KR101463117B1 - HANDOVER METHOD FOR MOBILE DEVICE AND METHOD FOR TRANSMITTING PACKET DATA FROM EXTERNAL NODE IN PROXY MOBILE IPv6 - Google Patents

Abstract

A handover method of a mobile terminal on a network based on a proxy mobile IPv6 protocol according to an embodiment of the present invention includes the steps of (a) when a first gateway is connected to a first access network connected to a first gateway, Generating a report message to convey a start message of the handover procedure to the gateway; (b) accessing a second access network connected to the first gateway and the second gateway to receive packet data from the second gateway, wherein the packet data is transmitted from the external node to the first gateway via a tunnel created between the first gateway and the second gateway Receiving packet data forwarded to a second gateway; And (c) receiving packet data from the second gateway when the received signal strength of the first gateway is less than the received signal strength of the second gateway in a state of being connected to the second access network, Receiving packet data transmitted from an external node to a second gateway through a tunnel, and sequentially connecting with the first access network and the second access network as the mobile terminal moves.

Description

TECHNICAL FIELD [0001] The present invention relates to a handover method of a mobile terminal and a method of transmitting packet data of an external node,

The present invention relates to a handover method of a mobile terminal and a packet data delivery method of an external node, and more particularly, to a handover method of a mobile terminal in a network based on a proxy mobile IPv6 protocol and a packet data delivery method of an external node.

PMIPv6 (Proxy Mobile IPv6) is a network-based mobility support protocol. Even if a mobile node (MN) such as a mobile terminal connected to a PMIPv6 domain moves from one network to another, It supports the mobile node so that the connection can be maintained without changing the IPv6 address.

Using Proxy Mobile IPv6 not only reduces the handover time of mobile terminal than the host based mobility support protocol such as MIPv6 (Mobile IPv6), but also has an advantage that mobile terminal does not have to directly participate in handover.

However, there is a limit in that the handover delay can not be eliminated completely and the packet loss problem during the handover can not be solved. In other words, Proxy Mobile IPv6 adopts a reactive method in which a mobile terminal performs a handover procedure after a connection with a network is disconnected. Therefore, when performing a connection with a network again, .

In order to solve such a problem, a fast handover technique has been proposed, which will be described with reference to FIG.

1 is a general flow diagram of a fast handover method of a mobile terminal in a network based on a proxy mobile IPv6 protocol.

In the proxy mobile IPv6 protocol, a Mobile Access Gateway (hereinafter referred to as 'MAG') is defined in place of the mobile terminal 100 to support mobility of the mobile terminal, and the first gateway 212 and the second gateway 222 And operates as a basic gateway in an access network (hereinafter referred to as 'access network') to which a mobile terminal is connected. At this time, the first gateway 212 operates in the first access network 210, and the second gateway 222 operates in the second access network 220. Also, an external node 300 such as an LMA (Local Mobility Anchor) operating as a kind of home agent for the mobile terminal 100 in the proxy mobile IPv6 domain is defined.

Referring to FIG. 1 (1), the first gateway 212 can receive / download packet data through a tunnel created between the external node 300 and the first gateway 212, To the mobile terminal 100 connected to the mobile terminal 100 (S11).

1, the mobile terminal 100 receiving the service of the first gateway 212 may determine that the RSS (Received Signal Strength) of the first gateway 212 is below a threshold value It is possible to detect the handover target. The mobile terminal 100 that has completed the search for the second gateway 222 that is the handover target informs the first access network 210 of information about the second gateway 222 (S20), and the first access network 210 And delivers a HO Indication message to the first gateway 212 (S21). Based on the information on the second gateway 222, the first gateway 212 transmits a Handover Initiate (HI) message and Hack (Handover Acknowledge) ') Message (S22, S23) to create a tunnel (S24).

The packet data sent from the external node 300 to the first gateway 212 via the tunnel S 10 shown in FIG. 1 (1) is transmitted to the second gateway 200 through the tunnel S 24 generated in (2) (S25, S26), and the packet data is buffered in the second gateway 222 (S26).

At this time, the first gateway 212 transmits a handover command (HO Command) to the first access network 210 (S27), and the first access network 210 transfers it to the mobile terminal 100 (S28 ). The mobile terminal 100 disconnects the first gateway 212 until the connection with the second gateway 222 is performed (S29).

Referring to FIG. 1 (3), when the mobile terminal 100 moves from the first access network 210 area to the second access network 220 area, the second gateway 222 and the mobile terminal 100, (S30). After the connection, the second gateway 222 transmits all the packet data, which is being buffered, to the mobile terminal 100 (S31). When the mobile terminal 100 uploads the packet data to the external node 300, the second gateway 222 transmits the packet data received from the mobile terminal 100 to the first gateway 212 (S32, S33), the first gateway 212 transmits the forwarded packet data to the external node 300 (S34, S35).

Referring to (4) of FIG. 1, the second gateway 222 and the foreign node 300 are connected to each other via a PBU (Proxy Binding Update) message and a PBA (Proxy Binding Acknowledgment (S40), a tunnel between them is created (S41), and the packet data can be transmitted and received through the tunnel.

However, if the mobile terminal 100 is moving at a very low speed using the fast handover technique of the mobile terminal in the network based on the proxy mobile IPv6 protocol, There is a problem that packet data can not be received.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a handover method of a mobile terminal capable of transmitting and receiving packet data stably to and from a mobile terminal regardless of the moving speed of the mobile terminal. The purpose is to provide.

In addition, some embodiments of the present invention provide a packet data delivery method of an external node capable of stably supporting a handover procedure of a mobile terminal while omitting a packet data buffering process occurring in a fast handover scheme, .

It should be understood, however, that the technical scope of the present invention is not limited to the above-described technical problems, and other technical problems may exist.

According to another aspect of the present invention, there is provided a method for handover of a mobile terminal on a network based on a proxy mobile IPv6 protocol, the method comprising the steps of: (a) Generating a report message such that the first gateway forwards a handover procedure initiation message to a second gateway, the second gateway being a handover target; (b) accessing a second access network connected to the first gateway and the second gateway to receive packet data from the second gateway, wherein the packet data is transmitted from an external node through a tunnel created between the first gateway and the second gateway Receiving packet data transmitted to the second gateway via the first gateway; And (c) receiving packet data from the second gateway when the received signal strength of the first gateway is less than the received signal strength of the second gateway in a state of being connected to the second access network, And receiving packet data transmitted from the external node to the second gateway through a tunnel created between the external nodes, wherein when the mobile terminal moves, the first access network and the second access network sequentially Respectively.

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According to the handover method of the mobile terminal of any one of the tasks of the present invention described above, by arranging the second access network connected to each of the first gateway and the second gateway, The node and the packet data can be stably transmitted and received.

Also, the handover method of a mobile terminal, which is one of the task solutions of the present invention, can reliably transmit packet data between the mobile terminal and the external node even when the mobile terminal is moving at a slow speed or when the mobile terminal stops moving just before handover It can transmit and receive.

Further, the handover method of a mobile terminal, which is one of the tasks of the present invention, can save resources used in a network by not buffering packet data like a fast handover method, Can be used for other mobile terminals, and can provide high quality service to more users.

1 is a general flow diagram of a fast handover method of a mobile terminal in a network based on a proxy mobile IPv6 protocol.
2 is a flowchart illustrating a handover method of a mobile terminal according to an embodiment of the present invention.
3 is a diagram illustrating an example of a network network to which the handover method of FIG. 2 is applied.
4 is a general flowchart of a handover method of a mobile terminal according to an embodiment of the present invention in a network based on a proxy mobile IPv6 protocol.
5 is a general flowchart of a packet data delivery method of an external node according to an embodiment of the present invention in a network based on a proxy mobile IPv6 protocol.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when an element is referred to as "comprising ", it means that it can include other elements as well, without departing from the other elements unless specifically stated otherwise.

FIG. 2 is a flowchart illustrating a handover method of a mobile terminal according to an embodiment of the present invention. FIG. 3 is a diagram illustrating an example of a network to which the handover method of FIG. 2 is applied.

A handover method of a mobile terminal according to an exemplary embodiment of the present invention is a method that can be used on a network based on a proxy mobile IPv6 protocol.

The mobile terminal 100 within the first access network 210 receives a service such as a call connection from the first gateway 220. The mobile terminal 100 may move out of the serviceable area by the first access network 210 as the mobile terminal 100 moves. At this time, the mobile terminal 100 moving to the neighboring third access network 250 area is automatically tuned to the second gateway 240, and can continuously receive service from the second gateway 240. Through such a handover technique, a user using the mobile terminal 100 can enjoy various services without interruption.

In particular, the technique proposed in the present invention may be applied to a first gateway 220 and a second gateway 240, which are present between the first access network 210 and the third access network 250 and are connected to the first gateway 220 and the second gateway 240, Gt; connection network 230. < / RTI > At this time, the mobile terminal 100 moves to be sequentially connected to the first access network 210, the second access network 230, and the third access network 250.

First, the mobile terminal 100 is connected to the first access network 210. The first gateway 220 transmits the packet data to the mobile terminal 100 through the first access network 210 (S110). At this time, the packet data is received from the external node 300 and transmitted through a tunnel formed between the first gateway 220 and the external node 300.

If the service by the first access network 210 becomes difficult as the mobile terminal 100 moves, the handover procedure can be started. The manner of determining the starting point of the handover procedure is not particularly limited. For example, in order to start the handover procedure when the fast handover technique is applied, the received signal strength RSS between the mobile terminal 100 and the first gateway 220 should be measured below a preset threshold value.

When the handover procedure is started, the mobile terminal 100 transmits an instruction message for handover to the first access network 210. At this time, the first gateway 220 receiving the instruction message from the first access network 210 creates a tunnel for data communication with the second gateway 240 that is searched for the handover target (S120).

The mobile terminal 100 is connected to the second access network 230 connected to the first gateway 220 and the second gateway 240 respectively after the first access network 210 is connected And the second gateway 240 may transmit the packet data to the mobile terminal 100 through the second access network 230 instead of the first gateway 220. [ That is, the second gateway 240 transmits the packet data transmitted from the external node 300 to the second gateway 240 through the first gateway 220 and the tunnel generated in step 120 in order, to the mobile terminal 100 (S130).

Then, it is determined whether the received signal strength RSS of the first gateway 220 is smaller than the received signal strength RSS of the second gateway 240 in relation to the mobile terminal 100 (S140).

If the RSS of the first gateway 220 is equal to or greater than the RSS of the second gateway 240, step S 130 may be repeated. Accordingly, even if the moving speed of the mobile terminal 100 is very slow, the mobile terminal 100 can utilize the data communication seamlessly and prevent packet data loss.

If the received signal strength RSS of the first gateway 220 is less than the received signal strength RSS of the second gateway 240, 2 access network 230 and then transmits the packet data through the third access network 250 connected to the mobile terminal 100 at step S150. At this time, the packet data is received from the external node 300 and transmitted through a tunnel formed between the second gateway 220 and the external node 300. In addition, the mobile terminal 100 moves to be sequentially connected to the first access network 210, the second access network 230, and the third access network 250. That is, when the mobile terminal 100 connected to the second access network 230 moves to be connected to the first access network 210, or when the mobile terminal 100 connected to the third access network 250 accesses the first access network 210 or the second access network 230 is not considered.

More specifically, it will be described with reference to Fig. 4 is a general flowchart of a handover method of a mobile terminal according to an embodiment of the present invention in a network based on a proxy mobile IPv6 protocol. The first access network 210, the second access network 230, and the third access network 250 as they move within the network based on the proxy mobile IPv6 protocol, and sequentially transmit and receive packet data to and from the external node 300 A mobile terminal (100) is disclosed. A first connection network 210 connected to the first gateway 220, a second connection network 230 connected to each of the first gateway 220 and the second gateway 240, a second connection network 230 connected to the second gateway 240, A third access network 250 is disclosed.

Referring to FIG. 4 (1), the mobile terminal 100 is connected to the first access network 210. A tunnel is formed between the first gateway 220 and the external node 300 (S210), and the packet data is transmitted to the first gateway 220 through the tunnel. The first gateway 220 transmits the packet data to the mobile terminal 100 through the first access network 210 (S211).

Referring to (2) of FIG. 4, a handover procedure occurs in the mobile terminal 100. The mobile terminal 100 informs the first access network 210 of information about the second gateway 240 as a handover target in step S220 and the first access network 210 notifies the first gateway 220 of a handover instruction (HO Indication) message (S221). The first gateway 220 having received the handover indication message transmits a handover initiation (HI) message to the second gateway 240 based on the information about the second gateway 240 (S222). In addition, the second gateway 240 transmits a handover-aware (HAck) message corresponding to the start message to the first gateway 220 (S223). Through the above-described process, a tunnel is created between the first gateway 220 and the second gateway 240 which is the handover target (S224).

The second gateway 240 transmits the packet data transmitted from the external node 300 to the second gateway 240 through the first gateway 220 and the tunnel generated through step S224 in order, do. That is, after the packet data is transmitted from the external node 300 to the first gateway 220 (S225), the packet data is transmitted to the second gateway 240 through the tunnel generated in the step S224 (S226). At this time, the first gateway 220 and the second gateway 240 are respectively connected to the first access network 210 and the second access network 230 via the second access network 230 connected to the mobile terminal 100, (240) transmits the packet data described above (S227). Since the buffering of the packet data is not performed by applying the technique proposed in the present invention, it is possible to save resources used in the network and use the resources for the other mobile terminals, To provide high-quality service.

Next, referring to (3) of FIG. 4, description will be made. 4 and 4 will be described with reference to the case where the received signal strength RSS of the first gateway 220 is smaller than the received signal strength RSS of the second gateway 240 in relation to the mobile terminal 100. [ Lt; / RTI > That is, if the RSS of the first gateway 220 is equal to or greater than the RSS of the second gateway 240, steps S225 through S227 may be performed.

If the above conditions are satisfied, the second gateway 240 exchanges a proxy binding update (PBU) message and a proxy binding aware (PBA) message with the external node 300 to form a tunnel (S230). The second gateway 240 can receive the packet data from the external node 300 through the tunnel formed in this manner (S231), and the second gateway 240 can transmit the received packet data to the mobile terminal 100 (S232).

The second gateway 240 may transmit the packet data received through steps S230 and S231 to the mobile terminal 100 through the third access network 250 as shown in (4) of FIG. 4 (S240). That is, depending on whether the mobile terminal 100 exists in the area of the second access network 230 or moves and exists in the area of the third access network 250, the route through which the packet data is delivered to the mobile terminal 100 is determined differently .

The process of downloading packet data from the mobile terminal 100 to the external node 300 has been described with reference to Figures 2 to 4 mainly in the case of downloading the packet data from the external node 300 to the mobile terminal 100 It will be readily understood that the invention can be explained in the above-described manner.

As described above, by applying the handover method of the mobile terminal according to an embodiment of the present invention, by arranging the second access network connected to each of the first gateway and the second gateway on the network based on the proxy mobile IPv6 protocol, The MS can stably transmit and receive packet data with the external node even during the handover procedure.

Also, according to the present invention, when the mobile terminal is moving at a low speed or when the mobile terminal stops moving just before handover, packet data can be transmitted and received between the mobile terminal and the external node without a substantial handover delay And loss of packet data can be minimized.

The method for transmitting packet data to the mobile terminal according to the handover (movement) of the mobile terminal will be described with reference to FIG. 5 is a general flowchart of a packet data delivery method of an external node according to an embodiment of the present invention in a network based on a proxy mobile IPv6 protocol. Reference will be made to FIG. 5 with reference to the reference numerals used in FIG.

First, when the mobile terminal 100 is connected to the first access network 210, the external node 300 transmits packet data to the first gateway 220 connected to the first access network 210 (S310) .

When the mobile terminal 100 is connected to the second access network 230, the external node 300 can access the first gateway 220 or the second access network 230 connected to the second access network 230, And transmits the packet data to the second gateway 240, which is a handover target connected to the second gateway 240 (S320). At this time, the packet data may be transmitted through the tunnel created by the handover procedure between the first gateway 220 and the second gateway 240. The direction in which the packet data is delivered may be from the first gateway 220 to the second gateway 240 or vice versa.

When the mobile terminal 100 is connected to the third access network 250, the external node 300 transmits packet data to the second gateway 240 connected to the third access network 250 (S330) .

The steps S310 to S330 are sequentially performed. That is, the mobile terminal 100 is sequentially connected to the first access network 210, the second access network 230, and the third access network 250, and for this connection, the mobile terminal 100 It is possible to move to the third access network 250 area after moving from the first access network 210 area to the second access network 230 area.

In step S320 and step S330, the external node 300 transmits the packet data to the second gateway 240 in response to the received signal strength RSS of the first gateway 220 in relation to the mobile terminal 100, Is smaller than the received signal strength (RSS) of the second gateway 240. Similarly, in step S310 and in step S320, the external node 300 transmits packet data to the first gateway 220 in response to the received signal strength RSS of the first gateway 220 in relation to the mobile terminal 100 Is equal to or greater than the received signal strength RSS of the second gateway 240.

As described above, according to the method of transmitting packet data of an external node according to an embodiment of the present invention, packets are transmitted to a first gateway or a second gateway in accordance with an access network to which a mobile terminal is connected on a network based on a proxy mobile IPv6 protocol By transmitting the data, the external node can send packet data reliably and reliably to the mobile terminal undergoing the handover procedure.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: mobile terminal 210: first access network
212: first gateway 220: second access network
222: second gateway 300: external node

Claims (6)

A handover method of a mobile terminal on a network based on a proxy mobile IPv6 protocol,
(a) generating a report message such that the first gateway transmits a start message of a handover procedure to a second gateway, which is a handover target, when the first gateway is connected to a first access network connected to the first gateway;
(b) accessing a second access network connected to the first gateway and the second gateway to receive packet data from the second gateway, wherein the packet data is transmitted from an external node through a tunnel created between the first gateway and the second gateway Receiving packet data transmitted to the second gateway via the first gateway; And
(c) if the received signal strength of the first gateway is less than the received signal strength of the second gateway in a state of being connected to the second access network, receiving packet data from the second gateway, Receiving packet data transmitted from the external node to the second gateway through a tunnel created between external nodes,
Wherein the mobile terminal is sequentially connected to the first access network and the second access network as the mobile terminal moves.
The method according to claim 1,
Wherein a tunnel created between the first gateway and the second gateway is generated after the initiation message and a acknowledgment message corresponding to the initiation message are generated after exchange between the first gateway and the second gateway, Over the way.
The method according to claim 1,
Wherein the tunnel generated between the second gateway and the external node is generated after a proxy binding update message and a proxy binding acknowledgment message corresponding to the proxy binding update message are exchanged between the second gateway and the external node, A handover method of a terminal.
The method according to claim 1,
(d) accessing a third access network connected to the second gateway to receive packet data from the second gateway, wherein the packet data is transmitted from the external node to the second gateway through a tunnel created between the second gateway and the external node Further comprising receiving the forwarded packet data,
Wherein the mobile terminal is sequentially connected to the first access network, the second access network, and the third access network as the mobile terminal moves.
The method according to claim 1,
(e) receiving packet data from the first gateway in a state of being connected to the first access network before the step (a), receiving packet data from the first gateway through the tunnel created between the first gateway and the external node And receiving packet data transmitted to the first gateway.
The method according to claim 1,
(f) repeating the step (b) if the received signal strength of the first gateway is greater than or equal to the received signal strength of the second gateway in the step (c) Way.

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