JP2009159352A - Mobile communication network - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the burden of setting and managing a node used for radio call in a radio access network when base stations are increased or decreased. SOLUTION: A node that performs radio call processing corresponds to an identifier of a paging area. The multicast address to be stored is stored, and when a radio call request arrives, the call request reaches the base station belonging to the paging area by transmitting the radio call request to the multicast address corresponding to the paging area identifier. Takes the form of performing call processing in the wireless section.
[Selection] Figure 1

Description

  The present invention relates to a mobile communication network that provides an IP access service, which performs a wireless call operation from a base station.

  Currently, a mobile packet communication service called 3.5 generation is provided, and an environment for using Internet connection services such as e-mail and WEB access is prepared. In IP communication using the mobile packet communication service, when there is no packet transmitted / received by the mobile terminal for a certain period of time, the mobile terminal is set to dormant or idle mode in order to extend the battery operating time by power saving of the mobile terminal. It becomes a dormant state called. The position of the mobile terminal in the idle mode is managed by a paging area in which a plurality of base stations are bundled, and a paging area identifier is stored in the HLR (Home Location Register) database in the mobile communication network as the position information of the mobile terminal. The When an incoming call or packet arrives at an idle terminal, a wireless call (paging) request is made to the base stations in the paging area having the identifier stored in the HLR all at once, and the mobile terminal Urge the return.

Wireless Broadband Textbook 3.5G / Next Generation Mobile Edition Impress 2006

Currently, the next generation mobile communication system called WiMAX (Worldwide Interoperability for Microwave Access) and LTE (Long Term Evolution) is being studied, and a radio access network (RAN: Radio) that connects these radio base stations. Access Network)
IP communication technology is used for. In these wireless communications, a service using IP packet communication is mainly used from a circuit-switched service which has been mainly used so far, and a service using IP packet communication called ALL IP is mainly used. In mobile communication, when the mobile terminal is not communicating, it enters a state of performing a power saving operation called idle mode, sleep mode, or dormant mode. When the mobile terminal enters the idle mode, Location registration is performed for the paging area used for wireless calling.
In addition to identifiers that differ for each cell or sector in the service area of the base station, the base stations that make up the RAN have identifiers related to areas managed by bundling a plurality of base stations called paging areas. When a packet addressed to the mobile terminal in the idle mode arrives at the RAN, the RAN performs a radio call process on the BS having the paging area identifier registered in the idle mode in order to return the mobile terminal in the idle mode to the active mode. Do.
For this reason, the paging area identifier and the identifiers of a plurality of base stations belonging to it are stored in association with each other in the node that requests the base station to perform radio call processing in the RAN, and the base station identifier and It is necessary to store the IP address correspondingly. Therefore, when changing the base station in the RAN or changing the configuration of the paging area, it is included in the node that performs the radio call request processing for the BS in addition to the change of the base station setting. Change of the correspondence table between the identifier of the paging area and the identifier of the base station, or the table of correspondence between the identifier of the base station and the IP address, and there is a problem that management becomes complicated .

The paging area identifier and the multicast address corresponding to the paging area identifier are stored in the node that performs the radio paging process, and when a radio paging request arrives, a radio paging request is transmitted to the multicast address corresponding to the paging area identifier. As a result, a call request arrives at a base station belonging to the paging area, and the base station performs a call processing for a radio section.

  By using the mobile communication network using the present invention, even when the number of base stations is increased or decreased, it is only necessary to set the paging area identifier and the corresponding multicast address as the paging area configuration information in the base station. . As a result, the node that performs the wireless call processing in the mobile communication network only needs to manage the paging area identifier and the corresponding multicast address, thereby reducing the management / setting items when the base station is increased or decreased. be able to.

FIG. 1 shows a system configuration of a mobile communication system using the present invention. In FIG. 1, (101) is an HA (Home Agent) device, which receives a location registration (Registration) from a mobile terminal (hereinafter abbreviated as MS) (109) or an access gateway (AGW) (103) and cares about the MS It has a function to manage, capture IP packets sent to the MS, encapsulate them, and forward them to the care-of address registered at the time of location registration.
(102) is a router, which transfers IP packets.
Reference numeral (103) denotes an access gateway (AGW) having a local mobility function for managing which base station (BS) (106) is under the control of the MS, and a BS (10 6 ), The packet addressed to the encapsulated MS transferred from the HA (101) to the AGW (103) is taken out, and then encapsulated again in the BS (106) communicating with the MS (109) A function to check whether the user is a valid user and a function to send billing information to the billing server. Have.
Furthermore, the AGW (103) may incorporate a function called a paging controller (PC) (104). The PC (104) can exist alone, and performs location management when the MS enters a power saving mode called an idle mode for power saving. For example, a node called WiSN is a node called ASN-GW (Access Serving Network Gateway) in a node like WiMAX, a function called sRNC (Session Reference Network Controller) in 3.9G UMB (Ultra Mobile Broadband), or LTE (Long Term) Evolution (Network) includes functions such as MME (Mobility Management entity).
The service area cell (107) of the base station (106) that communicates with the MS has an ID called BSID as a different identifier for each sector, and a plurality of service areas are combined to form an area (108) called a paging area. The paging area ID is also assigned to the paging area as a different identifier for each paging area. When the MS (109) enters the idle mode, the PC (104) registers the BSID of the identifier of the BS (106) with which communication is performed and the Paging Area ID advertised by the BS in the PC. When a packet addressed to the MS (109) in idle mode arrives at the AGW (103), the AGW (103) requests the PC (104) to wirelessly call the MS, and the Paging registered in the PC (104) Request the BS (106) having an Area ID to make a wireless call of the MS (109). When the MS (109) receives the wireless call request, it returns from the idle mode to the active mode and resumes communication.
(105) is a multicast router, and when a packet addressed to a multicast address is received and there are multiple interfaces for which multicast routing of the corresponding multicast address is set, the packet is copied for each interface and the corresponding interface Send to.
(110) indicates the communication partner (CN) of the MS (109).
FIG. 2 shows a configuration example of a table managed by the PC (104). (201) holds a Paging Area ID of the paging area (108), a correspondence table for the BSID of the BS (106) holding the ID, and a combination of the BSID and the IP address corresponding to the BSID. BS (106) holds BSID, Paging Area ID, and its own IP address.
Next, the operation at the time of wireless calling is shown using FIG. When MS (109) is in idle mode and CN (110) sends a packet addressed to MS (109) (301), it is encapsulated in AGW (103) via HA (101) It arrives as a packet (302). The AGW (103) is a packet transmitted to the terminal in the idle mode and is wireless so that the MS (109) returns to the active mode via the PC (104) because there is no BS in communication. A call request is made (303), and the packet is temporarily buffered. The PC (104) stores the Paging Area ID corresponding to the paging area (108) registered by the MS (109) at the time of transition to the idle mode, and refer to the tables (201) and (202) in FIG. Then, a wireless call request is transmitted to each BS (106) (304) (305) (307). When each BS (106) receives the wireless call request, it performs wireless call processing of the MS (109) toward each service area (107) using the paging channel in the wireless section (306). Upon receiving the wireless call request, the MS (109) returns from the idle mode, establishes a wireless link to the communicable BS2 (106) (308), and notifies the AGW of the return from the idle mode (309). ) ~ (312). Furthermore, after establishing a tunnel for transferring data packets with MS (109) between BS2 and AGW (105) (313), the packets buffered during calling by AGW are encapsulated in BS2. The data is transferred to the MS (109) from the BS2 (315).

Next, a procedure when multicast is used will be described. The PC (104) holds a correspondence table between the paging area ID of the paging area (108) and the corresponding multicast address (401). In addition, BS (106) holds the IP multicast address used to receive the wireless call request in addition to the BS identifier (BSID), Paging Area ID, and its own IP address in the information (203) held by the BS. (402).
FIG. 5 shows a sequence diagram at the time of calling when multicast is used, and FIG. 6 shows an operation when the PC (104) receives a wireless call request from the AGW. When MS (109) is in idle mode and CN (110) sends a packet addressed to MS (109) (301), it is encapsulated in AGW (103) via HA (101) It arrives as a packet (302). AGW (103) is a packet sent to the terminal in idle mode, and since there is no BS in communication, MS (109) returns to active mode via PC (104). A wireless call request is made (303), and the packet is temporarily buffered. The PC (104) stores the Paging Area ID corresponding to the paging area (108) registered by the MS (109) at the time of transition to the idle mode, and receives the wireless call request (601). It is confirmed whether there exists an entry (602). If there is no entry, the call request is rejected (603). If there is an entry, the Paging Area ID is extracted from the entry table (604), the multicast address corresponding to the Paging Area ID is searched with reference to the table (401) in FIG. The destination address of the request is set and transmitted (606). When the multicast router (105) in the mobile communication network receives the packet having the multicast address as the destination, the multicast router (105) searches the multicast routing table, and copies and transmits the packet to each interface that requires multicast routing ( 502) (503) (504). When each BS (106) configured to receive a packet addressed to a multicast corresponding to the Paging Area ID receives a radio call request, the MS (in the service area (107) uses the MS ( 109) is called (306). Upon receiving the paging request, the MS (109) returns from the idle mode, establishes a wireless link to the communicable BS2 (106) (308), and notifies the AGW of the return from the IDLE mode (309). ~ (312). Furthermore, after establishing a tunnel for transferring data packets with MS (109) between BS2 and AGW (105) (313), the packets buffered during calling by AGW are encapsulated in BS2. The data is transferred to the MS (109) from the BS2 (315).

  Next, the operation of the BS (106) that performs the multicast operation will be described. The BS previously holds its own identifier (BSID) and Paging Area ID to which the BS itself belongs as setting information, and the MS (109) operating in the service area (107) using the broadcast channel in the wireless section. ) (702). The BS (106) holds the identifier of the PC (104) used for location registration and its IP address when the MS (109) enters the idle mode. In addition, the multicast address corresponding to the BS's own unicast IP address and Paging Area ID is held, and both addresses are set as addresses received by itself (703). Furthermore, in order to perform a Join operation for the multicast address, an IGMP Join is transmitted to the multicast router (105) (704). In this case, SSM (Source-Specific-Multicast) that designates the source of the multicast packet may be used. When using the SSM, the PC (104) address held by the BS may be set as the address designated as the transmission source, or other setting items may be provided.

In FIG. 8, there is a paging area conversion agent having a function of managing a correspondence between a paging area identifier and a multicast used when a radio call request is transmitted to the BS in the network, and converting a call request destination into a multicast. The structure when doing is shown.
(801) is a correspondence table between the Paging Area ID and the IP address of the paging area conversion agent included in the PC (104). The equivalent to this correspondence table can also be set using (201) and (202). For example, a virtual BSID in (201) and a virtual BSID in (202) It can also be expressed by setting the IP address of the paging area conversion agent (802) to the IP address corresponding to this. The PC (104) stores the Paging Area ID corresponding to the paging area (108) that the MS (109) has registered at the time of transition to the idle mode, and an entry for the corresponding terminal exists when a call request is received. Make sure. If no entry exists, the call request is rejected. If there is an entry, the Paging Area ID is extracted from the entry table, the IP address of the paging area conversion agent corresponding to the Paging Area ID is searched with reference to the table of (801) in FIG. Is sent to the corresponding paging area conversion agent.
The paging area conversion agent (802) holds a correspondence table between the paging area ID of the paging area (108) and the corresponding multicast address (803). When the paging area conversion agent (802) receives the wireless call request from the PC (104), the paging area conversion agent (802) searches the multicast address corresponding to the Paging Area ID with reference to the table of (803) and sets it as the destination address of the wireless call request. Set and send.

Next, the PC (104) first transmits the first wireless call request by unicast only to the BS that the MS (109) has registered at the time of transition to the idle mode. FIG. 9 shows an operation when a wireless call request is transmitted again using multicast only when there is no response.
When the PC (104) receives the radio call request (303), the MS (109) transmits the first radio call request only to the BS (106) used for registration at the time of transition to the idle mode (304). . If there is no response for a certain period of time (901), the PC sends the second radio call request, but at this time the MS (109) will register with the paging area (108) that was registered at the time of transition to the idle mode. It may be transmitted to the multicast address corresponding to the corresponding Paging Area ID (902), or may be transmitted to the paging area conversion agent (802). As a result, the second wireless call request is transmitted to the multicast address, so the multicast router (105) in the mobile communication network copies and transmits the packet to the BS (106) having the multicast address ( 903) (904) (905). When each BS (106) configured to receive a packet addressed to a multicast corresponding to the Paging Area ID receives a radio call request, the MS (in the service area (107) uses the MS ( 109) is called (306).

Next, the PC transmits a radio call request first by unicast only to the BS that the MS (109) has registered at the time of transition to the idle mode, and only when there is no response from the MS (109). FIG. 10 shows the operation when (106) transmits a wireless call request again using multicast.
When receiving the wireless call request (303), the PC (104) transmits a wireless call request only to the BS (106) used for registration by the MS (109) during the transition to the idle mode (304). When BS (106) does not respond for a certain period of time from MS (109) (1001), it responds to the paging area ID held by BS itself in order to request a BS to make a wireless call request to the surroundings. Send to a multicast address. (1002). Since this request is transmitted to the multicast address, the multicast router (105) in the mobile communication network copies and transmits the packet to the BS (106) having the multicast address as the destination (1004) (1005) (1006). ). When each BS (106) configured to receive a packet addressed to a multicast corresponding to the Paging Area ID receives a radio call request, the MS (in the service area (107) uses the MS ( 109) is called (306).

  FIG. 11 shows a configuration example of the AGW (103) including the PC (104). (1101) is a CPU, (1102) is a memory, and (1104) is a network interface. There may be a plurality of network interfaces. Reference numeral (1103) denotes a system bus / switch. The CPU (1101), the memory (1102), and the network interface (1104) are connected to each other through a system bus / switch (1103). The CPU (1101) operates by a program stored in the memory (1102). In memory (1102), information on MS (109) in idle mode, Paging Area ID and BSID mapping table (201) (801), BSID and IP address mapping (202), It has data such as a table of correspondence (401) (803) of Paging Area ID and multicast address, a route table for transferring the packet next.

A configuration example of a mobile communication network. A network configuration example of AGW and PC. The sequence example at the time of a radio call. Network configuration example of AGW and PC when using multicast. The sequence example at the time of the radio call at the time of using multicast. The operation | movement flowchart of PC. The operation | movement flowchart of BS. Network configuration example of AGW and PC when using Paging Agent. Sequence example when using unicast and multicast. Sequence example when multicasting with BS. One configuration example of PC and AGW.

Explanation of symbols

101 Home Agent 102 Router 103 Access Gateway 104 Paging Controller 105 Multicast Router 106 Base Station 107 Base Station Service Area 108 Paging Area 109 Mobile Terminal 110 Communication Partner 802 Paging Agent 1101 CPU
1102 Memory 1103 System bus / switch 1104 Network interface.

Claims (7)

A plurality of mobile terminals, a plurality of base stations connected to the mobile terminal for wireless communication, and a packet addressed to the mobile terminal connected to the base station and connected to the mobile terminal for wireless communication In a mobile communication network composed of an access gateway device that transfers to the base station and a mobile terminal management device that manages the state of the mobile terminal,
The mobile terminal management device maintains a state (idle mode) when the wireless communication is temporarily interrupted and the wireless link is released, and the mobile terminal management device moves the mobile terminal when a packet addressed to the mobile terminal arrives at the access gateway. It has a function of requesting a base station to perform a wireless call (paging) of a terminal, and a function of managing a group of base stations called a paging area by bundling a plurality of base stations, to a base station belonging to the same paging area. Has been assigned an IP multicast address,
The mobile terminal performs location registration with the mobile terminal management device via the base station with an identifier indicating the paging area when transitioning to the idle mode,
The mobile terminal management apparatus sets the multicast address as a destination address when transmitting a wireless call request packet to a base station having a registered paging area identifier when the mobile terminal is wirelessly called. A mobile communication network characterized by:   The mobile communication network according to claim 1, wherein the base station holds at least a unicast address indicating its own IP address, an identifier indicating the paging area, and an IP multicast address corresponding to the paging area, Broadcasting the paging area identifier to mobile terminals in the serving cell, holding the address of the mobile terminal management device used for registration of the transition request from the mobile terminal to the idle state, and A mobile communication network characterized in that when a station is started up or when the mobile terminal makes a request for transition to an idle state, a participation process is performed on the group of multicast addresses.   2. The mobile communication network according to claim 1, wherein the mobile terminal management apparatus includes a combination of a paging area identifier and a corresponding multicast address, and a paging area that is notified when the mobile terminal is registered in the transition to the idle mode. A mobile communication network comprising means for storing an identifier.   The mobile communication network according to claim 1, wherein there is a paging area conversion agent for managing a correspondence between a paging area identifier and a multicast used when transmitting a radio call request addressed to the base station, and the mobile terminal management apparatus Is transmitted to the paging area conversion agent when the radio call request packet is transmitted, and the paging area conversion agent has a multicast address derived based on the identifier information of the paging area included in the received radio call request packet as a destination. A mobile communication network characterized by transmitting a set radio call request packet.   When the mobile terminal management device or paging area conversion agent according to claim 3 transmits a packet for requesting a wireless call, the mobile terminal transmits the unicast to the base station used when the mobile terminal transitions to the idle mode for the first time. When the mobile terminal does not respond to paging, the mobile communication network is characterized in that a multicast address is set as a destination and transmitted.   3. The base station according to claim 2, wherein when the received packet for requesting a radio call is received by unicast and there is no response after the call to the mobile terminal, the multicast address is set as the destination and transmitted. Mobile communication network.   3. The mobile communication network according to claim 2, wherein the base station uses Source-Specific-Multicast that specifies an address of a multicast transmission source when participating in the multicast group and uses the mobile station as the multicast transmission source. A mobile communication network, wherein an address of a terminal management device or an address of a paging area conversion agent according to claim 4 is designated.

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