelligent switch ISW1. When the mobile IP terminal STA1 discriminates that the paging identifier included in the received beacon is changed, the mobile IP terminal STA1 receives information on an access router AR1 from the access point AP1a and creates a care-of address. When the mobile IP terminal STA1 receives information on the intelligent ISW1, the mobile IP terminal STA1 transmits a paging request message to the intelligent switch ISW1, the paging request denoting a request of paging that transmits a notice of the arrival of a packet addressed to the MAC address of the mobile IP terminal STA1 to the access point. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention provides an access router connected to a communication network at a network layer level, an intelligent switch connected to the access router and an access point at a data link layer level, and a cell connected to the intelligent switch and capable of wireless communication. Wireless communication method comprising access point and mobile IP terminal connected to communication network via access point, intelligent switch and access router and having portability located on external link, mobile IP terminal in the wireless communication method, and access point And intelligent switches.

  With the recent development of communication networks and information devices, high-speed wireless services using mobile IP terminals such as notebook computers and PDAs and wireless LAN technology are being developed. In particular, a wireless LAN that does not require the installation of a LAN cable or a hub enables broadband data communication and is widely used in homes and offices.

  An example of a standard protocol that supports this wireless communication technology is mobile IP. Mobile IP is a technology that allows a mobile IP terminal to move to a work location without resetting application software or disconnecting the connected communication. Mobile IP is an Internet standard process protocol that is extended to provide mobility to an existing Internet protocol (IP). Specifically, mobile IP includes a home address (Home Address: HOA) used by a mobile IP terminal in a home link (network to which the mobile IP terminal originally belongs) and a care-of address (Care of) used in an external link (MN destination network). By using a dedicated agent (Home Agent: HA) having a correspondence relationship of Address: COA, packet transfer to a destination terminal is enabled (for example, Non-Patent Document 1).

  On the other hand, since IP addresses currently used on the Internet and the like are 32 bits, exhaustion of IP addresses is a problem. In order to cope with this, IPv6 indicating an address with 128 bits has been developed. In wireless communication, it is considered that communication using IPv6 will become common in the future.

  For example, as shown in FIG. 21, the communication network includes a mobile IPv6 network 1, a PSTN (Public Switched Telephone Network) 3 connected to the mobile IPv6 network 1 through a gateway GW1, and a gateway to the mobile IPv6 network 1. When the IPv4 network 2 connected via the GW 2 is connected, it becomes possible to communicate with each other. Connected to the mobile IPv6 network 1 are a RADIUS (Remote Authentication Dial-In User Service) server 10 for authenticating the terminal, a home agent HA, a SIP (Session Initiation Protocol) terminal 11 and the like. In addition, access routers AR1 and AR2 are connected to the mobile IPv6 network 1. Access point AR1 is connected to access points (base stations) AP1a, AP1b,... AP1n. The access point AP1a provides a cell capable of wireless communication at the frequency f1. The access points connected to the access router AR1 are set to be able to communicate at different frequencies at least in adjacent cells. The mobile IP terminal STA1 can communicate with information devices on the mobile IPv6 network via an access point and an access router that provide a cell in which the mobile IP terminal STA1 is located. In addition, a mobile IP terminal STA2 is connected to the access router AR2 via access points AP3a, AP3b... AP3n.

Here, the cell provided by the access point is the minimum unit for registering the location with the home agent using the mobile IP, and is the allocation unit of the care-of address. That is, when a packet with a care-of address corresponding to the access point AP1a is transmitted, an incoming call is called to the cell provided by the access point AP1a.
Internet-Draft “Mobility Support in IPv6” 24 edition (http://www.ietf.org/internet-drafts/draft-ietf-mobileip-ipv6-24.txt)

  However, in the communication system described in Non-Patent Document 1 described above, the care-of address is assigned in units of cells. Therefore, there is a problem that location registration with the home agent HA is required every time the mobile IP terminal STA1 crosses the cell. Specifically, in the mobile IP specification, the movement of a cell is equivalent to the movement of a segment. For the generation of a care-of address required for incoming calls, the home agent HA and a CN (Co-respondent Node) serving as a communication partner, A binding process including RR (Return Routability) is required.

  The cell for wireless communication is several meters to several tens of meters, and the cell frequently changes depending on the moving speed of the mobile IP terminal STA1, so that it becomes necessary to perform location registration processing each time.

  This is because the mobility management of the mobile IP terminal STA1 in wireless communication depends on the mobile IP which is the network layer of the layer 3, that is, the OSI basic reference model model. In the communication system described in Non-Patent Document 1 described above, for example, every time a cell moves, the mobile IP terminal STA1 transmits a movement management packet, that is, broadcasts wirelessly, and the battery of the mobile IP terminal STA1 is consumed. There is a problem that accelerates.

  Accordingly, the present invention has been made based on the above problems, and an object thereof is to provide a wireless communication method for reducing location registration processing, a mobile IP terminal, an access point, and an intelligent switch in the wireless communication method.

  In order to solve the above problems, the present invention is characterized in that an access router connected at a network layer level to a communication network to which a home agent is connected, and an intelligent switch in which an access router and an access point are connected at a data link layer level And an access point that is connected to the intelligent switch and provides a cell capable of wireless communication, and a mobile IP terminal that is connected to the communication network via the access point, the intelligent switch, and the access router and is located on an external link. The present invention relates to a wireless communication method used in a communication system. That is, in the wireless communication method according to the feature of the present invention, a beacon signal including a paging identifier corresponding to an intelligent switch to which an access point is connected is received from an access point by a mobile IP terminal located in a cell provided by the access point. A step in which the mobile IP terminal determines that the paging identifier included in the received beacon has changed, and the mobile IP terminal receives access router information from the access point and converts it into the access router information. A care-of address is created based on this, and when the mobile IP terminal receives intelligent switch information from the access point, it sends a notification to the access point that a packet addressed to the MAC address of the mobile IP terminal has arrived. Paging request message for requesting paging to comprises the steps that are sent to the intelligent switch.

  According to the present invention, it is possible to provide a wireless communication method for reducing location registration processing, a mobile IP terminal, an access point, and an intelligent switch in the wireless communication method.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

(Wireless communication method)
As shown in FIG. 1, a communication network according to the preferred embodiment of the present invention includes a mobile IPv6 network 1, a PSTN (Public Switched Telephone Network) connected to the mobile IPv6 network 1 via a gateway GW1. 3) When the IPv4 network 2 connected to the mobile IPv6 network 1 via the gateway GW2 is connected, it becomes possible to communicate with each other. Connected to the mobile IPv6 network 1 are a RADIUS (Remote Authentication Dial-In User Service) server 10 for authenticating the terminal, a home agent HA, a SIP (Session Initiation Protocol) terminal 11 and the like. In addition, access routers AR1 and AR2 are connected to the mobile IPv6 network 1 at the network layer level. Further, intelligent switches ISW1 and ISW2 are connected to the access router AR1 at the data link layer (L2) level. Access points (base stations) AP1a, AP1b,... AP1n are connected to the intelligent switch ISW1. The access point AP1a provides a cell capable of wireless communication at the frequency f1. The access points connected to the access router AR1 are set to be able to communicate at different frequencies at least in adjacent cells. The mobile IP terminal STA1 can communicate with information devices on the mobile IPv6 network via an access point and an access router that provide a cell in which the mobile IP terminal STA1 is located. In addition, a mobile IP terminal STA2 is connected to the access router AR2 via access points AP3a, AP3b... AP3n.

  In the best mode of the present invention, a set of cells provided by an access point connected to an intelligent switch is defined as a paging domain. Specifically, a set of cells provided by the access points AP1a, AP1b,... AP1n connected to the intelligent switch ISW1 is defined as a paging domain 5a. Here, the paging domain is a network that can communicate at the L2 level, and is a minimum unit for location registration with respect to the home agent HA, and is a unit for assigning a care-of address. That is, when a packet of a care-of address corresponding to the intelligent switch ISW1 is transmitted, an incoming call is called to the paging domain 5a provided by the access points AP1a, AP1b... AP1n connected to the intelligent switch ISW1.

  Therefore, for example, when the mobile IP terminal STA1 is located in the paging domain 5a, the same care-of address can always be used even if the cell in which the mobile IP terminal STA1 is located is changed, so that the location registration is performed with respect to the home agent HA. There is no need. On the other hand, when the mobile IP terminal STA1 moves over the paging domain 5a to the paging domain 5b, the care-of address corresponding to the new paging domain 5b is notified to the home agent HA by the conventional mobile IP procedure.

  Next, a communication method according to the preferred embodiment of the present invention will be described with reference to FIGS. Here, descriptions such as [IETF RFC 2461] and [IEEE 802.11] described in each step indicate standards applied to the respective processes.

  FIG. 2 is a sequence diagram when the access point AP1a is activated. When the access point AP1a is activated in step S101, a router solicitation message for transmitting a router advertisement message is transmitted to the access router AR1 in step S102. The source address (SA) of the router solicitation message is the MAC address of the access point AP1a, and the destination address (DA: Destination Address) is the MAC address corresponding to all router multicast addresses.

  Upon receiving the router solicitation message, the access router AR1 transmits a router notification message for notifying the network prefix to the access point AP1a in step S103. The source address of the router notification message is the MAC address of the access router AR1, and the destination address is the MAC address of the access point AP1a. Thereby, the access point AP1a can obtain the network prefix of the access router AR1.

  Further, in step S104, the access point AP1a transmits a Neighbor Solicitation message to the intelligent switch ISW1. The neighbor solicitation message is a message for requesting other nodes existing on the same link to notify the MAC address. Here, a message for acquiring the MAC address corresponding to the IP address of the intelligent switch ISW1 is transmitted. At this time, the transmission source address of the neighbor solicitation message is the MAC address of the access point AP1a, and the destination address is the MAC address corresponding to the requesting node multicast address of the ISW.

  When the intelligent switch ISW1 receives the neighbor solicitation message, it transmits a neighbor advertisement message including the MAC address of the intelligent switch ISW1 to the access point AP1a. Thereby, the access point AP1a can obtain the MAC address of the intelligent switch ISW1.

  FIG. 3 is a sequence diagram when the intelligent switch ISW1 is activated. When the intelligent switch ISW1 is activated in step S151, a router solicitation message for transmitting a router notification message is transmitted to the access router AR1 in step S152. The source address of the router solicitation message is the MAC address of the intelligent switch ISW1, and the destination address is a MAC address corresponding to all router multicast addresses.

  Upon receiving the router solicitation message, the access router AR1 transmits a router notification message for notifying the network prefix to the intelligent switch ISW1 in step S153. The source address of the router notification message is the MAC address of the access router AR1, and the destination address is the MAC address of the intelligent switch ISW1. Thereby, the access point AP1a can obtain the network prefix of the access router AR1.

  FIG. 4 is a sequence diagram when mobile IP terminal STA1 according to the preferred embodiment of the present invention performs location registration in an external link that is not a home link. Here, a case will be described in which mobile IP terminal STA1 moves from a paging domain that is not paging domain 5a into a cell provided by access point AP1a.

  In step S201, the access point AP1a periodically transmits a beacon signal including information regarding the access point AP1a to a cell provided by the access point AP1a. Specifically, the beacon signal includes the paging identifier of the paging domain 5a to which the access point AP1a belongs and the identifier of the access point AP1a. The identifier of the access point AP1a includes a BSSID (Basic Service Set Identifier) that is the MAC address of the access point and an ESSID (Extended Service Set Identifier) that is assigned by the operator or the company as the wireless unit ID.

  When the mobile IP terminal STA1 receives the beacon signal from the access point AP1a, the mobile IP terminal STA1 confirms the position of the mobile IP terminal STA1. When the paging identifier is changed, the mobile IP terminal STA1 has moved beyond the paging domain, that is, at layer 3, so that location registration is performed. If the paging identifier is not changed, and only the access point identifier is changed, the movement is performed in layer 2 and thus the care-of address is not changed.

  If the mobile IP terminal STA1 determines that the paging identifier included in the received beacon has changed, in step S202, the mobile IP terminal STA1 transmits an authentication request message at the data link layer level to the access point AP1a. . When the authentication request message is received from the mobile IP terminal STA1 by the access point AP1a, the IP address of the RADIUS server 10 stored in advance is read in step S203, and the authentication request of the mobile IP terminal STA1 is sent to the IP address of the RADIUS server 10 A message is sent. When the authentication request message is received by the RADIUS server 10, an authentication response message is transmitted to the access point Ap1a in step S204. When the access point AP1a receives the authentication response message from the RADIUS server 10, the authentication response message is transmitted to the mobile IP terminal STA1 in step S205.

  Next, the mobile IP terminal STA1 transmits an association request message to the access point AP1a in step S206, and in response to this, an association response message is transmitted from the access point AP1a in step S207. As a result, the association between the mobile IP terminal STA1 and the access point AP1a is established.

  When the association response message is transmitted by the access point AP1a, a network prefix notification message is further transmitted to the mobile IP terminal STA1 in step S208. The information transmitted here includes the access router information including the network prefix of the access router AR1, the default gateway (IP address of the access router AR1), the MAC address of the access router AR1, and the IP address and MAC address of the intelligent switch ISW1. Intelligent switch information.

  When the mobile IP terminal STA1 receives the network prefix, in step S209, a network prefix response message is transmitted to the access point AP1a, and the 64-bit MAC address of the mobile IP terminal STA1 ( The care-of address is generated by adding EUI-64).

  Next, in step S210, the mobile IP terminal STA1 transmits a location registration update message including the care-of address to the home agent HA. When the location registration update message is received by the home agent HA, a location registration authorization (Ack) message is transmitted to the mobile IP terminal STA1 in step S211.

  When the location registration authorization message is received by the mobile IP terminal STA1, a paging request message for requesting paging is transmitted to the intelligent switch ISW1 in step S212. Here, paging means that the intelligent switch ISW1 transmits a notification that a packet addressed to the MAC address of the mobile IP terminal STA1 has arrived to the access point AP1a. In the paging request message, the source address is the MAC address of the mobile IP terminal STA1, and the destination address is the MAC address of the intelligent switch ISW1.

  When the intelligent switch ISW1 receives the paging request message from the mobile IP terminal STA1, in step S213, the paging response message is transmitted to the mobile IP terminal STA1. In the paging response message, the source address is the MAC address of the intelligent switch ISW1, and the destination address is the MAC address of the mobile IP terminal STA1. When the paging response message is received by the mobile IP terminal STA1, the mobile IP terminal STA1 can make and receive calls.

  When the paging response message is transmitted by the intelligent switch ISW1, in step S214, a connection disconnection request message for disconnecting the association established between the mobile IP terminal STA1 and the access point AP1a is transmitted to the access point AP1a. The connection disconnection request message includes the MAC address of the mobile IP terminal STA1, the source address is the MAC address of the intelligent switch ISW1, and the destination address is the MAC address of the access point AP1a.

  FIG. 5 is a sequence diagram in the case of notifying the mobile IP terminal according to the preferred embodiment of the present invention that a packet has arrived.

  In step S251, when a packet addressed to the mobile IP terminal STA1 is transmitted from the access router AR1 to the intelligent switch ISW1, the intelligent switch ISW1 buffers the packet. As the destination address of this packet, the MAC address of the mobile IP terminal STA1 is designated.

  Next, in steps S252a to 252n, the intelligent switch ISW1 transmits a paging incoming request message indicating that a packet addressed to the MAC address of the mobile IP terminal has arrived at the access point connected to the intelligent switch ISW1. Here, the paging incoming request message is transmitted by unicast to the access points AP1a, AP1b... AP1n by the intelligent switch ISW1. This paging incoming request message includes the MAC address of the mobile IP terminal STA1 that is the notification destination of the incoming call, the source address is the MAC address of the intelligent switch ISW1, and the destination address is the MAC address of the access point. As shown in FIG. 2, the MAC address of the access point is acquired by the access point sending a neighbor solicitation message to the intelligent switch ISW1 when the access point is activated.

  When the paging incoming request message is transmitted from the intelligent switch ISW1 to the access point AP1a in step S252a, the access point AP1a transmits a beacon signal including the paging incoming request message to the mobile IP terminal STA1 in step S253a. Specifically, the destination MAC address of the packet received by the intelligent switch ISW1 in step S251, for example, the MAC address of the mobile IP terminal STA1 is included. When the mobile IP terminal STA1 receives a paging incoming request message addressed to itself, the mobile IP terminal STA1 performs processing for receiving a packet. On the other hand, since the mobile IP terminal STA1 is not located in the cell provided by the access point AP1b ... AP1n, the paging incoming request message transmitted from the access point AP1b ... AP1n is transmitted to the mobile IP terminal STA1 in steps S253b and S253n. Not received. Until the paging incoming termination request message is transmitted from the intelligent switch ISW1 to the access point, the access point intermittently transmits the paging incoming request message to the mobile IP terminal STA1.

  When a paging incoming request is received by the mobile IP terminal ST1 in step S253a, an authentication request message at the data link layer level is transmitted to the access point AP1a by the mobile IP terminal STA1 in step S254. When the access point AP1a receives the authentication request message from the mobile IP terminal STA1, in step S255, the IP address of the RADIUS server 10 stored in advance is read and the authentication request of the mobile IP terminal STA1 is sent to the IP address of the RADIUS server 10. A message is sent. When the authentication request message is received by the RADIUS server 10, an authentication response message is transmitted to the access point Ap1a in step S256. When the authentication response message is received from the RADIUS server 10 by the access point AP1a, the authentication response message is transmitted to the mobile IP terminal STA1 in step S257.

  Next, the mobile IP terminal STA1 transmits an association request message to the access point AP1a in step S258, and correspondingly, an association response message is transmitted from the access point AP1a in step S259. As a result, the association between the mobile IP terminal STA1 and the access point AP1a is established. This association is maintained until communication between the mobile IP terminal STA1 and the source of the incoming packet is completed. An abnormal disconnection may occur during this communication. Specifically, the association is disconnected when the mobile IP terminal STA1 receives a paging response message corresponding to the paging request message and the access point AP1a receives the connection disconnection request message from the intelligent switch ISW1.

  When the association is established between the mobile IP terminal STA1 and the access point AP1a, in response to the reception of the paging incoming request message in step S253a, the mobile IP terminal STA1 sends the paging incoming response message to the intelligent switch ISW1 in step S260. Sent to. In this paging incoming response message, the source address is the MAC address of the mobile IP terminal STA1, and the destination address is the MAC address of the intelligent switch ISW1.

  When the paging incoming response message is received by the intelligent switch ISW1, in step S261a to step S261n, a paging incoming end request message is transmitted to each of the plurality of access points by unicast. This paging incoming end request message includes the MAC address of the mobile IP terminal STA1 transmitted in steps S252a to S252n, the source address is the MAC address of the intelligent switch ISW1, and the destination address is the MAC address of the access point.

  When the paging incoming response message is received by the intelligent switch ISW1, the packet buffered in step S251 is transmitted to the MAC address of the mobile IP terminal STA1. In this way, as shown in step S263, communication between the mobile IP terminal STA and the communication network is established.

  For example, when connection aging or call disconnection occurs, the mobile IP terminal STA1 transmits a paging request message requesting paging to the intelligent switch ISW1 again in step S264. In the paging request message, the source address is the MAC address of the mobile IP terminal STA1, and the destination address is the MAC address of the intelligent switch ISW1.

  When the intelligent switch ISW1 receives a paging request message from the mobile IP terminal STA1, a paging response message is transmitted to the mobile IP terminal STA1 in step S265. In the paging response message, the source address is the MAC address of the intelligent switch ISW1, and the destination address is the MAC address of the mobile IP terminal STA1. When the paging response message is received by the mobile IP terminal STA1, the mobile IP terminal STA1 can make and receive calls again.

  When the paging response message is transmitted by the intelligent switch ISW1, in step S214, a connection disconnection request message for disconnecting the association established between the mobile IP terminal STA1 and the access point AP1a is transmitted to the access point AP1a.

  In the wireless communication method according to the preferred embodiment of the present invention, an intelligent switch accommodating a plurality of access points is installed between an access point and an access router. A set of cells provided by an access point accommodated in one intelligent switch is managed as a paging domain. When the mobile IP terminal moves beyond the paging domain, the mobility management is performed in the network layer (layer 3), that is, the conventional mobile IP procedure. When the mobile IP terminal moves without exceeding the paging domain, the mobility management is performed. Is performed in the data link layer (layer 2). As described above, the paging domain defined by the intelligent switch is a unit for calling a packet at the minimum unit of location registration of Mobile IP. With this configuration, the location registration (Binding) process needs to be performed only once for movement within the same paging domain. Therefore, even if the cell area provided by the access point is small or the mobile IP terminal moves frequently, location registration processing is not performed every time if the paging domain is not changed. The communication time required for the communication can be shortened. Furthermore, battery consumption of the mobile IP terminal can be reduced.

  Next, mobile IP terminals, access points, and intelligent switches used in the wireless communication method according to the preferred embodiment of the present invention will be described in detail.

(Mobile IP terminal)
The mobile IP terminal STA1 according to the preferred embodiment of the present invention independently determines whether it is a movement beyond the paging domain, that is, whether it is a layer 2 movement or a layer 3 movement, and the care-of address It has a function of generating, establishing an association with the access point AP1a, a location registration process to the home agent HA, and a paging request function to the intelligent switch ISW1.

  Specifically, as shown in FIG. 6, mobile IP terminal STA1 according to the preferred embodiment of the present invention includes central control unit 100, radio control unit 104, transceiver 105, and antenna 106. The central control unit 100 includes a central processing control device (CPU) 101, a ROM (Read Only Memory) 102, and a RAM (Random Access Memory) 103.

  The ROM 102 has a boot program executed when the mobile IP terminal STA1 is started, the RAM 103 has a program executed by the mobile IP terminal STA1, a data table 150 including a home address and a home agent IP address described later, and processing. Temporary storage data generated in the memory is stored.

  When the mobile IP terminal STA1 is started, the boot program stored in the ROM 102 is executed by the central processing control device 101. The central control unit 100 controls the radio control unit 104 to transmit / receive data to / from the access point AP1a via the antenna 106 and the transceiver 105. The radio control unit 104 receives a beacon signal transmitted from an access point and includes a paging identifier of a currently located paging domain. When the radio controller 104 determines that the currently located paging domain has been changed, the wireless control unit 104 establishes an association with the access point. Receives information on the access router and intelligent switch to which the access point is connected from the access point, creates a care-of address based on the information on the access router, reads out the home address and IP address of the home agent from the storage unit, and notices An intelligent paging request message that sends the address and home address to the IP address of the home agent, updates the location registration, and registers the destination address of the packet forwarded by the intelligent switch. It controls the process of transmitting the Entosuitchi. Further, upon receiving a paging incoming request message that is a notification that a packet addressed to the mobile IP terminal has arrived from the access point, the wireless control unit 104 controls processing for transmitting a paging incoming response to the intelligent switch. .

  As shown in FIG. 7, the data table 150 of the mobile IP terminal STA1 includes data about the mobile IP terminal STA1 itself, data about the access point, data about the access router, data about the intelligent switch, and data about the home agent.

(1) Data / home address information regarding the mobile IP terminal STA1 itself: IP address on the home link of the mobile IP terminal STA1, that is, a home address, a subnet mask, a default gateway (IP address of the access router), and the like. These pieces of information are statically stored as information unique to the mobile IP terminal STA1.
COA information: IP address, subnet mask, default gateway, etc. at the external link of the mobile IP terminal STA1. These pieces of information are generated when connected to the access point, that is, at the time of location registration shown in FIG.
STA-MAC address: the MAC address of the mobile IP terminal STA1. These pieces of information are statically stored as information unique to the mobile IP terminal STA1.
AP-ID: Access point wireless unit ID (ESSID). The mobile IP terminal STA1 determines an access point that may be connected based on this AP-ID.

(2) Data related to access point The data related to this access point includes the following data for each access point that is associated with the mobile IP terminal STA1.
AP-ID: The wireless part ID (BSSID and ESSID) of the detected access point.
-Paging ID: included in the beacon signal transmitted from the access point. When the paging ID is changed, the mobile IP terminal STA1 determines that the paging domain has been changed, and performs location registration processing.

(3) Data relating to access router The data relating to the access router is transmitted from the access point when the access point is detected.
Network prefix: The mobile IP terminal STA1 generates a care-of address based on this network prefix.
MAC address: MAC address of the access router.
-Default gateway: IP address of the access router

(4) Data and MAC address related to intelligent switch: The MAC address of the intelligent switch is used as a destination address requested by the mobile IP terminal STA1 for paging. Data regarding the intelligent switch is transmitted from the access point when the access point is detected.

(5) Data and IP address related to home agent: The IP address of the home agent is the destination IP address when the mobile IP terminal STA1 performs location registration update to the home agent.

  Next, with reference to FIGS. 8 to 10, the state transition of the mobile IP terminal STA1 according to the preferred embodiment of the present invention will be described.

  First, in step S1101, it is assumed that the mobile IP terminal STA1 is in a stopped state. When mobile IP terminal STA1 is activated, in step S1102, it searches for an access point and receives a beacon signal from the access point. This process corresponds to step S201 in FIG.

  When receiving the beacon signal, in step S1103, the mobile IP terminal STA1 transmits an L2 authentication request message to the RADIUS server via the access point, and in response to this, in step S1104, the L2 authentication is performed from the RADIUS server via the access point. Receive a response message. This process corresponds to steps S202 to S205 in FIG. If the authentication is not successful in step S1105, the process returns to step S1101, and the access point is searched again in step S1102.

  If authenticated in step S1105, the mobile IP terminal STA1 transmits an association request message to the access point in step S1106. Correspondingly, in step S1107, the mobile IP terminal STA1 receives the association request message from the access point. As a result, an association is established between the mobile IP terminal STA1 and the access point. This process corresponds to step S206 and step S207 in FIG.

  Next, in step S1108, the mobile IP terminal STA1 receives from the access point a network prefix notification message including information on the intelligent switch to which the access point is connected and information on the access router to which the intelligent switch is connected. In response to this, in step S1108, the mobile IP terminal STA1 transmits a network prefix response message to the access point. At this time, in step S1110, the mobile IP terminal STA1 generates a care-of address (COA) based on the network prefix included in the access router information received in step S1108 and the MAC address of the mobile IP terminal STA1 shown in FIG. To do. This process corresponds to step S208 and step S209 in FIG.

  When the care-of address is generated in step S1110, the mobile IP terminal STA1 transmits a location registration update message including the generated care-of address to the home agent in step S1111, and in response to this, the location registration authorization message in step S1112. Is received from the home agent. This process corresponds to steps S210 and S211 in FIG.

  When the location registration to the home agent is completed, the mobile IP terminal STA1 transmits a paging request message to the intelligent switch in step S1113, and correspondingly receives a paging response message from the intelligent switch in step S1114. Thereby, the mobile IP terminal STA1 can make / receive calls via the intelligent switch. This process corresponds to step S212 and step S213 in FIG.

  When the paging request to the intelligent switch is completed, in step S1115, the mobile IP terminal STA1 waits in a sleep state until an incoming call or outgoing call occurs. At this time, a beacon signal is periodically searched for an access point that can establish an association.

  Here, in step S1201, the mobile IP terminal STA1 receives the beacon signal from the access point, and recognizes that the paging domain identifier included in the beacon signal has changed, it is determined that the mobile IP terminal STA1 has moved beyond the paging domain. Proceeding to S1101, a connection is established with a newly recognized access point.

  On the other hand, if a call is requested from an application running on the mobile IP terminal STA1 in step S1202, the process proceeds to step S1204.

  In step S1204, the mobile IP terminal STA1 transmits an L2 authentication request message to the RADIUS server via the access point. In response to this, in step S1205, the mobile IP terminal STA1 receives an L2 authentication response message from the RADIUS server via the access point. If the authentication is not successful in step S1206, the process returns to step S1101, and the access point is searched again in step S1102.

  If authenticated in step S1206, the mobile IP terminal STA1 transmits an association request message to the access point in step S1207, and correspondingly receives an association request message from the access point in step S1208. In step S1209, an association is established between the mobile IP terminal STA1 and the access point.

  On the other hand, in step S1203 corresponding to step S253a in FIG. 5, when the paging incoming request message included in the beacon signal is received from the access point, and the MAC address of the mobile IP terminal STA1 itself is included in the paging incoming request message. The process proceeds to step S1210. On the other hand, if the mobile IP terminal STA1's own MAC address is not included, nothing is processed.

  In step S1210, the mobile IP terminal STA1 transmits an L2 authentication request message to the RADIUS server via the access point. Correspondingly, in step S1211, the mobile IP terminal STA1 receives an L2 authentication response message from the RADIUS server via the access point. This process corresponds to steps S254 to S257 in FIG. If not authenticated in step S1212, the process returns to step S1101, and in step S1102, the access point is searched again.

  If authenticated in step S1212, the mobile IP terminal STA1 transmits an association request message to the access point in step S1213. Correspondingly, in step S1214, the mobile IP terminal STA1 receives the association request message from the access point. At this time, in step S1215, the mobile IP terminal STA1 transmits a paging incoming response message to the intelligent switch. Thereby, in step S1216, an association is established between the mobile IP terminal STA1 and the access point. This process corresponds to steps S258 to S260 in FIG.

  When communication is enabled in step S1301, when a request message for real-time communication such as VoIP (Voice over Internet Protocol) is received as shown in step S1302, the mobile IP terminal STA1 transitions to VoIP communication in step S1303. . At this time, if disconnection of real-time communication is requested in step S1304, mobile IP terminal STA1 transmits a paging request message to the intelligent switch in step S1305, and in response to this, the paging response is sent from the intelligent switch in step S1306. Receive a message. Thereby, the mobile IP terminal STA1 can transit to the state of step S1115 and can make / receive calls again via the intelligent switch. This process corresponds to step S264 and step S265 in FIG. Here, the disconnection request for the real-time communication in step S1304 refers to a session disconnection due to, for example, receiving a bye signal from the communication destination terminal, pressing the disconnect button by the user of the mobile IP terminal STA1, or deterioration of the communication state. Etc.

  On the other hand, if a request message for non-real-time communication such as data communication is received in step S1307 while VoIP communication is being performed in step S1303, the state transits to a state in which VoIP and data are simultaneously communicated in step S1319.

  On the other hand, when communication is enabled in step S1301, when a request message for non-real-time communication such as data communication is received as shown in step S1311, the mobile IP terminal STA1 transitions to data communication in step S1312. At this time, a no-communication timer for monitoring the no-communication time is started.

  When the no-communication timer expires in step S1314 or the data session is disconnected in step S1313, the mobile IP terminal STA1 transmits a paging request message to the intelligent switch in step S1315. In step S1316, a paging response message is received from the intelligent switch. Thereby, the mobile IP terminal STA1 can transit to the state of step S1115 and can make / receive calls again via the intelligent switch. This process corresponds to step S264 and step S265 in FIG.

  On the other hand, when data communication is being performed in step S1302, when a request message for real-time communication such as VoIP is received in step S1317, the no-communication timer started in step S1312 is stopped in step S1318, and in step S1319, VoIP and Transition to a state in which data is communicated simultaneously.

  At this time, if disconnection of real-time communication is requested in step S1320, mobile IP terminal STA1 proceeds to step S1312, and transitions to a state where only data communication is performed. On the other hand, when the data session is disconnected in step S1321, the mobile IP terminal STA1 proceeds to step S1303 and transitions to a state where only VoIP communication is performed.

  As described above, the mobile IP terminal according to the preferred embodiment of the present invention receives the beacon signal including the paging identifier of the currently located paging domain transmitted from the access point, and determines that the currently located paging domain has been changed. Then, the location registration is performed with respect to the home agent. Since this paging domain is a set of cells provided by a plurality of access points, it is not necessary to perform location registration unless the paging domain is changed even if the mobile IP terminal moves and the access point is changed. Accordingly, since the mobile IP terminal can reduce the number of times of location registration compared to the communication method in which location registration is performed every time the access point shown in FIG. 21 changes, the processing load and battery of the mobile IP terminal can be reduced. This can reduce the consumption of energy.

  Although the mobile IP terminal STA1 has been described here, the same applies to the mobile IP terminal STA2.

(access point)
The access point AP1a according to the preferred embodiment of the present invention has a function of self-terminating an incoming request received from the intelligent switch ISW1 and placing a paging incoming request message designating the mobile IP terminal STA1 arriving in the beacon signal.

  Specifically, as shown in FIG. 11, the access point AP1a according to the preferred embodiment of the present invention includes a central control unit 200, a PHY (PHYsical sublayer) 205, a radio control unit 206, a transceiver 207, and an antenna 208. I have. The central control unit 200 includes a MAC control unit 201, a central processing control device (CPU) 202, a ROM 203, and a RAM 204.

  The ROM 203 has a boot program executed when the access point AP1a is started, the RAM 204 has a program executed by the access point AP1a, a data table 250 including access router information and intelligent switch information described later, and processing. Temporary storage data generated in the memory is stored. Here, the information of the access router is the network prefix of the access router, the IP address and MAC address of the access router, and the information of the intelligent switch is the IP address and MAC address of the intelligent switch.

  When the access point AP1a is activated, the central processing control device 202 executes the boot program stored in the ROM 203. The central control unit 200 controls the radio control unit 206 to transmit / receive data to / from the mobile IP terminal STA1 via the antenna 208 and the transceiver 207. The wireless control unit 206 transmits a beacon signal including the paging identifier of the paging domain 5a provided by the intelligent switch ISW1 to the cell, and when an association request message is transmitted from the mobile IP terminal STA1, the access router AR1 is transmitted to the mobile IP terminal STA1. Controls the process of sending the information. On the other hand, the MAC control unit 201 is a chip that realizes control of the data link layer, and transmits / receives to / from the intelligent switch ISW1 via the PHY 205 based on the MAC address used for the access point AP1a to connect to the intelligent switch ISW1. Is done. When the access point is activated, the PHY 205 receives the network prefix of the access router by transmitting a router solicitation message, and controls the process of receiving the MAC address of the intelligent switch by transmitting a neighbor solicitation message.

  As shown in FIG. 12, the data table 250 of the access point AP1a includes data about the access point AP1a itself, data about the intelligent switch, data about the mobile IP terminal STA1, data about the RADIUS server, and data about the access router.

(1) Data relating to the access point AP1a itself All data relating to the access point AP1a are statically stored with information unique to the access point AP1a.
Address information: IP address, subnet mask, and default gateway data of the access point AP1a.
MAC address: the MAC address of the access point AP1a itself.
AP-ID: the wireless unit ID (BSSID and ESSID) of the access point AP1a itself.
Paging ID: An identifier of a paging domain provided by the intelligent switch to which the access point AP1a is connected.

(2) Data / IP address related to intelligent switch: IP address of the intelligent switch to which the access point AP1a is connected. This data is stored in advance in the access point AP1a.
MAC address: the MAC address of the intelligent switch to which the access point AP1a is connected. This information is acquired by transmitting a neighbor solicitation message in which the IP address of the intelligent switch is designated and receiving a neighbor notification message when the access point AP1a is activated.

(3) Data on Mobile IP Terminal This information includes the following data for each mobile IP terminal with which association has been established based on the beacon signal transmitted by the access point AP1a. These data are acquired when the mobile IP terminal is connected, and are managed as a connection table to which the access point AP1a can be connected.
IP address: The IP address of the mobile IP terminal.
STA-MAC address: the MAC address of the mobile IP terminal.

(4) Data / IP address related to RADIUS server: IP address of the RADIUS server to which the access point AP1a requests authentication. This data is stored in advance in the access point AP1a.

(5) Data network prefix related to the access router: the network prefix of the access router to which the access point AP1a is connected in relation to the intelligent switch. This information is acquired by transmitting a router solicitation message and receiving a router advertisement message when the access point AP1a is activated.

  Next, state transition of the access point AP1a according to the best embodiment of the present invention will be described with reference to FIGS. Although not shown, when the access point AP1a is activated, the router solicitation message and the neighbor solicitation message described above are transmitted to obtain information on the access router and the intelligent switch in advance.

  First, in step S2101, the access point AP1a is in a standby state. While in the standby state, a beacon signal is intermittently transmitted to the mobile IP terminal in step S2102. If there is no response from the mobile IP terminal in step S2103, the process returns to step S2101 and enters a standby state.

  If there is a response from the mobile IP terminal in step S2103, in step S2104, the access point AP1a receives the L2 authentication request message from the mobile IP terminal, reads the data table 250, and acquires the IP address of the RADIUS server. Next, the access point AP1a transmits an L2 authentication request message to the IP address of the RADIUS server in step S2105, and receives an L2 authentication response message from the RADIUS server in step S2106. This process corresponds to steps S202 to S205 in FIG. If the authentication is not performed in step S2107, the access point AP1a transmits an L2 authentication response message indicating that the authentication has not been performed to the mobile IP terminal in step S2108, and returns to step S2101 to be in a standby state.

  If authenticated in step S2107, the access point AP1a transmits an L2 authentication response message indicating authentication in step S2109 to the mobile IP terminal. In step S2110, when the access point AP1a receives the association request message from the mobile IP terminal, in response to this, the access point AP1a transmits an association response message to the mobile IP terminal in step S2111. This process corresponds to step S206 and step S207 in FIG.

  If the prefix request message is not received from the mobile IP terminal in step S2112, the access point AP1a registers information of this mobile IP terminal in the connection table of the data table 250 in step S2115, and can communicate with the mobile IP terminal in step S2201. Transition to a different state. At this time, an association is established between the mobile IP terminal STA1 and the access point.

  On the other hand, when the prefix request message is received from the mobile IP terminal in step S2112, the access point AP1a reads the data table 250 to extract the network prefix of the access router in step S2113, and sends the network prefix notification message of the IPv6 address to the mobile IP. In response to this, a network prefix response message is received from the mobile IP terminal in step S2114. Thereafter, in step S2115, the access point AP1a registers the information of the mobile IP terminal in the connection table of the data table 250, and transitions to a state in which communication with the mobile IP terminal is possible in step S2201. This process corresponds to step S208 and step S209 in FIG. As a result, an association is established between the mobile IP terminal STA1 and the access point.

  Here, when the access point AP1a receives a frame from the mobile IP terminal in step S2202, the access point AP1a initializes a no-communication timer in step S2203, transmits the received frame to the intelligent switch in step S2204, and again in step S2201 the mobile IP terminal. Transition to a state where communication is possible. In step S2205, when the access point AP1a receives a frame addressed to the mobile IP terminal from the intelligent switch, the access point AP1a initializes a no-communication timer in step S2206, transmits the received frame to the mobile IP terminal in step S2207, and again returns to step S2201. Transition to a state in which communication with the mobile IP terminal is possible.

  On the other hand, when the access point AP1a receives a connection table deletion request message for disconnecting the association with a predetermined mobile IP terminal from the intelligent switch in step S2208, information on the mobile IP terminal is obtained from the connection table of the data table 250 in step S2209. It deletes, it returns to step S2101 again and will be in a standby state. This process corresponds to step S214 in FIG. If the no-communication timer expires in step S22210, the access point AP1a transmits a connection disconnection request message to the mobile IP terminal in step S2211. Further, in step S2212, the access point AP1a deletes information related to the mobile IP terminal from the connection table of the data table 250, returns to step S2101 again, and enters a standby state.

  When the access point AP1a receives a paging incoming request from the intelligent switch in which the MAC address of the mobile IP terminal is specified in step S2302 while in the standby state in step S2101, the access point AP1a transitions to the paging incoming state in step S2303. Next, in step S2304, the access point AP1a starts the paging incoming request by incorporating the incoming request message into the beacon signal, and in step S2305, the paging incoming request message is sent to the mobile IP terminal located in the cell provided by the access point AP1a. Send. This process corresponds to Step S252 and Step S253 in FIG.

  If there is no response from the mobile IP terminal in step S2306, the access point AP1a receives the paging incoming request end message from the intelligent switch in step S2307, and ends the paging incoming request in step S2308. Specifically, the incoming call request message incorporated in step S2304 is removed from the beacon signal transmitted by the access point AP1a. This process corresponds to step S261 in FIG. When the paging incoming request is completed, the process returns to step S2101 and enters a standby state.

  On the other hand, if there is a response from the mobile IP terminal to the paging incoming request message in step S2306, the access point AP1a receives the L2 authentication request message from the mobile IP terminal in step S2309, reads the data table 250, and Obtain the IP address of the RADIUS server. Next, the access point AP1a transmits an L2 authentication request message to the IP address of the RADIUS server in step S2310, and receives an L2 authentication response message from the RADIUS server in step S2311. This process corresponds to steps S254 to S257 in FIG. If the authentication is not performed in step S2312, the access point AP1a transmits an L2 authentication response message indicating that the authentication has not been performed to the mobile IP terminal in step S2313. In step S2307, the access point AP1a receives the paging incoming request from the intelligent switch. When the end message is received, the paging incoming request is ended in step S2308. This process corresponds to step S261 in FIG.

  When authenticated in step S2312, in step S2314, the access point AP1a transmits an L2 authentication response message indicating authentication to the mobile IP terminal. In step S2315, upon receiving the association request message from the mobile IP terminal, the access point AP1a transmits an association response message to the mobile IP terminal in step S2316. This process corresponds to Step S258 and Step S259 in FIG.

  In step S2317, when the access point AP1a receives the paging incoming response message addressed to the intelligent switch from the mobile IP terminal, in step S2318, the access point AP1a transfers the received paging incoming response message to the intelligent switch. This process corresponds to step S260 in FIG.

  Furthermore, when the access point AP1a receives a paging incoming request end message from the intelligent switch in step S2319, the access point AP1a ends the paging incoming request in step S2320. This process corresponds to step S261 in FIG. Thereafter, the access point AP1a transitions to a state in which it can communicate with the mobile IP terminal in step S2201.

  Although the access point AP1a has been described here, the same applies to other access points such as the access point AP1b.

(Intelligent switch)
When there is an incoming call from the access router AR1, the intelligent switch ISW1 according to the preferred embodiment of the present invention, based on the paging request message from the mobile IP terminal STA1, accesses the access points AP1a, AP1b,. A function of transmitting a paging incoming request to the AP 1n is provided.

  Specifically, as shown in FIG. 16, the intelligent switch ISW1 according to the preferred embodiment of the present invention includes a central control unit 301, a memory 302, an L2 switch LSI 303, 4-port PHYs 304a to 304d, an RS-232C interface 305, A power supply unit 306 is provided. The memory 302 includes a boot program executed when the intelligent switch ISW1 is activated, a network table of an access router, which will be described later, a data table 350 including an IP address and a MAC address of an access point, temporary storage data generated during processing, a port And the MAC learning table of the information device connected to the port destination.

  When the intelligent switch ISW1 is activated, the boot program stored in the memory 302 is executed by the central control unit 301. Further, the central control unit 301 controls the L2 switch LSI 303 to control the 4-port PHYs 304a to 304d connected to the L2 switch LSI 303 so as to communicate with the network. In the example shown in FIG. 16, since the intelligent switch ISW1 includes four 4-port PHYs, it has a total of 16 ports. By connecting these ports to the access router AR1, access points AP1a, AP1b... AP1n, the intelligent switch ISW1 can communicate with these information devices. Specifically, the intelligent switch ISW1 reads the destination MAC address of the packet received from these information devices, reads the MAC learning table stored in the memory 302, and extracts the port corresponding to the read MAC address. And send a packet to that port.

  The RS-232C interface 305 is an input / output interface from the outside. The power supply unit 306 is connected to an AC 100V power supply and supplies power to the intelligent switch ISW.

  Further, when receiving a paging request message for registering the destination address of the packet transferred by the intelligent switch ISW1 from the mobile IP terminal, the central control unit 301 transmits a paging response message to the mobile IP terminal. Further, when receiving the packet addressed to the mobile IP terminal, the central control unit 301 buffers the packet in the memory 302 and transmits a paging incoming request message indicating that the packet addressed to the mobile IP terminal has arrived to the access point. . Further, when receiving a paging incoming response from the mobile IP terminal, the central control unit 301 transmits a buffered packet to the mobile IP terminal and controls a process of transmitting a paging incoming end request message to the access point. When the central control unit 301 receives a paging request message for registering the destination address of the packet transferred by the intelligent switch ISW1 from the mobile IP terminal, the association for disconnecting the association established between the mobile IP terminal and the access point It is preferable to control the process of transmitting the connection disconnection request message.

  As shown in FIG. 17, the data table 350 of the intelligent switch ISW1 includes data regarding the intelligent switch itself, data regarding an access point, and data regarding an access router.

(1) Data relating to the intelligent switch All data relating to this is statically stored with information specific to the intelligent switch ISW1.
Address information: IP address, subnet mask, default gateway data of the intelligent switch ISW1 itself.
MAC address: the MAC address of the intelligent switch ISW1 itself.

(2) Data on Access Point This data includes the following information for each access point connected to the intelligent switch ISW1.
IP address: The IP address of the access point. This information is statically stored as information unique to the intelligent switch ISW1.
MAC address: The MAC address of the access point. This information is acquired by receiving the router solicitation message shown in FIG. 2 when the access point is activated.
Send port: The port number to which the access point is connected. This information is acquired by the port number that received the router solicitation message when the access point is activated.

(3) Data network prefix for access router: Network prefix of the access router connected to the intelligent switch ISW1. This information is acquired by transmitting a router solicitation message and receiving a router advertisement message when the intelligent switch ISW1 is activated.

  Next, referring to FIGS. 18 and 19, the state transition of the intelligent switch ISW1 according to the preferred embodiment of the present invention will be described. Although not shown in the figure, when the intelligent switch ISW1 is activated, the router solicitation message described above is transmitted to obtain information on the access router in advance.

  First, in step S3101, the intelligent switch ISW1 is activated and then waits in an initial state. When the paging request message is transmitted to the mobile IP terminal in step S3102, the intelligent switch receives the paging response message from the mobile IP terminal in step S3103. Further, in step S3104, the intelligent switch ISW1 transmits a connection disconnection request message that causes the access point to delete information related to the mobile IP terminal from the connection table of the data table 250, and transitions to the paging state in step S3201. When in the paging state, the intelligent switch ISW1 can receive and receive calls with the mobile IP terminal, and starts a timer that measures the no-communication time. This process corresponds to steps S212 to S214 in FIG.

  When the intelligent switch ISW1 receives a frame from the mobile IP terminal in step S3202 in the paging state in step S3201, based on the port number that received the frame and the MAC address of the mobile IP terminal, the intelligent switch ISW1 enters the MAC learning table in step S3203. In step S3204, the frame received in step S3202 is transferred to the destination, and the state transits to the unicast communication state in step S3105. Here, the unicast state is a state in which the MAC address of the mobile IP terminal STA1 is designated from the intelligent switch ISW1 and communication is performed by unicast.

  On the other hand, when the paging state is set in step S3201, the intelligent switch ISW1 stores the received frame in the memory 302 when receiving the frame addressed to the mobile IP terminal in step S3205. In step S3206, a paging incoming request message is transmitted to all access points connected to the intelligent switch ISW1. When the paging incoming response message is transmitted from the mobile IP terminal in step S3207, it is registered in the MAC learning table based on the port number that received the paging incoming response message and the MAC address of the mobile IP terminal in step S3208. If there is no paging incoming response, the paging incoming request message is transmitted again to all access points. Next, in step S3209, the intelligent switch ISW1 transmits a paging incoming termination request message to all the access points connected to the intelligent switch ISW1, and transmits the frames accumulated in step S3205 to the mobile IP terminal in unicast in step S3210. To do. Thereafter, the intelligent switch ISW1 transitions to the unicast state in step S3105. This process corresponds to steps S252 to S262 in FIG. If the non-communication timer expires in step S3311, the process transits to the initial state in step S3101.

  When the communication is performed in the unicast state in step S3105, the intelligent switch ISW1 starts a no-communication timer.

  In step S3106, when the intelligent switch ISW1 receives a frame from the mobile IP terminal, the intelligent switch ISW1 initializes a non-communication timer in step S3107, transfers the frame to the mobile IP terminal in step S3108, and transitions to the unicast state in step S3105 again. This process corresponds to step S263 in FIG.

  In step S3109, upon receiving a frame addressed to the mobile IP terminal, the intelligent switch ISW1 reads the memory 302 in step S3110 and refers to the MAC learning table to extract a port number that can be transmitted to the mobile IP terminal. In step S3111, the intelligent switch ISW1 transfers the frame to the mobile IP terminal via the extracted port. This process corresponds to step S263 in FIG.

  When the paging request message is transmitted to the mobile IP terminal in step S3112, the intelligent switch receives the paging response message from the mobile IP terminal in step S3113. Further, in step S3114, the intelligent switch ISW1 transmits a connection disconnection request message that causes the access point to delete information related to the mobile IP terminal from the connection table of the data table 250, and transitions to the paging state in step S3201. On the other hand, when the no-communication timer expires in step S3115, in step S3116, the intelligent switch ISW1 transmits a connection disconnection request message that causes the access point to delete information related to the mobile IP terminal from the connection table of the data table 250, and in step S3101. Transition to the initial state.

Next, a control flow of the intelligent switch ISW1 will be described with reference to FIG.
In step S41010, a packet arrives from the reception queue 351.
First, the control when the intelligent switch ISW1 is in the paging state in step S4102 will be described.

  If the received packet is the first packet from the network (S4103), the intelligent switch ISW1 buffers the received packet in the temporary buffer 352 of the memory 302, generates a paging incoming request message, and sends a paging incoming request to the access point. Send a message.

  When the received packet is the second packet or later from the network (S4104), the intelligent switch ISW1 stores the received packet in the temporary buffer 352.

  When the received packet is a paging incoming response message received from the mobile IP terminal (S4105), the intelligent switch ISW1 performs the discharge process of the temporary buffer 352. At this time, the intelligent switch ISW1 suppresses the incoming interrupt, then enqueues the queue of the temporary buffer 352 into the transmission queue 353, and transits to a unicast state in which unicast communication with the mobile IP terminal is possible. Thereafter, the intelligent switch ISW1 permits the inhibited interrupt.

  On the other hand, when the intelligent switch ISW1 is in the unicast state in step S4106, the intelligent switch ISW1 executes a general packet forward process for transferring the received packet to the packet transmission destination. Similarly, when the mobile IP terminal is in the state of steps S3112 to S3113 in FIG. 8, more specifically, in the state where the location registration process to the home agent is completed and the paging state cannot be changed, the general packet forward process is similarly performed. The packet transmitted here is discarded on the mobile IP terminal side.

  Although the intelligent switch ISW1 has been described here, the same applies to other intelligent switches such as the intelligent switch ISW2.

(Other embodiments)
As described above, the present invention has been described according to the best mode for carrying out the invention. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples, and operational techniques will be apparent to those skilled in the art.

  It goes without saying that the present invention includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

  The wireless communication method according to the present invention does not require location registration processing for a home agent even when a mobile IP terminal moves within a paging domain defined by a set of a plurality of cells provided by an access point. Can reduce the load on the mobile IP terminal.

1 is a system configuration diagram of a communication network according to a preferred embodiment of the present invention. It is a sequence diagram which shows a process when the access point which concerns on the best embodiment of this invention is started. It is a sequence diagram which shows a process when the intelligent switch which concerns on best embodiment of this invention is started. FIG. 10 is a sequence diagram showing processing when location registration is performed by a mobile IP terminal in the communication system according to the preferred embodiment of the present invention. It is a sequence diagram which shows a process when a packet arrives at a mobile IP terminal in the communication system which concerns on the best embodiment of this invention. It is a hardware block diagram of the mobile IP terminal which concerns on the best embodiment of this invention. It is an example of the data table managed with the mobile IP terminal which concerns on the best embodiment of this invention. It is a state transition diagram of the mobile IP terminal according to the best embodiment of the present invention. (Part 1) It is a state transition diagram of the mobile IP terminal according to the best embodiment of the present invention. (Part 2) It is a state transition diagram of the mobile IP terminal according to the best embodiment of the present invention. (Part 3) It is a hardware block diagram of the access point which concerns on the best embodiment of this invention. It is an example of the data table managed by the access point which concerns on the best embodiment of this invention. It is a state transition diagram of the access point which concerns on the best embodiment of this invention. (Part 1) It is a state transition diagram of the access point which concerns on the best embodiment of this invention. (Part 2) It is a state transition diagram of the access point which concerns on the best embodiment of this invention. (Part 3) It is a hardware block diagram of the intelligent switch which concerns on the best embodiment of this invention. It is an example of the data table managed by the intelligent switch which concerns on the best embodiment of this invention. It is a state transition diagram of the intelligent switch which concerns on the best embodiment of this invention. (Part 1) It is a state transition diagram of the intelligent switch which concerns on the best embodiment of this invention. (Part 2) It is a figure which shows the control flow of the intelligent switch which concerns on the best embodiment of this invention. It is a system block diagram of the conventional communication network.

Explanation of symbols

1 ... Mobile IPv6 network 2 ... IPv4 network 3 ... PSTN
5a, 5b ... paging domain 10 ... RADIUS server 11 ... SIP terminal 100, 200, 301 ... central control unit 101, 202 ... CPU
102, 203 ... ROM
103, 204 ... RAM
104, 206 ... wireless control unit 105, 207 ... transceiver 106, 208 ... antenna 150, 250, 350 ... data table 201 ... MAC control unit 205 ... PHY
302 ... Memory 303 ... L2 switch LSI
304 ... 4 port PHY
305 ... RS-232C interface 306 ... Power supply unit 351 ... Reception queue 352 ... Temporary buffer 353 ... Transmission queue AP1a, AP1b, AP1n ... Access point AR1, AR2 ... Access router GW1, GW2 ... Gateway Switch STA1, STA2 ... Mobile IP terminal

Claims (15)

An access router connected at a network layer level to a communication network to which a home agent is connected, an intelligent switch in which the access router and the access point are connected at a data link layer level, and wireless communication by being connected to the intelligent switch Wireless communication used in a communication system comprising an access point that provides a cell, and a mobile IP terminal that is connected to the communication network via the access point, the intelligent switch, and the access router and is located on an external link A method,
Receiving a beacon signal from the access point including a paging identifier corresponding to the intelligent switch to which the access point is connected by the mobile IP terminal located in a cell provided by the access point;
Determining by the mobile IP terminal that the paging identifier included in the received beacon has changed;
The mobile IP terminal receives the access router information from the access point and creates a care-of address based on the access router information, and transmits the care-of address to the home agent. When the intelligent switch information is received from the access point, a paging request message for requesting paging for sending a notification addressed to the MAC address of the mobile IP terminal from the home agent is sent to the access point. And a step of transmitting to the intelligent switch. When a packet is transmitted from the access router to the intelligent switch, the packet is buffered by the intelligent switch, and the access point connected to the intelligent switch is addressed to the MAC address of the mobile IP terminal. A paging incoming request message indicating that a packet has arrived is sent;
A paging incoming response message is transmitted to the intelligent switch when the mobile IP terminal receives the paging incoming request message;
The wireless communication method according to claim 1, further comprising the step of: transmitting the buffered packet to the MAC address of the mobile IP terminal by the intelligent switch. A plurality of the access points are connected to the intelligent switch,
The step of transmitting the paging incoming request message includes:
When a packet is transmitted from the access router to the intelligent switch, the intelligent switch buffers the packet, and the paging incoming request message is sent to each of the plurality of access points connected to the intelligent switch. Sent steps,
The wireless communication method according to claim 2, further comprising a step of transmitting a paging incoming end request message to each of the plurality of access points when a paging incoming response message is received by the intelligent switch. When the access point receives the paging incoming request message from the intelligent switch, the access point further includes the step of transmitting the beacon signal including the paging incoming request message to the mobile IP terminal. The wireless communication method according to claim 2. When the mobile IP terminal determines that the paging identifier included in the received beacon has changed, the mobile IP terminal transmits the authentication request message to the RADIUS server via the access point, and An authentication response message is transmitted to the mobile IP terminal via the access point by the RADIUS server, and when the mobile IP terminal is authenticated, an association request message is transmitted to the access point by the mobile IP terminal. To establish an association between the mobile IP terminal and the access point;
The connection request message for disconnecting the association is transmitted to the access point by the intelligent switch when the paging request message is transmitted to the intelligent switch. Wireless communication method. When the paging incoming request message is received by the mobile IP terminal, the authentication request message is transmitted to the RADIUS server via the access point by the mobile IP terminal, and via the access point by the RADIUS server. When an authentication response message is transmitted to the mobile IP terminal and the mobile IP terminal is authenticated, an association request message is transmitted to the access point by the mobile IP terminal, whereby the mobile IP terminal and the access The wireless communication method according to claim 2, further comprising: establishing an association with a point. The access router information includes at least a network prefix, an IP address, and a MAC address of the access router,
The wireless communication method according to claim 1, wherein the information of the intelligent switch includes at least an IP address and a MAC address of the intelligent switch. When the access point is activated,
Receiving a router advertisement message including a network prefix from the access router by sending a router solicitation message to all router multicast addresses by the access point;
The method further comprises: a neighbor notification message including a MAC address of the intelligent switch is received from the intelligent switch by sending a neighbor solicitation message to the intelligent switch by the access point. The wireless communication method according to 1. When the intelligent switch is activated,
The router according to claim 1, further comprising a step of receiving a router advertisement message including a network prefix from the access router by sending a router solicitation message to all router multicast addresses by the intelligent switch. Wireless communication method. An access router connected to a communication network at a network layer level, an intelligent switch connected between the access router and the access point at a data link layer level, and an access point connected to the intelligent switch and capable of wireless communication And a mobile IP terminal used in a communication system comprising a mobile IP terminal connected to the communication network via the access point, the intelligent switch and the access router and having a portability located on an external link,
A storage unit for storing the home address and the IP address of the home agent;
Receiving a beacon signal including the paging identifier of the paging domain currently located, transmitted from the access point;
When it is determined that the current paging domain has been changed, the access point is associated with the access point, and the access router and intelligent switch information to which the access point is connected are received from the access point.
Create a care-of address based on the information of the access router, read out the home address and the IP address of the home agent from the storage unit, and send the care-of address and the home address to the IP address of the home agent. Update location registration,
A central processing control device for transmitting to the intelligent switch a paging request message for registering a destination address of a packet transferred by the intelligent switch. The central processing control device further transmits a paging incoming response to the intelligent switch when receiving a paging incoming request message which is a notification that a packet addressed to the mobile IP terminal has arrived from the access point. The mobile IP terminal according to claim 10. An access router connected at a network layer level to a communication network to which a home agent is connected, an intelligent switch connected at the data link layer level to the access router and an access point, and connected to the intelligent switch for wireless communication An access point used for a communication system comprising: an access point that provides a cell; and a mobile IP terminal that is connected to the communication network via the access point, the intelligent switch, and the access router and has portability located on an external link Because
A storage unit for storing information on the access router and information on the intelligent switch;
The central switch transmits a beacon signal including a paging identifier of a paging domain provided by the intelligent switch to the cell, and transmits an access router information to the mobile IP terminal when an association request message is transmitted from the mobile IP terminal. An access point comprising a processing control device. The access router information is a network prefix of the access router, an IP address and a MAC address of the access router, and the intelligent switch information is an IP address and a MAC address of the intelligent switch,
The central processing controller is
When the access point is activated, it receives a network prefix of the access router by sending a router solicitation message, and receives a MAC address of the intelligent switch by sending a neighbor solicitation message. The access point according to claim 12. An access router connected at a network layer level to a communication network to which a home agent is connected, an intelligent switch connected at the data link layer level to the access router and an access point, and connected to the intelligent switch for wireless communication Intelligent switch used in a communication system comprising an access point that provides a cell, and a mobile IP terminal that is connected to the communication network via the access point, the intelligent switch, and the access router and is located on an external link Because
A storage unit for storing a network prefix of the access router, an IP address and a MAC address of the access point;
When a paging request message for registering a destination address of a packet transferred by the intelligent switch is received from the mobile IP terminal, a paging response message is transmitted to the mobile IP terminal, and when a packet addressed to the mobile IP terminal is received, the packet is transmitted. A paging incoming request message indicating that a packet addressed to the mobile IP terminal has arrived to an access point that includes the access point and is connected to the intelligent switch, and buffers the paging from the mobile IP terminal. When an incoming response is received, the buffered packet is transmitted to the mobile IP terminal, and a paging incoming termination request message is transmitted to the access point. Intelligent switch; and a location. The central processing control device further includes:
When a paging request message for registering a destination address of a packet forwarded by the intelligent switch is received from the mobile IP terminal, an association connection disconnection request message for disconnecting the association established between the mobile IP terminal and the access point is transmitted. The intelligent switch according to claim 14, wherein:

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