KR100395494B1 - Method of intra-domain handoff in Mobile IP networks - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to an intra-domain handoff method in a mobile IP network.

2. The technical problem to be solved by the invention

According to an embodiment of the present invention, when a domain server has a jurisdiction as one domain, when an external agent changes within a domain, authentication is not performed for a mobile subscriber in a home network, and a smooth handoff scheme is applied between external agents. It is intended to provide an intra-domain handoff method in a mobile IP communication network capable of minimizing data loss transmitted to mobile subscribers when off.

3. Summary of Solution to Invention

The present invention provides a method for intra-domain handoff in a Mobile Internet Protocol (MIP) network, wherein the second foreign agent is different from the first foreign agent that has been established in the domain due to the movement of the mobile subscriber. A first step of creating a temporary tunnel between the second foreign agent and the first foreign agent as the foreign agent changes. A second step of the second external agent updating visitor information through a home agent of a home network and delivering it to the mobile subscriber; And a third step of releasing the temporary tunnel between the first foreign agent and the second foreign agent and terminating the connection with the local domain server by the first foreign agent.

4. Important uses of the invention

The present invention is used for the Internet service.

Description

Method of intra-domain handoff in mobile IP network {Method of intra-domain handoff in Mobile IP networks}

The present invention relates to an intra-domain handoff method in a mobile IP communication network.

Mobile IP (Internet Protocol) technology has been proposed to provide a continuous connection service to a mobile subscriber using an Internet service in a mobile communication network regardless of its location and movement. However, such mobile IP technology supports users without changing the IP address of mobile subscribers, but does not consider commercialization such as authentication and billing of subscribers in initial design, and also occurs due to delay in registration when handoff occurs. It is defined to compensate for data loss in TCP (Transmission Cotrol Protocol) or higher layer.

Accordingly, a method of using a network access server (NAS) and a remote authentication dial in user service (RADIUS) server as a method for commercializing the Internet service by providing authentication and billing of subscribers to the Internet service has been proposed. Because it is designed to support the mobility that occurs due to the mobility characteristics of the subscriber.

On the other hand, as a supplement to the problem of not supporting the above mobility, a structure combining RADIUS and mobile IP technology has been proposed, but connection establishment delay occurs due to separate authentication procedure of subscriber and mobile IP registration. . In addition, the client-server structure of RADIUS does not support mobility for handoff between mobile operators that require message exchange between servers.

In order to solve the above RADIUS problem, the DIAMETER protocol has been proposed. In the network structure based on the DIAMETER protocol, messages can be exchanged between the server and the mobile IP and NASREQ ( Network Access Server REQuest).

The DIAMETER protocol is an end-to-end protocol that is proposed as a protocol to solve the limitations of the existing RADIUS. The DIAMETER protocol is a structure that transmits a mobile IP message as a data field of a DIAEMTER message. It is designed to efficiently perform message processing, provide strong security on protocols, and provide subscriber authentication and billing functions to provide the necessary functions needed for mobile operators to provide Internet services.

However, the DIAMETER protocol is currently under design and requires authentication of subscribers to the home DIAMETER server every time the hand-off of a foreign agent (FA) changes due to the session-based structure. Doing. As such, due to the characteristics of the DIAMETER protocol for subscriber authentication in a home network, a delay in processing a DIAMETER message for processing a handoff may occur. In addition, the delay of the handoff causes data loss of the mobile subscriber and there is a problem that the mobile subscriber may not properly use the Internet service when frequent handoff occurs.

The present invention has been proposed in order to solve the above problems, by setting a domain that is controlled by a domain server as one domain so that when the external agent is changed in one domain, the mobile network does not perform authentication for the mobile subscriber. It is an object of the present invention to provide an intra-domain handoff method in a mobile IP communication network which can minimize data loss transmitted to mobile subscribers during handoff by applying a smooth handoff scheme between agents.

1 is a configuration diagram of an embodiment of a mobile IP communication network based on a DIAMETER to which the present invention is applied.

2 is a diagram illustrating an embodiment of a structure and security between mobile IP communication networks based on a DIAMETER according to the present invention.

3 is a structural diagram of a message for a mobile IP registration request message used by a mobile subscriber in the present invention.

4 is a flow diagram of an embodiment of an intra-domain handoff scheme in a DIAMETER mobile IP communication network according to the present invention.

* Explanation of symbols for the main parts of the drawings

101: mobile subscriber 102: wireless access network

103: external agent 104: home agent

105: diamond server 106: router

In order to achieve the above object, the present invention provides a method for intra-domain handoff in a Mobile Internet Protocol (MIP) network, wherein a first external agent having a connection established within a domain due to the movement of a mobile subscriber is provided. A first step of creating a temporary tunnel between the second foreign agent and the first foreign agent as the foreign agent is replaced with another second foreign agent; A second step of the second external agent updating visitor information through a home agent of a home network and delivering it to the mobile subscriber; And a third step of releasing the temporary tunnel between the first foreign agent and the second foreign agent and terminating the connection with the local domain server by the first foreign agent.

In addition, the present invention relates to an intra-domain handoff method in a Mobile Internet Protocol (MIP) communication terminal, wherein the first external agent, other than the first external agent, has been established in a domain due to the movement of the mobile subscriber. A first step of establishing a connection for the mobile subscriber to transmit data traffic with the second foreign agent when the foreign agent changes to a second foreign agent; A second step of the mobile subscriber transmitting a Mobile Internet Protocol (MIP) registration request message to the second foreign agent such that a temporary tunnel is established between the first foreign agent and the second foreign agent; And a third step in which the mobile subscriber receives a mobile IP registration response message from the second external agent smoothly handed off from the home network and establishes a connection with the second external agent.

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.

Hereinafter, the present invention will be described with an example of a communication network based on a DIAMETER.

1 is a configuration diagram of an embodiment of a mobile IP communication network based on a DIAMETER to which the present invention is applied.

The mobile communication network providing the mobile IP service is visited by a mobile subscriber network (MS) 101 equipped with a mobile IP protocol, a base station, a control station and a packet switch (eg, a router), and the like. Foreign Agent (FA) 103 that manages mobile subscribers, and a home agent that performs the function of tunneling IP packets destined for the subscribers to the moved area when the mobile subscribers move to a network having a different subnet. (HA: Home Agent) 104, a DIAMETER server that performs authentication for mobile subscribers, assigns dynamic IP addresses, and distributes session keys (authentication keys) for use by mobile agents (external agents and home agents). 105, and a router 106 connecting the mobile agents 103, 104 and the DIAMETER server 105.

2 is a diagram illustrating an embodiment of a structure and security between mobile IP communication networks based on a DIAMETER according to the present invention.

The mobile IP communication network based on the DIAMETER according to the present invention is composed of a home network 21, a visited network 22, and a public internet 23. The dual home network 21 is a mobile subscriber's first mobile IP service. It refers to a network that subscribes to, the authentication for the mobile subscriber is always made in the home diameter (DIAMETER) server in the home network. In addition, the visited network 22 refers to a network that provides mobile subscribers with access to radio resources and networks. The home network 21 and the visited network 22 are connected to each other via the public Internet 23.

One domain consists of a number of external agents 103 and one home agent 104 (or home agents with load balancing) connected to one local DIAMETER server 105 and a wireless access network. It is configured and has a preset Security Association 1 (SA1) 201 between the systems in these one domain.

In addition, a security relationship between the DIAMETER servers 105 may be directly established between domains, or may be secured between DIAMETER servers 105 established through a proxy DIAMETER server. Relationship 2 (SA2) 202 is established.

If the subscriber requests the dynamic IP address after successful authentication of the mobile subscriber 101 in the home-diameter server 105, the IP address allocation is performed in the home network 21 or the visited network 22, and then moved. Generate session keys for use by agents (home and external agents). These session key values are encrypted and delivered directly to the home agent 104 and the foreign agent 103, which are mobile agents using the session key. When the mobile subscriber 101 and the mobile agents 103 and 104 receive these session keys, the security relationship 4 (SA4) 204 between the mobile subscriber 101 and the home agent 104 using the MS-HA session key. ), The security relationship 6 (SA6) 206 between the mobile subscriber 101 and the foreign agent 103 using the MS-FA session key, the foreign agent 103 and the home agent (using the FA-HA session key). A security relationship 5 (SA5) 205 between 104 is established.

The mobile subscriber 101 is initially assigned an MSAA (Authentication, Authorization and Accounting) key when applying for a service to the mobile operator, and secures a relationship between the mobile subscriber 101 and the home diameter server 105. 3 (SA3) 206 is set.

3 is a diagram illustrating a structure of a message for a mobile IP registration request message used by a mobile subscriber in the present invention.

Mobile IP (MIP) registration request message functions in addition to basic functions such as authentication support function in addition to mobile IP registration request message basic part 301 defined by IETF (Internet Engineering Task Force) Request For Comments 2002 (RFC2002). And an expansion portion 302 for addition.

Looking at the dual extension in more detail, the user identifier extension 303, which stands for Network Access Identifier (NAI), and the security relationship (SA4) between the mobile subscriber 101 and the home agent 104 ( MS-HA authentication extension 304 for 204, previous external agent authentication extension 305 containing IP address and authentication information for the previous external agent at handoff, challenge value delivered by the external agent MS-FA challenge extension 306 with MS, MS-FA authenticator 307 for security relationship (SA6) 206 between mobile subscriber and external agent and mobile subscriber at home DIAMETER server In order to have the authentication of the mobile subscriber to the authentication extension (308) in order. Extensions included in this extension may be optionally added to the mobile IP registration request message as needed.

4 is a flowchart illustrating an intra-domain handoff scheme in a DIAMETER mobile IP communication network according to the present invention.

When the mobile subscriber 41 first establishes a connection to the first external agent 42 (401), the first external agent 42 includes an agent advertisement including a challenge value that is a seed for authenticator generation. The message is sent to the mobile subscriber 41 (402). In this case, the connection establishment 401 for data traffic between the mobile subscriber 41 and the first foreign agent 42 may be changed by the method of the link layer of the mobile communication network.

The mobile subscriber 41 having received the agent advertisement message generates the basic portion 301 of the mobile IP registration request message and moves the data with the challenge value of the received agent advertisement message to the basic portion of the generated mobile IP message. Using the MS-AAA key value of the subscriber 41, a mobile IP registration request message including an authenticator generated and included is transmitted to the first external agent 42 (403).

The first foreign agent 42 generates a DIAMETER AA-Mobile IP-Request (AMR) message using respective field values of the received mobile IP registration request message and visits the local DIAMETER server. It transmits to the DIAMETER server 44 (404).

The visited DIAMETER server 44 determines the home network 21 by using a network access identifier (NAI) for the mobile subscriber 41 and sends an AMR message to the DIAMETER server of the home network. It transmits to the meter server 45 (405).

At this time, if the mobile subscriber 41 is not a home subscriber, the proxy DRM server or the visited DIAMETER server 44 directly transmits an AMR message to the home DIAMETER server 45. (405).

The home DIAMETER server 45 performs subscriber authentication using the mobile IP registration message field included in the received AMR message and the authenticator generated by the mobile subscriber 101. If the subscriber authentication succeeds, it determines whether to assign an IP to the dynamic subscriber, generates session keys for use by the mobile subscriber 41, the first external agent 42, and the home agent 45, and includes the generated session keys. -Agent Request) message is sent to the home agent 46 (406).

When the home agent 46 receives the HAR message, the home agent 46 stores the session keys to be used by the home agent 46 and uses the IP address of the mobile subscriber 41, the home agent 46, and the mobile IP registration message. Performs a mobile IP binding at and generates a mobile IP registration response message as a result. The FA-HA authenticator and the MS-HA authenticator are created by using the session keys storing the generated mobile IP registration response message as data, and then included in the mobile IP registration response message to the visited DIAMETER server 44 In step 407, a Home-Agent Answer (HAA) message is transmitted.

The home DIAMETER server 45 transmits an AMA message to the visiting DIAMETER server 44, which is a DIAMETER server of the network to which the mobile subscriber 41 belongs (408). The DIAMETER server 44 forwards the AMA message to the first foreign agent 42 (409).

Receiving the AMA message, the first foreign agent 42 stores the session keys for use by the first foreign agent 42 and uses the FA-HA session key among the stored session keys to generate the mobile IP generated by the home agent 46. Verify the registration response message. If the verification of the mobile IP registration response message succeeds, the mobile subscriber 41 is registered in the visitor table of the first external agent 42 and the FA-HA authenticator is deleted from the mobile IP registration response message generated by the home agent 46. Then, the newly created mobile IP registration response message including the MS-FA authenticator is transmitted to the mobile subscriber 41 (410).

The mobile subscriber 41 extracts the session keys from the mobile IP registration response message and de-encrypts them with the MS-AAA key and stores the session keys. Thereafter, the mobile subscriber 41 uses the stored session keys for generation and verification of the MS-FA authenticator and the MS-HA authenticator necessary for processing the mobile IP registration message.

On the other hand, when the foreign agent is changed in one domain due to the movement of the mobile subscriber 41, a connection for transmitting data traffic with the second external agent 43, which is a new external agent, is established (411), and the second external agent ( 43, an Agent Advertisement message including a challenge value, which is a seed for generating an authenticator, is received (412).

The mobile subscriber 41 recognizes that the mobile subscriber 41 has moved to the new foreign agent 43 area by using the address and subnet information of the second external agent 43 included in the received Agent Advertisement message, and then smoothes. Decide to require a handoff.

Once the smooth handoff is determined, the user identifier extension 303, the MS-HA authentication extension 304, the previous external agent authentication extension 305, the MS-FA challenge extension 306, and the MS-FA authenticator 307 And a mobile IP registration request message including the authentication extension 308 of the mobile subscriber to the second foreign agent 43 (413).

The second foreign agent 43 checks in the received mobile IP registration request message whether there is a previous foreign agent authentication extension 305 that includes the previous foreign agent IP address and the previous MS-FA authenticator, and if so, the second external agent. The agent 43 includes this extension in the binding update request message and sends it to the first foreign agent 42 (414).

Receiving the binding update request message, the first foreign agent 42 checks the MS-FA authenticator and if the extension is legitimate, sends a binding confirmation response message to the second foreign agent 43 (415) and the first foreign agent 42. In step 416, a temporary tunnel having a validity within 10 seconds from the second foreign agent 43 is generated (416), and when a packet corresponding to the mobile subscriber 41 that has moved arrives, it is transmitted through the tunnel.

The AMR message including the IP address of the first external agent is transmitted to the visited DIAMETER server 44 simultaneously with the binding update request message (417). The visited DIAMETER server 44 checks in the AMR message if there is an IP address of the first foreign agent 42 and if the first foreign agent 42 is an external agent in its domain zone, then the first external The MS-FA and FA-HA session keys of the corresponding mobile subscriber 41, which have been delivered to the agent 42, are found and included in the AMA message and forwarded to the second foreign agent 43 (418).

The second foreign agent 43 receives the AMA message (418) and confirms that the result code is successful and confirms that there is no mobile IP registration response field. If there is a mobile IP registration response field, it is determined that the home DIAEMTER server 45 is authenticated, and the mobile IP registration response field is used to perform the same process as the initial registration. On the other hand, if there is no mobile IP registration response field, it is determined to be a handoff in the domain, and the MS-FA and FA-HA session keys in the AMA message are extracted and the mobile IP registration request message transmitted by the mobile subscriber 41 is verified using the same. .

If the verification of the mobile IP registration request message sent by the mobile subscriber 41 succeeds, the mobile IP registration request message is sent directly to the home agent 46 by deleting the MS-AAA authenticator and the MS-FA authenticator and adding the FA-HA authenticator. Send (419).

The home agent 46 verifies the received mobile IP registration request message, updates the binding information, and transmits the mobile IP registration response message to the second external agent 43 (420).

When the second external agent 43 receives the mobile IP registration response message (420), it updates the visitor information and then transmits the mobile IP registration response message to the mobile subscriber 41 (421).

When the temporary tunnel is released after the valid time of the temporary tunnel has elapsed (422), the first foreign agent 42 releases the connection between the first foreign agent 42 and the visited DIAMETER server 44. The Session Termination Request (STR) message is transmitted to the visited DIAMETER server 44 (423), and the visited DIAMETER server 44 responds to the Session Termination Answer (STA) message (424). The handoff is completed by disconnecting the foreign agent 103.

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

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes can be made 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, in the case where a handoff in which a foreign agent is changed due to the movement of a mobile subscriber in a domain is required, registration delay while passing through DIAMETER servers by processing the handoff in the domain. Can be prevented. In particular, when a mobile subscriber uses visiting resources, the location registration delay can be greatly reduced when the distance between the external agent and the home agent is close.

In addition, the present invention can reduce the loss of data packets caused by the location registration delay by applying a smooth handoff scheme.

In addition, the present invention has an effect that can be implemented by extending a new function in each currently defined system by extending an existing message without defining a new message.

Claims (10)

In an intra-domain handoff method in a Mobile Internet Protocol (MIP) network, As the mobile agent changes the foreign agent to a second foreign agent other than the first foreign agent to which the connection is established in one domain, a temporary tunnel is created between the second foreign agent and the first foreign agent. A first step of making; A second step of the second external agent updating visitor information through a home agent of a home network and delivering it to the mobile subscriber; And A third step of releasing the temporary tunnel between the first foreign agent and the second foreign agent and terminating the connection with the local domain server by the first foreign agent; Intra-domain handoff method in a mobile IP network comprising a. The method of claim 1, The first step is, The movement of the mobile subscriber causes the external agent to switch to the second external agent other than the first external agent to which the connection is established in one domain, so that the second foreign agent can transmit data traffic with the mobile subscriber. A fourth step of establishing a connection for delivery; A fifth step of the second external agent sending an agent advertisement message including a challenge to the mobile subscriber and receiving a Mobile Internet Protocol (MIP) registration request message from the mobile subscriber; The second external agent sends an AA Mobile IP Request (AMR) message including the first external agent IP address to the local domain server and sends a mobile IP authentication response (AMA :) from the local domain server. AA Mobile IP Answer) a sixth step of receiving a message; And The second foreign agent checks a previous foreign agent authentication extension from the mobile IP registration request message and sends a binding update request message including the previous external agent authentication extension to the first external agent and binds from the first foreign agent. A seventh step of receiving a response message to create a temporary tunnel between the second foreign agent and the first foreign agent; Intra-domain handoff method in a mobile IP network comprising a. The method of claim 2, The mobile IP registration request message of the fifth step is It includes a user identifier extension, mobile subscriber (MS) -home agent (HA) authentication extension, previous external agent authentication extension, MS-FA (Foreign Agent) challenge extension, MS-FA authenticator and mobile subscriber authentication extension. An intra-domain handoff method in a mobile IP network. The method of claim 2, The sixth step, An eighth step of the second external agent sending a mobile IP authentication request (AMR) message including an IP address of the first external agent to the local domain server; The local domain server checks whether the IP address of the first external agent included in the mobile IP authentication request message received in the eighth step is its own domain area, and transmits the mobile subscriber to the first external agent. A ninth step of including a session key in an AA Mobile IP Answer (AMA) message and delivering the session key to the second external agent; And The local domain server checks whether the IP address of the first external agent included in the mobile IP authentication request message received in the eighth step is its own domain area, and if not the domain area of its own, the second external agent. Perform the initial registration for the tenth step Intra-domain handoff method in a mobile IP network comprising a. The method of claim 2, The seventh step, An eighth step of identifying a previous external agent authentication extension included in the mobile IP registration request message received in the fifth step; A ninth step of transmitting, by the second external agent, a binding update request message including a previous external agent authentication extension checked in the eighth step to the first external agent; And A tenth step in which the first foreign agent verifies the MS-FA authenticator and sends a binding confirmation response message to the second foreign agent to create a temporary tunnel between the first foreign agent and the second foreign agent; Intra-domain handoff method in a mobile IP network comprising a. The method of claim 1, The second step, A fourth step of the second external agent sending a mobile IP registration request message to a home agent of a home network to which the mobile subscriber first subscribed to a mobile IP service; A fifth step of receiving, by the second external agent, the mobile IP registration request message from the home agent after receiving the verification of the mobile IP registration request message; and A sixth step in which the second external agent updates visitor information using the received mobile IP registration response message and delivers it to the mobile subscriber; Intra-domain handoff method in a mobile IP network comprising a. The method according to any one of claims 1 to 6, The local domain server, Intra-domain handoff method in a mobile IP communication network, characterized in that the diameter server using the DIAMETER protocol. In the domain handoff method in a Mobile Internet Protocol (MIP) communication terminal, If the foreign agent changes to a second external agent other than the first external agent to which the connection was established in one domain due to the movement of the mobile subscriber, the mobile subscriber establishes a connection for delivering data traffic to the second external agent. Setting up a first step; A second step of the mobile subscriber transmitting a Mobile Internet Protocol (MIP) registration request message to the second foreign agent such that a temporary tunnel is established between the first foreign agent and the second foreign agent; And A third step in which the mobile subscriber receives a mobile IP registration response message from the second external agent smoothly handed off from the home network and establishes a connection with the second external agent; Intra-domain handoff method in a mobile IP communication terminal comprising a. The method of claim 8, The second step, Receiving, by the mobile subscriber, an agent advertisement message including a challenge from the second external agent; A fifth step of recognizing that the mobile subscriber has moved to the second external agent area by using the address and subnet information of the external agent included in the agent advertisement message received in the fourth step, and determining a smooth handoff; And A sixth step in which the mobile subscriber sends a mobile IP registration request message to the second foreign agent so that a temporary tunnel is established between the first foreign agent and the second foreign agent; Intra-domain handoff method in a mobile IP communication terminal comprising a. The method of claim 9, The mobile IP registration request message of the sixth step is It includes a user identifier extension, mobile subscriber (MS) -home agent (HA) authentication extension, previous external agent authentication extension, MS-FA (Foreign Agent) challenge extension, MS-FA authenticator and mobile subscriber authentication extension. An intra-domain handoff method in a mobile IP communication terminal.