KR100814101B1 - Fast handover method in network based localized mobility management protocol and apparatus for the same - Google Patents

Abstract

A fast handover method in a NetLMM(Network based Localized Mobility Management) protocol and an apparatus therefor are provided to reduce handover delay and packet loss significantly and support the handover of a mobile terminal in a network independent of lower media. A local anchor router(100) receives a handover initialization request message(S11). The local anchor router transmits a handover preparation request message to a new connection router(102)(S12). The local anchor router transmits a response message for the handover initialization request message to a mobile terminal(110)(S13). The local anchor router receives a handover alarm message(S15). The local anchor router receives a handover completion alarm message through the new connection router from the mobile terminal(S18). The local anchor router receives a terminal location registration request message from the new connection router(S19). The local anchor router receives a resource release request message for the mobile terminal to an old connection router(101)(S20).

Description

Fast Handover Method in Network based Localized Mobility Management Protocol and Apparatus for the same}

1 is a conceptual diagram illustrating a network structure that serves as an operating environment of a network-based regional mobility management protocol;

2 is a chart illustrating a handover procedure of a terminal in a high-speed network-based regional mobility management protocol according to the present invention;

3 is a block diagram illustrating a structure of a local anchor router capable of performing handover control message processing and buffering according to the present invention;

4 is a flowchart of a buffering operation performed in a local anchor router according to the present invention.

<Description of the reference numerals for the main parts of the drawings>

100: local anchor router

101: access router before the terminal performs handover

102: access router after the terminal performs handover

103: An access router existing in the network-based local mobility management domain

104: domain

110: mobile terminal

200: handover control message processing module

201: packet filter module

202: buffer management module

203: routing processing module

The present invention relates to a fast handover method and apparatus in a network based Localized Mobility Management (NetLMM) protocol, and more particularly, a terminal using a network based local mobility management protocol performs a handover. The present invention relates to a method for reducing delay and packet loss occurring in the process and an apparatus used therefor. The present invention includes a buffering method for fast handover performance and packet loss by using a message defined in a link signal and a media independent handover (MIH) service.

In general, when the terminal connected to the wireless service network moves from the area of the first connection point of the service network to the area of the second connection point, handover processing is desired.

Background Art Conventionally, an Internet mobility management protocol based on Mobile IP (MIP), which is underway in the Internet Engineering Task Force (IETF), is known. According to this technique, it is determined that the mobile terminal has moved the prefix included in the router advertisement by using the Router Advertisement message to compare with the prefix of the terminal, thereby generating an address to be used in the new subnet and performing duplicate checking. Perform. In addition, a function of periodically transmitting a location update (Binding Update) message is performed to notify the home agent and the related node of the location movement.

Therefore, not only a handover delay occurs, but a large overhead of a handover control message. Moreover, there is a problem in that mobility is provided only when the mobile terminal supports the mobile IP protocol.

On the other hand, in view of the above problems with the technology using a mobile IP, IETF network-based regional mobility management that allows the network to control the mobility of the terminal without changing the terminal's IP address in the service provider's domain without modification of the terminal ( NetLMM) protocol is under development.

According to the handover technology of the terminal in the network-based regional mobility management protocol currently under development, after the terminal completes the handover, it is determined that the terminal accesses the network in the new router 102 through a router discovery process. In addition, the mobility of the terminal is supported by transmitting a message for registering the location of the terminal to the local anchor router 100.

However, according to the above method, there is a high risk of packet loss during handover, and there is a problem in that communication is temporarily disconnected even after performing handover, and thus it is not possible to support handover or reliable application layer communication of a mobile terminal moving at high speed. Inappropriate

Therefore, there is an urgent need for a fast handover method and a method for reducing packet loss for a network-based regional mobility management protocol.

The present invention has been made to solve the above problems of the prior art, and to provide a method and apparatus that can be handovered at high speed under a network-based Local Mobility Management (NetLMM) protocol. In particular, it is an object of the present invention to provide an apparatus and method for drastically reducing handover delay and packet loss in a network-based regional mobility management protocol.

In addition, the network can support the handover of the terminal independently of the lower media, and to provide an apparatus and method that can ensure reliable communication through buffering.

In order to achieve the above technical problem, in the method and apparatus for fast handover in the network-based regional mobility management protocol of the present invention, a message defined by the Institute of Electrical and Electronics Engineers (IEEE) 802.21 Media Independent Handover (MIH) service is used. It includes a fast handover procedure using link signal attenuation information and a buffering method to reduce packet loss.

By detecting the attenuation of the lower link signal and setting the address of the terminal to the new router 102 to move in advance before the handover is performed, a high-speed network-based regional mobility capable of supporting seamless communication even after the terminal performs the handover. Along with the design of the management protocol, it is to provide a technology that guarantees reliable communication by reducing packet loss by buffering packets of terminals generated during handover.

The fast handover method in the network-based regional mobility management protocol of the present invention is a method for performing a handover between the access routers for a mobile terminal connected to a plurality of access routers belonging to a local anchor router. Receiving, by the local anchor router, a handover initialization request message from a mobile terminal that senses attenuation of a lower link signal through a previous access router that is already connected among the access routers, and (2) the local anchor router; Sending a handover preparation request message to a new access router to which a future access will be made among the access routers, and receiving a response message; and (3) the local anchor router sends the hand to the mobile terminal through the previous access router. Response message to the Over-Initiation Request message. (4) receiving the handover performance notification message from the mobile terminal through the previous access router from the mobile terminal, and (5) the link of the mobile terminal is disconnected and is connected to the new access router. Link layer handover is performed, and after the link of the mobile terminal is connected, the local anchor router receives a handover completion notification message from the mobile terminal through the new access router; and (6) the new access router. Receiving, from the local anchor router a terminal location registration request message, and sending a response message thereof; (7) the local anchor router sends a resource release request message of the mobile terminal to the legacy access router; Characterized in that the step consists of receiving.

In this case, after receiving the handover performance notification message, the local anchor router performs buffering to sequentially store packets destined for the mobile terminal, and after receiving the handover completion notification message, the local anchor. Preferably, the router further includes the step of sending all the buffered packets to the new access router sequentially and ending the buffering.

The buffering may include registering an IP address of the mobile terminal in a packet filter module for filtering IP packets at the local anchor router and examining a destination address of the packet by the packet filter module. And, when the packet is a general data packet, when the destination address is a mobile terminal that is not performing handover, routing processing is performed to the mobile terminal, and when the destination address is a mobile terminal which is performing handover. Preferably, the buffering process is performed.

The terminating of the buffering may be performed by removing the IP address of the mobile terminal registered in the packet filter module for filtering IP packets in the local anchor router.

On the other hand, in the network-based regional mobility management protocol of the present invention, the fast handover apparatus, in the apparatus for performing a handover between the access router for the mobile terminal connected to a plurality of access routers belonging to the local anchor router, It is provided in the local anchor router, receives the IP packet, investigates the type of the packet, and sends the packet to the handover control message processing module in the case of the handover control message packet, and sends it to the routing processing module in the case of the general data packet. A packet processing module for sending, a routing processing module for routing general data packets to the mobile terminal corresponding to a destination address of a packet, and the handover control provided in the local anchor router and received from the packet filter module. Handover control to analyze and process message packets The handover control message processing module comprises: (1) a handover initialization request from a mobile terminal that detects attenuation of a lower link signal through a previous access router that is already connected among the access routers; Upon receiving the message, a handover preparation request message is sent to a new access router to be connected in future, and (2) upon receiving a response message of the handover preparation request message, sends a handover preparation request message to the mobile terminal through the previous access router. Send a response message to the handover initialization request message, (3) after receiving a handover performance notification message from the mobile terminal through the previous access router, the link of the mobile terminal is disconnected, and with the new access router Link layer handover is made and the mobile end After the horse link is connected, when the mobile terminal receives a handover completion notification message from the mobile station through the new access router, and receives a terminal location registration request message from the new access router, the response message is sent; And transmitting a resource release request message of the mobile terminal to the access router and receiving the response message.

In this case, when the handover control message processing module receives the handover execution notification message, the handover control message processing module performs buffering to sequentially receive a packet destined for the mobile terminal performing the handover from the packet filter module and temporarily store the received packet. When the control message processing module receives the handover completion notification message, and further comprises a buffer management module for sending all the buffered packets to the new access router sequentially and terminate the buffering, the packet filter module, the received In the case where the IP packet is a general data packet, it is preferable that the destination address is examined and controlled to be sent to the buffer management module instead of to the routing processing module for the packet destined for the mobile terminal performing the handover. .

And, in order to perform the buffering, it is preferable that the IP address of the mobile terminal is registered in the packet filter module.

In addition, in order to terminate the buffering, preferably configured to remove the IP address of the mobile terminal registered in the packet filter module.

<Example>

EMBODIMENT OF THE INVENTION Hereinafter, this invention of the said structure is demonstrated in detail, referring an accompanying drawing. However, with respect to the elements having the same configuration and in charge of the same function, detailed description is omitted by keeping the same reference numerals even if the drawings are different.

1 is a conceptual diagram illustrating a network structure that becomes an operating environment of a network-based regional mobility management protocol, and illustrates an environment including a local anchor router 100 and a router 103 to which a terminal is connected.

When the counterpart node with which the mobile terminal communicates is in the same domain, if the connection routers 103 are connected, the access router 103 should also include a function for supporting mobility of the terminal. However, since this configuration requires a complicated handover operation, for convenience of description, the access routers 103 are only connected to the local anchor router 100.

In the present invention, in the case of the above-described configuration, a plurality of connection routers 103 belong to the local anchor router 100 in one domain 104, and any one of the connection routers 103 belongs to the local anchor router 100. When the mobile terminal 110 is connected, the mobile terminal 110 relates to a technique for performing a handover efficiently and stably to another access router 103 of the access router 103.

2 is a chart illustrating a handover procedure of a terminal in a high-speed network-based regional mobility management protocol according to the present invention. Here, the mobile terminal 110 is referred to as a connection router 103 that is connected before the handover is made, the previous connection router 101, and the connection router 103 to be connected after the handover is made a new connection router. It is referred to as (102).

According to the fast handover method in the network-based regional mobility management protocol of the present invention, the mobile terminal 110 periodically checks the strength of the signal with the access network. When this signal strength becomes smaller than the threshold, the mobile terminal senses the attenuation of the lower link signal. Then, the event for this transfer to the MIH service layer (S10). In addition, the mobile terminal 110, which senses the attenuation of the lower link signal, sends a handover initialization request message to the local anchor router 100 through the previously connected router 101 that is already connected. In this way, it is transmitted that the handover is to be performed (S11).

The local anchor router 100 sends a handover preparation request message to the new access router 102 to be connected in the future, and receives the response (S12). Through this, the address of the mobile terminal 110 to be moved is notified in advance, so that the mobile terminal 110 can perform communication immediately after performing the handover without additional location registration process.

In addition, the local anchor router 100 transmits a response message to the handover initialization request message to the mobile terminal 110 including information on the new router 102 through the previous access router 101 (S13). ).

Thereafter, when the mobile terminal 110 reaches the final threshold for performing the handover, the mobile terminal 110 transmits a handover performance notification message to the local anchor router 100 through the previous access router. (S14).

In this case, the local anchor router 100 receiving the message may start buffering (S15) in order to prevent packet loss occurring during the handover of the UE. Particularly preferably, after receiving the handover performance notification message, the local anchor router 100 may be configured to buffer the sequential temporary storage of packets destined for the mobile terminal 110. Details of this will be described later.

Thereafter, the mobile terminal 110 performs link layer handover (S16). That is, the link of the mobile terminal 110 is disconnected, the link layer handover with the new access router 102 is made, and the link of the mobile terminal 110 is connected.

Thereafter, the mobile terminal 110 transmits a handover completion notification message to the local anchor router 100 through the new access router 102 (S17).

In this case, the local anchor router 100 receiving the message may transmit a packet for the mobile terminal 110, which has been buffered, to the new access router 102 (S18). Particularly preferably, after receiving the handover completion notification message, the local anchor router 100 may be configured to send all the buffered packets to the new access router 102 in order to terminate the buffering. have. Details of this will be described later.

Thereafter, the new access router 102 sends a terminal location registration request message to the local anchor router 100, and the local anchor router 100 sends the response message. The local anchor router 100 sends a resource release request message of the mobile terminal 110 to the previous access router 101 and receives the response message. This completes the handover process.

3 is a block diagram illustrating a structure of a local anchor router capable of performing handover control message processing and buffering according to the present invention.

IP packets entering the local anchor router 100 enter the packet filter module 201 once. The packet filter module 201 checks the type of the incoming packet.

If the packet is a handover control message packet, it is sent to the handover control message processing module 200, and handover is performed through a series of processes described with reference to FIG. When the packet is a general data packet, the packet is sent to the routing processing module 203 and the normal local anchor router 100 performs routing to the mobile terminal 110 corresponding to the destination address of the packet. The routing processing module 203 is a module that can be implemented using a known technique for performing a conventional routing processing function according to the prior art.

However, as described above, in order to prevent the loss of the data packet during the handover, it may be configured to perform buffering. Hereinafter, the case where buffering is performed is demonstrated.

In this case, the packet filter module 201 checks not only the type of the incoming packet but also the destination address of the packet.

If the packet is a handover control message packet, it is sent to the handover control message processing module 200, and handover is performed through the series of processes described with reference to FIG. When the packet is a general data packet, the packet is sent to the routing processing module only when the destination address of the packet is not the terminal performing the handover, and the packet is routed to the mobile terminal 110 corresponding to the destination address of the packet. The difference is that the local anchor router 100 performs the processing.

When the packet is a general data packet and the destination address of the packet is a terminal performing a handover, the packet may be sent to the buffer management module 202. The processing contents of the buffer management module 202 will be described later.

In order to perform the buffering as described above, the handover control message processing module 200 not only processes the handover control message but also sends the IP address of the mobile terminal 110 to be buffered to the packet filter module 201. When receiving the packet of the terminal set in the packet filter module 201, it is preferable to transmit the packet for the mobile terminal 110 to the buffer management module 202. In this case, in order to end the buffering, the IP address of the mobile terminal 110 registered in the packet filter module 201 may be removed.

4 is a flowchart of a buffering operation performed in a local anchor router according to the present invention.

First, when the handover control message processing module 200 of the local anchor router 100 receives the handover performance notification message (N10), the IP address of the mobile terminal 110 is transmitted to the packet filter module 201. Register (N11).

Thereafter, if the packet filter module 201 receives a packet destined for the registered mobile terminal 110, the packet filter module 201 sends it to the buffer management module 202. The buffer management module 202 buffers N12 by temporarily storing them sequentially.

Thereafter, when the handover control message processing module 200 of the local anchor router 100 receives the handover completion notification message (N13), it instructs the buffer management module 202 to perform the buffered movement. All packets of the terminal 110 are sequentially sent to the new access router 102 (N14). When the buffer of the buffer management module 202 is empty by transmitting all the packets of the mobile terminal 110 so that the order of buffering does not occur, the packet filter module 201 is applied to the mobile terminal. The packet filter set in step (N15) is removed.

In the above, the present invention has been described in detail with reference to preferred embodiments, but the present invention is not limited thereto, and improvements and modifications within the scope not departing from the gist of the present invention should be interpreted to belong to the present invention. Do.

According to the present invention of the above configuration, there is provided a method and apparatus capable of high speed handover under a network-based regional mobility management (NetLMM) protocol. In particular, an apparatus and method are provided for significantly reducing handover delay and packet loss in a network-based regional mobility management protocol.

In addition, an apparatus and a method capable of supporting a handover of a terminal independently of a lower media and ensuring reliable communication through buffering are provided.

Claims (8)

In the method for performing a handover between the access router for a mobile terminal connected to a plurality of access router belonging to a local anchor router, (1) receiving, by the local anchor router, a handover initiation request message from the mobile terminal that detects attenuation of a lower link signal through a previous access router that is already connected among the access routers; (2) the local anchor router sending a handover preparation request message to a new access router to be accessed in future among the access routers, and receiving the response message; (3) the local anchor router sending a response message to the handover initialization request message to the mobile terminal through the previous access router; (4) receiving, by the local anchor router, a handover execution notification message from the mobile terminal through the previous access router; (5) the link of the mobile terminal is disconnected, a link layer handover with the new access router is made, and after the link of the mobile terminal is connected, the local anchor router from the mobile terminal through the new access router. Receiving a handover completion notification message, (6) receiving, by the local anchor router, a terminal location registration request message from the new access router and sending a response message; (7) the local anchor router sending a resource release request message of the mobile terminal to the previous access router and receiving the response message; A fast handover method in a network-based regional mobility management protocol, characterized in that consisting of. The method according to claim 1, After receiving the handover performance notification message, the local anchor router performing buffering to temporarily store packets destined for the mobile terminal sequentially; After receiving the handover completion notification message, the local anchor router sequentially sends all the buffered packets to the new access router and terminates the buffering. Fast handover method in a network-based regional mobility management protocol characterized in that it further comprises. The method according to claim 2, Performing the buffering, Registering an IP address of the mobile terminal in a packet filter module for filtering an IP packet in the local anchor router; Examining the destination address of the packet by the packet filter module; When the packet is a general data packet, when the destination address is a mobile terminal that is not during handover, routing processing is performed to the mobile terminal, and when the destination address is a mobile terminal that is during handover, Performing the buffering process A fast handover method in a network-based regional mobility management protocol, characterized in that consisting of. The method according to claim 3, Terminating the buffering, And removing the IP address of the mobile terminal registered in the packet filter module for filtering IP packets in the local anchor router. An apparatus for performing handover between access routers for mobile terminals connected to a plurality of access routers belonging to a local anchor router, the apparatus comprising: It is provided in the local anchor router, receives the IP packet, investigates the type of the packet, and sends the packet to the handover control message processing module in the case of the handover control message packet, and sends it to the routing processing module in the case of the general data packet. Outgoing packet filter module, A routing processing module for routing the general data packet to the mobile terminal corresponding to a destination address of the packet; And a handover control message processing module provided in the local anchor router and analyzing and processing the handover control message packet received from the packet filter module. The handover control message processing module, (1) When a handover initialization request message is received from the mobile terminal that has detected attenuation of a lower link signal through a previous access router that is already connected among the access routers, a new access router to be connected in the future among the access routers. Send a handover preparation request message (2) upon receiving the response message of the handover preparation request message, sending a response message to the handover initialization request message to the mobile terminal through the previous access router, (3) After receiving the handover performance notification message from the mobile terminal through the previous access router, the link of the mobile terminal is disconnected, a link layer handover with the new access router is performed, and the link of the mobile terminal is performed. Is connected, receives a handover completion notification message from the mobile terminal through the new access router, and receives a terminal location registration request message from the new access router, sends a response message, (4) Sending a resource release request message of the mobile terminal to the previous access router, and receives the response message A high speed handover apparatus in a network-based regional mobility management protocol, characterized in that to perform an operation. The method according to claim 5, When the handover control message processing module receives the handover execution notification message, buffering is performed to temporarily receive packets destined for the mobile terminal performing the handover from the packet filter module and temporarily store them sequentially. When the handover control message processing module receives the handover completion notification message, the handover control message processing module sequentially sends all the buffered packets to the new access router to terminate the buffering. Further provided with a buffer management module, When the received IP packet is a general data packet, the packet filter module examines the destination address and manages the buffer instead of sending a packet destined for the mobile terminal performing the handover to the routing processing module. Controlled to send to module A fast handover device in a network-based regional mobility management protocol, characterized in that. The method according to claim 6, In order to perform the buffering, the packet filter module is configured to register the IP address of the mobile terminal, the fast handover apparatus in a network-based regional mobility management protocol. The method according to claim 7, In order to terminate the buffering, the fast handover apparatus in a network-based local mobility management protocol, characterized in that for removing the IP address of the mobile terminal registered in the packet filter module.

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