KR20090046212A - Handover method and method for registration of a terminal in ip-based mobile communication system - Google Patents

Abstract

The present invention relates to a handover method and a terminal registration method of an IP-based mobile communication system, wherein an access point of a terminal on which an L2 layer handover is performed transmits a message of an L2 layer to a mobile agent of a handed over network as a trigger. And performing the L3 layer registration by the mobile agent of the handed over network that has received the trigger. The present invention has the effect of reducing the delay time required for handover processing during handover and registration of a network-based terminal and minimizing the mobility control function required for the terminal.

Terminal, access point, mobile agent, handover, L2, L3

Description

Handover method and method for registration of a terminal in IP-based mobile communication system

According to the present invention, IP-based mobile communication which reduces delay time due to movement and minimizes mobility control function required by the terminal by immediately performing the network-based L3 layer handover procedure immediately after the terminal MN completes the L2 layer handover. The present invention relates to a terminal handover method and a terminal registration method in a system.

The present invention is derived from the research conducted as part of the IT growth engine core technology development project of the Ministry of Information and Communication and the Ministry of Information and Telecommunication Research and Development. [Task Management No .: 2006-S-058-02, Title: ALL-IP-based Integrated Network] Service control technology development].

One of the recent major trends for terminal mobility management is the rise of network-based mobility control technology. Typical examples are PMIP (Proxy Mobile IP) developed by CISCO and NetLMM (Network-based Local Mobility Management) technology under discussion by IETF. Currently, the two technologies are converged toward using PMIPv6 as a signaling protocol for the NetLMM architecture. The main advantage of the network-based mobility control technology is that by adding the functions necessary to maintain a constant IP connection to the network while the terminal (MN) is moving, it is possible to minimize the addition and change of functions required for the terminal. In addition, in the terminal-based mobility control technology such as the conventional MIP, the MN recognizes the need for L3 handover on its own and greatly reduces the delay time required to discover a new FA and start the MIP registration procedure. to provide.

1 shows a NetLMM network structure necessary for managing mobility on a network basis. In this structure, the NetLMM domain (N _D ) is defined as the area where the local mobility of the terminal (MN) is managed based on the network, and serves as the HA of MIP where the NetLMM domain and the Internet network (N _I ) are connected. The LMA 101 is located. Under the LMA, a plurality of Mobility Access Gateways (102, 103) are connected to the MN (108) for the registration process when performing initial access and handover. The MAG serves as an access router of the terminal MN, and the terminal MN establishes a wireless connection through access points APs 104 to 107 connected to each MAG. The AP corresponds to an AP of a WLAN and a RAS of a WiBro.

The mobility management procedure of NetLMM is initiated by the access point (AP) notifying the corresponding MAG of an event occurring during the initial connection or L2 handover of the terminal (MN). The MAG notified of this stores the binding information for the fixed IP address HoA of the terminal MN and its own IP address, and then performs the procedure of registering the same binding information in the LMA. After receiving the registration request from the MAG, the LMA stores the binding information of the terminal MN, and then establishes an IP tunnel 109 between the MAG to which the terminal MN is connected. This IP tunnel is used to deliver a packet destined for the terminal (MN) in the future. When the terminal MN performs initial access, the procedure of receiving an HoA of the terminal MN is preceded by the registration procedure.

As described above, one of the key requirements of network-based mobility control technology is that the L3 mobility management elements in the network (e.g., NetLMM's MAG and PMIP's FA), in addition to the L2 functions provided by each access point (AP), It must have the ability to interact with the L3 layer. That is, in the NetLMM structure, in order for the MAG to perform the L3 registration procedure of the terminal MN, a trigger for recognizing the initial connection and the L2 handover situation of the terminal MN is required. It must be provided by an access point (AP) that maintains the connection. Currently, IEEE 802.21 MIH (Media Independent Handover) is considered as a technique for providing this trigger function.

On the other hand, PMIP uses the ARP (Address Resolution Protocol) request message transmitted by the terminal (MN) after handover to the area of the new FA as a trigger providing method for the L3 registration procedure of the FA, and the terminal (MN) after the handover. It is proposed to use the first data packet it transmits, or to use an explicit control message transmitted from the access point (AP) to the FA.

Another major requirement of the network-based mobility control technology is that MAG, FA, etc. are subject to MN static IP address (HoA) and registration request in order to handle the L3 registration procedure of a newly entered terminal (MN) in the network. This is to know the IP address of LMA, HA, etc. To this end, in NetLMM, a MAG in the same domain obtains the IP address of the LMA by using a protocol defined by itself, and explicitly informs the HoA of the terminal MN at the interface between the terminal MN and the MAG (MAG_GET_terminal (MN). ) _ID Function) is defined. In the case of PMIP, the FA knows the HoA of the terminal MN through the ARP request message or the sender address of the data packet provided by the terminal MN as a trigger of the L3 registration procedure. The PMIP does not specify how the FA finds the IP address of the HA of the terminal, and the solution in the PMIP implementation provided by CISCO is that each AP is the IP address of all HAs and the area managed by the HA (Subnet Mask). Maintain a table (Subnet Map) that manages information.

As such, the existing network-based mobility control technology requires an additional function such as an L3 layer or a MIH on an access point (AP) in order to be provided with a trigger of a procedure for the L3 registration procedure of a terminal (MN). In case of PMIP, the ARP request message of the terminal (MN) can be used as a trigger. Cause delay. When the first data packet received by the FA is used as a trigger, the handover of the terminal MN which receives the current packet but does not transmit it cannot be processed quickly. Another disadvantage is that NetLMM cannot control the mobility of terminals (MNs) between different domains, and it is possible to support inter-domain mobility by using PMIP. However, in this case, the IP of the HA registered by the terminal (MN) to the FA for the first time. To provide an address, additional L3 functionality is required for each access point.

Accordingly, an object of the present invention is to provide a handover in an IP-based mobile communication system that provides global mobility without requiring additional L3 functionality to a terminal (MN) and an access point (AP) of each access network. It provides a method and a terminal registration method.

In the IP-based mobile communication system according to an embodiment of the present invention to solve the above-mentioned problems, the handover method, a terminal, a first mobile agent for managing the first network to which the terminal currently belongs (HA to MIP In the IP-based mobile communication system including a second mobile agent (corresponding to FA of MIP) that manages a second network to which the terminal will move, the access point of the terminal on which the L2 layer handover is performed to the second network Transmitting a message of an L2 layer to the second mobile agent as a trigger; transmitting, by the first mobile agent, binding information of a terminal belonging to a first network to the second mobile agent; an L2 layer to a second network Sending, by the access point of the terminal MN on which the handover has been performed, to the second mobile agent as a trigger a message of an L2 layer, and the trigger According to the transmission receiving the second mobile agent is the binding information transmitted and a step of acting an L3 layer registered with said first mobile agent.

An initial registration method of a terminal (MN) of an IP-based mobile communication system according to an embodiment of the present invention comprises the steps of transmitting an L2 layer message as a trigger to a mobile agent managing a corresponding network by an access point having an L2 layer connection with the terminal. If the information on the L2 layer of the terminal capable of entering the network managed by the mobile agent does not match the information on the L2 layer included in the message transmitted as the trigger, the mobile agent is connected to the terminal connected to the access point. Transmitting an agent advertisement message; transmitting, by the terminal, an L2 address list to the mobile agent transmitting the agent advertisement message; and assigning an IP address from the mobile agent to the terminal, and assigning an assigned IP address. , IP address of the mobile agent and L2 of the terminal And a step in which the list is stored as a predetermined binding information of the terminal.

An initial registration method of a terminal (MN) of an IP-based mobile communication system according to an embodiment of the present invention comprises the steps of transmitting an L2 layer message as a trigger to a mobile agent managing a corresponding network by an access point having an L2 layer connection with the terminal. If the information on the L2 layer of the terminal that can enter the network managed by the mobile agent does not match the information on the L2 layer included in the message transmitted as the trigger, the terminal connected to the access point by the mobile agent Requesting the L2 address of the terminal to be transmitted to an authentication server capable of authenticating the message, and binding information of the terminal including the L2 address transmitted from the authentication server and the IP address of the mobile agent is stored in the mobile terminal. And storing the agent.

The present invention is a terminal mobility control technology based on MIP, and provides a network-based L3 handover function to reduce the delay time due to movement and to minimize the mobility control function required for the terminal. A key feature of the present invention, which is distinguished from conventional PMIP (Network Mobile Localized Mobility Management), network based mobility support technologies such as NetLMM, is a MIP MA (Mobile) from the access point (AP) to initiate the L3 registration procedure. Agent uses the L2 layer management (OAM) message as a trigger to be sent to initiate the L3 registration procedure. That is, when the terminal MN establishes an L2 connection with the new access point AP, the access point AP newly transmits an L2 OAM message to the mobile agent MA using the L2 address of the terminal MN. It informs the L2 address of the terminal MN. Each mobile agent (MA) retrieves the terminal (MN) binding information shared between neighboring mobile agents (MA) by using the received L2 address as a key, and uses the terminal (MN) HoA and HA address information obtained through the search. (MN) will act for L3 registration process.

One of the key benefits of this feature is the need for additional L3 functionality required by access points (APs) to take advantage of L3 layer triggers in traditional network-based mobility control technologies (e.g. PMIP and NetLMM). It is said that it does not. This means that in all access networks that support L2 layer management (OAM) protocols (e.g., IEEE 802.3ah or 802.1ag) between the access point (AP) and the mobile agent (MA), the access point (AP) This means that only the ability to forward OAM messages using L2 addresses is required. Many network equipment manufacturers are already producing equipment with a standard OAM protocol stack for L2 layer connectivity management and error detection, so the new L3 layer triggers access points (APs) and mobile agents (MAs). It is expected to be more advantageous than mounting it on.

Another major effect in this regard is that the access point (AP) can send a trigger for initiating the L3 registration procedure immediately after the establishment of the L2 connection with the terminal (MN) is completed, thereby reducing the overall latency for handover processing. Is that. That is, in the existing technology, the access point (AP) performs an explicit control message exchange in order to know the IP (L3) address of the terminal (MN), or performs an ARP (Address Resolution Protocol) request or data packet of the terminal (MN). The disadvantage of delaying the trigger transmission for initiating the L3 registration procedure until the IP address is obtained can be overcome.

In addition, in order to support global mobility through the network-based L3 registration procedure in the existing technology, the process of finding the IP address of the first registered HA after the terminal MN is obtained. This is necessary. Since NetLMM only considers local mobility within a single NetLMM domain, it does not address this issue, and the PMIP patent does not mention the process of obtaining the HA address of a terminal (MN). In the present invention, the mobile agent MA of the network to which the terminal MN is connected periodically transmits binding information of the L2 address, HoA, and HA address of the terminal MN to neighboring mobile agents MA adjacent thereto. Effectively supports the HA address acquisition procedure of the terminal (MN).

Hereinafter, with reference to the drawings will be described the present invention in more detail.

2 shows an example of a MIP network structure to which the present invention can be applied. Also be in accordance with the MIP application structure IETF MIP standard of the second mobile terminal (MN; 221) the initial access a home network (Home Network, N _H) mobile agent in (MA; 201) that after the charge of HA role terminal ( The mobile agents (MA) 202 and 203 of the foreign networks (N _F1 and N _F2 ) to which the MN travels play a role of FA. In this case, the mobile agents (MAs) in each network should be able to simultaneously perform the roles of HA and FA, but embodiments of the present invention described later are for convenience of description and the HA 201 and the FA 202 and 203. Assume a logical structure that separates them.

In FIG. 2, each home and external network connected through the core network N _C does not have to exactly match the range of the access network, and each access point AP 211 to 216 has a wireless connection to the terminal MN. Serves as a connection point. Unlike the structure of FIG. 2, as a MIP application method that operators generally adopt for the efficiency of network management, a structure in which HA is located in a core network and a FA is located in each access network may be considered. Note that the control procedure can be applied as is.

3 is a flowchart schematically illustrating a network-based mobility control procedure proposed by the present invention, and shows messages and internal processing functions transmitted and received by each functional element related to mobility control. In the example of the procedure illustrated in FIG. 3, the terminal MN performs initial L2 connection and L3 registration in the home network N _H to move in the order of the external network 1 (N _F1 ) and the external network 2 (N _F2 ). Shows. In this example, it is assumed that home network and external network 1, external network 1 and 2 are adjacent to each other.

The procedure of FIG. 3 begins with the step 301 of the terminal MN connecting to the home network N _H establishing an L2 connection with the access point AP0. This step utilizes the technology of the L2 layer provided by each access network and is not included in the scope of the present invention. After the L2 connection is completed, the terminal MN performs an initial L3 registration procedure step 302 for the HA in the home network. Within this step, the existing MIP initial registration procedure such as HoA allocation of the terminal MN, obtaining an HA address through the HA advertisement, and exchanging a Registration Request / Response message between the terminal MN and the HA is accepted. As an element, a detailed procedure of delivering the L2 address of the terminal MN to the HA is added. Through this, the HA configures the terminal (MN) binding information including the L2 address of the terminal (MN), the HoA, and the IP address of the HA itself, and records them in the terminal (MN) binding table (303). The HA periodically informs neighboring mobile agents MAs (corresponding to FA1 in FIG. 3) of the information in this binding table (304), and FA1 informs the terminal (MN) entry prediction table of the received terminal (MN) binding information. (305).

The first handover in FIG. 3 proceeds from home network N _H to external network 1 N _F1 . To this end, the terminal MN performs L2 handover by establishing an L2 connection to a new access point AP1 (306). When the establishment of the L2 connection is completed, the access point AP1 initiates a network-based L3 registration procedure for the terminal MN by transmitting a trigger using the management (OAM) message of the L2 layer to the FA1 (307). One of the most important features of the present invention is that the access point (AP) transmits the L2 management message by setting the L2 address of the newly connected terminal (MN) as a transmission address instead of its own L2 address, which is used as a trigger of the L3 registration procedure. FA is able to know the L2 address of the terminal (MN). This provides an advantage of performing a trigger function of transmitting a unique identifier (L2 address) of the terminal MN to the FA without requiring each access point AP to perform the function of the L3 layer.

Upon receiving the trigger for the L3 registration procedure, the FA1 searches the terminal MN entry prediction table that it maintains to obtain HoA and HA address information mapped to the L2 address of the terminal MN (308). The FA1 then transfers the registration request message to the HA instead of the terminal MN using the information thus obtained (309) and receives a registration reply message in response (310) to handle the L3 registration procedure of the terminal MN. do. When the registration for the HA is completed, FA1 additionally records CoA information of the terminal MN in the MN binding table managed by the agent (311), and sets the same CoA information to be set as the default router of the terminal (MN). Notify the terminal (MN) (312).

The final stage of performing the handover is to prepare the mobile station (MN) for the continuous movement of the FA1 to the mobile agent (MA; HA and FA2 in FIG. 3) adjacent to it, the L2 address of the terminal (MN), HoA and HA. Terminal (MN) binding information consisting of the address is to be transmitted (313). Accordingly, each mobile agent (MA; HA and FA2) records the terminal (MN) binding information received in its own terminal (MN) entry prediction table (314). The transmission of the MN binding information for the neighboring mobile agent MA is periodically repeated until the terminal MN leaves the area of FA1, and thus, in the terminal MN entry management table managed by each mobile agent MA. Used for the purpose of refreshing information.

The second handover in FIG. 3 proceeds from external network 1 (N _F1 ) to external network 2 (N _F2 ). As with the first handover procedure, the terminal MN begins with step 315 of performing L2 handover by establishing an L2 connection to a new access point AP2. Accordingly, the access point AP2 transmits a trigger to the FA2 using a management (OAM) message of the L2 layer to initiate a network-based L3 registration procedure for the terminal MN (316). Since this trigger message is also transmitted by the access point AP2 using the L2 address of the terminal MN as the transmission address, the FA2 receiving this can know the L2 address of the terminal MN to perform the L3 registration procedure. . Subsequently, the FA2 obtains HoA and HA address information mapped to the L2 address of the terminal MN through the terminal MN entry prediction table search (317). Using this information, the FA2 substitutes the L3 registration procedure of the terminal MN by exchanging a Registration Request 318 and Registration Reply 319 message with the HA. After registration for HA, FA2 records the CoA information of the terminal MN in the terminal MN binding table (320) and delivers the same CoA information to the terminal MN so that it can be set as the default router of the terminal MN. 321. Finally, the FA2 prepares for the continuous movement of the terminal MN by transmitting binding information consisting of the L2 address, the HoA, and the HA address of the terminal MN to the mobile agent MA (FA1 in FIG. 3) adjacent to the terminal (322). ).

Referring to FIG. 4, an OAM protocol that can be used as a trigger will be described in detail.

A representative L2 layer OAM protocol that can be used as a trigger delivered from an access point (AP) to a mobile agent (MA) is IEEE 802.3ah, which provides link state monitoring and error control signaling functions in Ethernet. The 802.3ah structure defines the structure for exchanging OAMDU (OAM Protocol Data Unit) between each node through the Operation, Administration & Maintenance (OAM) layer located directly above the Medium Access Control (MAC) layer. A rule is proposed to exchange periodic advertisement messages between the Ethernet nodes for OAM session maintenance and link information collection. In the present invention, as shown in step 41 of FIG. 4, the mobile agent (MA; 802.3ah OAM Advertisement) uses the L2 address of the terminal (MN) 421 to establish a new wireless L2 connection. By transmitting to 401, the AP provides a function of initiating a network-based mobility control procedure of the terminal MN without the need for additional functions of the MIH or L3 layer. This approach can be applied to any access network structure where the access point (AP) and mobile agent (MA) use IEEE 802.3 based Ethernet. That is, it provides an advantage that can be used regardless of the access technology for the wireless connection from the access point (AP) to the terminal (MN).

If the access point (AP) and the mobile agent (MA) are not connected to a single Ethernet link but are a network connected by an L2 switch (802.1D) or a VLAN switch (802.1Q), the OAM of 802.3ah Advertisement message cannot be directly connected from the access point (AP) to the mobile agent (MA). An alternative that can be used in this case is the IEEE 802.1ag Customer OAM protocol. The 802.1ag protocol provides a function of establishing a MAC OAM session on a multilink path connected by a bridge and a switch according to the 802.1 standard and delivering an OAM message defined by a network operator or operator between nodes. As illustrated in step 42 of FIG. 4, a switch 403 or the like exists between the mobile agent MA 402 and the access point AP 413 to the multi-linked network N _F2 . When it moves, the AP 413 may initiate a network-based mobility control procedure by sending an 802.1ag OAM message to the mobile agent MA using the L2 address of the terminal MN. Therefore, the trigger method using the OAM message of the L2 layer proposed in the present invention connects the L2 / VLAN switch as well as a single access network connecting the AP and the mobile agent (MA; HA / FA) based on Ethernet. It can be applied to extended access network structure.

FIG. 5 shows a detailed procedure for registering L3 of a terminal MN initially connected to a home network N _H in the present invention. In the first step, the terminal MN requests to establish an L2 connection to an accessible access point AP (501), thereby performing access authentication for determining whether to allow network access (502), and then for the L2 connection request. The procedure 503 of sending a response message to the terminal MN depends on the manner provided by each access technology. Since the trigger function of an access point (AP) that performs a network-based L3 registration procedure cannot distinguish between an initial access state and a handover situation of a terminal (MN), the L3 registration procedure is always performed for a terminal (MN) in which a new L2 connection is established. Send a trigger to initiate 504. The mobile agent MA (HA in FIG. 5), which has received this trigger, can identify the initial access situation and the handover situation of the terminal MN by searching the terminal MN entry prediction table (505). . In the case of FIG. 5, since binding information (HoA, HA address) of the terminal MN is not found, the mobile agent MA recognizes an initial connection state of the terminal MN and ignores the received trigger. The agent MA recognizes that its role for the terminal MN should be HA.

Subsequent procedure steps 506-510 are identical to the initial registration procedure defined in the MIP standard. The terminal MN receives the Agent Advertisement message broadcasted by the HA periodically so that the terminal MN can know the address of the HA to perform registration (507). In some cases, the terminal MN can quickly induce the Agent Advertisement message of the HA. The MN) may first broadcast an Agent Solicitation message (506). Thereafter, the terminal MN transmits a Registration Request message to the HA in order to perform initial registration for the HA (508). Since the HA recognizes the initial registration situation through the terminal MN entry prediction table search 505 described above, it performs the HoA allocation procedure for the terminal MN (509) and registers in response to the registration request. In operation 510, the message is transmitted to the terminal MN. In the last step, the terminal MN transfers a list of L2 addresses set to all its network interfaces to the HA (511). Accordingly, the HA records the L2 address list received in the binding information of the terminal MN (512), and sends a response message to the L2 address registration request to the terminal MN (513). Thereafter, the HA performs the terminal MN binding information transfer step 304 for the neighboring mobile agent MA as shown in FIG. 3 to prepare for the movement of the terminal MN to the neighboring network.

The initial registration procedure of the terminal MN may be performed based on a network as shown in FIG. 6. However, in this case, in order to perform the network-based step of obtaining the L2 address list of the terminal (MN) without the participation of the terminal, an interworking function of the server managing the profile information of the terminal, such as AAA (Authorization, Authentication, Account) server, and the HA is required. Do. The L2 connection establishment (601 to 603), the L3 registration start request (604), and the terminal (MN) entry anticipation table search step 605 in FIG. 6 are the same as those in FIG. In this case, the mobile agent MA recognizes an initial registration state of the terminal MN and performs a role of HA by performing a step of searching the terminal MN entry prediction table. Therefore, the HA substitutes for the HoA allocation procedure for the terminal (MN) (606). The HA then requests the AAA server the list of L2 addresses set for all network interfaces of the terminal (MN) (607) and receives the response (608) in the terminal (MN) binding information HoA, HA address (own address) And L2 address information (609). In the last step, if the HA also serves as a gateway router, the Agent Advertisement message is transmitted to the terminal MN to transmit information for setting the current gateway router of the terminal MN (610).

FIG. 7 illustrates a detailed procedure for handling handover based on a network when a terminal MN moves between two adjacent mobile agents MA (from HA to FA1 in the example of FIG. 7). First, in order to prepare for the movement of the terminal MN, while the terminal MN stays in the home network after completing initial registration with the HA, the HA periodically receives binding information of the terminal MN from the adjacent mobile agent MA. ; FA1) (701), and FA1 receives this information is recorded in the terminal (MN) entry prediction table managed by itself (702). The actual handover procedure between the two mobile agents (MA) is that the terminal MN detects an impending L2 connection disconnection with the existing access point AP0 (703) and establishes an L2 connection to the new access point AP1. Is started by steps 704-706.

When the establishment of a new L2 connection between the terminal MN and the access point AP1 is completed, the access point AP1 transmits a trigger message for initiating a network-based L3 registration procedure for the terminal MN to the FA1 ( 707). The FA1 retrieves the L2 address of the terminal MN obtained through the trigger message in its terminal MN entry prediction table to obtain HoA and HA address information of the terminal MN (708). Using this information, the FA1 transmits a Registration Request message to the HA (709), and receives a Registration Reply message in response (710) to perform the L3 registration procedure of the terminal MN. After completion of the L3 registration procedure, FA1 records its address in the MN binding table as CoA information of the terminal (MN) (711) and sends an Agent Advertisement message to inform the default gateway setting information of the terminal (MN). Transmit (712). In the last step, FA1 transmits the terminal MN binding information (ie, L2 address, HoA and HA address) to the mobile agent MA (HA in FIG. 7) adjacent to the terminal to prepare for further movement of the terminal MN. (713).

The network-based handover processing procedure shown in FIG. 7 can be equally applied to handover situations between different FAs as well as between HA and FA handover situations. That is, from step 703 of requesting establishment of an L2 connection to a new access point (AP), the neighboring mobile agents (MAs) are sent to neighboring mobile agents (MAs) in order to prepare for further movement of the terminal (MN) after completion of the network-based L3 registration procedure. MN) By repeating a series of steps of transmitting the binding information (713), it provides a function to maintain the IP connectivity by supporting the continuous mobility of the terminal (MN).

8 is a flowchart illustrating an example of handover of a terminal in an IP-based mobile communication system of the present invention.

As shown, when the terminal moves from the first network to the second network (S1), it is checked whether the terminal has completely left the first network and entered the second network (S2). In general, whether to leave the network is determined according to the measurement value of the Measurement Control signal transmitted from the network. In other words, the terminal compares the detection control signal with a measurement standard to determine whether the first network is out of position and whether the second network is in.

The terminal determining that the entry into the second network is made is connected to the access point of the second network L2 (S3). The access point transmits an L2 OAM signal having the L2 layer address of the L2 layer connected terminal as a source address to the second network management mobile agent (S4). After receiving the L2 OAM signal, the second network management mobile agent searches whether binding information having an L2 layer address matching the L2 layer address is stored in a binding information table (S5), and then, according to the matching binding information, L3 registration procedure for the network management mobile agent (S6). That is, the L3 registration procedure occurs between network management elements, not terminals. Therefore, the handover delay that occurs when the terminal performs L3 registration is eliminated, and resource saving of the terminal is possible.

In addition, the second network management mobile agent that has completed the L3 registration procedure transmits the binding information to the mobile agent managing the neighbor network (S7), so that L3 registration between the continuous network management elements is possible.

Meanwhile, the method of registering a terminal in a network in an IP-based mobile communication system may be performed by the following process. First, a terminal is connected to an access point of an arbitrary network in an L2 layer, and the access point transmits an L2 OAM message whose destination address is the L2 address of the L2 layer connected terminal to a corresponding network management mobile agent.

When the L2 OAM message is sent, the mobile agent must determine whether the terminal requires initial registration or handover. Therefore, it is searched whether the L2 layer address of the transmitted terminal is included in the binding information of the expected terminal.

If it is included, it is determined that the handover is performed instead of the initial registration of the terminal, and the handover procedure is performed according to the flowchart shown in FIG. 8. However, if not included, the mobile agent must perform L3 registration of the terminal as a home agent. 5 or 6 may be used as a method for the mobile agent to perform L3 registration of the terminal as a home agent. However, other methods of registering as a home agent will also belong to the scope of the present invention.

After completing the L3 registration procedure, the mobile agent transmits the binding information of the terminal to the mobile agent managing the neighbor network to enable handover of the terminal.

In the IP-based mobile communication system described above, the terminal handover method and the terminal registration method are not limited to the configuration and method of the above-described embodiments, and the embodiments may be modified in various ways.

1 is a network structure for applying NetLMM,

2 is a mobile IP network structure to which the present invention can be applied;

3 is an overall flowchart of a network-based mobility procedure proposed in the present invention,

4 is a network structure according to the type of L2 management (OAM) protocol,

5 and 6 are a flow chart of a detailed procedure of the first L3 registration method of the terminal,

7 is a flowchart of a detailed procedure of a network-based handover method of a terminal, and

8 is a flowchart illustrating the flow of handover in an IP-based mobile communication system according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

N _I : Internet Network N _D : NetLMM Domain

101: LMA (Localized Mobility Anchor)

102, 103: Mobility Access Gateway (MAG)

104 to 107: accessor access point 108: mobile node

109: IP Tunnel

N _C : Core Network

N _H : Home Network

N _F1 , N _F2 : Foreign Network

403: Ethernet Switch

Claims (13)

A handover method in an IP-based mobile communication system comprising a terminal, a first mobile agent managing a first network to which the terminal currently belongs, and a second mobile agent managing a second network to which the terminal will move. Transmitting, by the first mobile agent, address binding information of a terminal belonging to the first network to the second mobile agent; Transmitting, by the access point of the terminal on which the L2 layer handover is performed to the second network, as a trigger to the second mobile agent; And And a second mobile agent receiving the trigger to perform L3 layer registration with the first mobile agent according to the transmitted address binding information. The method of claim 1, In the trigger transmission step, The access point is a handover method in the IP-based mobile communication system, characterized in that for transmitting the L2 OAM message with the L2 layer address of the terminal as the source address to the second mobile agent. The method of claim 2, In the L3 layer registration step, The second mobile agent performs handover in the IP-based mobile communication system according to the L3 layer registration procedure according to the binding information matching the L2 layer address included in the trigger among the binding information transmitted by the first mobile agent. Way. The method of claim 3, wherein The L3 layer registration step, Searching, by the second mobile agent, an IP address of the handed over terminal and an IP address of the first mobile agent among the matching binding information; Requesting an L3 layer registration procedure using an IP address of the searched terminal and an IP address of a first mobile agent; And And the first mobile agent approves the L3 registration with the second mobile agent. The method of claim 1, After the L3 layer registration is completed, the second mobile agent recording CoA information of the handed over terminal in a binding information table of terminals belonging to a second network; And The second mobile agent further comprises the step of transmitting the recorded CoA information to the handed over terminal device handover method in an IP-based mobile communication system. The method of claim 1, The binding information transmitting step, Periodically transmitting, by the first mobile agent, the binding information to the second mobile agent; And the second mobile agent periodically updates binding information of a terminal belonging to an adjacent network. The method of claim 1, After the L3 layer registration is completed, the second mobile agent further comprises the step of transmitting the binding information of the terminal to the mobile agent of the neighbor network further handover method in an IP-based mobile communication system. The method of claim 1, The binding information includes an L2 layer address of a terminal, an IP address assigned to the terminal, and information about an IP address of a mobile agent managing a network to which the terminal belongs. Transmitting, by the access point having the L2 layer connection with the terminal, a L2 layer message as a trigger to the mobile agent managing the network; If the information about the L2 layer of the terminal that can enter the network managed by the mobile agent does not match the information about the L2 layer included in the message transmitted as the trigger, the mobile agent is an agent to the terminal connected to the access point Sending an advertising message; Transmitting, by the terminal, an L2 address list to a mobile agent that transmits the agent advertisement message; And Assigning an IP address from the mobile agent to the terminal, and storing the allocated IP address, the IP address of the mobile agent, and the L2 address of the terminal as binding information of the terminal. Terminal registration method of communication system. The method of claim 9, The mobile agent further comprises the step of periodically transmitting the binding information of the terminal to the mobile agent for managing the neighbor network. Transmitting, by the access point having the L2 layer connection with the terminal, a L2 layer message as a trigger to the mobile agent managing the network; If the information about the L2 layer of the terminal that can enter the network managed by the mobile agent and the information about the L2 layer included in the message transmitted as the trigger do not match, the mobile agent authenticates the terminal connected to the access point. Requesting transmission of an L2 address of the terminal to an authentication server capable of doing so; And And binding information of the terminal including the L2 address transmitted from the authentication server and the IP address of the mobile agent is stored in the mobile agent. The method of claim 11, The mobile agent further assigning an IP address of the terminal; The binding information terminal registration method of the IP-based mobile communication system, characterized in that further comprises an IP address of the terminal. The method of claim 11, The mobile agent further comprises the step of periodically transmitting the binding information of the terminal to the mobile agent for managing the neighbor network.

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