KR100403954B1 - Session establishment and management method for integrating network element in wireless telecommunication system - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a session establishment and management method for integrating network elements in a wireless communication system, and to a computer readable recording medium storing a program for realizing the method.

2. The technical problem to be solved by the invention

The present invention provides network elements such as a packet control function (PCF) and a packet data service node (PDSN) function to provide an efficient network structure and data service function in a next-generation mobile communication network-based integrated Internet protocol (ALL-IP) network. Session establishment and management to provide an efficient wireless communication data service by accommodating the integration but separating the control part and the bearer part of the PDSN, that is, separating the functions for establishing and managing sessions for bearer data processing and bearer data processing. A computer readable recording medium having recorded thereon a method and a program for realizing the method.

3. Summary of Solution to Invention

The present invention provides a packet control function for interworking a radio access network (RAN) to a packet network in a session establishment and management method for integrating network elements in a next-generation mobile communication network-based integrated internet protocol (ALL-IP) network. Packet data service node (hereinafter referred to as " PDSN ") which functions as a connection node for connecting a data subscriber connected through the radio access network (RAN) to the packet network. A first step of integrating one into a mobile Internet Protocol (Mobile IP) service and integrating the PCF's mobile IP external agent function and a link layer termination function of the mobile terminal into the PCF; Separating a control portion and a bearer portion of the PDSN; Performing a bearer data processing function of the PDSN by a bearer function processing unit of the PCF; And a fourth step in which a control function processor of an external agent controller (FAC) that manages a plurality of PCFs performs a session setup and management function for bearer data processing of the PDSN.

4. Important uses of the invention

The present invention is used for integrated Internet protocol (ALL-IP) network and the like.

Description

Session establishment and management method for integrating network elements in a wireless communication system {in session establishment and management method for integrating network element in wireless telecommunication system}

Present invention to perform a data service, etc. Network ^{3GPP2 (3 rd Generation Partnership Projects-} 2) IMT-2000 (International Mobile Telecommunication), UMTS (Universal Mobile Telecommunication Service) next-generation mobile communication network based integrated Internet Protocol (ALL-IP), such as A session for integrating network elements such as a Packet Data Serving Node (PDSN) function used for this purpose and a Packet Control Function (PCF) used in a Radio Access Network (RAN). A setting and management method and a computer-readable recording medium having recorded thereon a program for realizing the method.

1 is a configuration example of a conventional network, ^{3GPP2 (3 rd Generation Partnership Projects-} 2) Fig.

Radio access network (RAN) 12 is composed of a base station controller (BSC (Base Station Controller) + PCF) and a base station (BTS: Base station Transceiver Subsystem), etc., and visitor location register (VLR) Mobility management and authentication of a mobile station (MS) 11 is provided through 13 and a Home Location Register (HLR) 14.

When the basic authentication of the data call is completed, the radio access network (RAN) 12 establishes a virtual connection for the packet data service node (PDSN) 16 and the Generic Routing Encapsulation (GRE) protocol.

The Packet Data Service Node (PDSN) 16 establishes a Point-to-Point Protocol (PPP) connection with the MS 11 and establishes a Remote Authentication Dial (RADIUS) service. In User Service) transmits subscriber authentication and billing information.

When providing a mobile IP service, the packet data service node (PDSN) 16 performs a foreign agent (FA) function, and is a home agent (HA) 15 existing in the home network of the mobile station IP address. ) Performs functions such as location information management and tunnel setup for mobile IP.

As such, the conventional packet control function (PCF) is an interworking system of a radio access network (RAN) 12 for interworking with a packet network, and the packet data service node (PDSN) 16 is a radio access network (RAN) ( 12), it functions as an access node for connecting the data subscriber connected through the packet network to the packet network, and the radio access network (RAN) 12 and the packet network are completely separated.

However, in 3GPP2 network or ALL-IP network, the whole trend is evolving into one IP network, and the existing base station controller (BSC), packet control function (PCF) and packet data service node (PDSN) are connected to one wireless gateway. It is viewed as a system called a device (WAG: Wireless Access Gateway). Accordingly, access nodes of data subscribers are increasingly being moved to the lower level of the network as they are integrated into a single wireless access gateway (WAG).

In particular, in the IMT-2000 network and the All-IP network structure being standardized in 3GPP2, the system of the packet control function (PCF) and the packet data service node (PDSN), as shown in Figs. exist.

The packet control function (PCF) may exist inside a base station controller (BSC) system or may be implemented as a separate system. However, most developers implement an independent system to provide effective mobility in a mobile network.

In addition, the packet control function (PCF) is an IP protocol processing function for processing data packets, a packet data processing function, and an "RP Interface" for this, that is, a radio access network (RAN) and a packet data network (Packet Data Network). It uses the inter-interface and provides tunneling function through the virtual link connection for data transmission and the GRE protocol encapsulation and decapsulation of user data on the RP interface. Here, the RP interface is a connection method between the radio access network (RAN) and the packet data network (PDN) for connecting the data of the mobile station (MS) transmitted from the radio access network (RAN) to the packet data service node (PDSN).

In addition, the packet control function (PCF) performs a handoff processing function, a packet data charging information transfer function, and a packet data buffering function occurring on the RP interface.

In addition, the packet control function (PCF) is a temporary storage that allows the transmission of the link layer packets to be delivered to the mobile terminal (MS) received from the packet data service node (PDSN) over the air interface (Air Interface) ( Buffer) and packet segmentation function.

Meanwhile, the packet data service node (PDSN) is a service node of an IP-based packet network that provides a high speed packet data service. The packet data service node (PDSN) provides mobility of packet data services and various data related protocol processing functions. In addition, IKE (Internet Key Exchange) RADIUS processing functions (key, SPI distribution, billing function), mobile IP function, IP Security processing functions, etc. are performed.

In addition, the packet data service node PDSN performs PPP / GRE protocol processing to process packets received from the packet control function (PCF).

First, the control procedure for session establishment when the packet control function (PCF) and the packet data service node (PDSN) exist in different systems (see FIG. 4) will be described.

Referring to FIG. 4, a control procedure for establishing a conventional session is described. First, when a call control processor (CCP) transmits a PCF resource allocation request message (A9_Setup_A8) to a router (ATM switch), the router controls the packet controller ( PCF) sends a PCF resource allocation request message (virtual connection establishment request message) (402).

Then, the packet controller PCF transmits a PPP session establishment request message A11_Regist_Req to the packet data service node PDSN (403), and the packet data service node PDSN transmits a PPP session establishment response message to the packet data service node PDSN. PCF) (404).

Thereafter, the packet controller PCF transmits a PCF resource allocation response message (virtual connection establishment response message) A9_Connect_A8 to the router (405), and the router sends a PCF resource allocation response message (A9_Connect_A8) to the call control processor (CCP). Transmit (406).

However, when the packet control unit PCF and the packet data service node PDSN exist in different systems, there are the following problems.

First, in the service of a user packet of a mobile terminal (MS), since the processing thereof passes through a packet control function (PCF) and a packet data service node (PDSN), a delay for processing thereof increases. have. That is, in the transmission of the user packet of the mobile station MS, the delay is increased compared to the integrated system. This is because each time it goes through the network element, it goes through a Store and Forward process.

Second, since the current packet data service node (PDSN) handles both the control function and the bearer function as shown in FIG. 4, in the event of a failure, all session related information is lost. There is an inefficient problem of duplication of resource management occurring during hand-off.

Third, there is an inefficient problem of data transmission due to header overlap of GRE / PPP in the RP interface. In particular, when the connection layer end of the mobile terminal (MS) is in the packet data service node (PDSN) in the process of evolving to IPv6 (HA) in the future, the RP interface must adhere to the tunneling method of IPv4 (GFA). Therefore, in the future evolution to IPv6, it is reasonable to handle the connection layer protocol of the mobile terminal (MS) of the packet data service node (PDSN) in the packet control function (PCF).

As described above, in order to interwork with a radio access network (RAN) and an IP network in a 3GPP2 IMT-2000 network, a packet control function (PCF) is required in a radio access network (RAN), and a packet data service node (PDSN) is provided in an IP network. Was required. Therefore, in order to provide efficient network structure and data service function in IMT-2000 network and ALL-IP network, packet control function (PCF) and packet data service node (PDSN) functions can be integrated and accommodated. In particular, packet data service A scheme for separating the bearer processing portion and the control processing portion of the node (PDSN) function is essentially required.

The present invention has been proposed in order to solve the above problems, packet control function (PCF) and to provide an efficient network structure and data service functions in the next generation mobile communication network-based integrated Internet Protocol (ALL-IP) network, etc. Integrate network elements such as packet data service node (PDSN) function, but in particular, separate control part and bearer part of PDSN, that is, separate function for session establishment and management for bearer data processing part and bearer data processing. It is an object of the present invention to provide a session establishment and management method for providing an efficient wireless communication data service, and a computer readable recording medium recording a program for realizing the method.

1 is a configuration example of a conventional network, ^{3GPP2 (3 rd Generation Partnership Projects-} 2) Fig.

2 is an exemplary configuration diagram of a 3GPP2 Integrated Internet Protocol (ALL-IP) network to which the present invention is applied.

3 is an exemplary protocol configuration of a packet control function (PCF) having a simple IP function according to the present invention.

4 is a flowchart of a conventional session establishment process.

5 is a flowchart illustrating an embodiment of a session establishment and management method according to the present invention;

* Explanation of symbols for the main parts of the drawings

201: Wireless Access Gateway (WAG) 202: Authorization / Authentication / Charging (AAA) Security Manager

203: home location register (HLR) 204: existing service support function

205: location server 206: media gateway device

207: media gateway device control function unit 208: media resource function unit

209: Mobile IP Home Agent 210: Mobility Manager

211: Policy Manager 212: Resource Manager

213: roaming signal gateway device 214: service generation environment function

215: service manager 216: session manager

217: relay signal gateway device 218: home subscriber server

In order to achieve the above object, the present invention provides a session establishment and management method for integrating network elements in a next-generation mobile communication network-based integrated Internet protocol (ALL-IP) network, for linking a radio access network (RAN) to a packet network. A packet data service node (hereinafter referred to as "PDSN") that performs a packet control function (hereinafter referred to as "PCF") and a connection node for connecting a data subscriber connected through the radio access network (RAN) to the packet network. A first step of integrating a single function, wherein the first step of integrating a mobile IP external agent function of the PDSN and a link layer termination function of the mobile terminal in the PCF when providing a mobile internet protocol (mobile IP) service; Separating a control portion and a bearer portion of the PDSN; Performing a bearer data processing function of the PDSN by a bearer function processing unit of the PCF; And a fourth step of performing a control function processing unit of an external agent controller (FAC) that manages a plurality of PCFs to set up and manage a session for bearer data processing of the PDSN.

Meanwhile, the present invention provides a packet control for interworking a radio access network (RAN) to a packet network in a wireless communication system having a processor for session establishment and management for network element integration in an integrated internet protocol (ALL-IP) network. A packet data service node (hereinafter referred to as "PDSN") that performs a function (hereinafter referred to as "PCF") and a connection node for connecting a data subscriber connected through the radio access network (RAN) to the packet network. A first function of integrating a function into one, and incorporating a mobile IP external agent function of the PDSN and a link layer termination function of the mobile terminal into the PCF when providing a mobile Internet protocol (mobile IP) service; A second function of separating a control portion and a bearer portion of the PDSN; A third function in which a bearer function processing unit of the PCF performs a bearer data processing function of the PDSN; And a control function processing unit of an external agent controller (FAC) that manages a plurality of PCFs, and a program for realizing a fourth function of performing a session setting and management function for bearer data processing of the PDSN. Provide a record carrier.

The present invention provides a PDF's mobile IP external agent (FA) function and a PD's link layer termination of a mobile terminal (MS) in a system in which an existing packet control function (PCF) and a packet data service node (PDSN) function are independent. It accommodates the Tremination function, facilitating network configuration when evolving into ALL-IP network, reducing delay in data transmission, and controlling the control plane as a separate network element (FAC) to make PDSN It is possible to provide more efficient wireless data service while reducing the burden on bearer and control. That is, by separating the control plane and separating the bearer data processing function (bearer function) and the session setting and management function (control function) for bearer data processing, effective wireless communication data The service could be provided. That is, the bearer function of the PDSN is handled by the PCF, and the control function of the PDSN is handled by the FAC (FA Controller), thereby separating the bearer function and the control function.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is an exemplary configuration diagram of a 3GPP2 integrated internet protocol (ALL-IP) network to which the present invention is applied.

The wireless access gateway device (WAG) 201 is for interworking the existing base station controller (BSC), packet control function (PCF), packet data service node (PDSN) function, etc. into a single system, a radio controller, voice and data Perform gateway functions and more.

A base station controller (BSC) controls and manages one or more base stations (BTSs), and performs traffic and signaling, mobility management, and mobile terminal (MS) management related to call processing. Radio access network (RAN) is composed of a base station controller (BSC) and a base station (BTS).

The packet control function (PCF) may exist inside a base station controller (BSC) system or may be implemented as a separate system outside. The packet control function (PCF) may include data of a mobile terminal (MS) transmitted from a radio access network (RAN). PDSN).

The packet data service node (PDSN) performs an external agent (FA) function, delivers incoming and outgoing packets for packet data of the mobile station (MS) to an appropriate path, and establishes and manages a connection layer protocol of the mobile terminal (MS). Plays an end role.

Authorization / Authentication / Charging (AAA) The security manager 202 provides Internet protocol functions that support authentication, authorization, and billing functions.

The home location register (HLR) 203 has information such as subscriber information, IP priority, resources and authority usage for interdomain services.

The legacy service support unit 204 manages functions such as call processing, mobility management, resource management, security management, and service management, which were provided by the existing line-type wireless network.

The location server 205 has location information, a function such as a mobile location center, and a function of position measurement equipment (PDE).

The media gateway 206 performs functions such as protocol and address translation when the user's data is transferred to a public data network or another network.

The media gateway control function 207 controls and manages the media gateway devices 206.

The media resource function 208 performs a management function of allocating / releasing resources of the media gateway devices 206.

The Mobile IP Home Agent 209 manages the IP address of the external agent as a table of the location information on the mobile IP, and transfers the transmission data to the subscriber through tunnel and encryption as necessary. Perform.

The mobility manager 210 performs a handoff management function between the radio access gateway devices 201 or between networks.

The Policy Manager 211 manages policy data and rules and allows interaction with various policies.

The resource manager 212 manages resources necessary to provide a service to a network user.

The roaming signaling gateway 213 performs a function of converting packet signals into a signaling scheme of a circuit switched network or a signaling scheme of a circuit switched network into packet signals.

The service creation environment function unit 214 provides an operator with an environment in which new services and application services can be created.

The service manager 215 manages network authentication and all voice and data service logic.

Session Manager 216 establishes and manages sessions, states, and handoffs across multiple networks.

The trunk signal gateway 217 performs a function of converting the signaling method of the public switched telephone network (PSTN) and the signaling method of the core network.

A home subscriber server (HSS) 218 includes at least network elements such as AAA, HLR, EIR, LOC, UMS, and the like.

The Equipment Identity Register (EIR) is a database (DB) for device information.

The location related information DB (LOC) provides location related information required by the location server 205.

The Policy Repository stores data on subscribers, multimedia usage policies, quality of service, validity time and route.

The protocol structure for accommodating the mobile IP external agent (FA) function of the packet data service node (PDSN) in the packet control function (PCF) is shown in FIG.

Referring to FIG. 3, a User Datagram Protocol (UDP) processing unit 304, an Internet Protocol (IP) processing unit 305, an Internet Protocol encryption (IPsec) unit 309, and an end-to-end protocol ( The PPP: Point to Point Protocol (PPP) processing unit 306 conforms to a protocol defined by the Internet Engineer Task Force (IETF), and the link layer 307 is an asynchronous transfer mode or an Ethernet.

The base station controller interworking signal processing unit 301 is in charge of the interface of ISO 9 A9 (Standards related to the control processing of the base station controller (BSC) and the packet control function (PCF)) interface, and the data call related call received from the base station controller (BSC) Process various signals related to processing and resource management.

Authorization / Authentication / Charging (AAA) Protocol The client processing unit 302 performs authentication for accessing the IP network of the mobile terminal (MS) through the authorization / authentication / charging protocol, and authorizes / authenticates / charges the charging information generated in the system. It performs the function of forwarding to the AAA security manager 202.

The mobile IP external agent function processing unit 303 is a function block for processing messages related to the mobile terminal MS and the mobile IP, and manages a visitor list. This establishes tunneling with the mobile IP home agent 209 and, if necessary, also encrypts the IP.

Looking at the main functions of the packet control function (PCF) to accommodate the mobile IP external agent (FA) function of the packet data service node (PDSN), a call to the Dormant function, the base station controller (BSC) for the packet data service It handles existing packet control functions (PCFs) such as temporary storage of user packets, PPP packet splitting / combining functions, external agents of mobile IP, IP in IP processing, IP encryption, IP address assignment, and route. It provides functions of the existing packet data service node (PDSN), such as assignment and mobile IP message processing, remote authentication dial-up user service (RADIUS) or DIAMETER client function. However, the existing RP access signal processing is not performed, but it is used for PPP resource management using this signal. In addition, the conventional PPP allocation and release (including timer management) is to be done in the existing router (Router) in a separate centralized controller (FAC: FA Controller).

Looking at the process of forwarding and processing the packet, the packets received from the base station controller (BSC) are made into a complete end-to-end protocol (PPP) frame through a combination process if necessary, and the IP packet of the mobile station (MS) after PPP processing. Is transmitted to the IP network according to the general routing method. The packet received from the IP network is made into a PPP frame, and the packet is divided and transmitted according to the size of a radio link protocol (RLP) of the wireless network.

Here, IP packets transmitted to the IP network are delivered to the next hop along a path determined by a routing protocol.

Then, referring to FIG. 5, a control management procedure for integrating network elements such as a packet data service node (PDSN) function in a packet control function (PCF) to provide an efficient network structure and data service function is as follows. .

In FIG. 5, the control function processing unit (Control Entity) is driven by an external agent (FA) controller (FAC) that manages a plurality of packet control functions (PCF), the bearer function processing unit is driven by a packet control unit (PCF).

5 shows a control procedure on a logical connection structure rather than a physical connection.

First, the base station controller interworking signal processing unit 301 of the packet controller PCF performs a call processing function for establishing a data path with the base station controller BSC. Subsequently, when a data path with the base station controller BSC is established, a link layer is established with the mobile station MS. After the connection layer setup is completed, the packet controller (PCF) relays the message to the FA controller (FAC) upon receiving the mobile IP message from the mobile station (MS), and the FA controller (FAC) authenticates the existing authentication. After checking whether or not in the database (DB), if authentication is completed, the mobile IP home agent (HA) transmits a mobile IP registration request (MIP-RRQ) message, and if authentication is the first time, the authentication process is started.

When the existing PCF (FA bearer processing network entity) receives the A11 signal message for the GRE session allocation, it transmits the A11 message to the session allocation processing unit (finally, the control function processing unit (FAC)), the session allocation processing unit (control function processing unit ( FAC)) allocates PPP in a non-active state and transmits a key for the corresponding PPP session to the bearer function processing unit (PCF) to perform PPP configuration for the mobile host.

The control function processor (FAC) manages the PPP session key by a timer and when it expires, transmits a PPP session release command to the bearer function processor (PCF) using a MIP Reg-Update message, which is an existing A11 signal. .

Referring to FIG. 5, referring to a method for establishing and managing a session according to the present invention, first, when a call control processor (CCP) transmits a PCF resource allocation request message (A9_Setup_A8) to a router (ATM switch), the router transmits a packet. A PCF resource allocation request message (Virtual Connect Open Req) (A9_Setup_A8) is transmitted to the control unit PCF (502).

Subsequently, the packet control unit PCF transmits a PPP session establishment request message (PPP Session Open Req) to the control function processing unit (FAC) (503), and the control function processing unit (FAC) transmits a PPP session establishment command message (PPP Session Open Command). ) Is transmitted to the bearer function processing unit (PCF) (504). Then, the bearer function processing unit (PCF) transmits a PPP session establishment command response message (PPP Session Open Command OK) to the control function processing unit (FAC) in response thereto.

Next, the control function processor (FAC) receiving the PPP Session Open Command OK message transmits the PPP Session Open Reply message to the packet controller PCF (506). The packet control unit (PCF) transmits a PCF resource allocation response message (Virtual Connect Open OK) (A9_Setup_A8) to the router (507), and the router sends a PCF resource allocation response message (A9_Connect_A8) to the call control processor. And transmit (CCP) (508).

The method of the present invention as described above may be implemented as a program and stored in a computer-readable recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.).

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

As described above, the present invention eliminates the need for virtual link setting due to the disappearance of the RP interface between the PCF and the PDSN, eliminates the A10 and A11 processes, and eliminates the need for the GRE protocol, and also the GRE / PPP on the RP interface. The overhead is eliminated and the packet processing performed by the two network elements is integrated into one, which reduces the time delay in the data transmission process.

In addition, in the conventional process, all packets are transmitted through the PDSN and transmitted to the other host, but both PCF and PDSN have a burden of packet processing, but the present invention is easy to accept IPv6, processes only one system, and processes packets on its own network. Since routing can be done (routing), the burden on data transmission can be reduced.

In addition, the present invention conforms to the technical trend of downgrading the FA function of 3GPP2 to the RAN, and also can operate the network without changing the existing network by using the message used in the existing network as the allocation and termination of the PPP session. In addition, since a controller (FAC) that manages a control plane manages multiple bearer entities at the same time, it is possible to efficiently allocate and terminate PPP sessions in case of a failure of a bearer entity or a handoff of a mobile terminal.

Claims (5)

In the session establishment and management method for the integration of network elements in the next generation mobile communication network-based integrated Internet protocol (ALL-IP) network, A packet control function (hereinafter referred to as "PCF") for interworking a radio access network (RAN) to a packet network, and a function as a connection node for connecting a data subscriber connected through the radio access network (RAN) to the packet network. Integrate the functions of the Packet Data Service Nodes (hereinafter referred to as "PDSN") into one, A first step of integrating a mobile IP external agent function of the PDSN and a link layer termination function of a mobile terminal in the PCF when providing a mobile Internet protocol (mobile IP) service; Separating a control portion and a bearer portion of the PDSN; Performing a bearer data processing function of the PDSN by a bearer function processing unit of the PCF; And A fourth step in which a control function processor of an external agent controller (FAC) that manages a plurality of PCFs performs a session setup and management function for bearer data processing of the PDSN; Session establishment and management method for network element integration in a wireless communication system comprising a. The method of claim 1, The PCF is, When a signal message for Generic Routing Encapsulation (GRE) protocol session allocation is received, a session allocation message is transmitted to the control function processor, and the control function processor allocates a non-end end-to-end protocol (PPP). For end-to-end protocol (PPP) setting for a mobile host by transmitting a key for a corresponding end-to-end protocol (PPP) session to the bearer function processing unit (PCF). How to set up and manage sessions. The method of claim 2, The control function processing unit, After managing the end-to-end protocol (PPP) session key by the timer and ending (Expire), the end-to-end protocol (PPP) session release command is transmitted to the bearer function processing unit, and the end-to-end protocol (PPP) for the mobile host is transmitted. A session establishment and management method for integrating network elements in a wireless communication system, characterized in that to perform a release. The method according to any one of claims 1 to 3, The PCF is, Mobile Internet Protocol (IP) agent function, Internet protocol (IP in IP) processing function, Internet protocol (IP) address assignment function, routing and mobile Internet protocol (IP) message processing function, remote authentication dial-up user service Functions of existing PDSN such as RADIUS or DIAMETER client function, but does not perform signal processing by the existing access method (RP interface method) between the radio access network (RAN) and the packet network. It is used for end-to-end protocol (PPP) resource management, and the external agent controller (FAC) to perform the allocation and release (including timer management) of the end-to-end protocol (PPP) used in the existing router (Router) Session establishment and management method for network element integration in wireless communication system. In a wireless communication system having a processor for session establishment and management for integration of network elements in an integrated internet protocol (ALL-IP) network, A packet control function (hereinafter referred to as "PCF") for interworking a radio access network (RAN) to a packet network, and a function as a connection node for connecting a data subscriber connected through the radio access network (RAN) to the packet network. Integrate the functions of the Packet Data Service Nodes (hereinafter referred to as "PDSN") into one, A first function of integrating a mobile IP external agent function of the PDSN and a link layer termination function of a mobile terminal in the PCF when providing a mobile Internet protocol (mobile IP) service; A second function of separating a control portion and a bearer portion of the PDSN; A third function in which a bearer function processing unit of the PCF performs a bearer data processing function of the PDSN; And A fourth function of the control function processing unit of an external agent controller (FAC) that manages a plurality of PCFs to perform a session setup and management function for bearer data processing of the PDSN; A computer-readable recording medium having recorded thereon a program for realizing this.