WO2012155613A1

WO2012155613A1 - Method and system for relay node handover

Info

Publication number: WO2012155613A1
Application number: PCT/CN2012/072182
Authority: WO
Inventors: 陈琳; 陈思; 王昕�; 褚丽
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-08-11
Filing date: 2012-03-12
Publication date: 2012-11-22
Also published as: CN102932855A; CN102932855B

Abstract

A method and system for relay node handover, applicable to the handover process of a mobile relay node; the method comprising: a build-in serving gateway and a packet data gateway in a target donor eNB respectively establishing a relay node bearer after the relay node accesses the target donor eNB. The present invention ensures the successful forwarding of uplink and downlink data transmission during relay node handover, and reduces data transmission transit delay.

Description

Method and system for switching relay node

Technical field

The present invention relates to the field of wireless communication technologies, and in particular, to a method and system for switching a relay node.

Background technique

In order to meet the growing demand for large-bandwidth, high-speed mobile access, the Third Generation Partnership Projects (3GPP) has introduced the Long-Term Evolution advance (LTE-Advanced) standard. UTE-Advanced retains the core of LTE for the evolution of Long-Term Evolution (LTE). Based on this, a series of technologies are used to expand the frequency domain and airspace to improve spectrum utilization and increase. The purpose of system capacity, etc. Wireless Relay technology is one of the technologies in LTE-Advanced, which aims to extend the coverage of cells, reduce dead zones in communications, balance load, transfer services in hotspots, and save user equipment (User Equipment, referred to as UE) transmit power. As shown in Figure 1, a relay node (RN) provides similar functions and services to a UE accessing its cell, and accesses a service through a wireless interface in a manner similar to a normal UE. The eNB serving as the eNB is called a Donor eNB, or DeNB for short. The DeNB is connected to a Mobility Management Entity (MME).

With the large-scale construction and operation of high-speed railways, the demand for communication on trains continues to increase. The current high-speed railway has reached a speed of 350 km / h. Due to Doppler frequency shift, frequent cell switching, and high-speed rail car penetration loss, the coverage of existing network base stations is difficult to meet the high-speed rail communication quality requirements. Therefore, the industry proposes to deploy relay nodes on the high-speed rail. As shown in Figure 1, users in the high-speed train (such as UE1 and UE2) communicate directly with the relatively stationary RN, while the RN can be in the process of moving with the high-speed rail. Switching between different DeNBs avoids simultaneous handover of a large number of users in the high-speed rail car, ensuring communication quality between the UE and the RN. In addition, by enhancing the backbone connection between the mobile RN and the DeNB, the above problems of high-speed rail can be better solved.

However, the introduction of mobile RN will generate a large RN related standard in the existing LTE-Advanced. influences. In the existing network architecture, the S-GW (Serving Gateway) serves as an anchor point for handover between base stations, and is responsible for transmitting, forwarding, and routing data information between the base station and the packet data gateway, and is a downlink data packet. The P-GW (Packet Data Network Gateway) is the anchor point of the data bearer, responsible for packet forwarding, parsing, lawful interception, service-based charging, and service QoS (Quality of Service). )control. When the UE accesses the network, the eNB selects the connected MME for the user, and then the MME corresponding to the user further selects the connected S-GW and the P-GW for the user. When the UE moves, it will cause handover between the base stations, and the S-GW may change, and the P-GW does not change.

In the relay scenario, the DeNB has built-in S-GW and P-GW functions, as shown in Figure 2. When the RN accesses the DeNB, the MME selects the local S-GW and the P-GW located in the DeNB for the RN. Considering the scenario of RN handover, if the RN keeps the P-GW of the RN unchanged, and then switches from DeNB1 to DeNB2, the scenario shown in FIG. 3 occurs, that is, the data packet of the UE needs to pass through multiple DeNBs. Built-in GW forwarding, which will result in an increase in data transmission delay. Summary of the invention

An object of the embodiments of the present invention is to provide a handover method and system for a relay node to overcome the defect that the mobile RN increases the data transmission delay after the handover.

In order to solve the above problem, the embodiment of the present invention provides a handover method of a relay node, which is applied to a handover process of a mobile relay node (RN), and includes:

After the relay node accesses the target donor base station, the serving gateway and the packet data gateway built in the target donor base station respectively establish bearers of the relay node.

The method further includes: before the serving gateway and the packet data gateway establish the bearer of the relay node, the target mobility management entity first selects the serving gateway built in the target donor base station for the relay node, and And the selected serving gateway selects, for the relay node, a packet data gateway built in the target donor base station.

The method further includes: before the serving gateway and the packet data gateway are selected, the target donor base station sends a path switch request message to the target mobility management entity, where the bearer list of the relay node is carried; The step of the target mobility management entity first selecting a serving gateway built in the target donor base station for the relay node includes:

The target mobility management entity sends a create session request to the serving gateway according to the address of the serving gateway built in the target donor base station, according to the switching node type as the relay node, and determines that the service gateway needs to be relocated. Context information of the bearer corresponding to the uplink and downlink data transmission;

The step of the selected serving gateway selecting the packet data gateway built in the target donor base station for the relay node includes:

After receiving the request for creating a session, the serving gateway sends a create session request message or a bearer resource command message to the packet data gateway built in the target donor base station, where the bearer carries related information.

The method further includes: before the serving gateway and the packet data gateway are selected, in a handover preparation phase, the source donor base station stores the downlink data flow related to the relay node maintained by the packet data gateway of the source donor base station The template information, or the uplink data flow template information and the downlink data flow template information related to the relay node maintained by the packet data gateway built in the source donor base station, are sent to the target donor base station by using a handover request message; The downlink data flow template information is a set of downlink data packet filters, and each bearer corresponds to one downlink data flow template.

The steps of the service gateway and the packet data gateway respectively establishing the bearer of the relay node include:

The packet data gateway built in the target donor base station locally creates a default and a dedicated bearer corresponding to the relay node according to the bearer related information carried in the received create session request message, and creates the The bearer is associated with the corresponding downlink data flow template, and then returns a create session response message to the service gateway, where the bearer information that is successfully created is carried;

After receiving the session creation response message, the service gateway locally creates a bearer corresponding to the relay node according to the successfully created bearer information carried therein.

The packet data gateway built in the target donor base station according to the received bearer resource And the bearer-related information carried in the command message, the default and the dedicated bearer corresponding to the relay node are locally created, and the created bearer is associated with the corresponding downlink data flow template, and then returned to the service gateway to be created. a bearer request message, where the bearer information is successfully created; and the service gateway, after receiving the create bearer request message, locally creates a bearer corresponding to the relay node according to the successfully created bearer information carried therein, And sending a create bearer response message to the packet data gateway built in the target donor base station.

The method further includes: after completing the establishment of the bearer corresponding to the relay node, the serving gateway sends a create session response message to the target mobility management entity, where the bearer information that is successfully created is carried;

After receiving the create session response message, the target mobility management entity sends a path switch request acknowledgement message to the target donor base station, where the message indicates that the bearer failed to be created; and the target donor base station receives the After the path switch request acknowledgement message is described, the context information 'J of the bearer that failed to be created is divided.

The method further includes: the source donor base station transmitting a handover request message to the source mobility management entity of the relay node, where the bearer information to be forwarded and the relay node maintained by the packet data gateway built in the source donor base station are carried Corresponding downlink data flow template information, or carrying bearer information to be forwarded, and uplink data flow template information and downlink data flow template information related to the relay node maintained by the packet data gateway built in the source donor base station;

And the source mobility management entity selects a target mobility management entity for the relay node according to the mobility management entity selection rule, and then sends a forwarding relocation request message to the target mobility management entity, where the source mobility management entity saves a relay node context and a bearer context, and downlink data flow template information related to the relay node maintained by the packet data gateway built in the source donor base station, or carrying a relay node context saved by the source mobility management entity a bearer context, and uplink data flow template information and downlink data flow template information related to the relay node maintained by the packet data gateway built in the source donor base station;

After receiving the forwarding relocation request message, the target mobility management entity sends a create session request to the serving gateway built in the target donor base station according to the address of the serving gateway built in the target donor base station, where Context information of the bearer corresponding to the row data transmission; After receiving the creation session request, the serving gateway built in the target donor base station sends a create session request to the packet data gateway built in the target donor base station, where the bearer-related information is carried.

The packet data gateway built in the target donor base station locally creates a default and a dedicated bearer corresponding to the relay node according to the bearer related information carried in the created session request message, and the established The bearer is associated with the corresponding downlink data flow template, and then returns a create session response message to the service gateway, where the bearer information that is successfully created is carried;

After the service gateway receives the create session response message sent by the packet data gateway of the target donor base station, the service gateway locally creates the bearer corresponding to the relay node according to the successfully created bearer information carried therein.

The method further includes: after completing the establishment of the bearer corresponding to the relay node, the serving gateway sends a create session response message to the target mobility management entity, where only the bearer information that is successfully created is carried;

After receiving the session creation response message, the target mobility management entity sends a handover request message to the target donor base station, where the message carries: bearer information to be established and packet data gateway maintenance built in the source donor base station The downlink data flow template information related to the relay node, or carrying the bearer information to be established and the uplink data flow template information and the downlink data related to the relay node maintained by the packet data gateway built in the source donor base station Flow template information;

After receiving the handover request message, the target donor base station establishes a relevant context of the relay node, and then replies to the target mobility management entity with a handover request acknowledgement message.

The embodiment of the present invention further provides a handover system of a relay node, which is applied to a handover process of a mobile relay node, and includes:

a relay node configured to access the target donor base station during handover;

The target donor base station has a built-in service gateway and a packet data gateway, and the service gateway and the packet data gateway are configured to respectively establish bearers of the relay node. The system further includes a target mobility management entity, configured to: before the serving gateway and the packet data gateway establish the bearer of the relay node, first select, for the relay node, a built-in target base station The serving gateway selects, by the selected serving gateway, a packet data gateway built in the target donor base station for the relay node.

The target donor base station is configured to: before the target mobility management entity selects the serving gateway, send a path switch request message to the target mobility management entity, where the bearer list of the relay node is carried;

The target mobility management entity is configured to select a serving gateway built into the target donor base station for the relay node by:

And determining, according to the handover node type, that the relay node needs to relocate the service gateway, sending a create session request to the serving gateway according to the address of the serving gateway that is built in the target donor base station, where the bearer corresponding to the uplink and downlink data transmission is carried. Contextual information;

The selected serving gateway is configured to select, for the relay node, a packet data gateway built in the target donor base station by:

And after receiving the creation session request, sending a create session request message or a bearer resource command message to the packet data gateway built in the target donor base station, where the bearer related information is carried.

The system further includes a source donor base station configured to: in the handover preparation phase, the downlink data flow template information related to the relay node maintained by the packet data gateway built in the source donor base station, or be built in the The uplink data flow template information and the downlink data flow template information related to the relay node maintained by the packet data gateway of the source donor base station are sent to the target donor base station by using a handover request message; wherein, the downlink data flow template information is A group downlink packet filter, each bearer corresponding to one downlink data flow template.

The serving gateway and the packet data gateway are configured to respectively establish bearers of the relay node by:

The packet data gateway built in the target donor base station locally creates a default and a dedicated bearer corresponding to the relay node according to the bearer related information carried in the created session request message, and creates the The bearer is associated with the corresponding downlink data flow template, and then returns a create session response message to the service gateway, where the bearer information that is successfully created is carried; After receiving the session creation response message, the service gateway locally creates a bearer corresponding to the relay node according to the successfully created bearer information carried therein.

The packet data gateway built in the target donor base station locally creates a default and a dedicated bearer corresponding to the relay node according to the bearer related information carried in the received bearer resource command message, and creates the The bearer is associated with the corresponding downlink data flow template, and then returns a create bearer request message to the service gateway, where the bearer information that is successfully created is carried;

After receiving the create bearer request message, the serving gateway locally creates a bearer corresponding to the relay node according to the successfully created bearer information, and sends a create bearer response message to be built in the target donor. Packet data gateway of the base station.

The service gateway is further configured to: after completing the establishment of the bearer corresponding to the relay node, send a create session response message to the target mobility management entity, where the successfully created bearer information is carried;

The target mobility management entity is further configured to: after receiving the create session response message, send a path switch request acknowledgement message to the target donor base station, where the message indicates that the bearer failed to be created;

The target donor base station is further configured to delete the context information of the bearer that failed to be created after receiving the path switch request acknowledgement message.

The system also includes: a source donor base station, a source mobility management entity, and a target mobility management entity, wherein

The source donor base station is configured to: send a handover request message to the source mobility management entity of the relay node, where the bearer information to be forwarded and the relay node maintained by the packet data gateway built in the source donor base station are carried Related downlink data flow template letter, package,;

The source mobility management entity is configured to: select a target mobility management entity for the relay node according to a mobility management entity selection rule, and then send a forwarding relocation request message to the target mobility management entity, where the source mobility management is carried The relay node context and bearer context held by the entity, and the relay node maintained by the packet data gateway built in the source donor base station Downstream data flow template information, or carrying a relay node context and bearer context saved by the source mobility management entity, and an uplink data flow template related to the relay node maintained by the packet data gateway built in the source donor base station Information and downstream data flow template letter, package,;

The target mobility management entity is configured to: after receiving the forwarding relocation request message, send a create session request to a serving gateway built in the target donor base station according to an address of a serving gateway built in the target donor base station , carrying the context information of the bearer corresponding to the uplink and downlink data transmission;

The service gateway is further configured to: after receiving the request for creating a session, send a create session request to the packet data gateway built in the target donor base station, where the bearer-related information is carried.

The service gateway and the packet data gateway are configured to respectively establish bearers of the relay node by:

The packet data gateway built in the target donor base station locally creates a default and a dedicated bearer corresponding to the relay node according to the bearer related information carried in the created session request message, and creates the The bearer is associated with the corresponding downlink data flow template, and then returns a create session response message to the service gateway, where the bearer information that is successfully created is carried;

The service gateway is further configured to: after completing the establishment of the bearer corresponding to the relay node, send a create session response message to the target mobility management entity, where only the bearer information that is successfully created is carried;

The target mobility management entity is further configured to: after receiving the create session response message, send a handover request message to the target donor base station, where the message carries: bearer information to be established and built in the source donor base station The downlink data flow template information related to the relay node maintained by the packet data gateway, or carrying the bearer information to be established and the uplink data flow template related to the relay node maintained by the packet data gateway built in the source donor base station Information and downstream data flow template information;

The target donor base station is further configured to establish the relay node after receiving the handover request message The relevant context, and then reply to the target mobility management entity with a handover request acknowledgement message.

After the embodiment of the present invention is used, the mobility management entity selects a new S-GW and a P-GW built in the target DeNB for the RN, and selects the S-GW and the P in the selected S-GW and the P. - The GW establishes a bearer for the RN, thereby ensuring smooth forwarding of uplink and downlink data transmissions when the relay node switches, and reducing the delay of data transmission relay. BRIEF abstract

1 is a schematic diagram of handover of a relay node between different DeNBs in the prior art; FIG. 2 is a network diagram of a relay node in the prior art;

3( a ) and 3 ( b ) are schematic diagrams of a gateway in the prior art that remain unchanged before and after a relay node is switched;

4 is a schematic diagram of a gateway updated in a relay node handover process according to an embodiment of the present invention; FIG. 5 is a schematic diagram of a mobile relay node corresponding to an example 1 in establishing a data bearer at a packet data gateway during X2 handover according to an embodiment of the present invention; ;

6 is a schematic diagram of a mobile relay node corresponding to the second embodiment of the present invention establishing a data bearer at a packet data gateway during X2 handover;

7 is a schematic diagram of a mobile relay node corresponding to the third embodiment of the present invention establishing a data bearer at a packet data gateway during X2 handover;

8 is a schematic diagram of a mobile relay node corresponding to the first embodiment of the present invention, where a mobile relay node establishes a data bearer at a packet data gateway during S1 handover;

FIG. 9 is a schematic diagram of a mobile relay node corresponding to the second embodiment of the present invention establishing a data bearer at a packet data gateway during S1 handover. Preferred embodiment of the invention

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other. One way to solve the above problem is to change the DeNB connected to the RN during the handover of the RN, the target MME reselects the new S-GW and the P-GW for the RN, and in the new S-GW and Create a corresponding bearer on the P-GW.

Therefore, in this embodiment, a method for switching a mobile RN includes:

Step 10: During the mobile RN handover process, the target MME selects the target built in the target for the RN.

S-GW and P-GW on the DeNB;

The step specifically includes: the target MME first selects an S-GW built in the target DeNB for the RN, and the selected S-GW selects a P-GW located on the target DeNB for the RN; performs S on the target MME. -GW and P-GW before the selection, also includes:

The source DeNB initiates a process of switching the RN to the target DeNB; in the handover preparation phase, the source DeNB associates the RN-related downlink data flow template information maintained by the local P-GW, or the RN maintained by the local P-GW. The uplink data stream template information and the downlink data stream template information are sent to the target DeNB by using a handover request message. The downlink data flow template information refers to a group of downlink data packet filters, and each bearer corresponds to one downlink data flow template.

Step 20: Establish a bearer of the RN on the S-GW and the P-GW that are selected on the DeNB. Thereafter, the user served by the RN completes the corresponding path switch and then resumes the uplink and downlink data transmission. The schematic diagram of the system after switching is shown in Figure 4.

The steps of establishing the bearer of the RN include:

The target DeNB sends a path switch request message to the target MME, where the bearer list of the RN that needs to be switched is carried;

The target MME determines, according to the type of the relay node to be switched, that is, the entity to be switched is the RN, and determines that the RN needs to relocate the serving gateway;

The target MME sends a create session request to the S-GW according to the address of the S-GW built in the target DeNB, where the MME carries the context information of the bearer corresponding to the uplink and downlink data transmission;

The S-GW built in the target DeNB receives the above-mentioned creation session request, and is built into the target.

The P-GW of the DeNB sends a create session request or bearer resource command message, where the bearer-related information is carried; where the bearer-related information is parameter information used to describe the bearer;

Scenario 1 The P-GW, which is built in the target DeNB, locally creates a default and a dedicated bearer corresponding to the RN according to the bearer-related information carried in the created session request message, and associates the created bearer with the corresponding downlink data flow template. And then returning a create session response message to the S-GW built in the target DeNB, where the bearer information that is successfully created is carried;

The S-GW, which is built in the target DeNB, receives the create session response message sent by the P-GW of the target DeNB, and locally creates the bearer corresponding to the RN according to the successfully created bearer information carried in the target DeNB, and then sends a create session response message to the bearer. The target MME of the RN, where the created session response message also carries only the bearer information that is successfully created.

Scenario 2

The P-GW, which is built in the target DeNB, locally creates a default and a dedicated bearer corresponding to the RN according to the bearer-related information carried in the received bearer resource command message, and associates the created bearer with the corresponding downlink data flow template. And then returning a create bearer request message to the S-GW built in the target DeNB, where the bearer information that is successfully created is carried;

The S-GW, which is built in the target DeNB, receives the bearer request message sent by the P-GW that is built in the target DeNB, and then creates a bearer corresponding to the RN according to the successfully created bearer information carried in the message, and then sends a bearer response. The message is given to the P-GW built in the target DeNB. In addition, the S-GW built in the target DeNB also sends a create session response message to the target MME of the RN, which also carries only the successfully created bearer information.

In the foregoing two scenarios, after receiving the create session response message sent by the S-GW built in the target DeNB, the target MME of the RN sends a path switch request acknowledgement message to the target DeNB, where the message indicates which bearers are successfully created, and which The bearer creation fails. After receiving the path switch request acknowledgement message, the target DeNB deletes the context information of the bearer that failed to be created.

Before the target MME selects the S-GW and the P-GW that are built in the target DeNB, the step 10 may further include:

The source DeNB sends a handover request message to the source MME of the RN, where the bearer needs to be forwarded.

The EPS (Evolved Packet System) carries information such as the RN-related downlink data flow template information maintained by the P-GW of the source DeNB, and optionally carries the RN related to the P-GW maintained by the source DeNB. Upstream data flow template information; The source MME of the RN selects a target MME for the RN according to the MME selection rule, and then sends a Forward Relocation Request message to the target MME, where the RN context and bearer context saved by the source MME are carried, and the P-GW maintained in the source DeNB is maintained. And the information about the RN-related downlink data flow template, and optionally, the RN-related uplink data flow template information maintained by the P-GW built in the source DeNB;

After receiving the forwarding relocation request message, the target MME of the RN sends a create session request to the S-GW built in the target DeNB according to the S-GW address built in the target DeNB, where the context of the corresponding bearer of the uplink and downlink data transmission is carried. information. Further includes:

After receiving the session creation request, the S-GW, which is built in the target DeNB, sends a create session request to the P-GW built in the target DeNB, where the bearer-related information is carried;

The P-GW, which is built in the target DeNB, locally creates a default and a dedicated bearer corresponding to the RN according to the bearer-related information carried in the created session request message, and associates the created bearer with the corresponding downlink data flow template. And then returning a create session response message to the S-GW built in the target DeNB, where the bearer information that is successfully created is carried;

The S-GW, which is built in the target DeNB, receives the create session response message sent by the P-GW of the target DeNB, and locally creates the bearer corresponding to the RN according to the successfully created bearer information carried in the target DeNB, and then sends a create session response message to the bearer. The target MME of the RN, where the created session response message also carries only the bearer information that is successfully created;

After receiving the create session response message sent by the S-GW of the target DeNB, the target MME of the RN sends a handover request message to the target DeNB, where the message carries: bearer information to be established, and a P-GW built in the source DeNB. The information about the RN-related downlink data flow template that is maintained may optionally carry the RN-related uplink data flow template information maintained by the P-GW of the source DeNB. After receiving the target DeNB, the relevant context of the RN is established, and then the handover request acknowledgement message is returned to the target MME.

Further description will be made below with several embodiments of the invention.

Method embodiment 1 The method embodiment describes a method for a serving gateway and a packet data gateway update when the mobile RN performs X2 handover. Example 1 emphasizes the process of establishing a data bearer in the packet data gateway by using the session creation process, and the second embodiment focuses on the use of the bearer resource command and the creation of the bearer process packet data gateway to establish the data bearer, and the third example emphasizes the data in the packet data gateway. During the bearer setup process, since they are all local to the target DeNB, the message interaction between the serving gateway and the packet data gateway can be omitted.

Example one

The mobile RN switching method, as shown in Figure 5, includes the following steps:

(1) In the RN mobility process, the source DeNB decides to initiate an X2-based handover for the RN; in the handover preparation phase, the source DeNB carries the local packet data gateway maintained by the source DeNB in the RN handover request message sent to the target DeNB. The downlink TFT (Traffic Flow Template) information of the RN and the ERAB (E-UTRAN Radio Access Bearer) information of the RN may optionally carry the RN related to the local P-GW maintained by the source DeNB. Uplink TFT information;

(2) after receiving the message, the target DeNB according to the RN carried in the handover request message

The ERAB information is subject to admission control. For the ERAB agreed to accept, the handover request acknowledgement message is returned to the source DeNB;

(3) After the RN completes the random access to the target DeNB, the target DeNB sends a path switch request (Path Switch Request) message to the RN of the RN, where the RN carries the list of EPS bearers to be switched;

Based on the type of the RN, the MME of the RN determines that the handover of the mobile RN requires relocation of the S-GW. When the target DeNB establishes an S1 connection with the MME of the RN, the SI setup request message sent by the target DeNB to the MME carries the target DeNB local S-GW and the P-GW address;

(4) The MME saves the address information, and sends a create session request to the local S-GW of the target DeNB according to the previously obtained address of the local S-GW of the target DeNB, where the request carries the uplink and downlink data transmission corresponding bearer. Contextual information;

(5) After receiving the create session request, the local S-GW of the target DeNB sends the target DeNB to the target DeNB. The P-GW sends a create session request, where the EPS bearer related information is carried;

The local P-GW of the target DeNB locally creates a default EPS bearer corresponding to the RN and a dedicated EPS bearer according to the information about the EPS bearer carried in the created session request message, and associates it with the corresponding downlink TFT, and then goes to the target DeNB. The local S-GW returns a create session response message, which carries the successfully created EPS bearer information;

(6) After receiving the Create Session Response message sent by the local P-GW of the target DeNB, the local S-GW of the target DeNB locally creates an EPS bearer corresponding to the RN according to the successfully created EPS bearer information, and then sends a create session. Responding to the MME of the RN, where the create session response message indicates the successfully created EPS bearer information;

(7) After receiving the create session response message sent by the local S-GW of the target DeNB, the MME of the RN sends a Path switch request ack (Path Switch Request Acknowledgement) message to the target DeNB, where the message indicates which EPS bearers are successfully created, and which EPS bearer creation failed;

(8) After receiving the Path switch request ack message, the target DeNB deletes the failed EPS bearer context.

At this point, the RN's service gateway and packet data gateway are updated. Wait until the RN serves

After the UE completes the corresponding path switch, the uplink and downlink data transmission can be resumed.

Example two

The mobile RN switching method, as shown in Figure 6, includes the following steps:

(1) In the RN mobility process, the source DeNB decides to initiate an X2-based handover for the RN; in the handover preparation phase, the source DeNB sends the ERAB information of the RN in the RN handover request message sent to the target DeNB, optionally, The uplink TFT information related to the RN maintained by the local P-GW of the source DeNB may be carried;

(2) The target DeNB performs admission control according to the ERAB information of the RN carried in the received handover request message. For the ERAB of the RN that agrees to accept, the handover request acknowledgement message is returned to the source DeNB;

(3) After the RN completes the random access to the target DeNB, the target DeNB sends a path switch request message to the RN of the RN, where the RN carries the EPS bearer list to be switched; (4) The MME of the RN determines that the handover of the mobile RN needs to relocate the S-GW according to the type of the handover node, and then the MME of the RN reports the local S-GW address of the target DeNB to the local S-GW of the target DeNB. Sending a create session request, where the context information corresponding to the bearer of the uplink and downlink data transmission is carried;

(5) After receiving the create session request, the local S-GW of the target DeNB creates an EPS bearer corresponding to the RN at the local P-GW of the target DeNB, and associates it with the corresponding downlink TFT, and then creates an RN corresponding to the local D-eNB at the target DeNB. The EPS bearer, then sends a create session response message to the MME of the RN, wherein the create session response message indicates the successfully created EPS bearer information;

(6) After receiving the create session response message sent by the local S-GW of the target DeNB, the MME sends a Path switch request ack message to the target DeNB, which indicates which EPS bearers are successfully created and which EPS bearers are failed to be created.

(7) After receiving the Path switch request ack message, the target DeNB deletes the failed EPS bearer context.

At this point, the RN's service gateway and packet data gateway are updated. After the UE served by the RN completes the corresponding path switch, the uplink and downlink data transmission can be resumed.

Example three

The mobile RN switching method, as shown in Figure 7, includes the following steps:

(2) After receiving the message, the target DeNB performs admission control according to the ERAB information of the RN carried therein. For the ERAB of the RN that agrees to accept, the handover request acknowledgement message is returned to the source DeNB;

(3) After the RN completes the random access to the target DeNB, the target DeNB sends a path switch request message to the RN of the RN, where the RN carries the list of EPS bearers to be switched;

(4) The MME of the RN determines that the handover of the mobile RN needs to be re-determined according to the type of the handover node. Bit S-GW;

When the target DeNB establishes an SI connection with the MME of the RN, the SI setup request message sent to the MME carries the target DeNB local S-GW and the P-GW address; after receiving the message, the MME saves the address information, and then The address of the local S-GW sends a create session request to the local S-GW of the target DeNB, where the context information of the bearer corresponding to the uplink and downlink data transmission is carried.

(5) After receiving the request for creating a session, the local S-GW of the target DeNB sends a bearer resource command message to the local P-GW of the target DeNB, where the EPS bearer related information is carried;

(6) The local P-GW of the target DeNB locally creates a default EPS bearer corresponding to the RN and a proprietary EPS bearer according to the EPS bearer related information carried in the received bearer resource command message, and associates it with the corresponding downlink TFT, and then associates with the corresponding downlink TFT, and then Returning a create bearer request message to the local S-GW of the target DeNB, where the successfully created EPS bearer information is carried;

(7) The target DeNB local S-GW receives the Create Bearer message sent by the local P-GW of the target DeNB, and then locally creates an EPS bearer corresponding to the RN according to the successfully created EPS bearer information, and then sends the created bearer. The response message is sent to the local P-GW of the target DeNB, and the MME that creates the session response message is sent to the RN, and the successfully created EPS bearer information is indicated in the create session response message;

(8) After receiving the session creation response message sent by the local S-GW of the target DeNB, the MME sends a Path switch request ack message to the target DeNB, which indicates which EPS bearers are successfully created and which EPS bearers are failed to be created.

(9) After receiving the Path switch request ack message, the target DeNB deletes the failed EPS bearer context.

Method embodiment two

The method embodiment describes a method for the service gateway and the packet data gateway update when the mobile RN performs the S1 handover. Example 1 emphasizes the complete service gateway and packet data gateway update process, and instance 2 emphasizes that both the service gateway and the packet data gateway update process are in the target. The DeNB is local, so message interaction between the serving gateway and the packet data gateway can be omitted.

Example one

The mobile RN switching method, as shown in Figure 8, includes the following steps:

(1) In the RN moving process, in the handover preparation phase, the source DeNB determines that the MME needs to update the MME when switching to the target DeNB, and the source DeNB decides to initiate the S1 handover for the RN first;

(2) The source DeNB sends a Handover Required message to the source MME of the RN, where the information carries the information such as the EPS bearer to be forwarded;

(3) The source MME of the RN selects a target MME for the RN according to the MME selection rule, and then sends a Forward relocation request message to the target of the RN.

(4) After receiving the message, the target MME of the RN determines that the handover of the mobile RN needs to relocate the S-GW according to the type of the handover node, and the MME of the RN sends the local S to the target DeNB according to the local S-GW address of the target DeNB. - The GW sends a create session request, where the context information of the bearer corresponding to the uplink and downlink data transmission is carried;

(5) After receiving the request for creating a session, the local S-GW of the target DeNB sends a create session request to the local P-GW of the target DeNB, where the EPS bearer related information is carried;

(6) The target DeNB The local P-GW locally creates an EPS bearer corresponding to the RN according to the EPS bearer related information carried in the created session request message, and associates it with the corresponding downlink TFT, and then to the local D- of the target DeNB. The GW returns a create session response message, which carries the successfully created EPS bearer information;

(7) The target DeNB local S-GW receives the Create Session Response message sent by the local S-GW of the target DeNB, and locally creates an EPS bearer corresponding to the RN according to the successfully created EPS bearer information carried in the message, and then sends the EPS bearer corresponding to the RN to the RN. The MME sends a create session response message, where the create session response message indicates the successfully created EPS bearer information;

(8) After receiving the create session response message sent by the local S-GW of the target DeNB, the MME of the RN sends a Handover Request message to the target DeNB, where the bearer information to be established is carried, and the source DeNB sends the target bearer to the target DeNB. Information such as container. (9) The target DeNB may establish a related context of the RN according to the received Handover request, including bearer information and security context information, and then send a Handover request Acknowledge message to the target MME, where the established EPS bearer list and the target DeNB are carried. To the container of the source DeNB, and so on. The EPS bearer list includes the TEID and address information allocated by the target DeNB for downlink data, and the TEID (Tunnel Endpoint Identifier) and address information used for direct forwarding of the data X2;

(10) The target of the RN sends a Forward Relocation Response message to the source MME of the RN, where the message includes the established EPS bearer list and the container of the target DeNB to the source DeNB;

(11) The source MME of the RN sends a Handover command message to the source.

a DeNB, where the container information of the target to the source DeNB is included;

(12) The source DeNB sends a Handover command message of the received RN to the RN;

(13) The RN performs subsequent handover execution and handover completion.

Example two

The mobile RN switching method, as shown in Figure 9, includes the following steps:

(2) The source DeNB sends a Handover Required message to the source MME of the RN, where the information such as the EPS bearer that needs to be forwarded is carried;

(3) The source MME of the RN selects a target MME for the RN according to the MME selection rule, and then sends a Forward relocation request message to the selected target MME, where the MME RN context and the EPS bearer context are carried.

(4) After receiving the message, the target MME of the RN determines that the handover of the mobile RN needs to relocate the S-GW according to the type of the handover node, and then, to the local S-GW of the target DeNB according to the local S-GW address of the target DeNB. Sending a create session request, where the context information corresponding to the bearer of the uplink and downlink data transmission is carried;

(5) After the local S-GW of the target DeNB receives the request to create a session, the target DeNB The P-GW creates an EPS bearer corresponding to the RN and associates it with the corresponding downlink TFT, and creates an EPS bearer corresponding to the RN in the local D-eNB local S-GW, and then sends a session creation response message to the MME of the RN, where the session response message is created. Indicates the EPS bearer information that was successfully created;

(6) After receiving the create session response message sent by the local S-GW of the target DeNB, the MME sends a Handover Request message to the target DeNB, where the MME carries the information of the EPS bearer to be established and the information sent by the source to the target DeNB.

(7) The target DeNB may establish a related context of the RN, including bearer information and security context information, according to the received Handover Request message, and then send a Handover request Acknowledge message to the target MME, where the established EPS bearer list and the target DeNB are carried. To the container of the source DeNB, the EPS bearer list includes TEID and address information allocated by the target DeNB for downlink data, and TEID and address information for direct forwarding of the data X2;

(8) The target MME of the RN sends a Forward Relocation Response message to the source MME of the RN, which carries the established EPS bearer list and the information of the target to the source DeNB;

(9) The source MME of the RN sends a Handover command message to the source DeNB, which includes the container information of the target to the source DeNB, and sends the received RN's handover command to the RN;

(10) The RN performs subsequent handover execution and handover completion.

In this embodiment, a handover system of a relay node is applied to a handover process of a mobile relay node, and includes:

a relay node, configured to access the target donor base station during the handover process;

The target donor base station has a built-in service gateway and a packet data gateway, and the service gateway and the packet data gateway are configured to respectively establish bearers of the relay node.

Preferably, the system further includes a target mobility management entity, configured to: before establishing the bearer of the relay node, first select, for the relay node, a service gateway built in the target donor base station, The selected serving gateway selects a packet data gateway located at the target donor base station for the relay node. Preferably, the target donor base station is configured to: before the target mobility management entity performs the selection of the serving gateway and the packet data gateway, send a path switch request message to the target mobility management entity, where the relay node is carried Bearer list

The target mobility management entity first selects a serving gateway built in the target donor base station for the relay node by:

And when the switching node type is a relay node, and when it is determined that the serving gateway needs to be relocated, the session is sent to the serving gateway according to the address of the serving gateway that is built in the target donor base station, where the uplink and downlink data transmission corresponding bearer is carried. Contextual information;

The selected serving gateway selects a packet data gateway located at the target donor base station for the relay node by:

And after receiving the creation session request, sending a create session request or a bearer resource command message to the packet data gateway built in the target donor base station, where the bearer related information is carried.

Preferably, the system further includes a source donor base station, configured to: in the handover preparation phase, the downlink data flow template information related to the relay node maintained by the local packet data gateway, or be built in the The uplink data flow template information and the downlink data flow template information related to the relay node maintained by the packet data gateway of the source donor base station are sent to the target donor base station by using a handover request message; wherein, the downlink data flow template information is A group downlink packet filter, each bearer corresponding to one downlink data flow template.

Preferably, the serving gateway and the packet data gateway are configured to respectively establish the loading of the relay node by: a packet data gateway built in the target donor base station according to the received session creation request message And carrying the bearer-related information, creating a default and a dedicated bearer corresponding to the relay node, and associating with the corresponding downlink data flow template, and then returning a create session response message to the service gateway, where Create successful bearer information;

Preferably, the serving gateway and the packet data gateway respectively establish bearers of the relay node by: The packet data gateway built in the target donor base station locally creates a default and a dedicated bearer corresponding to the relay node according to the bearer related information carried in the received bearer resource command message, and creates the The bearer is associated with the corresponding downlink data flow template, and then returns a create bearer request message to the service gateway, where the bearer information that is successfully created is carried;

Preferably, the service gateway is further configured to: after completing the establishment of the bearer corresponding to the relay node, send a create session response message to the target mobility management entity, where the successfully created bearer information is carried;

Preferably, the system further includes: a source donor base station, a source mobility management entity, and a target mobility management entity, where

The source mobility management entity is configured to: select a target mobility management entity for the relay node according to a mobility management entity selection rule, and then send a forwarding relocation request message to the target mobility management entity, where the source mobility management is carried a relay node context and a bearer context saved by the entity, and downlink data flow template information related to the relay node maintained by the packet data gateway built in the source donor base station, or carrying the relay saved by the source mobility management entity a node context and a bearer context, and an uplink data flow template information and a downlink data flow template message associated with the relay node maintained by the packet data gateway of the source donor base station, and a packet;

The target mobility management entity is configured to: after receiving the forwarding relocation request message, the root Sending a create session request to the serving gateway built in the target donor base station, where the context information of the corresponding bearer of the uplink and downlink data transmission is carried, according to the service gateway address of the target donor base station;

Preferably, the serving gateway and the packet data gateway are configured to respectively establish bearers of the relay node by:

The packet data gateway built in the target donor base station locally creates a default and a dedicated bearer corresponding to the relay node according to the received bearer-related information carried in the created session request message, and associates with the corresponding The downlink data flow template, and then returning a create session response message to the service gateway, where the bearer information that is successfully created is carried;

Preferably, the service gateway is further configured to: after completing the establishment of the bearer corresponding to the relay node, send a create session response message to the target mobility management entity, where only the bearer information for creating the success is carried;

The target donor base station is further configured to establish a relevant context of the relay node after receiving the handover request message, and then reply a handover request acknowledgement message to the target mobility management entity.

One of ordinary skill in the art can understand that all or part of the above steps can be completed by a program to instruct related hardware, and the program can be stored in a computer readable storage medium, such as read only. Memory, disk or disc, etc. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the foregoing embodiment may be implemented in the form of hardware, or may be implemented in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software.

The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. In view of the present invention, various other modifications, equivalents, improvements, etc., should be made without departing from the spirit and scope of the invention. It is included in the scope of protection of the present invention.

One of ordinary skill in the art will appreciate that all or a portion of the above steps may be accomplished by a program instructing the associated hardware, such as a read-only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the above embodiment may be implemented in the form of hardware or in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software.

Industrial applicability

Compared with the prior art, in the present invention, with the change of the DeNB switched by the RN, the mobility management entity selects a new S-GW and a P-GW built in the target DeNB for the RN, and in the selected S - The GW and the P-GW establish bearers for the RN, thereby ensuring smooth forwarding of uplink and downlink data transmissions during handover of the relay node, and reducing delay of data transmission relay.

Claims

Claim

A handover method for a relay node, which is applied to a handover process of a mobile relay node, comprising: a service gateway built in the target donor base station after the relay node accesses the target donor base station, and The packet data gateway establishes a bearer of the relay node, respectively.

2. The method of claim 1 further comprising:

Before the serving gateway and the packet data gateway establish the bearer of the relay node, the target mobility management entity first selects the serving gateway built in the target donor base station for the relay node, and the selected service The gateway selects a packet data gateway built in the target donor base station for the relay node.

3. The method of claim 2, further comprising:

Before the serving gateway and the packet data gateway are selected, the target donor base station sends a path switch request message to the target mobility management entity, where the bearer list of the relay node is carried;

The step of the target mobility management entity selecting the service gateway built in the target donor base station for the relay node first includes:

4. The method of claim 3, further comprising:

Before the serving gateway and the packet data gateway are selected, in the handover preparation phase, the source donor base station is to be associated with the relay node maintained by the packet data gateway of the source donor base station. And the downlink data flow template information and the downlink data flow template information related to the relay node maintained by the packet data gateway built in the source donor base station, and sent to the target donor by using a handover request message The downlink data flow template information is a set of downlink data packet filters, and each bearer corresponds to one downlink data flow template.

5. The method of claim 4, wherein

6. The method of claim 4, wherein

The packet data gateway built in the target donor base station locally creates a default and a dedicated bearer corresponding to the relay node according to the bearer related information carried in the received bearer resource command message, and And the created bearer is associated with the corresponding downlink data flow template, and then returns a create bearer request message to the service gateway, where the bearer information is successfully created; and after the service gateway receives the create bearer request message, according to the And carrying the successfully created bearer information to locally create a bearer corresponding to the relay node, and sending a bearer response message to a packet data gateway built in the target donor base station.

7. The method of claim 5 or 6, further comprising:

After completing the establishment of the bearer corresponding to the relay node, the serving gateway sends a create session response message to the target mobility management entity, where the successfully created bearer information is carried; the target mobility management entity receives After the session response message is created, sending a path switch request acknowledgement message to the target donor base station, where the message indicates that the bearer failed to be created; After receiving the path switch request acknowledgement message, the target donor base station divides the context information 'J of the bearer that failed to be created.

8. The method of claim 1 further comprising:

The source donor base station sends a handover request message to the source mobility management entity of the relay node, where the bearer information to be forwarded and the downlink data flow related to the relay node maintained by the packet data gateway built in the source donor base station are carried. The template information, or carrying the bearer information to be forwarded, and the uplink data flow template information and the downlink data flow template information related to the relay node maintained by the packet data gateway built in the source donor base station;

And the source mobility management entity selects a target mobility management entity for the relay node according to the mobility management entity selection rule, and then sends a forwarding relocation request message to the target mobility management entity, where the source mobility management entity saves a relay node context and a bearer context, and downlink data flow template information related to the relay node maintained by the packet data gateway built in the source donor base station, or carrying a relay node context saved by the source mobility management entity a bearer context, and the uplink data flow template information and the downlink data flow template information associated with the relay node maintained by the packet data gateway built in the source donor base station;

After receiving the forwarding relocation request message, the target mobility management entity sends a create session request to the serving gateway built in the target donor base station according to the address of the serving gateway built in the target donor base station, where Context information of the bearer corresponding to the row data transmission;

After receiving the creation session request, the serving gateway built in the target donor base station sends a create session request to the packet data gateway built in the target donor base station, where the bearer-related information is carried.

9. The method of claim 8 wherein

The packet data gateway built in the target donor base station locally creates a default and a dedicated bearer corresponding to the relay node according to the bearer related information carried in the created session request message, and the established The bearer is associated with the corresponding downstream data flow template, and then to the service The service gateway returns a create session response message, which carries the bearer information that is successfully created; and the service gateway receives the create session response message sent by the packet data gateway built in the target donor base station, and then according to the successfully created bearer information carried in the Create a bearer corresponding to the relay node locally.

10. The method of claim 9 further comprising:

After completing the establishment of the bearer corresponding to the relay node, the serving gateway sends a create session response message to the target mobility management entity, where only the bearer information that is successfully created is carried;

11. A handover system for a relay node, applied to a handover procedure of a mobile relay node, comprising: a relay node configured to access a target donor base station during handover;

The target donor base station has a built-in service gateway and a packet data gateway, and the service gateway and the packet data gateway are configured to establish bearers of the relay node respectively.

12. The system of claim 11 further comprising

a target mobility management entity, configured to: before the service gateway and the packet data gateway establish a bearer of the relay node, first select, for the relay node, a service gateway built in the target donor base station, by selecting The outgoing service gateway selects a packet data gateway built into the target donor base station for the relay node.

13. The system of claim 12, wherein

The target donor base station is configured to: before the target mobility management entity selects the serving gateway, send a path switch request message to the target mobility management entity, where the bearer list of the relay node is carried; The target mobility management entity is configured to select a serving gateway built in the target donor base station for the relay node by:

14. The system of claim 13 further comprising:

a source donor base station, configured to: in a handover preparation phase, downlink data flow template information related to the relay node maintained by a packet data gateway built in the source donor base station, or to be built in the source donor base station The uplink data flow template information and the downlink data flow template information related to the relay node maintained by the packet data gateway are sent to the target donor base station by using a handover request message; wherein, the downlink data flow template information is a group of downlink data packet filtering Each bearer corresponds to a downstream data flow template.

15. The system of claim 14 wherein

16. The system of claim 14 wherein

The service gateway and the packet data gateway are configured to respectively establish bearers of the relay node by: The packet data gateway built in the target donor base station locally creates a default and a dedicated bearer corresponding to the relay node according to the bearer related information carried in the received bearer resource command message, and creates the The bearer is associated with the corresponding downlink data flow template, and then returns a create bearer request message to the service gateway, where the bearer information that is successfully created is carried;

17. The system of claim 15 or 16, wherein

18. The system of claim 11 further comprising: a source donor base station, a source mobility management entity, and a target mobility management entity, wherein said source donor base station is configured to: transmit to said source mobile management entity of said relay node a handover request message, where the bearer information to be forwarded and the downlink data flow template letter related to the relay node maintained by the packet data gateway built in the source donor base station are included;

The source mobility management entity is configured to: select a target mobility management entity for the relay node according to a mobility management entity selection rule, and then send a forwarding relocation request message to the target mobility management entity, where the source mobility management is carried a relay node context and a bearer context saved by the entity, and downlink data flow template information related to the relay node maintained by the packet data gateway built in the source donor base station, or carrying the relay saved by the source mobility management entity a node context and a bearer context, and an uplink data flow template information and a downlink data flow template message associated with the relay node maintained by the packet data gateway of the source donor base station, and a packet; The target mobility management entity is configured to: after receiving the forwarding relocation request message, send a create session request to a serving gateway built in the target donor base station according to an address of a serving gateway built in the target donor base station , carrying the context information of the bearer corresponding to the uplink and downlink data transmission;

The system of claim 18, wherein the serving gateway and the packet data gateway are configured to establish a bearer of the relay node by:

20. The system of claim 19, wherein