WO2012031507A1

WO2012031507A1 - Method and system for migration of data transmission channel

Info

Publication number: WO2012031507A1
Application number: PCT/CN2011/077446
Authority: WO
Inventors: 邓云
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-09-07
Filing date: 2011-07-21
Publication date: 2012-03-15
Also published as: CN102404809A

Abstract

A method and a system for migration of data transmission channel are provided by the invention. The method includes that: when a user equipment (UE) is reestablished to an object base station (62), the object base station (62) sends signaling of path migration request to a core network (64)(S302); when the core network (64) receives the signaling, the data transmission channel of the user equipment is migrated to the data transmission channel between the core network (64) and the object base station (62). The invention achieves that a new cell can provides data service for the UE when the UE is reestablished to the new cell.

Description

The present invention relates to the field of communications, and in particular to a data transmission channel migration method and system. BACKGROUND With the development of flat network architecture and the emergence of various high-speed broadband mobile access methods, an evolved wireless communication system can not only provide higher transmission rate, shorter transmission delay, and lower cost, but also Ability to support mobility between internal access systems of the Third Generation Partnership Projects (3GPP) and mobility between 3GPP access systems and non-3GPP access systems, thereby facilitating mobile communication systems The next generation architecture concept. 1 is a schematic diagram of a base station layout in a Long Term Evolution (LTE) architecture according to the related art. As shown in FIG. 1, an LTE/System Architecture Evolution (SAE) proposed by a wireless communication network is used. The next-generation architecture evolved base station (eNodeB, referred to as e B) constitutes an evolved radio access network (Evolved Radio Access Network, E-RAN for short); the evolved packet core network is composed of Mobility Management Entity (Mobility Management Entity) , referred to as MME) and Serving Gateway (S-GW for short) entities. The interface between the eNB and the core network is an S1 interface, where the interface between the eNB and the MME is represented as an S1-MME, which is used to complete the mobility management and the control plane function of the S1 interface; the interface between the eNB and the S-GW It is expressed as S1-U and is used to complete the routing and delivery of user data. The eNBs are connected to each other through an X2 interface. The X2 interface is used to complete the mobility management function of the user equipment (User Equipment, UE for short) in the active state and the information exchange between the peer eNBs. In the LTE system, for the integrity of the mobile communication system, when the UE detects the radio link failure, the handover fails, the underlying detection of the integrity protection check fails, or the wireless connection reconfiguration cannot be satisfied (RRC Connection Reconfiguration, where RRC is wireless) In the case of resource control, that is, Radio Resource Control), the idea of RRC Connection Re-establishment is introduced, in which case the UE needs to perform a cell selection procedure in order to select a suitable cell (selected suitable cell scale) For a new cell, the new cell may be a cell in which the original UE establishes a connection, or may be another cell. A prerequisite for the UE to initiate RRC connection reestablishment is that the security of the access layer must be activated. If the security of the access layer is not activated at this time, the UE cannot perform RRC connection reestablishment, but directly enters the idle state. 2 is a flowchart of wireless connection reconstruction of an LTE system according to the related art. As shown in FIG. 2, a specific process of wireless connection reconstruction includes the following steps S201 to S203. Step S201: The UE sends a radio connection reestablishment request (RRC Connection Reestablishment Request) signaling to the base station in the new cell, and carries a Cell Radio Network Temporary Identifier (C-RNTI for short). And rebuilding the physical cell identifier (Physical Cell Identifier, abbreviated as PCI), the truncated message integrity authentication code (short MAC-I), and the reason for the reconstruction of the original cell where the UE is located before the triggering. Step S202: After the base station allocates the required radio resource to the UE, the base station sends a radio link reestablishment (RRC Connection Reestablishment) signaling to the UE, where the signaling includes a signaling radio bearer configured by the base station for the UE. The parameters of SRB). Step S203: After receiving the radio connection re-establishment signaling sent by the base station, the UE configures a new parameter, and sends a radio link reestablishment complete (RRC Connection Reestablishment Complete) signaling to the base station. After the wireless connection reestablishment is completed, the UE re-establishes the dedicated channel SRB for signaling in the new cell, and then the UE needs to establish a dedicated data radio bearer (Data Radio Bearer, DRB for data transmission) for data transmission. transmission. If the new cell selected during the UE reestablishment belongs to the same base station as the original cell where the UE is triggered before the re-establishment, the general packet radio service originally established for the UE between the base station and the core network is

(General Packet Radio Service, GPRS for short) GPRS tunneling protocol (GTP tunnel) can continue to be used; if the new cell selected during UE reestablishment belongs to a different base station than the original cell where the UE triggers the re-establishment The continuation of using the GTP tunnel between the base station and the core network of the original cell may be problematic because the core network also sends the downlink data of the UE to the base station to which the original cell belongs, and the new cell selected during the UE reestablishment cannot be obtained. The downlink data of the UE cannot continue to provide services for the UE. For this problem, the existing protocol does not give a treatment method. SUMMARY OF THE INVENTION A main object of the present invention is to provide a data transmission channel migration solution, so as to at least solve the problem that the new cell reconstructed by the UE in the related art cannot obtain the downlink data of the UE, so that the UE cannot be served. In order to achieve the above object, according to an aspect of the present invention, a data transmission channel migration method is provided. The method includes: after the user equipment reestablishes to the target base station, the target base station sends signaling requesting path migration to the core network; after receiving the signaling, the core network migrates the data transmission channel of the user equipment to the core network and the target base station. The data transmission channel between. Preferably, the data transmission channel comprises a downlink general packet radio service tunneling protocol tunnel and/or an uplink general packet radio service tunneling protocol tunnel. Preferably, before the target base station sends the signaling requesting the path migration to the core network, the method further includes: before the target base station receives the wireless connection reestablishment request sent by the user equipment, the target base station passes the X2 interface signaling or the S1 interface signaling. Get context information for the user device. Preferably, before the target base station sends the signaling requesting the path migration to the core network, the method further includes: the target base station reconfiguring the data radio bearer for the user equipment. Preferably, after the data transmission channel of the user equipment is migrated to the data transmission channel between the core network and the target base station, the method further includes: the core network returns a response requesting the path migration to the target base station; the response includes the core network as a user The new S1 application layer identifier assigned by the device and the uplink list information of the migrated radio access bearer. Preferably, the signaling requesting the path migration is a path migration request, a reestablishment notification signaling, or a handover notification signaling. Preferably, the signaling requesting the path migration includes the information of at least one of the following: an S1 application layer identifier allocated by the mobility management entity for the user equipment, an identifier and address information of the radio access bearer to be migrated, and a target cell reestablished by the user equipment. Identify, trigger the reason for the path migration. In order to achieve the above object, according to another aspect of the present invention, a data transmission channel migration system is provided, the system comprising: a target base station, configured to send a request path migration message to a core network after the user equipment reestablishes to the target base station The core network is configured to migrate the data transmission channel of the user equipment to the data transmission channel between the core network and the target base station after receiving the signaling. Preferably, the target base station is configured to obtain the context information of the user equipment by using X2 interface signaling or S1 interface signaling before receiving the wireless connection reestablishment request sent by the user equipment. Preferably, the target base station is configured to reconfigure the data radio bearer for the user equipment before transmitting the signaling requesting path migration to the core network. Preferably, the core network is configured to return a response requesting path migration to the target base station after migrating the data transmission channel of the user equipment to the data transmission channel between the core network and the target base station. With the present invention, after the UE is re-established to the target base station, the target base station sends a signaling requesting path migration to the core network, and then the core network migrates the data transmission channel of the UE, and solves the new cell reconstructed by the UE in the related art. The downlink data of the UE cannot be obtained, so that the UE cannot be served, and the new cell can be provided with the data service after the UE reestablishes the new cell. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, In the drawings: FIG. 1 is a schematic diagram of a base station layout in an LTE architecture according to the related art; FIG. 2 is a flowchart of wireless connection reconstruction of an LTE system according to the related art; FIG. 3 is a data transmission channel migration according to an embodiment of the present invention. FIG. 4 is a schematic diagram of a process for restoring data transmission in a new cell after UE reconstruction according to Embodiment 1 of the present invention; FIG. 5 is a flowchart of restoring data transmission in a new cell after UE reconstruction according to Embodiment 2 of the present invention; FIG. 6 is a structural block diagram of a data transmission channel migration system according to an embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. The embodiment of the invention provides a data transmission channel migration method. FIG. 3 is a flowchart of a data transmission channel migration method according to an embodiment of the present invention. As shown in FIG. 3, the method includes steps S302 to S304. Step S302: After the UE reestablishes to the target base station, the target base station sends signaling requesting path migration to the core network. Step S304, after receiving the signaling, the core network migrates the data transmission channel of the UE to a data transmission channel between the core network and the target base station. For example, the core network may send the data of the UE to the target base station, and then send the data to the UE through the target base station, and no longer send the data of the UE to the source base station. In this embodiment, after the UE reestablishes the target base station, the target base station sends signaling requesting path migration to the core network, thereby migrating the data transmission channel of the UE to the data transmission channel between the core network and the target base station, and solving the related In the technology, the new cell reconstructed by the UE cannot obtain the downlink data of the UE, so that the UE cannot be served, and the effect that the new cell can provide the data service for the UE after the new cell is reconstructed by the UE is achieved. The foregoing data transmission channel may include: a downlink general packet radio service tunnel protocol tunnel and/or an uplink general packet radio service tunnel protocol tunnel. Before the UE does not trigger the wireless connection re-establishment, the data transmission channel refers to a data transmission channel between the source base station and the core network where the UE is located; after the UE is re-established, the data transmission channel refers to a data transmission channel between the core network and the target base station. . Therefore, in this embodiment, the uplink channel and/or the downlink channel of the UE can be migrated, so that the uplink data transmission and the downlink data transmission of the UE can be effectively performed. In an implementation manner of the present invention, before the target base station receives the wireless connection reestablishment request sent by the UE, the target base station may obtain the context information of the UE by using the X2 interface signaling or the S1 interface signaling, so that the context information may be determined according to the context information. Whether to accept the reconstruction request of the UE. Preferably, before the target base station sends signaling requesting path migration to the core network, the target base station first reconfigures the data radio bearer for the UE. This embodiment is practical. In another implementation manner of the present invention, after the data transmission channel of the user equipment of the user equipment is migrated to the data transmission channel between the core network and the target base station, the core network also returns a response requesting the path migration to the target base station; The response includes the new S1 application layer identifier allocated by the core network for the user equipment and the uplink list information of the migrated radio access bearer. With this embodiment, the target base station can confirm whether the data transmission channel is successful. Preferably, the signaling for requesting path migration is path migration request, reestablishment notification signaling, or handover notification signaling. This embodiment proposes several signalings that can be used for path migration, and is highly operable. Preferably, the signaling for requesting path migration includes information of at least one of the following: an S1 application layer identifier allocated by the mobility management entity for the UE, an identifier and address information of the radio access bearer to be migrated, a target cell identifier reconstructed by the UE, The reason for triggering a path migration. This embodiment provides that the signaling of the path migration contains the content of the information, and is highly practical. The implementation process of the embodiment of the present invention will be described in detail below with reference to the accompanying drawings. In the LTE system, there is an X2 interface between the base station 1 and the base station 2, and the UE is located in the cell 1 to which the base station 1 belongs, and is in a connected state. At this time, the base station 1 and the core network have been established for the UE. Transmitting signaling and data S1 connection (UE-associated logical SI-connection). The UE in the connected state receives the measurement configuration sent by the base station 1, performs measurement and reports the measurement report to meet the interference control and mobility requirements. At some point, the UE reports to the base station 1 a measurement report that the signal quality of the cell 2 is higher than the signal quality of the serving cell (ie, cell 1) by a predetermined offset, and the cell 2 belongs to the base station 2. After receiving the measurement report from the UE, the base station 1 makes a handover decision, and wishes to switch the UE to the cell 2. However, in the process of the handover, the UE triggers the reestablishment due to the failure of the radio link or the failure of the RRC connection reconfiguration. At this time, the UE selects the cell 2 as the reconstructed new cell, and FIG. 4 is the UE re-establishment according to the first embodiment of the present invention. A schematic diagram of a process of restoring data transmission in a new cell, as shown in FIG. 4, the process includes the following steps. Step S401, the UE reports to the base station 1 a measurement report that the signal quality of the cell 2 is higher than the signal quality of the serving cell by a predetermined offset. In this embodiment, the base station 1 is referred to as a source base station. Step S402a, the base station 1 makes a handover decision, and selects the cell 2 as the target cell for the handover. The base station 1 sends a handover request (Handover Request) to the base station 2 (ie, the target base station) through the X2 interface, where the context information of the UE is included, for example, The cell radio network temporary identifier of the UE in the source cell (ie, the serving cell, the cell 1), the physical cell identifier of the source cell, the encryption key Ke B* of the UE in the target cell, and the reconstruction information of the UE in the target cell (Reestablishment) may be included. Info), etc., wherein the reconstruction information includes a truncated message integrity authentication code (short MAC-I). The target cell may also be included in the handover request. Step S403: After receiving the handover request, the base station 2 performs access control according to the context information of the UE, allocates resources for the UE, and returns a handover request acknowledgement to the base station 1. (Handover Request Acknowledged UE interrupts the handover process due to trigger re-establishment Go to step S402b. Since the handover is interrupted, the base station

1 The handover request acknowledgement sent by the base station 2 may not be received, or the base station 1 may not complete the handover command to the UE even if it receives the handover request acknowledgement. Step S402b, after the step S401, the UE triggers the wireless connection reestablishment due to the detection of the radio link failure, the integrity protection check failure, or the failure to satisfy the wireless connection reconfiguration requirement. The UE performs cell selection and selects cell 2 as the reconstructed new cell. The UE reads the system message of cell 2 (Cell_2). Step S403b: The UE initiates a random access in the cell 2, and sends an RRC Connection Reestablishment Request (RRC Connection Reestablishment Request) message to the base station 2, where the RRC connection reestablishment request message may include the short MAC-I calculated by the UE and the time when the UE triggers the reestablishment. The physical layer identifier (Physical Cell Identifier, abbreviated as PCI) and the Cell Radio Network Temporary Identifier (C-RNTI). Step S404b: After receiving the RRC connection reestablishment request message sent by the UE, the base station 2 queries the corresponding short MAC-I saved by the C-RNTI and the PCI carried in the message, and queries the short MAC-I and the message. The short MAC-I is compared to determine whether the two are consistent. If they are consistent, the base station 2 accepts the RRC connection reestablishment request of the UE, and sends an RRC Connection Reestablishment message to the UE. If not, the base station 2 The RRC connection reestablishment request of the UE is rejected. Base The station 2 can obtain the context information of the UE in the handover request sent by the base station 1, and includes the UE's reconstruction information (Reestablishment lnfo) in the target cell, etc., therefore, the authenticity of the UE can be verified, and whether to accept the reconstruction is determined. request. Step S405b: After receiving the radio connection re-establishment signaling sent by the base station 2, the UE configures a new parameter, and sends a radio link reestablishment complete (RRC Connection Reestablishment Complete) signaling to the base station 2. At this point, the UE completes the reconstruction of the SRB. Step S406b, the base station 2 sends an RRC Connection Reconfiguration (RRC Connection Reconfiguration) to the UE, which includes configuration information, measurement configuration information, and the like of the DRB (which may be more than one DRB depending on the number of DRBs included in the context information of the UE). Since the UE has been re-established to the new cell, the radio link configuration parameters adopted by the UE in the source cell cannot be applied to the new cell, and the base station 2 needs to allocate new radio link resources to the UE through the RRC connection reconfiguration, so that the UE can be normal. Restore data radio bearers to pass data. Step S407b, after receiving the RRC connection reconfiguration, the UE applies the configuration parameters therein, and returns RRC Connection Reconfiguration Complete to the base station 2, step S408b, after receiving the RRC connection reconfiguration, the base station 2 receives the RRC connection reconfiguration complete. It is known that the UE has successfully reconstructed the DRB. In order to enable the UE to maintain data transmission (uplink and downlink), the base station 2 sends signaling requesting path migration to the core network, and the mobility management entity is included in the signaling requesting path migration. The S1 application layer identifier (Source MME UE S1AP ID) assigned by the UE, the E-UTRAN Radio Access Bearer Identifier (E-RAB ID) and the address information (including the transport layer address Transport layer) Address and GTP tunnel terminal identifier GTP-TEID), target cell identifier reconstructed by the UE. Signaling for requesting path migration may reuse a Path Switch Request in the existing protocol, or may use a new SI interface letter. Let, for example, rebuild the migration request. It should be noted that the radio access bearer that needs to be migrated corresponds to the step. In the S406b DRB, one radio access bearer (E-UTRAN Radio Access Bearer, referred to as E-RAB) corresponds to one DRB. Step S409b, after receiving the signaling requesting path migration, the core network is based on the core network. The S1 application layer identifier allocated by the UE is retrieved to obtain the configuration parameter of the UE, and the new S1 application layer identifier is allocated to the UE, and the downlink GTP tunnel of the UE is migrated. Then, the core network sends a response to the base station 2, and the response is The new S1 application layer identifier (MME UE S1AP ID) that is allocated to the UE by the core network, and the E-RAB To Be Switched in Uplink List (E-RAB To Be Switched in Uplink List). The data transmission can be smoothly continued, because the GTP tunnel of the UE is restored between the base station 2 and the core network through steps S408b and S409b, so that the UE on the core network side The downlink data can reach the base station 2 smoothly, and is sent to the UE through the air interface through the base station 2. The processing of the uplink data is reversed. In this embodiment, the handover procedure is performed before the reestablishment process. As long as the base station 2 has obtained the context information of the UE when receiving the RRC connection reestablishment request sent by the UE, the reestablishment process can be completed. In an actual network, the source base station may send the context information of the UE to the neighboring base station in advance for the reconstruction that the UE may trigger (not based on the handover decision, that is, the UE is not sent by the signaling of the handover request). Context information), which ensures that the re-establishment of the UE is successful, and the service can be continued to avoid the UE's connection release due to the UE reestablishing the base station without the UE context information, which affects the user experience. Embodiment 2 In the LTE system, there is no X2 interface between the base station 1 and the base station 2, and the UE is located in the cell to which the base station 1 belongs.

1, and in a connected state, at this time, a UE-associated logical SI-connection for transmitting signaling and data has been established between the base station 1 and the core network. The UE in the connected state receives the measurement configuration sent by the base station 1, performs measurement and reports the measurement report to meet the interference control and mobility requirements. At some point, the UE reports to the base station 1 a measurement report that the signal quality of the cell 2 is higher than the signal quality of the serving cell (cell 1) by a predetermined offset, and the cell 2 belongs to the base station 2. After receiving the measurement report of the UE, the base station 1 makes a handover decision, and wishes to handover the UE to the cell 2. However, in the process of handover, the UE triggers the reestablishment due to the failure of the radio link or the failure of the RRC connection reconfiguration, and the UE selects the cell 3 (also belonging to the base station 2) as the reconstructed new cell, and FIG. 5 is a second embodiment according to the present invention. A schematic diagram of a process for restoring data transmission in a new cell after UE reconstruction, as shown in FIG. 5, the process includes the following steps. Step S501: The UE reports to the base station 1 a measurement report that the signal quality of the cell 2 is higher than the signal quality of the serving cell by a predetermined offset. In this embodiment, the base station 1 is referred to as a source base station. In step S502a, the base station 1 makes a handover decision, and selects the cell 2 as the target cell of the handover. The base station 1 sends a handover requirement (Handover Required), which includes the context information of the UE, for example, may include the UE in the source cell (the serving cell) The cell radio network temporary identifier of the cell 1), the physical cell identifier of the source cell, the encryption key KeNB* of the UE in the target cell, and the reestablishment information of the UE in the target cell, etc., and the reconstruction information includes the truncated message integrity. Authentication code (short MAC-I). The handover requirement also includes the identity of the target cell and the target base station. Step S503a: After receiving the handover requirement, the core network sends a handover request to the base station 2. The handover request includes a new S1 application layer identifier (MME UE S1AP ID) allocated by the core network for the UE, and a configuration parameter of the GTP tunnel, such as a transport layer address and a GTP Tunnel Endpoint Identifier. Step S504a, after receiving the handover request, the base station 2 performs access control according to the context information of the UE, allocates resources for the UE, and returns a handover request acknowledgement to the core network (Handover Request Acknowledged step S505a, the core network sends a handover command to the base station 1 (Handover Command).

The UE interrupts the handover procedure due to the trigger re-establishment, and proceeds to step S502b. Since the handover is interrupted, the base station 1 may not receive the handover command sent by the core network, or the base station 1 may not be able to complete the handover command to the UE even if the handover command is received. Step S502b, after the step S501, the UE triggers the wireless connection reestablishment due to detecting the failure of the radio link, the failure of the integrity protection check, or the requirement of the wireless connection reconfiguration. The UE performs cell selection and selects cell 3 as the reconstructed new cell. The UE reads the system message of cell 3 (Cell_3). Step S503b, the UE initiates random access in the cell 3, and sends an RRC connection reestablishment request to the base station 2 (RRC).

The Connection Reestablishment Request message includes the PCI and C-RNTI of the cell in which the short MAC-I UE that the UE calculates triggers the re-establishment in the RRC Connection Reestablishment Request message. Step S504b: After receiving the RRC connection reestablishment request message sent by the UE, the base station 2 queries the corresponding short MAC-I saved by the C-RNTI and the PCI carried in the message, and queries the short MAC-I and the message. The short MAC-I carried in the comparison is compared to determine whether they are consistent. If they are consistent, the base station 2 accepts the RRC connection reestablishment request of the UE, and sends an RRC Connection Reestablishment message to the UE; if not, the base station 2 rejects The RRC connection reestablishment request of the UE. The base station 2 can obtain the context information of the UE from the handover request sent by the base station 1 (through the core network), including the reestablishment information of the UE in the target cell, etc., so that the base station 2 can verify the authenticity of the UE. Decide whether to accept its request for reconstruction. Step S505b: After receiving the radio connection re-establishment signaling sent by the base station 2, the UE configures a new parameter, and sends a radio link reestablishment complete (RRC Connection Reestablishment Complete) signaling to the base station 2. At this point, the UE completes the reconstruction of the SRB. Step S506b, the base station 2 sends an RRC Connection Reconfiguration (RRC Connection Reconfiguration) to the UE, which includes configuration information, measurement configuration information, and the like of the DRB (which may be more than one DRB depending on the number of DRBs included in the context information of the UE). Step S507b: After receiving the RRC connection reconfiguration, the UE applies the configuration parameters therein to return the RRC Connection Reconfiguration Complete to the base station 2. Step S508b, after receiving the RRC connection reconfiguration, the base station 2 learns that the UE has successfully reestablished the DRB. In order to enable the UE to maintain data transmission (uplink and downlink), the base station 2 sends a signaling requesting path migration to the core network. The signaling may be a re-establishment notification, a handover notification (Handover Notify), or other newly added S1 interface signaling, where the signaling includes an S1 application layer identifier (MME UE S1AP ID) allocated by the core network to the UE in step S503a. After receiving the signaling of the request path switching, the core network learns that the UE has migrated to the base station 2. The GTP tunnel for transmitting data between the core network and the base station 2 for the UE can be used for uplink and downlink data transmission of the UE. In this embodiment, the core network does not send a response requesting path migration, because the core network has already communicated with the base station 2 in step S503a, and the address information related to the radio access bearer is configured for the UE. In this embodiment, after the UE reestablishes the cell to be managed by the non-source base station, if the target base station obtains the context information of the UE by using the S1 handover signaling, the information about the S1 application layer identifier allocated by the core network for the UE is obtained. After the target base station reconfigures the DRB of the UE, the target base station only needs to notify the core network that the UE has migrated to the target base station, and the core network stops transmitting the downlink data of the UE to the source base station, and then sends the downlink of the UE to the target base station. data. In this way, the UE can continue to carry out the business after the reconstruction. In this embodiment, the handover procedure is performed before the reestablishment process. As long as the base station 2 has obtained the context information of the UE when receiving the RRC connection reestablishment request sent by the UE, the reestablishment process can be completed. In the actual network, the source base station may send the context information of the UE to the neighboring base station in advance through the S1 signaling, so that the UE can be successfully re-established and the service can be continued. In the LTE system, there is an X2 interface between the base station 1 and the base station 2, and the UE is located in the cell 1 to which the base station 1 belongs, and is in a connected state. At this time, the base station 1 and the core network have been established for the UE. For the transmission of signaling and data (UE-associated logical SI-connection). The base station 1 obtains the success information of the UE for the possible reconstruction. Therefore, the context information of the UE is sent to the neighboring base station (including the base station 2) through the X2 interface, and the context information of the UE includes the UE in the source cell (the serving cell, the cell 1). The cell radio network temporary identifier, the UE's encryption key Ke B* in the target cell, the UE's reestablishment information in the target cell, etc., and the reconstruction information includes a truncated message integrity authentication code (short MAC-I). The base station 1 may transmit the context information of the UE by using a handover request or handover preparation signaling. The context information of the UE may also be carried by the newly added X2 interface signaling, and sent to the adjacent base station to cope with possible (or potential) reconstruction of the UE. .

The UE triggers the reestablishment due to the failure of the radio link, and selects the cell under the jurisdiction of the neighboring base station (δΡ, the target base station) for reconstruction. The SRB can be restored through the RRC connection reestablishment procedure, and the DRB can be restored through the RRC connection reconfiguration process. After the target base station learns that the UE has recovered the DRB through the RRC connection reconfiguration complete signaling, The target base station sends a signaling requesting path migration to the core network, and the signaling requesting the path migration includes the S1 application layer identifier (Source MME UE S1AP ID) allocated by the mobility management entity for the UE, and the radio access bearer to be migrated. The E-UTB (E-UTRAN Radio Access Bearer Identifier) and the address information (including the transport layer address and the GTP tunnel terminal identifier GTP-TEID), and the target cell identifier reconstructed by the UE. The signaling requesting the path migration may reuse the path migration request in the existing protocol, or may use the newly added S1 interface signaling, such as rebuilding the migration request. In the signaling requesting the path migration, the cell of the cause may be added to indicate the cause of the path migration. In this embodiment, the reason is the reestablishment of the UE. It should be noted that, if the UE has established multiple radio access bearers, and the radio access bearers are all restored after the UE is reestablished, the signaling for requesting path migration may include identifiers of multiple radio access bearers. Corresponding address information. Correspondingly, after receiving the signaling requesting the path migration, the core network needs to return a response to the target base station, including the S1 application layer identifier newly allocated by the core network for the UE, and the uplink list information of the migrated radio access bearer (E- RABs Switched in Uplink Item IEs). In this way, the core network and the target base station can continue to provide uplink and downlink data transmission for the UE, which ensures that the UE can continue to perform services. In this embodiment, the target base station may send the signaling requesting the path migration to the core network in the process of the RRC connection reconfiguration DRB, δΡ, without waiting for the target base station to receive the RRC connection reconfiguration complete signaling sent by the UE. The signaling of requesting path migration is sent, because the target base station usually obtains the DRB for the UE through RRC signaling, and the target base station sends the signaling requesting the path migration in advance to enable the downlink data to reach the target base station faster, and can be sent to the target base station as soon as possible. UE. If the UE cannot apply the RRC connection reconfiguration (ie, the RRC connection reconfiguration is not successful), the target base station may subsequently send a request to release the radio access bearer to the core network, requesting the core network to release the data access bearer that has not been successfully recovered. The embodiment of the present invention further provides a data transmission channel migration system, which can be used to implement the foregoing data transmission channel migration method provided by the embodiment of the present invention. FIG. 6 is a structural block diagram of a data transmission channel migration system according to an embodiment of the present invention. As shown in FIG. 6, the system includes: a target base station 62, configured to send a request path migration to a core network after the UE reestablishes to the target base station. Signaling; The core network 64, coupled to the target base station 62, is configured to migrate the data transmission channel of the user equipment to a data transmission channel between the core network and the target base station after receiving the signaling. The new data transmission channel may include a downlink general packet radio service tunneling protocol tunnel and/or an uplink general packet radio service tunneling protocol tunnel. Preferably, the new data transmission channel is a data transmission channel between the core network 64 and the target base station 62. In a preferred implementation manner of the present invention, the target base station 62 is configured to obtain the context information of the UE by using X2 interface signaling or S1 interface signaling before receiving the wireless connection reestablishment request sent by the UE. In another preferred implementation of the invention, the target base station 62 is arranged to reconfigure the data radio bearer for the UE before transmitting the signaling requesting path migration to the core network 64. In still another preferred implementation of the present invention, the core network 64 is configured to return a response requesting a path migration to the target base station 62 after migrating the data transmission channel of the UE to the data transmission channel between the core network and the target base station. The response includes the new S1 application layer identifier allocated by the core network for the UE and the uplink list information of the migrated radio access bearer. Preferably, the signaling requesting the path migration is a path migration request, a reestablishment notification signaling, or a handover notification signaling. Preferably, the signaling for requesting path migration includes information of at least one of the following: an S1 application layer identifier allocated by the mobility management entity for the UE, an identifier and address information of the radio access bearer to be migrated, a target cell identifier reconstructed by the UE, The reason for triggering a path migration. In summary, after the UE is reestablished to the target base station, the target base station can restore the connection of the UE on the S1 interface in time, and the uplink and downlink data of the UE can continue to be transmitted after the reconstruction. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device and, in some cases, may be different from the order herein. The steps shown or described are performed, or they are separately fabricated into individual integrated circuit modules, or a plurality of modules or steps are fabricated as a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention. Industrial Applicability After the user equipment is re-established to the cell to which the new base station belongs, the new base station will cause the core network to migrate the data transmission channel of the UE, so that the new cell reconstructed by the UE can continue to provide data transmission services for the UE, thereby improving User satisfaction. The invention has small changes to the existing protocol, and is simple to implement and flexible in configuration.

Claims

Claim

A data transmission channel migration method, comprising:

After the user equipment reestablishes to the target base station, the target base station sends signaling requesting path migration to the core network;

After receiving the signaling, the core network migrates a data transmission channel of the user equipment to a data transmission channel between the core network and the target base station.

2. The method according to claim 1, wherein the data transmission channel comprises a downlink general packet radio service tunneling protocol tunnel and/or an uplink general packet radio service tunneling protocol tunnel.

The method according to claim 1, wherein, before the target base station sends the signaling requesting the path migration to the core network, the method further includes:

Before the target base station receives the wireless connection reestablishment request sent by the user equipment, the target base station obtains the context information of the user equipment by using X2 interface signaling or S1 interface signaling.

The target base station reconfigures a data radio bearer for the user equipment.

The method according to claim 1, wherein after the data transmission channel of the user equipment is migrated to a data transmission channel between the core network and the target base station, the method further includes: The core network returns a response requesting the path migration to the target base station; the response includes the new S1 application layer identifier allocated by the core network for the user equipment and the uplink list information of the migrated radio access bearer.

The method according to any one of claims 1 to 5, wherein the signaling for requesting path migration is a path migration request, a reestablishment notification signaling, or a handover notification signaling.

The method according to any one of claims 1 to 5, wherein the signaling of the request path migration includes information of at least one of the following:

The S1 application layer identifier allocated by the mobility management entity for the user equipment, the identifier and address information of the radio access bearer to be migrated, the target cell identifier reconstructed by the user equipment, and the reason for triggering the path migration.

8. A data transmission channel migration system, comprising:

And the target base station is configured to send, after the user equipment reestablishes to the target base station, the signaling for requesting path migration to the core network;

The core network is configured to, after receiving the signaling, migrate a data transmission channel of the user equipment to a data transmission channel between the core network and the target base station.

The system according to claim 8, wherein the target base station is configured to obtain the user equipment by X2 interface signaling or S1 interface signaling before receiving the wireless connection reestablishment request sent by the user equipment. Contextual information.

10. The system according to claim 8, wherein the target base station is configured to reconfigure a data radio bearer for the user equipment before transmitting the signaling requesting path migration to the core network.

11. The system according to claim 8, wherein the core network is configured to migrate a data transmission channel of the user equipment to a data transmission channel between the core network and the target base station, to the The target base station returns a response requesting path migration.