JP2006165971A - Communication system and communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To apply movement management even to a mobile terminal connected through a cable to a network regardless of the type of the mobile terminal. <P>SOLUTION: A connection control server 112 which has received from a terminal 101 a communication message related with communication with a terminal 102 transmits the terminal ID of the terminal 102 to a location registration database 111. The location registration database 111 reads a range area number to which the received terminal ID belongs, and returns it. The connection control server 112 transmits the terminal ID of the terminal 102 and a communication message to a radio base station 103 identified from the received range area number. The radio base station 103 wirelessly transmits the received communication message to the terminal 102. When the communication message is a request for calling, the terminal 102 requests communication through a subscriber router 107 connected through a cable to the terminal 101 being the origin of transmission. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a communication system and a communication method.

  As the movement management related to the movement of the wired terminal over a wide area, movement management by an IP (Internet Protocol) layer (layer 3) and movement management by a higher layer are mainly used. Non-Patent Document 1 describes the former mobility management, that is, mobile IP technology. The mobile IP technology will be described below.

In the mobile IP technology, a mobile terminal (MN: Mobile Node) is used with a home address (HoA) used in a home link (network to which the mobile terminal originally belongs) and an external link (destination network of the mobile terminal). A care-of address (CoA) is assigned. The correspondence between the home address and the care-of address is held in a dedicated agent (HA), and packet transfer to the mobile terminal is enabled by using this dedicated agent.
First, the basic operation of mobile IP technology in mobile IPv4 (Internet Protocol version 4) will be described. The process of operation of the mobile IP network when the mobile terminal moves is roughly composed of the following three.

(1) Acquisition of care-of address in external link When a mobile terminal moves out of its home link, it receives an agent advertisement (Agent Advertisement) from a foreign agent (FA) and confirms that it has moved to the external link. To detect. At that time, the mobile terminal acquires a care-of address from the agent advertisement. This care-of address is the address of the foreign agent and can be shared and used by a plurality of mobile terminals under the foreign agent.

(2) Location Registration After acquiring the care-of address in the external link, the mobile terminal sends a location registration message (Registration Request) that associates the relationship between the home address of the mobile terminal and the acquired care-of address to the external agent. After processing the location registration message, the foreign agent relays it to the dedicated agent. When the location registration is successful, the dedicated agent holds the correspondence information (Binding Cache Entry) between the home address and care-of address of the mobile terminal.

(3) Packet transfer The dedicated agent whose location registration has been completed thereafter captures packets addressed to the home address of the mobile terminal. Then, the care-of address is acquired based on the correspondence information between the home address and the care-of address of the mobile terminal registered inside at the time of location registration. Then, the IP data of the packet addressed to the captured home address is encapsulated in the packet addressed to the care-of address, and transferred to the external agent. Thereafter, the foreign agent that has received the packet whose destination is the care-of address transfers the packet to the mobile terminal. When a packet is transmitted from a mobile terminal, if there is no need to go through a dedicated agent, the packet is delivered to a correspondent node (CN) by a standard IP routing mechanism. In this way, in the dedicated agent, since the correspondence between the home address and the care-of address is maintained, the communication partner terminal can transmit packets addressed to the same home address without being aware of the movement of the mobile terminal. Packets can also be received at the destination external link.

Next, the basic operation of the mobile IP technology in mobile IPv6 (Internet Protocol version 6) will be described. IPv6 is designed in consideration of mobile IP technology, and mobile IPv6 itself has been improved based on consideration of mobile IPv4. Below, it demonstrates centering around the change from Mobile IPv4 mentioned above.
The operation of Mobile IPv6 is roughly divided into the following four because the route optimization function is added as a standard.

(1) Acquisition of Care-of Address in External Link When a mobile terminal moves out of its home link, it receives a router advertisement (RA) from an IPv6 router. Of course, the upper bits of the address of a packet using IPv6 include information specific to the network, which is called prefix information. In addition, a low-order bit of an address can be generated at a node connected to the network, and a unique address can be generated together with prefix information received from the network. Therefore, the mobile terminal detects that the mobile terminal has moved to the current external link by detecting prefix information different from the network before the movement from the address information of the router advertisement. At that time, the mobile terminal generates a care-of address from the prefix information by an IPv6 address generation function.
As described above, in IPv6, care-of addresses can be assigned to individual mobile terminals by taking advantage of the feature of having a rich address space. Therefore, in IPv6, it is not necessary to install an external agent that was necessary in the case of IPv4. Furthermore, since the mobile terminal has an automatic address generation function, a dedicated device such as DHCP (Dynamic Host Configuration Protocol) for assigning an IP address is not necessary.

(2) Location registration After generating a care-of address on the external link, the mobile terminal sends a location registration message (called “Binding Update” in mobile IPv6) that associates the relationship between the home address and the care-of address, as in Mobile IPv4. Send to dedicated agent. The dedicated agent authenticates the home address of the mobile terminal, and if the validity is confirmed, registers the correspondence information (Binding Cache Entry) between the home address of the mobile terminal and the care-of address. In the case of IPv6, it is standard to apply IPsec for encryption and authentication of IP packets at the time of location registration, so that the validity of the home address and the security of the registration message are always maintained regardless of where the mobile terminal moves. It can be guaranteed and a secure mobility service can be easily provided.

(3) Packet transfer The dedicated agent whose location registration has been completed thereafter captures packets addressed to the home address of the mobile terminal. Then, the care-of address is acquired based on the correspondence information between the home address and the care-of address of the mobile terminal registered inside at the time of location registration. Then, the IP data of the packet addressed to the home address taken in is encapsulated in the packet addressed to this care-of address and transferred to the mobile terminal. Also, when sending packets from a mobile terminal, use the reverse tunneling function (Reverse Tunneling) and set up a reverse tunnel for the dedicated agent before optimizing the route described later. Send a packet to

(4) Route optimization function Generally, in mobile IP, the packet transfer from the communication partner terminal to the mobile terminal and the packet transfer from the mobile terminal to the communication partner terminal go through a dedicated agent. Even in the case where there is a nearby location, there is a possibility that a problem called a triangular route in which a communication route via a dedicated agent far away is formed. In response to this problem, in Mobile IPv6, after a mobile terminal and a communication partner terminal start communication via a dedicated agent, the route is changed to a route that does not pass through the dedicated agent, and direct communication is performed between the mobile terminal and the communication partner terminal. The possible route optimization function (Route Optimization) is standardized as a basic function.
In the mobile IPv6 route optimization function, the mobile terminal needs to notify the communication partner terminal of the care-of address of the mobile terminal. However, unlike the relationship between the mobile terminal and the dedicated agent, the mobile terminal and the communication partner terminal have a large number of unspecified relationships that do not have security information in advance. It is necessary to build a temporary trust relationship. Therefore, a test procedure (Return Routability Procedure) for the communication partner terminal to confirm that the mobile terminal is a valid owner of the home address and care-of address is defined. In this procedure, before starting route optimization, the mobile terminal is authenticated between the mobile terminal and the communication partner terminal using both the route through the dedicated agent and the route through the optimized (not through the dedicated agent) route. Temporary key delivery is performed, and the validity of the home address and care-of address is confirmed by matching the keys of both paths. Further, by including this key in the location registration message to the communication partner terminal, it is possible to establish a trust relationship between the mobile terminal and the communication partner terminal.

  The mobile IP technology described above is mobility management in the IP layer, but there is also a method for performing mobility management in an upper layer. For example, it is assumed that a communication partner is designated by a SIP-URI (Universal Resource Identifier) which is an address used for SIP (Session Initiation Protocol) which is an IP telephone protocol. In this case, if there is no movement, the other party's IP address can be acquired by pulling the SIP-URI with DNS (Domain Name System), so that communication with the other party using IP becomes possible. It is assumed that a communication partner moves, connects to a new network, and acquires a new IP address without changing the SIP-URI. In this case, the correspondence table of the IP address corresponding to the SIP-URI is rewritten by the Dynamic DNS technology. As a result, when DNS is subtracted based on the SIP-URI, a new IP address is obtained and communication with a desired partner can be performed.

Next, a basic configuration of a PDC (second generation mobile phone) network (circuit switching mode) employed in an existing mobile communication network will be described.
The PDC network is composed of two levels, a mobile gateway relay level and a mobile subscriber level, and a home location register (HLR) is provided as a location registration database. The PDC network consists of the following basic components, interconnection function with other networks, automatic tracking connection function at incoming call and relay gateway mobile communication control station (MGC: Mobile Gateway Center), area management and A subscriber mobile communication control station (MCC) having a subscriber connection function, an HLR in which subscriber information such as a mobile terminal number and a service area is registered, a base station (BS), and a mobile It consists of a terminal (mobile station) (MS: Mobile Station). Here, base station control functions (assignment of radio channels to mobile terminals, execution of switching control, etc.) are built in the MCC.
The outline of the procedure of (1) location registration, (2) outgoing call processing, and (3) incoming call processing, which are basic operations of the mobile communication network, will be described below.

(1) Location registration In a mobile communication system based on a cell system, since a mobile terminal itself moves spatially, it is necessary to keep track of its location on the network side. For this purpose, location registration is essential. The position of the mobile terminal is managed in a paging area (PA) unit, and the PA for each terminal is held in the HLR. Paging means wireless calling and is called a paging area because when an incoming call arrives at a mobile terminal, it is called all at once in the area. The basic location registration process is as follows.
(I) In the mobile communication network, the PA number of the location is transmitted from the base station through a broadcast channel that can be received by all mobile terminals. The mobile terminal receives the PA number and stores it inside.
(Ii) When a change in the PA number received by the mobile terminal after moving is detected, location registration is performed. The mobile terminal transmits a location registration request to the HLR, and the HLR rewrites the location information.
(Iii) When the location registration is completed, a location registration completion signal is transmitted from the HLR to the mobile terminal.

(2) Outgoing process An outline of a basic connection procedure when making a call from a mobile terminal is shown below.
(I) A request for setting a signal channel for transferring a call setting signal from the calling terminal to the BS is made, and the BS sets the signal channel.
(Ii) Dial the destination telephone number from the calling terminal, and send a call setup request including the telephone number to the MCC via the BS. The MCC authenticates the terminal based on the subscriber information stored in the HLR.
(Iii) The MCC instructs the BS to allocate a voice channel for calling to the calling terminal.
(Iv) The MCC issues a call setup request to the MGC. If the destination is a fixed network or a mobile terminal of another operator, the MGC routes the call there. On the other hand, if the destination is a mobile terminal of a subscriber of his network, the location information is inquired of the HLR.
(V) If the destination is a mobile terminal, a call setup signal is routed based on the location information, and a simultaneous call is made from the BS in the paging area to which the destination mobile terminal belongs. When the destination that is the connection target responds, the connection is established and a call can be made.

(3) Incoming call processing An outline of a connection procedure when receiving a call to a mobile terminal is shown.
(I) An incoming request (call setting request) from a fixed network or another mobile communication network is first delivered to the MGC, including the destination telephone number.
(Ii) The MGC routes the call to the MCC to which the terminating mobile terminal belongs. For this reason, the HLR checks in which MCC cover range the destination mobile terminal is located from the held terminal location information. Based on information from the HLR, the MCC makes a simultaneous call through the BS of the corresponding paging area.
(Iii) The mobile terminal that has received the paging signal requests the BS to set a signal channel for transferring a call setting signal, and the BS sets the signal channel.
(Iv) The MCC authenticates the destination mobile terminal based on the subscriber information stored in the HLR, sends a call setting request signal to the destination mobile terminal, and sets the voice channel for the call to the BS. Instruct the terminal to give it.
(V) When the destination mobile terminal rings and the destination answers, a connection is established and a call can be made.

In the circuit switching method, the wireless line is monopolized even when information is not actually flowing, so in the case of data communication where the actual data transmission time is shorter than the overall communication time, the efficiency of using the wireless line is Extremely worse. On the other hand, in the packet switching method, since it is possible to wait for each packet, a wireless line can be shared by a plurality of communications, and the use efficiency can be increased also in data communications. A typical existing network as a wireless packet system will be described. The packet gateway relay processing device (PGW: Packet Gateway Module) is a device for interconnecting with other networks such as the Internet and corporate networks. When a user packet arrives from another network, the mobile communication service control device (M-SCP) : Mobile-Service Control Point) location information, and has a function of routing to a packet subscriber processing device (PPM) that manages the area where the mobile terminal exists. The PPM is opposed to the mobile terminal via the base station, transmits and receives user packets, and has functions such as assembling / disassembling into packets in the wireless section, authentication, concealment, and accounting. Also, in order to enable data communication, a mobile message packet gateway device (M-PGW: Mobile Message-PGW) having a function for terminating communication protocols with mobile terminals and servers and connecting them to each other. ) Is arranged. On the other hand, the management server has a gateway function to connect the wireless packet system network to the Internet. Specifically, it has an information distribution function, a mail transmission / reception function, a storage function, an information provider management function, and an information fee billing function. The IP address of the user IP packet is associated with the telephone number of the mobile terminal by the PGW having a gateway function, accesses the M-SCP to acquire the location information of the mobile terminal, and the connection process is performed using it. If the position of the mobile terminal changes due to movement, the movement is controlled by re-tunneling the route.
Rick Telecom, “WIRELESS Plus”, [online], [searched on September 30, 2004], Internet <URL: http://www2.ric.co.jp/plus/wireless/miOO1_01_0402.html>

  However, since the conventional technology described above is based on the premise that the mobile terminal is a specific wireless terminal, it cannot be applied to other mobile terminals. Therefore, it has been difficult to apply to mobile management when the mobile terminal is a terminal connected to a network by wire.

  The present invention has been made in view of such circumstances, and a communication system and a communication method capable of performing mobility management for a mobile terminal connected to a network by wire regardless of the type of the mobile terminal. The purpose is to provide.

  In order to solve the above problems, the invention described in claim 1 is a communication system in which a connection control device, a location information storage device, a radio base station, and a plurality of terminals are connected via a network. The communication destination terminal is a message related to communication using a wire, a wireless transmission / reception unit that communicates wirelessly with the wireless base station, a wired transmission / reception unit that performs wired communication with a communication device configuring the network, and A communication means for receiving a communication message from the radio base station and performing communication via the communication device with a terminal that is the transmission source of the communication message, and the terminal of the transmission source is a terminal identifier of a communication destination terminal And a communication message transmitting means for transmitting a communication message to the connection control device, wherein the connection control device communicates with the terminal identifier of the communication destination terminal from the source terminal. A communication message receiving means for receiving a message; a location information requesting means for sending a terminal identifier of a communication destination terminal received by the communication message receiving means to the location information storage device; and Corresponding to the terminal identifier of the communication destination terminal transmitted to the storage device, the position information request response reception means for receiving the identification information of the radio base station to which the communication destination terminal belongs, and the position information request response reception means receive A communication message transfer means for transmitting a terminal identifier of a communication destination terminal received by the communication message receiving means and a communication message to the radio base station identified by the identification information of the radio base station, and storing the position information The apparatus comprises a storage means for storing a terminal identifier and identification information of the radio base station to which the terminal identified by the terminal identifier belongs, Receiving a terminal identifier of the communication destination terminal from the connection control device, and reading out the identification information of the radio base station corresponding to the terminal identifier of the communication destination terminal from the storage means and returning the position information request answering means The wireless base station receives a terminal identifier and a communication message of a communication destination terminal from the connection control apparatus, and wirelessly transmits the communication message to a terminal identified by the terminal identifier of the communication destination terminal. It is a communication system characterized by having a means.

  The invention according to claim 2 is the communication system according to claim 1, wherein the communication destination terminal implements an Internet protocol, and the terminal identifier is used for identifying the terminal in the Internet protocol. Unlike information, it is characterized by not depending on the location of the terminal.

  The invention described in claim 3 is the communication system according to claim 1 or 2, wherein the communication message is a message for requesting a call.

  The invention according to claim 4 is the communication system according to claim 3, wherein the communication means of the communication destination terminal receives a message for requesting a call from the radio base station. A message for making a call is transmitted to the source terminal that has transmitted the message for requesting the call.

  The invention according to claim 5 is a communication system formed by connecting a connection control device, a location information storage device, a radio base station, and a plurality of terminals via a network, and the communication destination terminal Has wireless transmission / reception means for wirelessly communicating with the wireless base station, and address request answering means for receiving an address request from the wireless base station and returning address information indicating its network address. The terminal includes a communication message transmitting unit that transmits a terminal identifier of a communication destination terminal and a communication message that is a message related to communication to the connection control apparatus, and the connection control apparatus includes the transmission source terminal. A communication message receiving means for receiving a terminal identifier and a communication message of a communication destination terminal, and an end of the communication destination terminal received by the communication message receiving means A location information requesting means for transmitting an identifier to the location information storage device, and a radio to which the communication destination terminal belongs in correspondence with a terminal identifier of the communication destination terminal transmitted by the location information requesting means to the location information storage device Position information request response receiving means for receiving base station identification information, and communication received by the communication message receiving means to the radio base station identified by the radio base station identification information received by the position information request response receiving means Address request means for transmitting the terminal identifier of the previous terminal, and an address for receiving the address information of the communication destination terminal corresponding to the terminal identifier of the communication destination terminal transmitted by the address request means to the radio base station The communication message receiving means receives the request response receiving means and the address information of the communication destination terminal received by the address request answer receiving means. A communication message transfer means for transmitting the communication message, wherein the location information storage device stores a terminal identifier and identification information of the radio base station to which the terminal identified by the terminal identifier belongs. And a position information request answering means for receiving the terminal identifier of the communication destination terminal from the connection control device, reading out the identification information of the radio base station corresponding to the terminal identifier of the communication destination terminal from the storage means, and returning it. And the radio base station receives an address request notification means for receiving a terminal identifier of a communication destination terminal from the connection control device and transmitting an address request to a terminal identified by the terminal identifier of the communication destination terminal. The address request notifying means receives address information corresponding to the address request transmitted to the terminal, and sends the address information to the connection control device. A communication system characterized by having a response request reply means.

  The invention according to claim 6 is the communication system according to claim 5, wherein the communication destination terminal further includes wired transmission / reception means for performing wired communication with a communication device configuring the network. The address request answering means returns address information indicating a network address used for communication via the communication device.

  The invention according to claim 7 is the communication system according to claim 5 or 6, wherein the communication destination terminal implements an Internet protocol, and the terminal identifier is a terminal in the Internet protocol. Unlike the information for identification, it is characterized by not depending on the position of the terminal.

  The invention according to claim 8 is the communication system according to any one of claims 5 to 7, wherein the communication message is a message for requesting start of communication. Features.

  The invention according to claim 9 is a communication method used in a communication system formed by connecting a connection control device, a location information storage device, a radio base station, and a plurality of terminals via a network. The communication destination terminal is connected to a communication device constituting the network by wire, and the location information storage device includes a terminal identifier and identification information of the radio base station to which the terminal identified by the terminal identifier belongs The transmission source terminal transmits a terminal identifier of the communication destination terminal and a communication message that is a message related to communication using wired communication to the connection control device, and the connection control A device receives a terminal identifier and a communication message of a communication destination terminal from the source terminal, and transmits the received terminal identifier of the communication destination terminal to the location information storage device. The location information storage device receives the terminal identifier of the communication destination terminal from the connection control device, reads out the identification information of the radio base station corresponding to the terminal identifier of the communication destination terminal from the storage means, and returns it, The connection control device receives identification information of a radio base station to which the terminal of the communication destination belongs from the position information storage device, and transmits the identification information of the communication destination to the radio base station identified by the received identification information of the radio base station. The terminal identifier of the terminal and the communication message are transmitted, and the wireless base station receives the terminal identifier and communication message of the communication destination terminal from the connection control apparatus, and is identified by the terminal identifier of the communication destination terminal The communication message is transmitted wirelessly, and the communication destination terminal receives the communication message from the wireless base station, and communicates with the transmission source terminal of the communication message. Performing communication through the device is a communication method characterized by.

  The invention according to claim 10 is a communication method used in a communication system formed by connecting a connection control device, a location information storage device, a radio base station, and a plurality of terminals via a network. The location information storage device includes storage means for storing a terminal identifier and identification information of the radio base station to which the terminal identified by the terminal identifier belongs, and the source terminal is a terminal of a communication destination terminal An identifier and a communication message that is a message related to communication are transmitted to the connection control device, and the connection control device receives and receives the terminal identifier of the communication destination terminal and the communication message from the source terminal. The terminal identifier of the communication destination terminal is transmitted to the position information storage device, the position information storage device receives the terminal identifier of the communication destination terminal from the connection control device, and the received communication destination The identification information of the radio base station corresponding to the terminal identifier of the terminal is read from the storage means and returned, and the connection control device receives the identification information of the radio base station to which the communication destination terminal belongs from the location information storage device The terminal identifier of the communication destination terminal is transmitted to the wireless base station identified by the received identification information of the wireless base station, and the wireless base station transmits the terminal identifier of the communication destination terminal from the connection control device. Receiving and transmitting an address request to the communication destination terminal identified by the terminal identifier of the communication destination terminal, the communication destination terminal receiving the address request from the radio base station and indicating its own network address Address information is returned, and the radio base station receives the address information of the communication destination terminal from the communication destination terminal, transmits this address information to the connection control device, and A control device receives address information of the communication destination terminal from the radio base station, and transmits the communication message using the received address information of the communication destination terminal. is there.

  According to the present invention, it is possible to perform mobility management for a mobile terminal connected to a network by wire regardless of the type of mobile terminal. In addition, integration with mobility management used for telephones and the like becomes easy.

The communication system of the present invention will be described in detail below with reference to the drawings.
FIG. 1 shows an overall configuration diagram of a communication system according to an embodiment of the present invention. In FIG. 1, terminals 101 and 102 are IP terminals that perform communication using IP (Internet Protocol), and are connected to a network that is an IP network. The terminal 102 is a terminal that moves in the network. A location registration database 111 and a connection control server 112 are further connected to the network. The network includes subscriber routers 105, 106, 107, and 108 (hereinafter collectively referred to simply as “subscriber routers”), relay routers 109 and 110 (hereinafter collectively referred to simply as “relay routers”), and the like. It consists of a communication device that routes IP packets. In the network shown in the figure, relay routers 109 and 110 are connected. Subscriber routers 105 and 106 are connected to the relay router 109, and subscriber routers 107 and 108 are connected to the relay router 110. Has been. Further, a radio base station (hereinafter referred to as “BS”, BS: Base Station) 104 is connected to the subscriber router 106, and a BS 103 is connected to the subscriber router 108. A terminal 101 is connected to 105 and a terminal 102 is connected to a subscriber router 107. A location registration database 111 as a location information storage device is connected to the relay router 110, and a connection control server 112 as a connection control device is connected to the relay router 109.
Note that it is not essential in the present invention that the terminals 101 and 102 are IP terminals and that the network to which the terminals 101 and 102 are connected is an IP network. If the network is not an IP network, it can be easily inferred by replacing the IP address with a network address. BSs 103 and 104 (hereinafter collectively referred to simply as “BS”) are accommodated in the subscriber router. The device accommodating the BS may be the same as the device accommodating a general terminal or a different device. This is not related to the essence of the present invention.
In the present embodiment, a description will be given assuming that a communication request from terminal 101 to terminal 102 has occurred.

BSs 103 and 104 communicate with terminal 102 wirelessly. BSs 103 and 104 broadcast their own paging area numbers by radio. This paging area number can be used as identification information for identifying each BS.
The terminal 101 is a computer terminal such as a personal computer, for example, and transmits / receives data to / from the network via the subscriber router 105. The terminal 101 includes a wired transmission / reception device for connecting to a subscriber router by wire.

The terminal 102 is a portable computer terminal such as a notebook personal computer (notebook personal computer), for example, and transmits and receives data to and from the network via a subscriber router or BS. The terminal 102 includes a wired transmission / reception device for connecting to a subscriber router by wire, and a wireless transmission / reception device for connecting to a BS by radio. When the terminal 102 is in the radio area of a BS, the terminal 102 can communicate with the BS using a radio transmission / reception apparatus. The terminal 102 stores therein the paging area number of the radio area of the BS in which the terminal 102 exists.
The location registration database 111 is a device that stores location information indicating to which BS a terminal (for example, the terminal 102) having a wireless transmission / reception device belongs, and BS address information indicating a network address of each BS. The connection control server 112 is a device that mediates communication requests between terminals connected to the network.

Next, the operation of the communication system shown in FIG. 1 will be described.
FIG. 2 is a schematic diagram of a signal sequence of the communication system, and FIG. 3 is a flowchart of a connection operation in the communication system.
The terminal 102 is a portable computer terminal as described above, and is connected to a network by wire and transmits / receives information via the network, but the connection position of the wire, that is, the subscriber router of the connection destination often changes. Is done. As a result, a physical location change including a wireless area change and a change in the IP address of the terminal 102 occur.

  BSs 103 and 104 wirelessly broadcast their own paging area numbers. The terminal 102 receives a paging area number different from the paging area number held therein from the BS 103 or BS 104, thereby recognizing a change in the area in which the terminal 102 is currently located. When the terminal 102 recognizes the change of the area in which it is located, (1) it updates the paging area number held by itself, and (2) the wireless area in which it is located via the BS / subscriber router / relay router. The paging area number, that is, the in-service area number is notified to the location registration database 111. Based on the notification received from the terminal 102, the location registration database 111 stores therein a set of {terminal ID, area number} as location information. The terminal ID used here is information that uniquely identifies the terminal, is different from information used to identify the terminal in IP, and does not depend on the position of the terminal, that is, the geographical position, This information is not changed by the BS to which the terminal belongs and the subscriber router connected to the terminal.

  In the figure, it is assumed that the terminal 102 has moved to the wireless area of the BS 103. The terminal 102 recognizes that the located area has been changed based on the paging area number that is wirelessly notified from the BS 103. The terminal 102 notifies the location registration database 111 of the terminal ID for identifying itself and the area number indicating the paging area number of the BS 103. As a result, the location registration database 111 registers {terminal ID: terminal ID of the terminal 102, visited area number: paging area number of the BS 103} in the {terminal ID, visited area number} table stored therein. . Further, the terminal 102 acquires an IP address for performing communication with the network via the subscriber router 107. For example, when the terminal 102 uses IPv6, the IP address is generated from the upper bits (prefix information) of the IP address received from the network and the lower bits of the IP address generated from the identification information unique to its own hardware. . Alternatively, an IP address may be acquired from an IP address assignment device (not shown) such as DHCP (Dynamic Host Configuration Protocol) connected via a network.

<Step S210 in FIG. 2, Step S310 in FIG. 3>
In order to make a communication request with the terminal 102, the terminal 101 first generates a communication request message. The terminal 101 sets an identifier indicating itself as a sender address of the communication request message and an identifier indicating the terminal 102 as a receiver address. As an identifier indicating the terminal 102, a terminal ID or an upper address is used. The upper address includes, for example, SIP-URI (Session Initiation Protocol-Universal Resource Identifier) and tel-URI. The SIP-URI is a URI used for SIP which is one of IP telephone protocols, and the tel-URI is a URI used as a telephone number. Further, the terminal 101 generates an IP packet containing the generated communication request message, and sets its own IP address as the sender address of this IP packet and the IP address of the connection control server 112 as the receiver address. Specifically, for example, an IP packet is composed of a header in which information for routing such as the IP address of the caller and the callee is set, and a payload in which actual data is set. Set the communication request message. The terminal 101 sets and transmits the own IP address as the sender address and the IP address of the connection control server 112 as the receiver address in the header part of the IP packet. The IP packet including the communication request message is transmitted to the connection control server 112 via the subscriber router 105 and the relay router 109.

<Step S220 in FIG. 2, Step S320 in FIG. 3>
When the connection control server 112 receives the IP packet transmitted from the terminal 101, the connection control server 112 extracts a message from the IP packet and determines that the message is a communication request message. Then, the connection control server 112 identifies the terminal ID of the communication request destination terminal from the recipient address of the extracted communication request message. When the terminal ID is used for the recipient address of the communication request message, this terminal ID is used. When a higher address is used instead of the terminal ID as the recipient address of the communication request message, the connection control server 112 holds a correspondence table between the higher address and the terminal ID in advance. This correspondence table between the higher address and the terminal ID is a fixed table that does not need to be updated for the movement of the terminal. The connection control server 112 acquires the terminal ID corresponding to the upper address included in the communication request message by referring to the correspondence table between the upper address and the terminal ID.

When specifying the terminal ID, the connection control server 112 determines whether or not “location registration database should be referred” in the communication request message. This can be done by either (1) using a specific part of the recipient address such as the lower bits of the recipient address, or (2) using the communication request message itself as a communication request message with location registration reference. .
Specifically, when the lower bits of the recipient address are used as in (1), the connection control server 112 stores in advance the lower bits of the recipient address to be referred to the location registration database. When the lower bits of the recipient address to be referred to the location registration database stored therein and the lower bits of the incoming address included in the communication request message match, the location registration database should be referred to. Judge that there is. Further, when the communication request message itself is a communication request message with a location registration reference as in (2), when the communication request message is received, it is determined that all location registration databases should be referred to.
When the connection control server 112 determines that “the location registration database should be referred to”, the connection control server 112 transmits a location information request message to the location registration database 111 together with the terminal ID of the communication request destination (terminal 102). Specifically, the connection control server 112 generates an IP packet in which the location information request message and the terminal ID are put, and the IP address of the connection control server 112 is located in the sender address of this IP packet, and the destination address is located. The IP address of the registration database 111 is set and transmitted.

<Step S330 in FIG. 2, Step S330 in FIG. 3>
The location registration database 111 that has received the IP packet including the location information request message and the terminal ID searches the {terminal ID, area area number} table stored therein and corresponds to the received terminal ID. Get the area number. Here, the area number indicated by the paging area number of BS 103 corresponding to the terminal ID of terminal 102 is acquired. Further, the connection control server 112 reads out the IP address of the BS 103 corresponding to the acquired area number from the correspondence table of {area area number, BS address} as BS address information previously held therein. The connection control server 112 creates a location information request reply message and returns the read BS address to the connection control server 112 together with the terminal ID.

<Step S240 in FIG. 2, Step S340 in FIG. 3>
The connection control server 112 that has received the location information request reply message generates an IP address request message in which the IP address of the connection control server 112 is set as the caller address and the terminal ID of the terminal 102 is set as the callee address. Then, the connection control server 112 generates an IP packet containing this IP address request message. The connection control server 112 sets the IP address of the connection control server 112 as the sender address of the IP packet and sets the IP address of the BS 103 obtained by the location request reply as the receiver address, and transmits it.

<Step S250 in FIG. 2, Step S350 in FIG. 3>
The BS 103 that has received the IP packet including the IP address request message extracts the IP address request message from the IP packet. Then, the BS 103 transmits the extracted IP address request message to the terminal 102 identified by the terminal ID set in the recipient address of the IP address request message via a wireless channel.

<Step S260 in FIG. 2, Step S360 in FIG. 3>
The terminal 102 that has received the IP address request message reads its own IP address from the inside. The terminal 102 creates an IP address request reply message for notifying the read own IP address, and returns it to the connection control server 112 together with the terminal ID. Specifically, the created IP address request reply message and terminal ID are transmitted to the BS 103 via a wireless channel.

<Step S270 in FIG. 2, Step S370 in FIG. 3>
When the BS 103 receives the IP address request reply message and the terminal ID from the terminal 102, the BS 103 generates an IP packet including the received IP address request reply message and the terminal ID. The BS 103 sets the IP address of the BS 103 as the sender address of this IP packet and transmits the IP address of the connection control server 112 as the receiver address.

<FIG. 2 Step S280, FIG. 3 Step S380, Step S390>
The connection control server 112 receives the IP packet including the IP address request reply message. The connection control server 112 extracts an IP address request reply message from the received IP packet, and acquires the IP address of the terminal 102. Subsequently, the connection control server 112 generates an IP packet containing the communication request message from the terminal 101 to the terminal 102 received in step S320. The connection control server 112 sets the IP address of the connection control server 112 as the sender address of the IP packet and sets the IP address of the terminal 102 acquired from the IP address request reply message as the receiver address and transmits the IP packet. The IP packet including the communication request message is transmitted to the terminal 102 via the relay routers 109 and 110 and the subscriber router 107. Thereby, communication between the terminal 101 and the terminal 102 is started. That is, the terminal 102 that has received the communication request message performs communication with the terminal 101 using the identifier of the terminal 101 included in the communication request message. Note that the terminal 102 performs communication after receiving the communication request message using a wired connection with the subscriber router 107.

Although the above is an example of a communication request with the terminal 102 that may be moving, there is a method in which the terminal 101 issues a call request to the terminal 102 as a similar form. This will be described below.
In order for the terminal 101 to make a call request to the terminal 102, a call request message is generated. The terminal 101 sets an identifier indicating itself to the caller address of the call request message, and sets an identifier indicating the terminal 102 to the callee address. As an identifier indicating the terminal 102, a terminal ID or an upper address (such as SIP-URI or tel-URI) is used. The generated call request message is transmitted in an IP packet having the sender address as its own IP address and the recipient address as the IP address of the connection control server 112. The IP packet including the call request message is transmitted to the connection control server 112 via the subscriber router 105 and the relay router 109. The connection control server 112 extracts a message from the received IP packet and recognizes that it is a call request message. Then, the connection control server 112 identifies the call request destination terminal ID from the callee address of the extracted call request message. At this time, if the callee address is not the terminal ID but the upper address, the connection control server 112 refers to the correspondence table between the upper address and the terminal ID stored in advance in advance, and determines the terminal ID from the upper address. To get. The correspondence table between the higher address and the terminal ID is a fixed table that does not need to be updated for the movement of the terminal 102.

  The connection control server 112 obtains the terminal ID of the call request destination (terminal 102), and transmits a position information request message together with the terminal ID to the position registration database 111. Specifically, the location information request message and the terminal ID are transmitted in an IP packet having the sender address as the IP address of the connection control server 112 and the recipient address as the IP address of the location registration database 111. In the location registration database 111 that has received the location information request message and the terminal ID, the {terminal ID, location area number} table is searched to acquire the location area number corresponding to the received terminal ID. Then, the IP address of the BS 103 corresponding to the acquired in-service area number is read out from the correspondence table of {in-service area number field number, BS address} held in advance. Then, a location information request reply message is created, and the BS address is returned to the connection control server 112 together with the terminal ID.

The connection control server 112 that has received the location information request reply message generates an IP packet containing the call request message. The connection control server 112 sets the IP address of the connection control server 112 as the sender address of the IP packet, and sets the IP address of the BS 103 obtained by the location information request reply message as the receiver address and transmits it. The BS 103 that has received the IP packet including the call request message extracts the call request message from the IP packet. The BS 103 transmits the call request message to the terminal 102 identified by the terminal ID included in the callee address of the call request message through a wireless channel.
The terminal 102 that has received the call request message recognizes that the call request is requested from the terminal 101 by the sender address of the call request message. The terminal 102 uses the identifier of the terminal 101 included in the caller address of the call request message, and transmits a call request to the terminal 101 through a normal communication procedure via a wired connection with the subscriber router 107. Thus, a call connection procedure is performed with the terminal 101 that has received the call request message from the terminal 102.

In the above embodiment, the terminal 101 describes an example in which a communication request message and a call request message are transmitted to the terminal 102. However, the same processing is performed on a message related to an arbitrary communication or call. Also good.
Further, in the above embodiment, the terminal 102 notifies the location registration database 111 of its own terminal ID and area number, but the BS notifies its own terminal ID so that the BS Receiving a terminal ID from a terminal in the paging area, recognizing the terminal that has newly entered its own paging area, and registering the terminal ID of the terminal and its own paging area number as a location area number You may notify to the database 111.

  According to the above embodiment, it is possible to perform mobility management for a mobile terminal connected to a network by wire regardless of the type of mobile terminal. Thereby, for example, a small wireless transmission / reception module can be attached to a terminal such as a personal computer that transmits / receives main information (sound, video, text, etc.) by wire, and the position management of the terminal can be performed by this wireless transmission / reception module. Furthermore, integration with mobility management used for telephones and the like becomes easy. In addition, a node for maintaining the address information in the home network of the mobile terminal moving in the network and the address information in the destination network and managing the movement by holding the location information of the mobile terminal It is possible to efficiently manage the movement of mobile terminals without having to install a node for each home network or a node for rewriting the correspondence information between the upper address and the IP address in the destination network. it can.

  The terminals 101 and 102, the BSs 103 and 104, the subscriber routers 105, 106, 107 and 108, the relay routers 109 and 110, the location registration database 111, and the connection control server 112 have a computer system therein. ing. The operation processes of the terminals 101 and 102, the BSs 103 and 104, the subscriber routers 105, 106, 107, and 108, the relay routers 109 and 110, the location registration database 111, and the connection control server 112 are in the form of a program. Is stored in a computer-readable recording medium, and the above-described processing is performed by the computer system reading and executing this program. The computer system here includes an OS and hardware such as peripheral devices.

  In addition to ROM, “computer-readable recording medium” refers to a portable medium such as a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, or a storage device such as a hard disk built in a computer system. That means. Furthermore, the “computer-readable recording medium” refers to a volatile memory (RAM) inside a computer system that becomes a client or a system when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

It is a block diagram of the communication system as one embodiment of this invention. It is a figure which shows the signal sequence in the communication system by the embodiment. It is a figure which shows the flowchart of the connection operation | movement in the communication system by the embodiment.

Explanation of symbols

101, 102 ... terminal 103, 104 ... BS (radio base station)
105, 106, 107, 108 ... Subscriber router (communication device)
109, 110 ... Relay router (communication device)
111 ... Location registration database (location information storage device)
112 ... Connection control server (connection control device)

Claims (10)

A communication system comprising a connection control device, a location information storage device, a radio base station, and a plurality of terminals connected via a network,
The terminal of the communication destination is
Wireless transceiver means for wirelessly communicating with the wireless base station;
A wired transmission / reception means for performing wired communication with a communication device constituting the network;
A communication unit that receives a communication message that is a message related to communication using wired communication from the wireless base station, and has a communication unit that performs communication via the communication device with the terminal that is the source of the communication message;
The terminal of the sender is
A communication message transmitting means for transmitting a terminal identifier of a communication destination terminal and a communication message to the connection control device;
The connection control device includes:
A communication message receiving means for receiving a terminal identifier of a communication destination terminal and a communication message from the source terminal;
Position information requesting means for transmitting a terminal identifier of a communication destination terminal received by the communication message receiving means to the position information storage device;
Corresponding to the terminal identifier of the communication destination terminal transmitted by the position information requesting means to the position information storage device, the position information request reply receiving means for receiving the identification information of the radio base station to which the communication destination terminal belongs;
Communication message transfer means for transmitting the terminal identifier of the communication destination terminal received by the communication message receiving means and the communication message to the radio base station identified by the identification information of the radio base station received by the position information request reply receiving means And
The location information storage device
Storage means for storing a terminal identifier and identification information of the radio base station to which the terminal identified by the terminal identifier belongs;
Receiving a terminal identifier of a communication destination terminal from the connection control device, and reading out the identification information of the radio base station corresponding to the terminal identifier of the communication destination terminal from the storage means and returning a position information request answering means. And
The radio base station is
Receiving a terminal identifier and a communication message of a communication destination terminal from the connection control device, and having wireless communication means for wirelessly transmitting the communication message to a terminal identified by the terminal identifier of the communication destination terminal;
A communication system characterized by the above. The communication destination terminal implements an Internet protocol,
The communication system according to claim 1, wherein the terminal identifier is different from information for identifying a terminal in the Internet protocol and does not depend on a position of the terminal.   The communication system according to claim 1, wherein the communication message is a message for requesting a call.   The communication means of the communication destination terminal receives a message for requesting a call from the radio base station, and issues a call to the caller terminal that has transmitted the message for requesting the call. The communication system according to claim 3, wherein a message for performing is transmitted. A communication system comprising a connection control device, a location information storage device, a radio base station, and a plurality of terminals connected via a network,
The terminal of the communication destination is
Wireless transceiver means for wirelessly communicating with the wireless base station;
An address request answering means for receiving an address request from the radio base station and returning address information indicating its own network address;
The terminal of the sender is
A communication message transmitting means for transmitting a terminal identifier of a communication destination terminal and a communication message that is a message related to communication to the connection control device;
The connection control device includes:
A communication message receiving means for receiving a terminal identifier of a communication destination terminal and a communication message from the source terminal;
Position information requesting means for transmitting a terminal identifier of a communication destination terminal received by the communication message receiving means to the position information storage device;
Corresponding to the terminal identifier of the communication destination terminal transmitted by the position information requesting means to the position information storage device, the position information request reply receiving means for receiving the identification information of the radio base station to which the communication destination terminal belongs;
Address request means for transmitting the terminal identifier of the communication destination terminal received by the communication message receiving means to the radio base station identified by the identification information of the radio base station received by the location information request answer receiving means;
In response to the terminal identifier of the communication destination terminal transmitted by the address request means to the radio base station, an address request response reception means for receiving address information of the communication destination terminal;
Communication message transfer means for transmitting the communication message received by the communication message receiving means using the address information of the communication destination terminal received by the address request answer receiving means,
The location information storage device
Storage means for storing a terminal identifier and identification information of the radio base station to which the terminal identified by the terminal identifier belongs;
Receiving a terminal identifier of a communication destination terminal from the connection control device, and reading out the identification information of the radio base station corresponding to the terminal identifier of the communication destination terminal from the storage means and returning a position information request answering means. And
The radio base station is
An address request notification means for receiving a terminal identifier of a communication destination terminal from the connection control device and transmitting an address request to a terminal identified by the terminal identifier of the communication destination terminal;
The address request notifying means receives address information corresponding to the address request transmitted to the terminal, and has an address request answering means for transmitting the address information to the connection control device.
A communication system characterized by the above. The terminal of the communication destination is
A wired transmission / reception means for performing wired communication with a communication device constituting the network;
The address request answering unit returns address information indicating a network address used for communication via the communication device;
The communication system according to claim 5. The communication destination terminal implements an Internet protocol,
7. The communication system according to claim 5, wherein the terminal identifier is different from information for identifying a terminal in the Internet protocol and does not depend on a position of the terminal.   The communication system according to any one of claims 5 to 7, wherein the communication message is a message for requesting the start of communication. A communication method used in a communication system formed by connecting a connection control device, a location information storage device, a radio base station, and a plurality of terminals via a network,
The terminal of the communication destination is
It is connected with a communication device constituting the network by wire,
The location information storage device
Storage means for storing a terminal identifier and identification information of the radio base station to which the terminal identified by the terminal identifier belongs,
The terminal of origin is
A terminal identifier of a communication destination terminal and a communication message that is a message related to communication using wired communication to the connection control device;
The connection control device
Receiving a terminal identifier and a communication message of a destination terminal from the source terminal;
The terminal identifier of the received communication destination terminal is transmitted to the location information storage device,
The position information storage device
Receiving the terminal identifier of the communication destination terminal from the connection control device, reading back the identification information of the radio base station corresponding to the terminal identifier of the communication destination terminal from the storage means,
The connection control device
Receiving the identification information of the radio base station to which the communication destination terminal belongs from the location information storage device;
Transmitting the terminal identifier of the terminal of the communication destination and the communication message to the radio base station identified by the received identification information of the radio base station;
The radio base station is
Receiving a terminal identifier and a communication message of a communication destination terminal from the connection control device, and wirelessly transmitting the communication message to a terminal identified by the terminal identifier of the communication destination terminal;
The terminal of the communication destination
Receiving the communication message from the radio base station, and performing communication via the communication device with a terminal that is the source of the communication message;
A communication method characterized by the above. A communication method used in a communication system formed by connecting a connection control device, a location information storage device, a radio base station, and a plurality of terminals via a network,
The location information storage device
Storage means for storing a terminal identifier and identification information of the radio base station to which the terminal identified by the terminal identifier belongs,
The terminal of origin is
A terminal identifier of a communication destination terminal and a communication message that is a message related to communication are transmitted to the connection control device;
The connection control device
Receiving a terminal identifier and a communication message of a destination terminal from the source terminal;
The terminal identifier of the received communication destination terminal is transmitted to the location information storage device,
The position information storage device
Receiving the terminal identifier of the communication destination terminal from the connection control device, reading back the identification information of the radio base station corresponding to the received terminal identifier of the communication destination terminal from the storage means,
The connection control device
Receiving the identification information of the radio base station to which the communication destination terminal belongs from the location information storage device;
Transmitting the terminal identifier of the communication destination terminal to the wireless base station identified by the received identification information of the wireless base station;
The radio base station is
Receiving a terminal identifier of the communication destination terminal from the connection control device, and transmitting an address request to the communication destination terminal identified by the terminal identifier of the communication destination terminal;
The terminal of the communication destination
Receiving an address request from the radio base station, returning address information indicating its own network address;
The radio base station is
Receiving address information of the communication destination terminal from the communication destination terminal, and transmitting the address information to the connection control device;
The connection control device
Receiving address information of the communication destination terminal from the radio base station;
Using the received address information of the communication destination terminal, the communication message is transmitted.
A communication method characterized by the above.

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