KR100918386B1 - Apparatus and Method for Handover based Mobile IP Network Using Layer-2 Trigger - Google Patents

Abstract

An apparatus and method for supporting handover of a mobile IP network using two-layer information are disclosed. The handover support apparatus receives a registration request message for instructing the home server to register the address of the second network from a mobile terminal that predicts handover from the first network to the new second network, and receives the received registration request message. To transmit the address registration of the second network and tunneling of the data directed to the mobile terminal to the second network, and forward the tunneled data to the first network until the mobile terminal accesses the second network. It provides seamless multimedia service to mobile terminals without buffering in IP network.

Handover, Subnetwork, LLH

Description

Apparatus and Method for Handover based Mobile IP Network Using Layer-2 Trigger}

The present invention relates to an apparatus and a method for supporting handover of a mobile IP network. More specifically, a mobile IP-based wireless internet terminal supports handover so that a service is not interrupted by maintaining an internet connection even when a handover needs to be performed while moving. An apparatus and method are provided.

As a conventional technology for providing mobility of an IP-based terminal, a method of providing a third layer mobility based on mobile IP has been mainly studied.

These mobile IP-based technologies are divided into two groups: hierarchical mobility management that separately manages regional mobility and regional mobility control procedures, and proactive management that performs mobile IP handover procedures before the second layer handover procedure. have.

In general, handover exists separately at the second and third layers of the network. They are each independently related, and generally in a sequential relationship in which the third layer is performed after being performed in the second layer. As a result, the total time consumed when performing the handover is long, resulting in data packet loss, and the quality of the application service being serviced at the upper layer is degraded.

The proactive management method is to solve this problem, and a representative technique is, in particular, proposed by the IETF, and has a Low Latency Handoff (LHH) technique that advances the FA registration time using the second layer trigger signal. However, when the second layer trigger signal is generated and the LLH technique is deeply related, there is a problem that packet loss occurs when there is no buffer.

SUMMARY OF THE INVENTION The present invention provides a handover support apparatus and method for maintaining a connection to an Internet by using two-layer information even when a wireless Internet terminal needs handover while moving in a mobile IP network. There is.

In order to achieve the above technical problem, an embodiment of a handover support apparatus for a mobile IP network according to the present invention includes a method for providing a home server from a mobile terminal that predicts handover from a first network to a new second network. A registration request message receiver which receives a registration request message instructing registration of an address of the network; Tunneling until the registration request message transmitting unit and the mobile terminal access the second network by transmitting the received registration request message to the home server and instructing the registration of the address of the second network and the tunneling of the data directed to the mobile terminal to the second network. And a data forwarding unit for forwarding the data to the first network.

In order to achieve the above technical problem, an embodiment of a handover method of a mobile IP network according to the present invention provides a second server to a home server from a mobile terminal predicting handover from a first network to a new second network. Receiving a registration request message indicating address registration of a network; Sending the received registration request message to the home server to instruct the registration of the address of the second network and the tunneling of the data directed to the mobile terminal to the second network and removing the tunneled data until the mobile terminal accesses the second network. Forwarding to one network.

In order to achieve the above technical problem, the present invention provides a computer-readable recording medium having recorded thereon a program for executing a handover method of a mobile IP network on a computer.

As described above, according to the present invention, while moving in a mobile IP network, a seamless multimedia service can be provided without additional buffering.

The following merely illustrates the principles of the invention. Therefore, those skilled in the art, although not explicitly described or illustrated herein, can embody the principles of the present invention and invent various devices that fall within the spirit and scope of the present invention. Furthermore, all conditional terms and embodiments listed herein are in principle clearly intended for the purpose of understanding the concept of the invention and are not to be limited to the specifically listed embodiments and states. Should be. In addition, it is to be understood that all detailed descriptions, including the principles, aspects, and embodiments of the present invention, as well as listing specific embodiments, are intended to include structural and functional equivalents of these matters. In addition, these equivalents should be understood to include not only equivalents now known, but also equivalents to be developed in the future, that is, all devices invented to perform the same function regardless of structure.

Thus, the functionality of the various elements shown in the figures, including functional blocks represented by a processor or similar concept, can be provided by the use of dedicated hardware as well as hardware capable of executing software in conjunction with appropriate software. When provided by a processor, the functionality may be provided by a single dedicated processor, by a single shared processor or by a plurality of individual processors, some of which may be shared. In addition, the use of terms presented in terms of processor, control, or similar concept should not be interpreted exclusively as a citation of hardware capable of executing software, and without limitation, ROM for storing digital signal processor (DSP) hardware, software. (ROM), RAM, and non-volatile memory are to be understood to implicitly include. Other well known hardware may also be included.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. In describing the present invention, when it is determined that the detailed description of the related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram showing the configuration of a mobile IP network according to an embodiment of the present invention.

Referring to FIG. 1, the wireless IP network according to the present embodiment includes a terminal 101, a home server 102, and external nodes 103 and 104.

The home server 102 manages the address of the terminal 101 and the address of the network to which the terminal is connected in order to support handover in a wireless Internet environment, and tunnels data destined for the terminal to the network to which the terminal is connected.

The external nodes 103 and 104 control the network connected to the terminal 101 and serve as endpoints of the tunnel between the home server and the network. According to the handover by the movement of the terminal, it may be divided into a first external node 103 that controls the old network and a second external node 104 that manages the new network.

The tunnel 105 between the home server and the external node is used to deliver data traffic to the area where the terminal moves.

The link 106 between the terminal and the external node means that the terminal is connected to a network controlled by the external node.

2 is a diagram illustrating a configuration of a handover support apparatus included in an external node of a mobile IP network according to an embodiment of the present invention, and FIG. 3 is a handover method performed by the handover support apparatus illustrated in FIG. 2. It is a flowchart shown.

Referring to FIG. 2, the apparatus for supporting handover of a mobile IP network according to the present embodiment includes a registration request message receiving unit 210, a registration request message transmitting unit 220, and a data forwarding unit 230.

The registration request message receiving unit 210 transmits the second network 204 from the mobile terminal 201 to the home server 202 in anticipation of a handover from the first network 203 to the new second network 204. A registration request message indicating address registration is received (S310).

The mobile terminal 210 detects the propagation of the second network 204 at the data link layer (second layer), receives a handover prediction trigger signal for predicting a handover from the first network to the second network, and then 2 The mobile IP based handover preparation process is performed by sending a registration request message to register the network address with the home server 202 (Procactive method).

The registration request message includes the address of the mobile terminal, the address of the first network, the address of the second network, and the address of the home server, thereby allowing the home server to register the address of the mobile terminal and the address of the second network, thereby supporting handover. Register the address of the mobile terminal and the address of the second network in the data forwarding section of the device.

The registration request message transmitting unit 220 transmits the registration request message received by the registration request message receiving unit 210 to the home server 210 to register the address of the second network 204 and to send data to the mobile terminal 201. Instructing tunneling to the second network 204 (S320).

The data forwarding unit 230 forwards the tunneled data to the first network 203 until the mobile terminal 201 accesses the second network 204 (S330). In addition, the data forwarding unit may be implemented to directly transmit tunneled data to the mobile terminal after the mobile terminal 201 accesses the second network 204.

4 is a diagram showing in detail the configuration of the data forwarding unit of the handover support apparatus according to an embodiment of the present invention.

Referring to FIG. 4, the data forwarding unit according to the present embodiment includes a terminal register 410, a tunnel address register 420, a tunnel generator 430, and a data transmitter 440.

The terminal registration unit 410 registers the address of the mobile terminal 201.

The tunnel address register 420 registers the address of the first network. The tunnel address register 420 may be registered by binding the address of the first network to the address of the mobile terminal 201 registered in the terminal register 410.

The tunnel address register 420 manages the address of the registered first network by deleting the address of the first network when receiving the link up trigger signal indicating that a link to the mobile terminal is formed in the data link layer.

The tunnel generator 430 generates a forwarding tunnel between the first network 203 and the second network 204 using the address of the first network 203 registered in the tunnel address register 420.

The data transmission unit 440 transmits the tunneled data, which is a destination of the mobile terminal address registered in the terminal registration unit 410, through the forwarding tunnel until the mobile terminal 201 accesses the second network 204.

The data transmission unit 440 checks the terminal registration unit 410 and the tunnel address registration unit 420, and the address of the mobile terminal 201 is registered in the terminal registration unit 410, but the mobile terminal is registered in the tunnel address registration unit 430. If the address of the first network 203 for 201 is registered, it is determined that the mobile terminal 201 is still connected to the first network 203.

However, when the address of the mobile terminal 201 is registered only in the terminal register, and the address of the first network 203 for the mobile terminal 201 is not registered in the tunnel address register 430, the mobile terminal 201. It is determined that is connected to the second network (204).

5 is a diagram illustrating a handover process in a mobile IPv4 environment according to an embodiment of the present invention.

Referring to FIG. 5, the mobile IPv4 environment according to the present embodiment includes a terminal 501, an HA 502, and FAs 503 and 504.

In the physical layer (first layer) / datalink layer (second layer) of the terminal 501, a two-layer trigger that detects a radio signal of a new FA area and predicts a handover occurs.

The HA (Home Agent) 502 is a network node defined in mobile IPv4 (MIPv4) and corresponds to the home server 102 shown in FIG. 1. The HA 502 binds the address of the terminal and the care-of address (CoA) address and manages it as a table. When receiving the traffic destined for the terminal stored in the table, the HA 502 tunnels and delivers the address to the CoA address bound to the table. In charge.

FA (Foreign Agent, 503 ~ 504) is a network node defined in MIPv4, corresponding to the external nodes (103, 104) shown in FIG. FA (503 to 504) means the endpoint of the tunnel started from the HA (502) has a CoA address registered to the HA (502) as an IP address, and the mobile terminal connected to the area controlled by the HA (502) to the visitor list Taking care of it. In addition, unlike the FA on the existing MIPv4 has a tunnel table, it is possible to create a tunnel 507 between the new FA (504) and the old FA (503). Here, the area of FA means a subnetwork in the IP layer (third layer).

The trigger signal of the second layer is divided into a handover prediction signal for predicting handover, a linkdown signal for indicating that the second layer link is interrupted, and a linkup signal for indicating that the second layer link is connected.

The terminal 501 receives a trigger signal at the second layer and acquires a new CoA address (new FA address) based on the signal.

The terminal 501 generates an SF_RegReq message including its own address (HoA), the previous CoA address, and the HA address along with the acquired new CoA address, and delivers the SF_RegReq message to the new FA 504.

Upon receiving the SF_RegReq message, the new FA 504 registers the previous CoA address by mapping the previous CoA address to the terminal address in the tunnel table. This is for creating a tunnel 507 between FAs. The terminal registers the address of the terminal in the visitor list, and indicates that the terminal 501 has visited its own area.

If the terminal 501 is registered in both the tunnel table and the visitor list managed by the new FA 504, tunneling from the HA 502 because it means that the terminal 401 is still connected to the previous FA 503. The data traffic transmitted through the tunneled back to the previous FA (503) to deliver the data traffic. If the terminal 501 is registered only in the visitor list, it means that the terminal is connected to the new FA 504, so that the traffic is directly transmitted to the terminal 501.

The new FA 504 also generates and forwards an HRqst message to the old FA 503 to create the old FA 503 and the tunnel 507.

The new FA 504 transmits an SF_RegReq message to the HA 502, and receives the HA 502, which registers the UE's address and the new CoA address in a table (mobility binding). As a result, all traffic destined for the terminal 501 tunnels the new CoA address (new FA) to the endpoint.

The HA 502 responds to the new FA 504 by generating an SF_RegReply message after the mobility binding.

Upon receiving the SF_RegReply message, the new FA 504 temporarily stores the SF_RegReply message in order to deliver it when the terminal 501 accesses it.

As a result of performing the current step, when the traffic destined for the terminal 501 arrives at the HA 402, the traffic is tunneled to the new FA 504 by the bound information, and the new FA 504 receiving the tunneled data is received. ) Confirms that the corresponding terminal 501 is registered in the tunnel table and the visitor list, and tunnels back to the previous FA 503 to transmit data traffic. A terminal still connected to the previous FA 503 may receive traffic.

As the terminal further moves to the area of the new FA 54, the connection (layer 2 link) to the previous FA 503 is broken, thereby connecting to the new FA 504. As a result, link down / up occurs simultaneously in the second layer of the terminal, and link up occurs in the second layer of the new FA 504.

The new FA 504 acquiring the generated link-up terminates the tunnel 507 with the previous FA 503 by recognizing that the corresponding terminal 401 is connected to it and removing the corresponding information from the tunnel table. As a result, data traffic tunneled from the HA 402 can be immediately transmitted to the terminal 401.

6A, 6B, and 6C are diagrams sequentially illustrating a flow of messages occurring in a handover process in a mobile IPv4 environment according to an embodiment of the present invention.

Referring to FIG. 6A, the mobile terminal 601 receives data through the tunnel 605-1 between the HA 602 and the previous FA 603 while connected to the previous FA 603.

Referring to FIG. 6B, the HA 602 registers (binds) a new CoA in advance by a trigger predicting handover in the second layer of the mobile terminal 601. As a result, data traffic is passing from the HA 602 through the tunnel 605-2 formed in the new FA 604 to the new area.

Unlike the LLH which does not receive traffic normally when the terminal 601 does not immediately access the new FA 604 for some reason and still maintains a link with the previous FA 603, in this embodiment, the new FA 604 By creating a tunnel 607 between and the previous FA 603, traffic that may be lost is passed back to the previous FA 603. Thus, even if the mobile terminal 601 is still connected to the previous FA 603, it can normally receive data traffic.

Referring to FIG. 6C, the terminal 601 disconnects from the previous FA 603 and connects to the new FA 604 (606-2). In this case, the new FA 604 can forward the data traffic directly to the mobile terminal 601 by removing the tunnel 607 with the previous FA 603 so that the mobile terminal 601 can apply the application without data loss during handover. You can get services.

7 is a diagram sequentially illustrating a flow of a handover process in a mobile IPv4 environment according to an embodiment of the present invention.

Referring to FIG. 7, first, a second layer trigger signal for informing a handover is generated and the terminal receives it (S701). After receiving the trigger signal, the terminal generates a new CoA and SF_RegReq message (S702) and delivers it to the new FA (S703). Upon receiving the SF_RegReq message, the new FA forwards the SF_RegReq message to the HA again (S704), and stores the corresponding information in the tunnel table (S705) to create a tunnel with the previous FA. The HRqst a message is generated and delivered to the previous FA (S706), and a tunnel with the previous FA is generated (S707).

After receiving the SF_RegReq message, the HA stores tunnel information with the new FA to generate a tunnel (S708), and since then, the data traffic for the corresponding UE received by the HA tunnels to the generated tunnel (S709). In response to the SF_RegReq message, the HA generates an SF_RegReply message and delivers it to the new FA (S710). The new FA, which has received the SF_RegReply message, temporarily stores this message (S711). The new FA tunnels the tunneled traffic from the HA back to the previous FA (S712). When the terminal disconnects from the previous FA and accesses the new FA, the terminal receives a linkdown trigger signal, and the new FA receives a linkup trigger signal (S713). Receiving the link-up trigger signal, the new FA deletes the previous FA and tunneling information (S714) and transfers the SF_RegReply message, which has been temporarily stored, to the UE (S715). The tunneled data traffic is directly transmitted from the HA to the terminal (S716). As a result, the terminal receiving the link up trigger signal receives the traffic in the new area.

The handover method according to the invention can also be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, hard disk, floppy disk, flash memory, optical data storage device, and also carrier waves (for example, transmission over the Internet). It is also included to be implemented in the form of. The computer readable recording medium can also be distributed over computer systems connected over a computer network so that the computer readable code is stored and executed in a distributed fashion. Also, the font ROM data structure according to the present invention can be read by a computer on a recording medium such as a computer readable ROM, RAM, CD-ROM, magnetic tape, hard disk, floppy disk, flash memory, optical data storage device, and the like. It can be implemented as code.

As described above, the present invention has been described based on the preferred embodiments, but these embodiments are intended to illustrate the present invention, not to limit the present invention, and those skilled in the art to which the present invention pertains should be practiced without departing from the spirit of the present invention. It will be apparent that various changes, modifications, or adjustments to the examples are possible. Therefore, the protection scope of the present invention will be limited only by the appended claims, and should be construed as including all such changes, modifications or adjustments.

1 is a diagram showing the configuration of a mobile IP network according to an embodiment of the present invention.

2 is a diagram illustrating a configuration of a handover support apparatus included in an external node of a mobile IP network according to an embodiment of the present invention.

3 is a flowchart illustrating a handover method performed in a handover support apparatus according to an embodiment of the present invention.

4 is a diagram illustrating in detail the configuration of the data forwarding unit 203 of the handover support apparatus according to an embodiment of the present invention.

5 is a diagram illustrating a handover process in a mobile IPv4 environment according to an embodiment of the present invention.

6A, 6B, and 6C are diagrams sequentially illustrating a flow of messages occurring in a handover process in a mobile IPv4 environment according to an embodiment of the present invention.

7 is a diagram sequentially illustrating a flow of a handover process in a mobile IPv4 environment according to an embodiment of the present invention.

Claims (17)

In the handover support apparatus of the mobile IP network including a home server for receiving the address of the network connected to the mobile terminal tunneling the data toward the mobile terminal to the registered address network, A registration request message receiving unit which receives a registration request message instructing the home server to register an address of the second network from a mobile terminal predicting handover from a first network to a new second network; A registration request message transmission unit for transmitting the received registration request message to the home server to instruct address registration of the second network and tunneling of data directed to the mobile terminal to the second network; And And a data forwarding unit for forwarding the tunneled data to the first network until the mobile terminal accesses the second network. The method of claim 1, The mobile terminal detects the propagation of the second network in the data link layer and receives a handover prediction trigger signal for predicting the handover. The method of claim 1, And the registration request message includes an address of the mobile terminal, an address of the first network, an address of the second network, and an address of the home server. The method of claim 1, The data forwarding unit And the mobile terminal directly transmits the tunneled data to the mobile terminal after the mobile terminal accesses the second network. The method of claim 1, The data forwarding unit A terminal registration unit for registering the address of the mobile terminal; A tunnel address registration unit for registering the address of the first network; A tunnel generation unit generating a forwarding tunnel between the first network and the second network using the registered first network address; And And a data transmission unit configured to transmit tunneled data via the forwarding tunnel to the registered mobile terminal address as a destination until the mobile terminal accesses the second network. . The method of claim 5, The tunnel address registration unit And receiving a link up trigger signal indicating that a link to the mobile terminal is formed at the data link layer, and deleting the address of the first network. The method of claim 6, The data transmission unit And determining whether the mobile terminal accesses the second network according to whether the address of the first network is registered in the tunnel address registration unit. The method of claim 5, And the tunnel address registration unit binds an address of the first network to an address of the mobile terminal. In the handover method of a mobile IP network including a home server for receiving the address of the network connected to the mobile terminal tunneling the data toward the mobile terminal to the registered address network, (a) receiving a registration request message instructing the home server to register an address of the second network from a mobile terminal predicting handover from the first network to the second network; (b) sending the received registration request message to the home server to instruct address registration of the second network and tunneling of data directed to the mobile terminal to the second network; And (c) forwarding the tunneled data to the first network until the mobile terminal accesses the second network. The method of claim 9, The mobile terminal detects the propagation of the second network in the data link layer and receives a handover prediction trigger signal for predicting the handover. The method of claim 9, And the registration request message includes at least one of an address of the mobile terminal, an address of the first network, an address of the second network, and an address of the home server. The method of claim 9, and (d) transmitting the tunneled data directly to the mobile terminal after the mobile terminal connects to the second network. The method of claim 9, Step (c) is (c-1) registering the address of the mobile terminal; (c-2) registering an address of the first network; (c-3) generating a forwarding tunnel between the first network and the second network by using an address of the registered first network; (c-4) transmitting, through the forwarding tunnel, tunneled data destined for the registered mobile terminal address until the mobile terminal accesses the second network. Handover method. The method of claim 13, (c-5) if a link up trigger signal indicating that a link to the mobile terminal is formed in the data link layer, deleting the address of the first network; Handover method. The method of claim 14, Step (c-4) is And determining whether the mobile terminal accesses the second network according to whether the address of the first network is registered. The method of claim 13, Step (c-2) is And binding the address of the first network to the address of the mobile terminal. A computer-readable recording medium having recorded thereon a program for executing the method according to any one of claims 9 to 16.

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