WO2009117927A1

WO2009117927A1 - Method for transmitting context information of mobile node, mobile system and device

Info

Publication number: WO2009117927A1
Application number: PCT/CN2009/070870
Authority: WO
Inventors: 勇川隆次; 夏晋伟; 王云贵; 严为
Original assignee: 华为技术有限公司
Priority date: 2008-03-28
Filing date: 2009-03-18
Publication date: 2009-10-01
Also published as: CN101547408A; CN101547408B

Abstract

A method for transmitting context information of mobile node (MN), a mobile node handover method, mobile communication system and local management device are provided in the present invention. The method for transmitting context information of the MN includes: receiving context notice message sent by a previous access device, and the said context notice message taking context information of the MN; obtaining a new access device address of the MN; sending the context information of the MN to the new access device according to the address of the new access device.

Description

Context information transmission method for mobile node, mobile communication system and device The present application claims to be filed on March 28, 2008, the Chinese Patent Office, the application number is 200810066220.9, the invention name is "mobile node context information transmission method, mobile communication system and device The priority of the Chinese Patent Application, the entire contents of which is incorporated herein by reference. Technical field

The present invention relates to mobile communication technologies, and in particular, to a mobile node handover method, a context information transmission method of a mobile node, a mobile communication system, and a local management device.

Background technique

Proxy Mobile IPv6 (ΡΜΙΡνό) is an extension of Mobile IPv6, which is different from Mobile IPv6: In ΡΜΙΡν6, Mobile Access Gateway (MAG) or Access Router (Access Router, AR) simulates the home link, notifies the mobile node (Mobile Node, MN) of the home prefix, so that the MN thinks that it is always at home; MAG replaces the MN to the Local Mobility Anchor (LMA) or the home agent (Home) Agent, HA) sends a registration message. The care-of address in the registration message uses the interface address of the MAG or AR. The LMA/HA receives the proxy binding update request of the MAG/AR, and creates a binding cache entry for the MN. MN ID, interface ID, prefix, etc. A two-way tunnel is established between the MAG/AR and the LMA/HA for transmitting the MN's 4 messages. Its "3⁄4 text transmission and reception process is as follows:

When the peer node sends a packet to the home address of the MN, the packet is intercepted by the LMA/HA of the MN. The LMA/HA queries the binding list according to the home prefix and passes the bidirectional tunnel between the LMA/HA and the MAG/AR. The packet is sent to the MAG/AR for processing. After the packet is decapsulated, the MAG/AR sends the packet to the MN according to the destination address of the packet.

When the MN sends a packet to the peer node, the MAG/AR receives the packet and sends the packet to the LMA/HA through the bidirectional tunnel between the MAG/AR and the LMA/HA. The LMA/HA strips the packet. The outer IP packet header sends the inner packet directly to the peer node.

When the mobile node MN moves from the previous Mobile Access Gateway (PMAG) or the former Access Router (PAR) to the new mobile access network When the New Mobile Access Gateway (NMAG) or the New Access Router (NAR) is used, the services it enjoys are inevitably interrupted by interruptions or delays. When the MN enters the NMAG/NAR link, It needs to re-establish all the services that it has enjoyed before. This process will lead to MN's service delay and increase the packet loss rate.

The Context Transfer Protocol (CXTP) is designed to reduce latency and packet loss during MN handover. The front mobile access gateway PMAG or the former access router PAR directly transmits the service information that the MN enjoys, that is, the context information Context, to the new mobile access network NMAG or the new access router NAR, whether before, after, or after the handover. After receiving the context information of the MN, the NMAG/NAR establishes the original service connection instead of the MN.

As shown in FIG. 1, it is a flowchart of a mobile node switching method provided in the prior art. The method includes the following steps:

5101. The mobile node MN sends the handover signaling to the forward access device PMAG after the new access device is detected, and the handover signaling carries the address information of the new access device NMAG.

5102. After receiving the handover signaling sent by the MN, the PMAG performs handover preparation. Specifically, after receiving the packet with the MN as the destination address, the PMAG does not forward the packet to the MN but performs local storage.

S103: The PMAG sends a context notification message to the NMAG according to the address information of the new access device NMAG carried in the handover signaling sent by the MN, and carries the context information of the MN.

After receiving the context notification message, the NMAG sends a context confirmation message to the PMAG to confirm that the context information of the MN has been received.

After receiving the context confirmation message sent by the NMAG, the PMAG sends the buffered destination address to the NMAG.

5106. The NMAG cache receives the packet whose destination address is MN.

5107. The NMAG detects the mobile node that accesses the local according to the received context information.

5108. When the NMAG finds that the MN notified by the PMAG is locally attached, the buffered destination address is sent to the MN by the MN.

During the research, the inventor found that the scheme requires a tunnel between the PMAG and the NMAG to cache and forward the data packets to the MN. If no security tunnel is established between the MAGs, there is a security risk. If a security tunnel is established between the MAGs. Due to the uncertainty of MN mobility, dynamic/static establishment of secure tunnels is required between all MAGs, which is a big challenge for actual network deployment/application. Summary of the invention

Embodiments of the present invention provide a mobile node handover method, a context information transmission method of a mobile node, a mobile communication system, and a local management device. The local management device forwards the context information of the mobile node, which avoids the security problem caused by directly transmitting the context information of the mobile node between the former access device and the new access device, and reduces the networking cost.

A method for switching a mobile node according to an embodiment of the present invention includes:

Receiving, by the new access device, a context notification message of the mobile node sent by the local management device; detecting, by the mobile node that accesses the new access device, when detecting that the mobile node corresponding to the context information has been attached locally, The local management device establishes a formal binding relationship.

A method for transmitting a context information of a mobile node according to an embodiment of the present invention includes: receiving a context notification message sent by an access device before receiving, where the context notification message carries context information of a mobile node;

Obtaining an address of the new access device of the mobile node;

Sending context information of the mobile node to the new access device according to an address of the new access device.

A mobile communication system provided by an embodiment of the present invention includes:

a front access device, a local management device, and a new access device, wherein

The pre-access device is configured to send a context notification message of the mobile node to the local management device;

The local management device is configured to acquire an address of the new access device, and obtain context information of the mobile node from the context notification message, and send the acquired context information of the mobile node to the new access device;

The new access device is configured to receive the context information of the mobile node sent by the local management device, and detect the mobile node that is local to the new access device, and detect the mobile node corresponding to the context information. When it is attached locally, a formal binding relationship is established with the local management device.

A local management device provided by the embodiment of the present invention includes:

a receiving unit, configured to receive a context notification message sent by the pre-access device, where the context notification message carries context information of the mobile node;

An address obtaining unit, configured to acquire an address of the new access device; And a sending unit, configured to send context information of the mobile node to the new access device. The embodiment of the present invention utilizes the trust relationship between the local management device and the access device, and the local management device sends the context information of the mobile node received from the former access device to the new access device, thereby increasing the security of the system. Moreover, the embodiment of the present invention does not need to establish a physical connection between the former access device and the new access device, which saves the networking cost. In addition, the embodiment of the present invention can also establish a temporary tunnel between the new access device and the local management device before the handover of the mobile node, thereby avoiding data packet loss and improving the switching speed. DRAWINGS

1 is a flowchart of a method for handover of a mobile node in the prior art;

2 is a flowchart of a method for switching a mobile node according to an embodiment of the present invention;

3 is a schematic structural diagram of a mobile communication system according to an embodiment of the present invention;

4A and FIG. 4B are schematic diagrams showing the structure of a local management device according to an embodiment of the present invention. detailed description

The mobile node handover method, the mobile node context transmission method, system and device disclosed in the embodiments of the present invention are applicable to the former mobile access gateway PMAG/pre-access router PAR and the new mobile access network NMAG/new access router NAR attribution In the same local mobile anchor LMA / home agent situation.

In the embodiment of the present invention, when the current access device finds that the mobile node that is locally attached needs to perform handover, the context information of the mobile node is sent to the local management by using a bidirectional tunnel between itself and the local management device. device. After receiving the context notification message, the local management device acquires the address of the new access device according to the content of the context notification message or according to the network policy, and sends the context notification message to the new according to the address of the new access device. Access device. When the new access device finds that the mobile node is already attached to the local device, it initiates a binding message and establishes a binding relationship between itself and the local management device for sending the uplink or downlink text of the mobile node.

The embodiments of the present invention can be used for both normal mobile node handover and mobile node fast handover. When a fast handover is performed, although the mobile node is not attached to the new access device, a temporary binding relationship is established between the new access device and the local management device for transmitting the uplink packet of the mobile node. It can avoid the loss of messages and improve the switching speed.

FIG. 2 is a flowchart of a method for switching a node according to an embodiment of the present invention. as shown in picture 2, The method includes the following steps:

5201. The pre-access device PMAG establishes a bidirectional tunnel between the LMA and the LMA after the mobile node MN is attached to the local device, that is, a formal binding relationship is established.

5202. The former access device PMAG detects the mobile node attached to the local.

The detection includes the PMAG automatically discovering that the mobile node MN is about to perform handover or receiving a notification message to be handed over by the MN to be handed over.

S203. The front access device, when the PMAG detects that the MN needs to leave the local handover to another access device, sends a context notification message to the local management device LMA, where the context notification message carries the context information of the mobile node MN to be handed over. The context information includes: one or more of multicast information, Generic Routing Encapsulation (GRE) information, ID of the MN, ID of the interface of the MN, home address of the MN, and handover sequence number.

When the current access device PMAG can learn the address of the new access device NMAG, the context information may also include the address information of the new access device NMAG. The address of the NMAG may be an address that the PMAG can uniquely determine, or one or more candidate NMAG addresses determined according to a certain policy.

5204. The local management device sends a context confirmation message to the PMAG after receiving the context notification message sent by the PMAG.

After receiving the context notification message sent by the PMAG, the local management device LMA obtains the context information of the MN from the context notification message, and parses the NMAG address of the new access device from the context notification message. The device PMAG can learn the address of the new access device NMAG, or calculate the NMAG address according to a certain network policy.

The NMAG address parsed or calculated by the LMA may be a certain address, and may also be one or more candidate NMAG addresses.

The LMA transmits the context information of the mobile node to the one or more NMAGs that are determined or candidate.

5206. The NMAG that receives the mobility node context information sends a context confirmation message to the LMA.

When the NMAG that receives the context information of the mobile node is a plurality of candidate NMAGs, the multiple candidate NMAGs respectively send a context confirmation message to the LMA.

After receiving the context confirmation message sent by the NMAG, the LMA establishes a temporary tunnel between the NMAG and the LMA, that is, a temporary binding relationship. After the LMA receives the context confirmation message sent by multiple candidate NMAGs, a temporary tunnel is established between the LMA and each candidate NMAG.

Each temporary tunnel is set to have a Transient Lifetime (TL).

After the temporary tunnel is established, the data packet sent to the MN also passes through the tunnel between the PMAG and the LMA to the MN. However, the data packet sent from the MN is simultaneously transmitted through the tunnel between the PMAG and the LMA and between the NMAG and the LMA. When there are multiple candidate NMAGs, the data packets sent from the MN are simultaneously sent to the LMA through the tunnel between the multiple NMAGs and the LAM.

5208. The NMAG that receives the mobility node context information detects the mobile node connected to the local according to the context information of the mobile node.

If there are multiple candidate NMAGs, the multiple NMAGs detect the mobile node connected to the local according to the context information of the mobile node that they receive. Specifically, the NMAG determines whether a mobile node is connected to the local by detecting the layer 2 link information, and then matches the mobile node connected to the local to the context information of the received mobile node.

5209. When the NMAG detects that the mobile node corresponding to the context information is connected to the local device, a formal tunnel is established with the LMA, that is, a formal binding relationship. After the formal tunnel is established, the data packet sent from the MN or the data packet destined for the MN is transmitted through the formal tunnel.

When there are multiple candidate NMAGs, if the mobile node MN is already attached to a certain NMAG, the tunnel between the other candidate NMAGs and the LMA is always a temporary tunnel until

The temporary period of the temporary tunnel TL expires (ie TL=0); or

The NMAG attached to the MN has established a formal tunnel with the LMA before the expiration of the lifetime of the temporary tunnel (that is, the NMAG attached to the MN has established a formal binding relationship with the LMA); or

After the LMA receives the undo binding from the PMAG, the temporary tunnel is deleted.

5210. Delete a bidirectional tunnel established between the PMAG and the LMA based on the mobile node.

The access device may be a mobile access gateway PMAG or an access router PAR. The local management device may be a local mobility anchor LMA or a home agent HA of the MN.

FIG. 3 is a schematic structural diagram of a mobile communication system according to an embodiment of the present invention. As shown in FIG. 3, when the mobile node 304 is attached to the front access device 302, the uplink data packet or the downlink data packet of the mobile node is transmitted through the tunnel between the front access device 302 and the local management device 301.

The pre-access device 302 is to be aware of the state of the mobile node 304, when the mobile node 304 forwards the message to the access device 302 that it is about to initiate a handover, or the pre-access device 302 discovers the mobile node 304. When the handover is about to occur, the front access device 302 sends a context notification message to the local management device 301, and transmits the context information of the mobile node 304 to the local management device 301. The local management device 301 acquires context information of the mobile node 304 from the context notification message and caches it. In addition, the context notification message sent by the former access device 302 may also carry the address of the new access device 303.

When the context notification message carries the address of the new access device, the local management device 301 acquires the address of the new access device 303 from the context notification message; when the context notification message does not carry the address of the new access device, the local management device 301: Acquire or calculate an address of the new access device 303 according to a certain network policy by using context information of the mobile node carried in the context notification message.

The local management device 301 notifies the new access device 303 of the context information of the mobile node. After receiving the context information of the mobile node, the new access device 303 establishes a temporary tunnel with the local management device 301 according to the context information.

After the temporary tunnel is established, all data packets destined for the mobile node 304 are still transmitted to the mobile node 304 via the tunnel between the pre-access device 302 and the local management device 301, but the data packets sent from the mobile node 304 are simultaneously The tunnel between the front access device 302 and the local management device 301 and the tunnel between the new access device 303 and the local management device 301 are sent to the local management device 301, and then the local management device 301 forwards according to the destination address. .

After the temporary tunnel is successfully established, the new access device 303 detects the mobile node that accesses the local device. When the mobile node corresponding to the context information is found to be local, the new access device 303 and the local management device 301 are established. Formal tunnel.

If the context notification message carries multiple candidate new access device addresses, or the local management device 301 calculates multiple candidate new access device addresses, the local management device 301 provides each candidate new access device. Sending the context information of the mobile node, all new access devices that receive the candidate for the context information sent by the local management device establish a temporary tunnel with the local management device 301. After the temporary tunnel is established, all the destination addresses are the mobile node 304. The data packet is still transmitted to the mobile node 304 via the tunnel between the pre-access device 302 and the local management device 301, but the data packets sent from the mobile node 304 are simultaneously passed between the pre-access device 302 and the local management device 301. The tunnel between the tunnel and all the candidate new access devices and the local management device 301 is sent to the local management device 301, and then the local management device 301 forwards according to the destination address. All candidate new access devices detect the mobile node accessing the local. If a candidate new access device finds that the mobile node corresponding to the context information has been attached locally, the candidate new access device and Local management device Established a formal tunnel in 301. After the formal tunnel establishment is completed, the local management device 301 deletes the tunnel established between itself and the former access device 302 based on the context information of the mobile node 304. The other temporary tunnels expire at their own lifetime TL (ie, TL=0); or after the formal tunnel between the mobile node 304 and the new access device 303 is established, or the local management device 301 receives the pre-access device 302. The issued binding is revoked and deleted.

The local management device may be a local mobility anchor LMA or a home agent HA of the mobile node, and the access device may be a mobile access gateway MAG or an access router AR.

FIG. 4A is a schematic structural diagram of a local management device according to an embodiment of the present invention. As shown in FIG. 4A and FIG. 4B, the local management device includes:

The receiving unit 41 is configured to receive a context notification message, where the context notification message carries context information of the mobile node;

The parsing unit 42 is configured to obtain context information of the mobile node from the context notification message; the storage unit 43 is configured to store context information of the mobile node obtained by the parsing unit 42 from the context notification message;

An address obtaining unit 44, configured to acquire an address of the new access device;

The address obtaining unit 44 may be the address resolution unit 441 in FIG. 4A, configured to acquire an address of the new access device from the context notification message when the context notification message carries the address of the new access device. ;

The address obtaining unit 44 may also be the address calculating unit 442 in FIG. 4B, configured to acquire an address of the new access device of the mobile node according to a network policy;

The sending unit 45 is configured to send context information of the mobile node to the new access device. The embodiment of the present invention utilizes the trust relationship between the local management device and the access device, and the local management device sends the context information of the mobile node received from the former access device to the new access device, thereby increasing the security of the system. Moreover, the embodiment of the present invention does not need to establish a physical connection between the front access device and the new access device, which saves the networking cost. In addition, the embodiment of the present invention can also establish a temporary tunnel between the new access device and the local management device before the switching of the mobile node, thereby avoiding data packet loss and improving the switching speed.

The above description is only a preferred embodiment of the present invention, and any modifications, equivalents, and improvements made by those skilled in the art without departing from the principles of the present invention should be Within the scope of protection of the invention.

Claims

Rights request

A method for transmitting a context information of a mobile node, comprising:

Receiving a context notification message sent by the access device, where the context notification message carries context information of the mobile node;

Obtaining an address of the new access device of the mobile node;

2. The method according to claim 1, wherein the acquiring the address of the new access device of the mobile node comprises:

Acquiring an address of the new access device of the mobile node from the context notification message; or acquiring an address of the new access device of the mobile node according to a network policy.

A mobile node switching method, comprising:

4. The method of claim 3, wherein

Before the new access device receives the context notification message sent by the local management device, the method further includes: when the front access device detects that the mobile node needs to perform a handover or receives a notification that the mobile node sends a handover to be generated, Sending, by the local management device, a context notification message, carrying context information of the mobile node;

After the receiving the formal notification relationship with the local management device after receiving the context notification message of the mobile node sent by the local management device, the method further includes:

And the new access device establishes a temporary binding relationship with the local management device according to the context information of the mobile node.

The method according to claim 3, further comprising: the local management device Obtaining an address of the new access device of the mobile node, specifically:

Obtaining, by the local management device, an address of the new access device of the mobile node according to a network policy; or

And obtaining, by the local management device, an address of the new access device of the mobile node from a context notification message sent by the former access device.

6. A method according to any one of claims 3-5, characterized in that

The context information includes: one or more of multicast information, general route encapsulation GRE information, ID of a mobile node, an interface ID of a mobile node, a home address of a mobile node, an address of a new access device, and a handover sequence number. ;

The local management device is a local mobility anchor or a home agent of the mobile node;

The pre-access device and the new access device are mobile access gateways or access routers.

A mobile communication system, comprising: a front access device, a local management device, and a new access device, wherein

The local management device is configured to acquire an address of the new access device, and obtain context information of the mobile node from the context notification message, and send the context information of the mobile node to the new access device.

8. The system according to claim 7, further comprising:

The pre-access device is further configured to detect the mobile node attached to the local node before sending the context notification message of the mobile node to the local management device, and when detecting that the mobile node needs to switch or receive the mobile node A context notification message of the mobile node is generated when the notification of the handover is to be performed, and the context notification message carries the context information of the mobile node.

The system according to claim 7 or 8, wherein the local management device acquires an address of the new access device of the mobile node according to the context notification message, which is specifically:

Obtaining, by the local management device, an address of the new access device of the mobile node from the context notification message;

Or the local management device acquires an address of the new access device of the mobile node according to a network policy.

10. A system according to claims 7-9, characterized in that

11. A local management device, comprising:

a receiving unit, configured to receive a context notification message, where the context notification message carries context information of the mobile node;

An address obtaining unit, configured to acquire an address of the new access device;

And a sending unit, configured to send context information of the mobile node to the new access device.

The local management device according to claim 11, further comprising: a parsing unit, configured to acquire context information of the mobile node from the context notification message, and a storage unit, configured to store the parsing unit from The context information of the mobile node acquired in the context notification message.

The local management device according to claim 11, wherein the address obtaining unit comprises:

An address resolution unit, configured to obtain, from the context notification message, an address of a new access device of the mobile node; or

An address calculation unit, configured to acquire an address of the new access device of the mobile node according to a network policy.