CN104301883B

CN104301883B - A kind of cooperative multipoint transmission control method and device in cell switch process

Info

Publication number: CN104301883B
Application number: CN201310298378.XA
Authority: CN
Inventors: 付喆
Original assignee: China Academy of Telecommunications Technology CATT
Current assignee: China Academy of Telecommunications Technology CATT; Datang Mobile Communications Equipment Co Ltd
Priority date: 2013-07-16
Filing date: 2013-07-16
Publication date: 2018-01-16
Anticipated expiration: 2033-07-16
Also published as: CN104301883A; WO2015007210A1

Abstract

The invention discloses the cooperative multipoint transmission control method and device in a kind of cell switch process.Its method includes：Serving BS judges whether target BS supports the cooperative multipoint transmission to terminal after it is determined that carrying out cell switching to terminal；If, other access network nodes in gathering to cooperation send handoff notification message, wherein the identification information of carried terminal, the identification information of target BS and cooperative multipoint transmission maintain configured information, if not, the cooperative multipoint transmission to terminal is deactivated, the message of instruction deactivation cooperative multipoint transmission is sent to other access network nodes.If other access network nodes receive handoff notification message, determine that terminal continues cooperative multipoint transmission after switching to target BS；If receiving the message for deactivating cooperative multipoint transmission, the cooperative multipoint transmission of the terminal is deactivated.The embodiment of the present invention, solve when performing the terminal of cooperative multipoint transmission and carrying out cell switching, the problem of how processing the cooperative multipoint transmission of the terminal.

Description

Coordinated multi-point transmission control method and device in cell switching process

Technical Field

The present invention relates to the field of wireless communications technologies, and in particular, to a coordinated multi-point transmission control method and apparatus in a cell handover process.

Background

In a Long Term Evolution (LTE) system, a cell handover process performed by a UE is as follows:

the source evolved node b (eNB) makes a decision to perform X2 handover for a User Equipment (UE) according to a measurement result reported by the UE.

The source eNB sends a handover request message to the target eNB.

After receiving the switching request message, the target eNB configures a new bearer for the UE, and if the configuration is successful, the target eNB returns a switching response message to the source eNB.

After receiving the handover response message, the source eNB sends a Radio Resource Control (RRC) reconfiguration message to the UE, and stops receiving and sending the data plane and the control plane.

And after receiving the RRC reconfiguration message, the UE starts to stop receiving and transmitting the data plane and the control plane of the source eNB and performs uplink and downlink synchronous operation with the target eNB. After finishing downlink synchronization, the UE initiates a contention-free random access process, finishes uplink synchronization through the contention-free random access process, sends an RRC reconfiguration completion message to the target eNB, and after receiving the message, the target eNB returns an Acknowledgement (ACK) message of the RLC and starts to send downlink data at the same time. And after receiving the RLC ACK message, the UE starts uplink transmission on the data plane.

Furthermore, on the network side, to ensure lossless operation of AM data, the source eNB forwards PDCP SDUs that are not acknowledged or newly arrived to the target eNB.

After receiving the RRC reconfiguration complete message, the target eNB informs the core network to switch the path, and after receiving the confirmation from the core network, the target eNB informs the source eNB to release the old bearer.

In order to reduce the neighboring cell interference of the UE at the coverage edge of the cell, a Long Term Evolution-advanced (LTE-a) system employs a Coordinated-Multiple-Point (CoMP) transmission technology. The coordinated multipoint Transmission technology refers to that multiple Transmission Points (TPs) separated from each other in a geographical location participate in data Transmission for one UE cooperatively or jointly receive data sent by one UE. Generally, the multiple transmission points may be base stations of different cells, or may be Radio heads (RRHs) of the same base station and different cells thereunder.

Whether a central node exists or not is used for carrying out global optimization scheduling, and the implementation scheme of the CoMP technology is divided into non-central cooperation scheduling and central cooperation scheduling. In a central cooperation scheduling scenario, a Central Cooperation Node (CCN) and a serving base station cooperate to schedule transmission of CoMP UEs. And under the non-central scheduling scene, multiple times of interaction of scheduling information is carried out among the cooperative base stations, and the transmission of the CoMP UE is scheduled in an iterative scheduling mode. Herein, CoMP UE refers to UE supporting coordinated multipoint transmission.

In the prior art, when the cell switching is performed on the UE, the serving base station performs resource scheduling on the UE alone on the basis of the premise, and the problem of how to handle coordinated multi-point transmission of the CoMP UE when the cell switching is performed on the CoMP UE performing the coordinated multi-point transmission is not considered.

Disclosure of Invention

The invention aims to provide a coordinated multi-point transmission control method and a coordinated multi-point transmission control device in a cell switching process, which are used for solving the problem of how to process coordinated multi-point transmission of CoMP UE when the CoMP UE executing the coordinated multi-point transmission carries out cell switching.

The purpose of the invention is realized by the following technical scheme:

the embodiment of the invention provides a coordinated multi-point transmission control method in a cell switching process. Wherein, the cell switching process comprises: the service base station sends a switching request message to a target base station after determining to perform cell switching on the terminal, and sends a switching command to the terminal after receiving a switching request response message sent by the target base station so as to indicate the terminal to be switched to the cell of the target base station. Wherein the terminal is a terminal performing coordinated multipoint transmission.

In the cell handover process, a coordinated multi-point transmission control method includes:

after determining to perform cell switching on the terminal, the serving base station judges whether the target base station supports coordinated multi-point transmission to the terminal;

if the target base station supports the coordinated multi-point transmission of the terminal, the service base station sends a switching notification message to other access network nodes in a coordinated set participating in the coordinated multi-point transmission of the terminal, wherein the switching notification message carries the identification information of the terminal, the identification information of the target base station and coordinated multi-point transmission maintenance indication information;

if the target base station does not support the coordinated multi-point transmission of the terminal, the service base station deactivates the coordinated multi-point transmission of the terminal, and sends a message indicating to deactivate the coordinated multi-point transmission to other access network nodes in a coordinated set participating in the coordinated multi-point transmission of the terminal, wherein the message indicating to deactivate the multi-point transmission carries the identification information of the terminal and the indication information of deactivating the coordinated multi-point transmission.

In the method provided by the embodiment of the invention, in the process of cell switching of the terminal, if the target base station is determined to support the coordinated multi-point transmission of the terminal, the coordinated multi-point transmission of the terminal is maintained, and if the target base station is determined not to support the coordinated multi-point transmission of the terminal, the coordinated multi-point transmission of the terminal is deactivated, and other access network nodes in a coordinated set are instructed to deactivate the coordinated multi-point transmission aiming at the terminal, so that the continuity of the coordinated multi-point transmission of the terminal is not required to be ensured, and the problem of how to process the coordinated multi-point transmission of the CoMP UE when the CoMP UE executing the coordinated multi-point transmission performs the cell switching is solved.

In the embodiment of the present invention, the serving base station may obtain the information in multiple ways to determine whether the target base station supports the coordinated multi-point transmission to the terminal, and the following lists several implementation ways:

in the first mode, the serving base station determines whether the target base station supports coordinated multi-point transmission to the terminal according to the indication information of whether the target base station supports coordinated multi-point transmission to the terminal, which is carried in the handover request response message.

In this way, optionally, the serving base station may carry, in the handover request message sent to the target base station, CoMP transmission capability request information, where the CoMP transmission capability request information is used to indicate that the target base station sends indication information indicating whether the target base station supports coordinated multi-point transmission for the terminal. Further, the serving base station may also carry, in the handover request message, indication information whether the serving base station supports coordinated multi-point transmission to the terminal.

And secondly, the service base station judges whether the target base station supports the coordinated multi-point transmission to the terminal according to the indication information which is sent by the OAM in advance and is used for judging whether each base station supports the coordinated multi-point transmission to the terminal.

And thirdly, the service base station judges whether the target base station supports the coordinated multi-point transmission of the terminal according to the indication information which is interacted among the base stations in advance and supports the coordinated multi-point transmission of the terminal.

And the service base station judges whether the target base station supports the coordinated multi-point transmission for the terminal according to the indication information which is sent by the central coordination point in the coordination set in advance and is used for judging whether each base station supports the coordinated multi-point transmission for the terminal.

Obviously, the precondition of the fourth method is that the collaboration set includes the central collaboration point.

Based on any implementation manner described above, preferably, the specific implementation means for the serving base station to determine whether the target base station supports coordinated multi-point transmission to the terminal may include, but is not limited to:

if the indication information indicating whether the target base station supports the coordinated multi-point transmission of the terminal indicates that the target base station does not support the coordinated multi-point transmission, the serving base station judges that the target base station does not support the coordinated multi-point transmission of the terminal;

if the indication information indicating whether the target base station supports the coordinated multi-point transmission of the terminal indicates that the target base station does not support the coordinated multi-point transmission of the central scheduling mode, but the coordinated multi-point transmission of the terminal is in the central scheduling mode, the serving base station judges that the target base station does not support the coordinated multi-point transmission of the terminal;

if the indication information indicating whether the target base station supports the coordinated multi-point transmission of the terminal indicates that the target base station supports the coordinated multi-point transmission of the central scheduling mode and the coordinated multi-point transmission of the terminal is in the central scheduling mode, the serving base station judges that the target base station supports the coordinated multi-point transmission of the terminal; if the indication information of whether the target base station supports the coordinated multi-point transmission of the terminal indicates that the target base station supports the coordinated multi-point transmission of the central scheduling mode, the indication information of whether the target base station supports the coordinated multi-point transmission of the terminal also indicates the identification information of the central coordinated point of the coordinated set where the target base station is located.

Based on any of the above implementation manners, preferably, after determining to perform cell handover on the terminal, the serving base station determines whether the target base station supports coordinated multi-point transmission for the terminal. And if the cell is switched to S1, deactivating the coordinated multi-point transmission of the terminal, and sending a message indicating to deactivate the coordinated multi-point transmission to other access network nodes in a coordinated set participating in the coordinated multi-point transmission of the terminal, wherein the message indicating to deactivate the multi-point transmission carries the identification information of the terminal and the indication information for deactivating the coordinated multi-point transmission.

When the serving base station and the target base station are not in the same Mobility Management Entity (MME), the X2 handover cannot be performed, and the S1 handover is required. S1 is complicated to switch, and if the cooperative node transmission of the terminal is still maintained, the corresponding information needs to be sent to the core network node. To simplify the handover procedure, the coordinated multipoint transmission to the terminal may be deactivated when the determination is S1 handover.

In the embodiment of the present invention, the cooperation set participating in the coordinated multi-point transmission of the terminal may include a central coordination point, and may also include other coordination base stations other than the serving base station.

Based on the above-mentioned method embodiment at any serving base station side, for the case where the target base station supports coordinated multi-point transmission to the terminal. Preferably, if the indication information indicating whether the target base station supports the coordinated multi-point transmission to the terminal indicates that the target base station supports the coordinated multi-point transmission in the central scheduling mode and the identification information of the central coordinated point in the coordinated set in which the target base station is located, and the coordinated multi-point transmission of the terminal is in the central scheduling mode, the serving base station sends a handover notification message to other access network nodes in the coordinated set participating in the coordinated multi-point transmission of the terminal, specifically: the service base station sends a switching notification message to a central cooperation point in a cooperation set participating in the cooperation multipoint transmission of the terminal, wherein the switching notification message also carries identification information of the central cooperation point of the cooperation set where the target base station is located.

On this basis, preferably, before the serving base station sends the handover notification message to the central cooperating point in the cooperating set participating in the coordinated multi-point transmission of the terminal, whether the target base station and the serving base station belong to the same central cooperating point is determined according to the identification information of the central cooperating point of the cooperating set where the target base station is located;

if not, the service base station sends the switching notification message to the target base station, so that the target base station sends the switching notification message to a central cooperation point in a cooperation set where the target base station is located;

and if the terminal belongs to the cooperative set, the service base station sends a switching notification message to a central cooperative point in the cooperative set participating in the cooperative multipoint transmission of the terminal.

Based on the above-mentioned method embodiment at any serving base station side, for the case that the target base station does not support coordinated multi-point transmission to the terminal. In one case, if the cooperation set participating in the coordinated multi-point transmission of the terminal includes the central cooperation point, preferably, sending a message indicating to deactivate the coordinated multi-point transmission to other access network nodes in the cooperation set participating in the coordinated multi-point transmission of the terminal includes: sending a message indicating deactivation of coordinated multipoint transmission to the central coordination point; after sending the message indicating to deactivate coordinated multipoint transmission to the central coordination point, the serving base station may further receive the identification information of the terminal, the data that is not transmitted to the terminal or has not received the correct acknowledgement of the terminal, the start position information of the data, and the end position information of the data sent by the central coordination point, and store the identification information of the terminal, the data, the start position information of the data, and the end position information of the data in an associated manner.

On the basis of this situation, if the cooperation set participating in the coordinated multi-point transmission of the terminal further includes other cooperating base stations except the serving base station, preferably, the method further includes sending a message indicating to deactivate the coordinated multi-point transmission to other access network nodes participating in the cooperation set participating in the coordinated multi-point transmission of the terminal, and further including: and sending a message indicating the deactivation of coordinated multi-point transmission to other coordinated base stations in the coordinated set.

And informing other cooperative base stations to deactivate the cooperative multi-point transmission of the terminal, thereby avoiding the interference of other cooperative base stations on the cell switching process or the communication after the switching because other cooperative base stations continue to carry out scheduling/transmission for the multi-point cooperative transmission of the terminal.

Based on the above-mentioned method embodiment at any serving base station side, for the case that the target base station does not support coordinated multi-point transmission to the terminal. In another case, if the cooperation set participating in the coordinated multi-point transmission of the terminal includes other cooperation base stations except the serving base station but does not include the central cooperation point, sending a message indicating to deactivate the coordinated multi-point transmission to other access network nodes participating in the cooperation set participating in the coordinated multi-point transmission of the terminal, including: sending a message indicating to deactivate coordinated multi-point transmission to other coordinated base stations in the coordinated set; after sending the message indicating to deactivate coordinated multipoint transmission to other coordinated base stations in the coordinated set, the serving base station may further receive the identification information of the terminal, the data that is not transmitted to the terminal or has not received the correct acknowledgement of the terminal, the start position information of the data, and the end position information of the data sent by other coordinated base stations, and store the identification information of the terminal, the data, the start position information of the data, and the end position information of the data in an associated manner.

In the cell handover process, a coordinated multi-point transmission control method at an access network node (the access network node is an access network node other than a serving base station of a terminal in a coordinated set participating in coordinated multi-point transmission of the terminal) side includes:

an access network node except the terminal service base station in a coordinated set participating in coordinated multi-point transmission of a terminal receives a message indicating to deactivate coordinated multi-point transmission, wherein the message indicating to deactivate the multi-point transmission carries identification information of the terminal and indication information for deactivating the coordinated multi-point transmission; the access network node determines the terminal according to the identification information of the terminal and deactivates the coordinated multi-point transmission of the terminal according to the indication of the indication information for deactivating the coordinated multi-point transmission; or,

the access network node receives a switching notification message, wherein the switching notification message carries the identification information of the terminal, the identification information of the target base station and the coordinated multi-point transmission maintenance indication information; the access network node determines the terminal according to the identification information of the terminal, determines the target base station according to the identification information of the target base station, and determines that the terminal continues to perform coordinated multi-point transmission after being switched to the target base station according to the coordinated multi-point transmission maintaining indication information.

In the method provided by the embodiment of the invention, in the process of cell switching of the terminal, if the indication message indicating the deactivation of the coordinated multi-point transmission is received, other access network nodes in the coordinated set deactivate the coordinated multi-point transmission aiming at the terminal according to the indication of the service base station, and the continuity of the coordinated multi-point transmission of the terminal does not need to be ensured. If receiving the switching notification message, the access network node determines to maintain the coordinated multipoint transmission of the terminal. The problem of how to process the coordinated multi-point transmission of the CoMP UE when the CoMP UE executing the CoMP transmission carries out cell switching is solved.

The access network node may be a central cooperation point in the cooperation set, or may be another cooperation base station other than the serving base station in the cooperation set.

If the access network node is a central cooperating point, preferably, the handover notification message further carries identification information of the central cooperating point of the cooperating set where the target base station is located.

Based on any of the above embodiments of the access network, preferably, after determining that the terminal continues to perform coordinated multipoint transmission after being switched to the target base station, the method further includes:

suspending scheduling control of coordinated multipoint transmission to the terminal;

judging whether the central cooperation point of the cooperation set of the target base station is the local central cooperation point or not according to the identification information of the central cooperation point of the cooperation set of the target base station;

if the central cooperation point of the cooperation set where the target base station is located is the central cooperation point, after the terminal is confirmed to be switched to the target base station, a path switching process is not started to a core network node, and scheduling control of cooperative multi-point transmission is continuously carried out on the terminal.

After the central cooperation point of the cooperation set where the target base station is located is determined to be the central cooperation point, a path switching process does not need to be started to a core network node, so that the influence of the switching process on a core network is reduced, and unnecessary network function reconfiguration process and loss are avoided.

Based on any of the above method embodiments on the access network node side, preferably, if the access network node is a central cooperative point, after receiving a message indicating to deactivate coordinated multipoint transmission sent by a serving base station of a terminal, the access network node also sends identification information of the terminal, data that is not transmitted to the terminal or that is not received a correct acknowledgement of the terminal, start position information of the data, and end position information of the data to the serving base station of the terminal; if the access network node is other cooperative base stations, the access network node receives a message which is sent by a service base station of a terminal and indicates to deactivate cooperative multipoint transmission, and then sends the identification information of the terminal and data which is not transmitted to the terminal or does not receive the correct confirmation of the terminal to the service base station of the terminal; or, the other cooperative base stations send the identification information of the terminal, the data which is not transmitted to the terminal or received the correct confirmation of the terminal, the start position information of the data and the end position information of the data to the serving base station of the terminal.

Based on any of the above embodiments of the method at the access network node side, if the access network node is a central cooperative point, preferably, after receiving the message indicating deactivation of cooperative multipoint transmission sent by the serving base station of the terminal, the central cooperative point also sends a message indicating deactivation of cooperative multipoint transmission to other cooperative base stations except the serving base station in the cooperative set participating in cooperative multipoint transmission of the terminal, and the message indicating deactivation of cooperative multipoint transmission sent to other cooperative base stations carries the identification information of the terminal and the indication information of deactivation of cooperative multipoint transmission.

An embodiment of the present invention provides a base station, including:

the cell switching judgment module is used for determining cell switching of the terminal;

a message receiving and sending module, configured to send a handover request message to a target base station after the cell handover decision module determines to perform cell handover on the terminal; after receiving a switching request response message sent by the target base station, sending a switching command to the terminal to indicate the terminal to switch to a cell of the target base station, wherein the terminal is a terminal for executing coordinated multi-point transmission;

a coordinated multi-point transmission control module, configured to determine whether the target base station supports coordinated multi-point transmission for the terminal after the cell handover decision module determines to perform cell handover for the terminal; if the target base station supports the coordinated multi-point transmission of the terminal, sending a switching notification message to other access network nodes in a coordinated set participating in the coordinated multi-point transmission of the terminal, wherein the switching notification message carries identification information of the terminal, identification information of the target base station and coordinated multi-point transmission maintaining indication information; and if the target base station does not support the coordinated multi-point transmission of the terminal, deactivating the coordinated multi-point transmission of the terminal, and sending a message for indicating to deactivate the coordinated multi-point transmission to other access network nodes in a coordinated set participating in the coordinated multi-point transmission of the terminal, wherein the message for indicating to deactivate the multi-point transmission carries the identification information of the terminal and the indication information for deactivating the coordinated multi-point transmission.

In the cell switching process of the terminal, the base station provided in the embodiment of the present invention maintains the coordinated multi-point transmission of the terminal if it is determined that the target base station supports the coordinated multi-point transmission of the terminal, deactivates the coordinated multi-point transmission of the terminal if it is determined that the target base station does not support the coordinated multi-point transmission of the terminal, and instructs other access network nodes in the coordinated set to deactivate the coordinated multi-point transmission for the terminal, so that it is not necessary to ensure the continuity of the coordinated multi-point transmission of the terminal, and a problem of how to handle the coordinated multi-point transmission of the CoMP UE when the CoMP UE performing the coordinated multi-point transmission performs the cell switching is solved.

Preferably, when determining whether the target base station supports coordinated multi-point transmission to the terminal, the coordinated multi-point transmission control module is specifically configured to:

judging whether the target base station supports the coordinated multi-point transmission of the terminal or not according to the indication information of whether the target base station supports the coordinated multi-point transmission of the terminal or not, which is carried in the switching request response message; or,

judging whether the target base station supports the coordinated multi-point transmission of the terminal or not according to indication information which is sent by OAM in advance and is used for indicating whether each base station supports the coordinated multi-point transmission of the terminal or not; or,

judging whether the target base station supports the coordinated multi-point transmission of the terminal or not according to indication information whether the base stations support the coordinated multi-point transmission of the terminal or not interacted in advance; or,

and judging whether the target base station supports the coordinated multi-point transmission of the terminal or not according to indication information which is sent by a central coordinated point in the coordinated set in advance and is used for indicating whether each base station supports the coordinated multi-point transmission of the terminal or not.

On the basis of the above preferred embodiment, further, when determining whether the target base station supports coordinated multipoint transmission to the terminal, the coordinated multipoint transmission control module may specifically be configured to:

if the indication information indicating whether the target base station supports the coordinated multi-point transmission of the terminal indicates that the target base station does not support the coordinated multi-point transmission, judging that the target base station does not support the coordinated multi-point transmission of the terminal;

if the indication information indicating whether the target base station supports the coordinated multi-point transmission of the terminal indicates that the target base station does not support the coordinated multi-point transmission of a central scheduling mode, but the coordinated multi-point transmission of the terminal is in the central scheduling mode, judging that the target base station does not support the coordinated multi-point transmission of the terminal;

if the indication information indicating whether the target base station supports the coordinated multi-point transmission of the terminal indicates that the target base station supports the coordinated multi-point transmission of the central scheduling mode and the coordinated multi-point transmission of the terminal is in the central scheduling mode, judging that the target base station supports the coordinated multi-point transmission of the terminal; and if the indication information of whether the target base station supports the coordinated multi-point transmission of the terminal indicates that the target base station supports the coordinated multi-point transmission of the central scheduling mode, the indication information of whether the target base station supports the coordinated multi-point transmission of the terminal also indicates the identification information of the central coordinated point of the coordinated set where the target base station is located.

Based on any of the foregoing embodiments of the base station, preferably, after the cell handover decision module determines to perform cell handover on the terminal, before the coordinated multi-point transmission control module determines whether the target base station supports coordinated multi-point transmission for the terminal, the coordinated multi-point transmission control module is further configured to:

and if the cell is determined to be switched to S1, deactivating the coordinated multi-point transmission of the terminal, and sending a message indicating to deactivate the coordinated multi-point transmission to other access network nodes in a coordinated set participating in the coordinated multi-point transmission of the terminal, wherein the message indicating to deactivate the multi-point transmission carries the identification information of the terminal and the indication information for deactivating the coordinated multi-point transmission.

Based on any of the foregoing embodiments of the base station, preferably, if the indication information indicating whether the target base station supports the coordinated multi-point transmission for the terminal indicates that the target base station supports the coordinated multi-point transmission in the central scheduling mode and the identification information of the central coordinated point in the coordinated set where the target base station is located, and the coordinated multi-point transmission for the terminal is in the central scheduling mode, the coordinated multi-point transmission control module is specifically configured to:

and sending a switching notification message to a central cooperative point in a cooperative set participating in the cooperative multipoint transmission of the terminal, wherein the switching notification message also carries identification information of the central cooperative point of the cooperative set where the target base station is located.

On this basis, preferably, when sending the handover notification message to the central cooperating point in the cooperating set participating in the coordinated multipoint transmission of the terminal, the coordinated multipoint transmission control module is specifically configured to:

judging whether the target base station and the service base station belong to the same central cooperation point or not according to the identification information of the central cooperation point of the cooperation set where the target base station is located;

if not, sending the switching notification message to the target base station so that the target base station sends the switching notification message to a central cooperation point in a cooperation set where the target base station is located;

and if the terminal belongs to the cooperative set, sending a switching notification message to a central cooperative point in the cooperative set participating in the cooperative multipoint transmission of the terminal.

Based on any of the foregoing embodiments of the base station, preferably, if the cooperation set participating in the coordinated multi-point transmission of the terminal includes the central cooperation point, when the coordinated multi-point transmission control module sends a message indicating to deactivate the coordinated multi-point transmission to other access network nodes in the cooperation set participating in the coordinated multi-point transmission of the terminal, the method is specifically configured to:

sending a message to the central cooperating point indicating deactivation of coordinated multipoint transmission;

after sending a message indicating to deactivate coordinated multipoint transmission to the central coordinated point, the coordinated multipoint transmission control module is further configured to: the terminal identification information sent by the central cooperation point, the data which is not transmitted to the terminal or received the correct confirmation of the terminal, the start position information of the data and the end position information of the data; and storing the identification information of the terminal, the data, the start position information of the data and the end position information of the data in an associated manner.

On this basis, preferably, if the coordinated set participating in the coordinated multi-point transmission of the terminal further includes other coordinated base stations except the base station, the coordinated multi-point transmission control module is further configured to, when sending the message indicating to deactivate the coordinated multi-point transmission to other access network nodes participating in the coordinated set participating in the coordinated multi-point transmission of the terminal:

and sending a message indicating the deactivation of coordinated multi-point transmission to other coordinated base stations in the coordinated set.

Based on any of the foregoing embodiments of the base station, preferably, if the cooperation set participating in the coordinated multi-point transmission of the terminal includes other cooperation base stations except the base station but does not include the central cooperation point, when the coordinated multi-point transmission sends a message indicating to deactivate the coordinated multi-point transmission to other access network nodes in the cooperation set participating in the coordinated multi-point transmission of the terminal, the method is specifically configured to:

sending a message indicating deactivation of coordinated multi-point transmission to other coordinated base stations in the coordinated set;

after sending a message indicating to deactivate coordinated multipoint transmission to other coordinated base stations in the coordinated set, the coordinated multipoint transmission control module is further configured to: receiving identification information of the terminal, data which is not transmitted to the terminal or received correct confirmation of the terminal, starting position information of the data and ending position information of the data, wherein the identification information of the terminal is sent by other cooperative base stations; and storing the identification information of the terminal, the data, the start position information of the data and the end position information of the data in an associated manner.

The embodiment of the invention provides an access network node, which is an access network node except a terminal service base station in a cooperation set participating in coordinated multi-point transmission of a terminal, and comprises:

a coordinated multi-point transmission indication receiving module, configured to receive a message indicating deactivation of coordinated multi-point transmission, where the message indicating deactivation of multi-point transmission carries identification information of the terminal and indication information of deactivation of coordinated multi-point transmission; or receiving a handover notification message, where the handover notification message carries the identifier information of the terminal, the identifier information of the target base station, and the coordinated multi-point transmission maintenance indication information;

a coordinated multipoint transmission deactivation module, configured to, when the coordinated multipoint transmission indication receiving module receives a message indicating deactivation of coordinated multipoint transmission, determine the terminal according to the identifier information of the terminal, and deactivate coordinated multipoint transmission of the terminal according to the indication of the indication information for deactivating coordinated multipoint transmission;

and a coordinated multi-point transmission maintaining module, configured to, when the coordinated multi-point transmission indication receiving module receives the handover notification message, determine the terminal according to the identifier information of the terminal, determine the target base station according to the identifier information of the target base station, and determine that the terminal is handed over to the target base station and then continue coordinated multi-point transmission according to the coordinated multi-point transmission maintaining indication message.

In the cell switching process of the terminal, if the access network node receives the indication message indicating the deactivation of the coordinated multi-point transmission, other access network nodes in the coordinated set deactivate the coordinated multi-point transmission for the terminal according to the indication of the serving base station, and the continuity of the coordinated multi-point transmission of the terminal does not need to be ensured. If receiving the switching notification message, the access network node determines to maintain the coordinated multipoint transmission of the terminal. The problem of how to process coordinated multi-point transmission of CoMP UE when the CoMP UE executing CoMP transmission carries out cell switching is solved.

Preferably, if the access network node is a central cooperating point, the handover notification message further carries identification information of the central cooperating point of the cooperating set where the target base station is located.

Based on any of the foregoing access network node embodiments, preferably, after the coordinated multi-point transmission maintaining module determines that the terminal continues coordinated multi-point transmission after being switched to the target base station, the coordinated multi-point transmission maintaining module is further configured to:

judging whether the central cooperation point of the cooperation set where the target base station is located is the local central cooperation point according to the identification information of the central cooperation point of the cooperation set where the target base station is located;

If the access network node is a central cooperation point, preferably, the access network node further comprises a first data sending module;

after the coordinated multi-point transmission indication receiving module receives a message which is sent by a service base station of a terminal and indicates that coordinated multi-point transmission is deactivated, the first data sending module is used for sending identification information of the terminal, data which is not transmitted to the terminal or does not receive correct confirmation of the terminal, starting position information of the data and ending position information of the data to the service base station of the terminal;

if the access network node is a cooperative base station other than the serving base station, preferably, the access network node further includes a second data sending module;

after the coordinated multi-point transmission indication receiving module sends the message indicating the deactivation of coordinated multi-point transmission, the second data sending module is used for sending the identification information of the terminal and the data which is not transmitted to the terminal or does not receive the correct confirmation of the terminal to the service base station of the terminal; or, after the coordinated multi-point transmission indication receiving module sends the message indicating the deactivation of coordinated multi-point transmission, the second data sending module is configured to send the identification information of the terminal, the data that is not transmitted to the terminal or that is not received the correct acknowledgement of the terminal, the start position information of the data, and the end position information of the data to the serving base station of the terminal.

On this basis, preferably, if the access network node is a central cooperative point, the access network node further includes a coordinated multi-point transmission indication sending module;

after the coordinated multi-point transmission indication receiving module receives a message which is sent by a service base station of a terminal and indicates to deactivate coordinated multi-point transmission, the coordinated multi-point transmission indication sending module is used for sending a message which indicates to deactivate coordinated multi-point transmission to other coordinated base stations except the service base station in a coordinated set participating in coordinated multi-point transmission of the terminal, and the message which indicates to deactivate coordinated multi-point transmission and sent to the other coordinated base stations carries identification information of the terminal and indication information for deactivating coordinated multi-point transmission.

The embodiment of the invention provides a coordinated multi-point transmission control device in a switching process, which comprises the following steps:

a processor configured to perform a cell handover procedure and coordinated multipoint transmission control in the cell handover procedure;

the processor is configured to, when executing a cell handover procedure, specifically: after determining to perform cell switching on the terminal, sending a switching request message to a target base station, and after receiving a switching request response message sent by the target base station, sending a switching command to the terminal to instruct the terminal to switch to the cell of the target base station. Wherein the terminal is a terminal performing coordinated multipoint transmission.

The processor is configured to, when performing coordinated multipoint transmission control in a cell handover process, specifically: after determining to perform cell switching on the terminal, judging whether the target base station supports coordinated multi-point transmission on the terminal; if the target base station supports the coordinated multi-point transmission of the terminal, sending a switching notification message to other access network nodes in a coordinated set participating in the coordinated multi-point transmission of the terminal, wherein the switching notification message carries identification information of the terminal, identification information of the target base station and coordinated multi-point transmission maintaining indication information; and if the target base station does not support the coordinated multi-point transmission of the terminal, deactivating the coordinated multi-point transmission of the terminal, and sending a message for indicating to deactivate the coordinated multi-point transmission to other access network nodes in a coordinated set participating in the coordinated multi-point transmission of the terminal, wherein the message for indicating to deactivate the multi-point transmission carries the identification information of the terminal and the indication information for deactivating the coordinated multi-point transmission.

An embodiment of the present invention provides another coordinated multi-point transmission control apparatus in a handover process, including:

a processor configured to receive a message indicating to deactivate coordinated multi-point transmission, where the message indicating to deactivate the multi-point transmission carries identification information of the terminal and indication information of deactivating the coordinated multi-point transmission; the access network node determines the terminal according to the identification information of the terminal and deactivates the coordinated multi-point transmission of the terminal according to the indication of the indication information for deactivating the coordinated multi-point transmission; or receiving a switching notification message, where the switching notification message carries identification information of the terminal, identification information of the target base station, and coordinated multi-point transmission maintenance indication information; and the access network node determines the terminal according to the identification information of the terminal, determines the target base station according to the identification information of the target base station, and determines that the terminal is switched to the target base station and then continues coordinated multi-point transmission according to the coordinated multi-point transmission maintaining indication information.

In the cell switching process of the terminal, the device provided in the embodiment of the present invention maintains the coordinated multi-point transmission of the terminal if it is determined that the target base station supports the coordinated multi-point transmission of the terminal, and deactivates the coordinated multi-point transmission of the terminal if it is determined that the target base station does not support the coordinated multi-point transmission of the terminal, without ensuring the continuity of the coordinated multi-point transmission of the terminal, thereby solving the problem of how to handle the coordinated multi-point transmission of the CoMP UE when the CoMP UE performing the coordinated multi-point transmission performs the cell switching.

Drawings

FIG. 1 is a schematic diagram of a first method provided by an embodiment of the present invention;

FIG. 2 is a schematic diagram of a second method provided by an embodiment of the present invention;

FIG. 3 is a schematic diagram of a third method provided by an embodiment of the present invention;

FIG. 4 is a schematic diagram of a fourth method provided by the embodiments of the present invention;

FIG. 5 is a schematic diagram of a fifth method provided by the embodiment of the invention;

fig. 6 is a schematic diagram of a base station according to an embodiment of the present invention;

fig. 7 is a schematic diagram of an access network node according to an embodiment of the present invention.

Detailed Description

The core idea of the embodiment of the invention is as follows: in the process of cell switching, if the target base station is determined to support the coordinated multi-point transmission to the terminal, the coordinated multi-point transmission of the terminal is maintained, if the target base station is determined not to support the coordinated multi-point transmission to the terminal, the coordinated multi-point transmission of the terminal is deactivated, and other access network nodes in a coordinated set are indicated to deactivate the coordinated multi-point transmission aiming at the terminal, so that the continuity of the coordinated multi-point transmission of the terminal is not required to be ensured.

The embodiment of the invention is not only suitable for LTE and LTE-A networks, but also suitable for other communication networks with CoMP transmission.

Before describing the embodiments of the present invention in detail with reference to the accompanying drawings, terms related to the embodiments of the present invention will be explained.

CoMP UE refers to UE supporting CoMP transmission. The technical problem to be solved by the invention is how to handle coordinated multipoint transmission of the CoMP UE when the CoMP UE executing the coordinated multipoint transmission performs cell switching. Therefore, the terminals involved in the embodiments of the present invention refer to CoMP UEs performing CoMP transmission unless otherwise specified.

The base station may be an eNB in an LTE system, or may refer to an access network node having a function of a base station in a subsequent evolution release.

The serving base station refers to a base station to which a cell accessed by the terminal belongs.

The cooperative set refers to a set formed by access network nodes providing CoMP transmission service for the terminal.

The cooperating set may include a CCN and at least one cooperating base station including a serving base station of the terminal.

A CCN, which may be acted upon by one cooperative base station in the cooperation set; or an independent logic function entity with strong scheduling/data processing capability and capable of performing CoMP transmission scheduling, where the independent logic function entity is deployed in one cooperative base station in the cooperation set or in one independent network entity.

The CCN may be OAM preconfigured, or may be autonomously selected and determined by each cooperative base station in a certain area (for example, each cooperative base station in a certain area selects a base station providing wide coverage). The interface between the CCN and each cooperative base station in the cooperative set may use the existing X2 interface, or may define a new interface, and may establish an interface connection when the CCN is activated.

The technical solutions provided by the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in fig. 1, a cell switching process and a coordinated multi-point transmission control method in the cell switching process provided by the embodiment of the present invention specifically include the following operations:

step 100, the serving base station determines to perform cell switching on the terminal.

Step 110, the serving base station sends a handover request message to the target base station.

Step 120, the serving base station receives a handover request response message sent by the target base station.

Step 130, the serving base station sends a handover command to the terminal to instruct the terminal to handover to the cell of the target base station.

After determining to perform cell handover on the terminal, the serving base station further performs step 140 to determine whether the target base station supports coordinated multi-point transmission for the terminal.

If so, step 150 is performed, otherwise, step 160 is performed.

Step 150, the serving base station sends a handover notification message to other access network nodes in the coordinated set participating in the coordinated multi-point transmission of the terminal, where the handover notification message carries the identification information of the terminal, the identification information of the target base station, and the coordinated multi-point transmission maintenance indication information.

Step 160, the serving base station deactivates the coordinated multi-point transmission to the terminal, and sends a message indicating to deactivate the coordinated multi-point transmission to other access network nodes in the coordinated set participating in the coordinated multi-point transmission of the terminal, where the message indicating to deactivate the multi-point transmission carries the identification information of the terminal and the indication information of deactivating the coordinated multi-point transmission.

The service base station deactivates the coordinated multi-point transmission to the terminal, which means that the terminal is no longer scheduled and/or transmitted according to the information interaction with other access network nodes in the coordinated set. Which operations are specifically included depends on the CoMP transmission mode of the UE, the CoMP capability of the serving base station, and the like, and the embodiments of the present invention are not limited in particular.

In the processing flow shown in fig. 1, in the process of cell switching for a terminal, if it is determined that a target base station supports coordinated multi-point transmission for the terminal, a serving base station maintains coordinated multi-point transmission for the terminal, and if it is determined that the target base station does not support coordinated multi-point transmission for the terminal, deactivates coordinated multi-point transmission for the terminal, and instructs other access network nodes in a coordination set to deactivate coordinated multi-point transmission for the terminal, it is not necessary to ensure continuity of coordinated multi-point transmission for the terminal, and a problem of how to handle coordinated multi-point transmission for a CoMP UE performing coordinated multi-point transmission when the CoMP UE performs cell switching is solved. In addition, as can be seen from fig. 1, the CoMP transmission control method provided in the embodiment of the present invention does not change the original cell handover procedure, and can be executed in parallel with the original cell handover procedure, and the implementation manner is simple, and the delay of cell handover is not caused.

The serving base station may obtain the information in various ways to achieve the determination of whether the target base station supports the coordinated multi-point transmission for the terminal. The invention is only exemplified as follows:

the implementation mode is as follows:

and the service base station judges whether the target base station supports the coordinated multi-point transmission of the terminal or not according to the indication information whether the target base station supports the coordinated multi-point transmission of the terminal or not, which is carried in the switching request response message.

If the target base station does not support coordinated multi-point transmission, the indication information carried in the handover request response message sent by the target base station may be information that the target base station does not support coordinated multi-point transmission, and the serving base station determines that the target base station does not support coordinated multi-point transmission for the terminal according to the indication information.

If the target base station supports coordinated multi-point transmission, the indication information carried in the handover request response sent by the target base station may be information that the base station supports coordinated multi-point transmission and information of a supported coordinated multi-point transmission mode. Further, if the target base station supports coordinated multi-point transmission in the central scheduling mode, the indication information may be identification information of a CCN to which the target base station belongs (optionally, information that the base station supports coordinated multi-point transmission and information of a coordinated multi-point transmission mode supported by the target base station are also included); if the target base station does not support coordinated multi-point transmission in the central scheduling mode, the indication information may be information that coordinated multi-point transmission is supported and information that coordinated multi-point transmission in the central scheduling mode is not supported, or the indication information may be information that the target base station supports coordinated multi-point transmission in the non-central scheduling mode. For example, the terminal currently performs coordinated multi-point transmission of central scheduling, and the handover request response message carries information that the base station supports coordinated multi-point transmission and information that the base station does not support a central scheduling mode, so the serving base station determines, according to the indication information, that the target base station does not support coordinated multi-point transmission for the terminal. For another example, the terminal currently performs coordinated multi-point transmission of central scheduling, and the handover request response message carries information that the base station supports coordinated multi-point transmission and information that the base station supports a central scheduling mode, so that the serving base station determines, according to the indication information, that the target base station supports coordinated multi-point transmission for the terminal.

If the indication information carried in the switching request response is the information that the base station supports the coordinated multi-point transmission and the information that the base station supports the central scheduling mode. And the coordinated multi-point transmission of the terminal is in a central scheduling mode, the serving base station sending the handover notification message to other access network nodes in the coordinated set participating in the coordinated multi-point transmission of the terminal may specifically be sending the handover notification message to a central coordination point in the coordinated set participating in the coordinated multi-point transmission of the terminal, and optionally, the handover request response also carries identification information of the central coordination point of the coordinated set to which the target base station belongs.

In this implementation manner, optionally, the serving base station may further carry CoMP transmission capability request information in the handover request message sent to the target base station, where the CoMP transmission capability request information is used to indicate that the target base station sends indication information indicating whether the target base station supports coordinated multi-point transmission for the terminal. Further, the serving base station may also carry, in the handover request message, indication information whether the serving base station supports coordinated multi-point transmission to the terminal.

The implementation mode two is as follows:

the OAM sends the indication information whether each base station supports the coordinated multi-point transmission of the terminal to each base station in advance.

And the service base station judges whether the target base station supports the coordinated multi-point transmission to the terminal according to the indication information which is sent by the OAM in advance and is used for indicating whether each base station supports the coordinated multi-point transmission to the terminal.

Specifically, for a base station that does not support coordinated multi-point transmission, the indication information that is sent by the OAM whether the base station supports coordinated multi-point transmission to the terminal is that the base station does not support coordinated multi-point transmission, and then the serving base station determines, according to the indication information, that the target base station does not support coordinated multi-point transmission to the terminal.

For a base station supporting coordinated multi-point transmission, the indication information that is sent by the OAM and that whether the base station supports coordinated multi-point transmission to the terminal is specifically, information that the base station supports coordinated multi-point transmission and information of a coordinated multi-point transmission mode supported by the base station (for example, whether a central scheduling mode is supported), and optionally, further includes identification information of a CCN to which the base station belongs. Specifically, if the base station supports coordinated multi-point transmission in the central scheduling mode, the indication information may be identification information of a CCN to which the target base station belongs (optionally, information that the base station supports coordinated multi-point transmission and information of a coordinated multi-point transmission mode supported by the base station are also included); the indication information may be information that supports coordinated multipoint transmission in the central scheduling mode and information that does not support coordinated multipoint transmission in the central scheduling mode, or the indication information may be information that the base station supports coordinated multipoint transmission in the non-central scheduling mode. For example, the terminal currently performs coordinated multi-point transmission for central scheduling, and the indication information is information that the base station supports coordinated multi-point transmission and information that the base station does not support a central scheduling mode, so the serving base station determines that the target base station does not support coordinated multi-point transmission for the terminal according to the indication information. For another example, the terminal currently performs coordinated multi-point transmission for center scheduling, and the indication information is information that the base station supports coordinated multi-point transmission and information that the base station supports a center scheduling mode, then the serving base station determines that the target base station supports coordinated multi-point transmission for the terminal according to the indication information.

If the indication information sent by OAM is information that the base station supports coordinated multi-point transmission and information that the base station supports a central scheduling mode. And the coordinated multi-point transmission of the terminal is in a central scheduling mode, the serving base station sending the handover notification message to other access network nodes in the coordinated set participating in the coordinated multi-point transmission of the terminal may specifically be sending the handover notification message to a central coordination point in the coordinated set participating in the coordinated multi-point transmission of the terminal, and optionally, the handover request response also carries identification information of the central coordination point of the coordinated set to which the target base station belongs.

The implementation mode is three:

and the base stations interact indication information of whether each base station supports the coordinated multi-point transmission of the terminal in advance.

Specifically, for a base station that does not support coordinated multi-point transmission, the indication information that is sent by the base station whether to support coordinated multi-point transmission to the terminal is that the base station does not support coordinated multi-point transmission, and then the serving base station determines, according to the indication information, that the target base station does not support coordinated multi-point transmission to the terminal.

For a base station supporting coordinated multi-point transmission, the indication information that is sent by the base station and whether the base station supports coordinated multi-point transmission for the terminal is specifically that the information that the base station supports coordinated multi-point transmission and the information of a coordinated multi-point transmission mode supported by the base station (for example, whether the base station supports a central scheduling mode) are selectable, and further include identification information of a CCN to which the base station belongs. Specifically, if the base station supports coordinated multi-point transmission in the central scheduling mode, the indication information may be identification information of a CCN to which the target base station belongs (optionally, information that the base station supports coordinated multi-point transmission and information of a coordinated multi-point transmission mode supported by the base station are also included); the indication information may be information that supports coordinated multipoint transmission in the central scheduling mode and information that does not support coordinated multipoint transmission in the central scheduling mode, or the indication information may be information that the base station supports coordinated multipoint transmission in the non-central scheduling mode. For example, the terminal currently performs coordinated multi-point transmission for central scheduling, and the indication information is information that the base station supports coordinated multi-point transmission and information that the base station does not support a central scheduling mode, so the serving base station determines that the target base station does not support coordinated multi-point transmission for the terminal according to the indication information. For another example, the terminal currently performs coordinated multi-point transmission for center scheduling, and the indication information is information that the base station supports coordinated multi-point transmission and information that the base station supports a center scheduling mode, then the serving base station determines that the target base station supports coordinated multi-point transmission for the terminal according to the indication information.

If the indication information interacted with the target base station in advance is the information that the target base station supports coordinated multi-point transmission and the information that the target base station supports the central scheduling mode. And the coordinated multi-point transmission of the terminal is in a central scheduling mode, the serving base station sending the handover notification message to other access network nodes in the coordinated set participating in the coordinated multi-point transmission of the terminal may specifically be sending the handover notification message to a central coordination point in the coordinated set participating in the coordinated multi-point transmission of the terminal, and optionally, the handover request response also carries identification information of the central coordination point of the coordinated set to which the target base station belongs.

And the service base station judges whether the target base station supports the coordinated multi-point transmission of the terminal according to the indication information which is interacted between the base stations in advance and whether the indication information supports the coordinated multi-point transmission of the terminal.

The implementation mode is four:

a central cooperation point in a cooperation set where a service base station is located sends indication information whether each base station in a network supports cooperative multi-point transmission to the terminal to the base stations in the cooperation set in advance.

Specifically, for a base station that does not support coordinated multi-point transmission, the indication information that is sent by the central coordinated point and whether the base station supports coordinated multi-point transmission to the terminal is that the base station does not support coordinated multi-point transmission, and then the serving base station determines, according to the indication information, that the target base station does not support coordinated multi-point transmission to the terminal.

For a base station supporting coordinated multi-point transmission, the indication information that is sent by the central coordinated point and whether the base station supports coordinated multi-point transmission for the terminal is specifically information that the base station supports coordinated multi-point transmission and information of a coordinated multi-point transmission mode supported by the base station (for example, whether the base station supports a central scheduling mode), and optionally, identification information of a CCN to which the base station belongs. Specifically, if the base station supports coordinated multi-point transmission in the central scheduling mode, the indication information may be identification information of a CCN to which the target base station belongs (optionally, information that the base station supports coordinated multi-point transmission and information of a coordinated multi-point transmission mode supported by the base station are also included); the indication information may be information that supports coordinated multipoint transmission in the central scheduling mode and information that does not support coordinated multipoint transmission in the central scheduling mode, or the indication information may be information that the base station supports coordinated multipoint transmission in the non-central scheduling mode. For example, the terminal currently performs coordinated multi-point transmission for central scheduling, and the indication information is information that the base station supports coordinated multi-point transmission and information that the base station does not support a central scheduling mode, so the serving base station determines that the target base station does not support coordinated multi-point transmission for the terminal according to the indication information. For another example, the terminal currently performs coordinated multi-point transmission for center scheduling, and the indication information is information that the base station supports coordinated multi-point transmission and information that the base station supports a center scheduling mode, then the serving base station determines that the target base station supports coordinated multi-point transmission for the terminal according to the indication information.

If the indication information sent by the CCN in advance is the information that the target base station supports coordinated multi-point transmission and the information that the target base station supports the central scheduling mode. And the coordinated multi-point transmission of the terminal is in a central scheduling mode, the serving base station sending the handover notification message to other access network nodes in the coordinated set participating in the coordinated multi-point transmission of the terminal may specifically be sending the handover notification message to a central coordination point in the coordinated set participating in the coordinated multi-point transmission of the terminal, and optionally, the handover request response also carries identification information of the central coordination point of the coordinated set to which the target base station belongs.

And the central cooperation points share the indication information of whether the base station in the cooperation set supports the cooperative multi-point transmission of the terminal through information interaction.

Based on any implementation manner, preferably, before the serving base station sends the handover notification message to the central cooperation point in the cooperation set participating in the coordinated multi-point transmission of the terminal, whether the target base station and the serving base station belong to the same central cooperation point may be determined according to the identification information of the central cooperation point of the cooperation set where the target base station is located; if not, the service base station sends the switching notification message to the target base station so that the target base station sends the switching notification message to a central cooperation point in a cooperation set of the target base station; and if the terminal belongs to the cooperative set, the service base station sends a switching notification message to a central cooperative point in the cooperative set participating in the cooperative multipoint transmission of the terminal.

In addition, in the S1 handover process in which the MME changes or cannot perform X2 handover, the serving base station may further notify the source MME of the target base station identifier and the CCN identifier to which the target base station belongs in the handover required process, the source MME notifies the target MME of the target base station identifier and the CCN identifier to which the target base station belongs (if MME relocation), the target MME notifies the CCN target base station identifier to which the target base station belongs and handover information, and then the CCN instructs the target base station to handover, and notifies the target base station of a handover related message (in this case, the MME needs to maintain a relationship list between the base station and the CCN). And the non-transmitted CoMP UE data is interacted to the target base station by the serving base station.

Based on the above-mentioned method embodiment at any serving base station side, for the case that the target base station does not support coordinated multi-point transmission to the terminal. The access network nodes included in the cooperating set are different, and accordingly, the specific implementation manner of step 160 is also different.

The first condition is as follows: if the cooperation set participating in the coordinated multi-point transmission of the terminal only includes the central cooperation point and the serving base station, then sending a message indicating to deactivate the coordinated multi-point transmission to other access network nodes participating in the cooperation set participating in the coordinated multi-point transmission of the terminal means: and sending a message indicating the deactivation of the coordinated multipoint transmission to the central coordinated point.

The message indicating to deactivate coordinated multi-point transmission sent to the central coordination point may also carry information of a deactivation reason, identification information of the serving base station, and/or identification information of the source cell, in addition to the above information.

Case two: if the cooperation set participating in the coordinated multi-point transmission of the terminal includes the central cooperation node, the serving base station, and other cooperation base stations except the serving base station, then sending the message indicating to deactivate the coordinated multi-point transmission to other access network nodes participating in the cooperation set participating in the coordinated multi-point transmission of the terminal may refer to: and sending a message indicating to deactivate coordinated multi-point transmission to the central coordinated point, and sending a message indicating to deactivate coordinated multi-point transmission to other coordinated base stations in the coordinated set.

The message which is sent to the central cooperative point and indicates to deactivate the coordinated multi-point transmission may carry information of a deactivation reason, and the like, in addition to the above information.

The message indicating to deactivate coordinated multi-point transmission sent to other coordinated base stations may also carry identification information of the serving base station, identification information of the source cell, time-frequency resource information corresponding to coordinated multi-point transmission of the terminal, and/or information of a deactivation reason, and the like, in addition to the above information.

Case three: if the cooperation set participating in the coordinated multi-point transmission of the terminal includes the central cooperation node, the serving base station, and other cooperation base stations except the serving base station, then sending the message indicating to deactivate the coordinated multi-point transmission to other access network nodes participating in the cooperation set participating in the coordinated multi-point transmission of the terminal may further refer to: sending only a message to the central cooperating point indicating deactivation of coordinated multipoint transmission.

Correspondingly, after receiving the message indicating the deactivation of the coordinated multi-point transmission, the central coordinated point sends a message indicating the deactivation of the coordinated multi-point transmission to other coordinated base stations in the coordinated set.

The message indicating to deactivate coordinated multi-point transmission sent to other coordinated base stations may carry, in addition to the above information, a serving base station identifier/source cell identifier, time-frequency resource information corresponding to coordinated multi-point transmission of the terminal, and/or information of a deactivation reason, and the like.

Case four: if only the serving base station and other cooperative base stations except the serving base station are in the cooperative set participating in the cooperative multipoint transmission of the terminal, then sending the message indicating to deactivate the cooperative multipoint transmission to other access network nodes in the cooperative set participating in the cooperative multipoint transmission of the terminal may also refer to: and sending a message indicating to deactivate coordinated multipoint transmission to other coordinated base stations in the coordinated set.

The message indicating to deactivate coordinated multi-point transmission sent to other coordinated base stations may also carry, in addition to the information, a serving base station identifier/source cell identifier, time-frequency resource information corresponding to coordinated multi-point transmission of the terminal, and/or information of a deactivation reason, and the like.

For the above cases one to three, if the central cooperating point still has data that is not transmitted to the terminal or does not receive the ACK of the terminal, the data is also transmitted to the serving base station. Then, after sending the message indicating to deactivate coordinated multipoint transmission to the central coordination point, the serving base station may further receive the identification information of the terminal, the data that is not transmitted to the terminal or that does not receive the ACK of the terminal, the start position information of the data, and the end position information of the data, which are sent by the central coordination point; then, the serving base station stores the identification information of the terminal, the data, the start position information of the data, and the end position information of the data in association with each other.

In case four, if there are other cooperative base stations that have data that are not transmitted to the terminal or have not received ACK from the terminal, the data are also transmitted to the serving base station. Then, after sending a message indicating to deactivate coordinated multipoint transmission to other coordinated base stations in the coordinated set, the serving base station may also receive the identification information of the terminal sent by other coordinated base stations, data that is not transmitted to the terminal or that does not receive ACK of the terminal, start position information of the data, and end position information of the data; then, the serving base station stores the identification information of the terminal, the data, the start position information of the data, and the end position information of the data in association with each other.

The purpose of association storage is that when the serving base station needs to process the data of the terminal, the serving base station can determine the data of the terminal and corresponding data information through an association relationship. The invention does not limit the concrete implementation mode of the association storage.

For the above cases one to four, if the serving base station receives data sent by the central cooperative point or other cooperative base stations and not transmitted to the terminal or not received ACK of the terminal, the data may be exchanged to the target base station, or the data may be sequentially scheduled for the terminal according to the start position information and the end position information of the data before receiving the handover request response message sent by the target base station according to the unicast mode.

Another coordinated multi-point transmission control method in a cell handover process provided by the embodiment of the present invention is shown in fig. 2, and specifically includes the following operations:

step 200, an access network node except a serving base station of a terminal in a coordinated set participating in coordinated multipoint transmission of the terminal receives a message indicating deactivation of coordinated multipoint transmission.

Wherein, the message for indicating the deactivation of the multipoint transmission at least carries the identification information of the terminal and the indication information for deactivating the coordinated multipoint transmission.

Step 210, the access network node determines the terminal according to the identification information of the terminal, and deactivates the coordinated multi-point transmission of the terminal according to the indication of the indication information for deactivating the coordinated multi-point transmission.

In this embodiment of the present invention, the access network node may be a CCN in the cooperative set, or may be another cooperative base station besides the serving base station in the cooperative set.

If the access network node is a CCN, the message indicating the deactivation of coordinated multipoint transmission may further carry information of a deactivation reason, identification information of the serving base station, and/or identification information of the source cell.

If the access network node is another cooperative base station, the message for deactivating the cooperative multi-point transmission may further carry identification information of the serving base station, identification information of the source cell, time-frequency resource information corresponding to the cooperative multi-point transmission of the terminal, and/or information of a deactivation reason, and the like.

The deactivating of the coordinated multi-point transmission to the terminal by the access network node means stopping all behaviors that may affect the scheduling of the serving base station to the terminal. Which operations are specifically included depends on the CoMP transmission mode of the UE, the CoMP capability of the access network node, and the like, and the embodiments of the present invention are not limited in particular.

For example, if the access network node is a CCN, the CCN does not perform scheduling control for the UE after receiving the message indicating deactivation of coordinated multipoint transmission. If the data plane path of the coordinated multi-point transmission to the terminal is S-GW < - > CCN < - > service base station < - > terminal, the CCN does not perform data transmission to the UE any more. If the CCN also has the function of caching the data of the terminal, the CCN does not cache the data of the terminal any more and clears the data in the cache.

For example, if the access network node is another cooperative base station, the other cooperative base station stops data transmission for the terminal after receiving the message indicating deactivation of the cooperative multipoint transmission, and releases the time-frequency resource corresponding to CoMP transmission of the terminal. If the terminal is restricted from using the precoding matrix during CoMP transmission, the other cooperative base stations may also release the restriction on the precoding matrix. In addition, for the data which is not transmitted, other cooperative base stations can be interacted with the service base station, and can also be discarded without being interacted with the service base station.

In the processing flow shown in fig. 2, in the cell handover process of the terminal, other access network nodes in the cooperation set deactivate the coordinated multi-point transmission for the terminal, and the continuity of the coordinated multi-point transmission of the terminal does not need to be ensured, so that the problem of how to handle the coordinated multi-point transmission of the CoMP UE when the CoMP UE performing the coordinated multi-point transmission performs the cell handover is solved.

Based on the embodiment shown in fig. 2, if the access network node is a CCN, and after receiving the message indicating deactivation of coordinated multipoint transmission, the CCN has data that the ACK for the terminal is not transmitted or received to the terminal. Then, after receiving the message indicating to deactivate coordinated multipoint transmission sent by the serving base station of the terminal, the CCN may also send the identification information of the terminal, the data that is not transmitted to the terminal or that does not receive the ACK of the terminal, the start position information of the data, and the end position information of the data to the serving base station of the terminal.

Based on the above-mentioned method embodiment at any access network node side in fig. 2, if the access network node is CCN, and there are other cooperative base stations in the cooperative set. Then, after receiving the message indicating to deactivate the coordinated multi-point transmission sent by the serving base station of the terminal, the CCN may also send a message indicating to deactivate the coordinated multi-point transmission to other coordinated base stations except the serving base station in the coordinated set participating in the coordinated multi-point transmission of the terminal, where the message indicating to deactivate the coordinated multi-point transmission sent to the other coordinated base stations at least carries the identification information of the terminal and the indication information of deactivating the coordinated multi-point transmission. Optionally, the message indicating to deactivate coordinated multi-point transmission may further carry a serving base station identifier, a source cell identifier, time-frequency resource information corresponding to coordinated multi-point transmission of the terminal, and/or information of a deactivation reason, and the like.

As can be seen from the description of the method embodiment at the serving base station side, when other cooperative base stations are also included in the cooperative set, the serving base station may also send a message indicating to deactivate the cooperative multipoint transmission to the other cooperative base stations. In order to avoid repeated transmission, it may be preconfigured or agreed whether the message indicating deactivation of coordinated multipoint transmission is specifically transmitted by the CCN or the serving base station to the other coordinated base stations.

Based on the embodiment shown in fig. 2, if the access network node is a cooperative base station other than the serving base station, the cooperative base station still has data that the ACK of the terminal is not transmitted or received to the terminal. Then, after receiving the message indicating to deactivate coordinated multipoint transmission sent by the serving base station of the terminal, the other coordinated base stations may also send the identification information of the terminal and the data that is not transmitted to the terminal or does not receive the ACK of the terminal to the serving base station of the terminal. Optionally, start position information of the data and end position information of the data are also transmitted.

Another coordinated multi-point transmission control method in a cell handover process provided in the embodiment of the present invention is shown in fig. 3, and specifically includes the following operations:

step 300, an access network node except a serving base station of the terminal in a coordinated set participating in coordinated multipoint transmission of the terminal receives a handover notification message.

Wherein, the handover notification message at least carries the identification information of the terminal, the identification information of the target base station, and the coordinated multi-point transmission maintenance indication information.

Step 310, the access network node determines the terminal according to the identification information of the terminal, determines the target base station according to the identification information of the target base station, and determines that the terminal is switched to the target base station and then continues coordinated multi-point transmission according to the coordinated multi-point transmission maintaining indication information.

In the cell switching process of the terminal, the access network node provided by the embodiment of the invention determines to maintain the coordinated multi-point transmission of the terminal if receiving the switching notification message. The problem of how to process the coordinated multi-point transmission of the CoMP UE when the CoMP UE executing the CoMP transmission carries out cell switching is solved.

The access network node in the embodiment of the present invention may be a CCN in the cooperative set, or may be another cooperative base station other than the serving base station in the cooperative set.

If the access network node is the CCN in the cooperative set, preferably, the handover notification message further carries identification information of a central cooperative point of the cooperative set where the target base station is located.

If the access network node is the CCN in the above cooperation set, based on any embodiment of fig. 3, preferably, after determining that the terminal continues to perform coordinated multipoint transmission after switching to the target base station, the method further includes: suspending scheduling control of coordinated multipoint transmission to the terminal; then, judging whether the central cooperation point of the cooperation set where the target base station is located is the central cooperation point according to the identification information of the central cooperation point of the cooperation set where the target base station is located; if so, after confirming that the terminal is switched to the target base station, not starting a path switching process to the core network node, and continuing to perform scheduling control of coordinated multi-point transmission on the terminal.

If not, the central cooperation point may not perform processing, or may notify the serving base station, so that the serving base station sends the handover notification message to the target base station.

If the access network node is the CCN in the above cooperation set, based on any embodiment of fig. 3, preferably, after determining that the terminal continues to perform coordinated multipoint transmission after switching to the target base station, the method further includes: suspending coordinated multipoint transmission to the terminal; and after confirming that the terminal is switched to the target base station, interacting with the target base station, and continuously performing coordinated multi-point transmission on the terminal.

The method provided by the embodiment of the invention will be described below by taking a network side node as an example.

Before describing the processing procedure, a data transmission architecture in a CoMP center scheduling scenario applying the method is introduced first.

The first structure is as follows: the data transmission path between the CoMP UE and the core network is S-GW < - > service base station < - > CoMP UE (namely, a data direct connection interface exists between the S-GW and the service base station of the CoMP UE), and both the CCN and the service base station have scheduling functions.

Under the architecture, the cooperative scheduling performed by the CCN and the serving base station can be implemented in the following ways:

the CCN executes a main scheduling function for the CoMP UE, and the service base station executes CoMPUE data transmission and non-CoMP UE scheduling and data transmission according to the CCN scheduling;

the CCN executes a main scheduling function for the CoMP UE and is responsible for the CoMP UE to schedule coordinated multi-point transmission and transmission, and the service base station is responsible for the scheduling and data transmission of the single-point transmission and transmission of the CoMP UE, the scheduling of non-CoMP UE and the like;

the CCN performs pre-scheduling of CoMP UEs, and the serving base station performs actual scheduling of CoMP UEs.

In addition, the CCN may further have a function of buffering CoMP UE data and a corresponding buffer (buffer).

And a second framework: the data transmission path between the CoMP UE and the core network is S-GW < - > CCN < - > service base station < - > UE (namely, a data direct connection interface exists between the S-GW and the CCN), and both the CCN and the service base station have scheduling functions.

Under the framework, the CCN is a data relay point between the CoMP UE and the core network. In the process of establishing the RCC connection of the UE, the service base station acquires the type of the UE, and if the UE supports CoMP transmission, the service base station judges whether to indicate a RAN side user plane anchor point connected with the UE of a core network to be CCN according to the type of the UE (whether the UE supports CoMP transmission), the CoMP supporting capability condition of the current network and network side strategies and other factors; or the user plane anchor is established in the serving base station by using the prior art, and the user plane anchor can be changed into the CCN through processes of switching, path switching request (path switch request) and the like when the coordinated multipoint transmission of the CoMP UE is triggered. Particularly, the control plane anchor point of the user under the framework can be a serving base station of the UE, and a control plane path can also be changed into an MME < - > CCN < - > serving base station < - > terminal, so that the switching overhead is reduced.

The implementation of scheduling under this architecture is similar to the architecture, and is not described here again.

For the first architecture, taking an example of switching the CoMP UE from the serving base station supporting CoMP transmission to the X2 of the target base station not supporting CoMP transmission, a switching process and a CoMP transmission control method in the switching process are shown in fig. 4, and specifically include the following operations:

step 400, the serving base station determines to perform cell handover for the CoMP UE.

Specifically, the serving base station determines whether the handover condition is satisfied according to a reported handover measurement report result (such as RSRP/RSRQ) of the CoMP UE. And if so, determining to perform cell switching on the CoMP UE.

Step 410a, the serving base station sends a handover request message to each candidate target base station.

The handover request message includes handover preparation related parameters to help the candidate target base station perform admission decision, radio resource allocation, and the like.

Optionally, the handover request message further includes CoMP transmission capability request information, where the CoMP transmission capability request information is used to indicate that the target base station sends indication information indicating whether the target base station supports coordinated multi-point transmission for the terminal. Further, the serving base station may also carry, in the handover request message, indication information whether the serving base station supports coordinated multi-point transmission to the terminal.

Step 420a, allowing the candidate target base station receiving the CoMP UE to send a handover request response to the serving base station.

Specifically, each candidate target base station receives a handover request message sent by a serving base station, and performs admission judgment according to information such as quality of service (QoS) information, current interference, load conditions, and the like of a bearer to be admitted. And if the alternative target base station allows the CoMP UE to be accepted, performing bottom-layer configuration to prepare for handover.

And the switching request response message returned to the service base station by the alternative target base station at least carries the radio resource configuration information of the CoMPUE.

Optionally, the handover request response message returned by the candidate target base station to the serving base station may further carry information indicating whether CoMP transmission is supported and information indicating a supported CoMP transmission mode. The CoMP transmission capability request information sent by the serving base station may be sent after being received, or may be actively sent. Depending on a predetermined configuration or convention.

Step 430a, after receiving the handover request response message sent by the candidate target base station, the serving base station sends a handover command to the CoMP UE, stops receiving and sending data of the CoMP UE on the local base station, and interacts untransmitted or unacknowledged data with the target base station.

If a plurality of candidate target base stations return a switching request response message to the service base station, the service base station selects one from the candidate target base stations as the target base station.

The handover command sent by the serving base station to the CoMP UE may be carried in the RRC connection reconfiguration message.

Step 440a, after performing uplink and downlink synchronization with the target base station, the CoMP UE switches to the cell of the target base station.

Specifically, after receiving the handover command sent by the serving base station, the CoMP UE stops data transceiving with the serving base station, performs uplink and downlink synchronization operation with the target base station, and performs radio resource and bearer reconfiguration.

After the synchronization is completed, the CoMP UE returns a handover complete message (RRC reconfiguration complete message) to the target base station. After receiving the message, the target base station returns an ACK message of the RLC and starts to send downlink data at the same time; and informing the core network to switch the path (triggering the path switch request process, informing the core network that the data transmission path is changed into SGW < -target base station < -CoMP UE). After receiving the path switch request ack, the target base station notifies the serving base station to release the old bearer and the UE context. And after receiving the ACK of the RRC reconfiguration completion message, the CoMP UE transmits uplink data with the target base station target.

Optionally, the target base station (i.e., the switched serving base station) determines whether to start CoMP transmission for the CoMP UE according to the type of the CoMP UE (whether to support CoMP transmission), the wireless channel condition of the CoMP UE, the CoMP supporting capability of the base station, a base station policy, and other factors.

If it is determined that CoMP transmission is initiated for the CoMP UE, but the previously configured transmission mode for the UE is not TM10, the target base station needs to reconfigure the CoMP UE transmission mode to TM 10.

And if the target base station determines not to start the CoMP transmission of the CoMP UE, scheduling the CoMP UE according to a single-point transmission mode.

And if the target base station determines to start the CoMP transmission of the CoMP UE, the target base station sends a message indicating the CoMP transmission activation to the CCN of the cooperation set where the target base station is located.

Specifically, if the target base station does not establish a connection with its CCN, the target base station triggers a connection establishment procedure with the CCN, and sends a message indicating CoMP transmission activation to its CCN after the connection establishment is completed. The message at least includes identification information of the CoMP UE, identification information of the target base station, identification information of the current access cell, and/or information such as an activation reason.

If the target base station and the CCN thereof are in the second architecture, the target base station judges that the coordinated multi-point transmission function of the CoMPUE is activated and informs the CCN, and simultaneously triggers a switching process, or a path switch request, or other existing processes, changes the data transmission anchor point of the CoMP UE, and changes the data transmission anchor point of the CoMP UE into the CCN. Alternatively, coordinated multipoint transmission by the CoMP UE may also be activated by the CCN.

Step 430b, the serving base station determines that the target base station does not support CoMP transmission for the CoMP UE according to the information indicating whether CoMP transmission is supported and the information of the supported CoMP transmission mode, which are carried in the handover request response.

It should be noted that, if the serving base station learns in advance whether the target base station supports the information of CoMP transmission and the supported CoMP transmission mode by other means (such as the second to fourth embodiments described in the above embodiment), it may be determined that the target base station does not support CoMP transmission for the CoMP UE at any time after determining to perform cell handover.

Step 440b, the serving base station deactivates CoMP transmission to the CoMP UE and sends a message indicating the deactivation of CoMP transmission to the CCN.

The message which is sent to the CCN and indicates the CoMP transmission deactivation at least carries the identification information of the CoMP UE and the CoMP transmission deactivation indication information. Optionally, information such as a deactivation reason may also be carried.

It should be noted that step 430a and step 430b may be performed in parallel, and there is no chronological restriction.

Step 450b, after receiving the message indicating the CoMP transmission deactivation sent by the serving base station, the CCN performs an operation of deactivating the CoMP transmission on the CoMP UE.

Specifically, the CCN first determines, according to the identification information of the CoMP UE carried in the message, the CoMP UE to which the message is directed. Then, according to the CoMP transmission deactivation indication information carried in the message, the coordinated multi-point transmission control function of the CoMP UE is deactivated, the data transmission of the CoMP UE is no longer scheduled and controlled, the data transmission of the CoMP UE is no longer performed, and all behaviors that may affect the scheduling of the service base station on the CoMP UE are stopped. If the CCN further has a data temporary storage function for the CoMP UE and a corresponding buffer, the CCN further deactivates the data temporary storage function for the CoMP UE and clears the data in the buffer.

If the message also carries the information of the deactivation reason, the CCN also records the deactivation reason so as to be used by the subsequent analysis control.

Optionally, if the coordinated set participating in the CoMP transmission of the CoMP UE further includes other coordinated base stations except the serving base station, the serving base station may send a message indicating that the CoMP transmission is deactivated to the other coordinated base stations in the coordinated set.

The message which is sent to other cooperative base stations and indicates the CoMP transmission deactivation at least carries the identification information of the CoMP UE and the CoMP transmission deactivation indication information. Optionally, at least one of the following information may be included: identification information of the serving base station, identification information of the source cell, time-frequency resource information corresponding to CoMP transmission of the CoMP UE, deactivation reason, and the like.

It should be noted that this operation may be performed in parallel without any chronological constraints as in step 440 b.

Optionally, if the coordinated set participating in the CoMP transmission of the CoMP UE further includes other coordinated base stations except the serving base station, the CCN may also send a message indicating that the CoMP transmission is deactivated to other coordinated base stations in the coordinated set after receiving the message indicating that the CoMP transmission is deactivated.

And after receiving the message indicating the CoMP transmission deactivation, other cooperative base stations in the cooperative set deactivate the CoMP transmission to the CoMP UE.

Specifically, the other cooperative base stations first determine, according to the identification information of the CoMP UE carried in the message, the CoMP UE to which the message is directed. Then, according to the CoMP transmission deactivation indication information carried in the message, data transmission to the CoMP UE is not performed any more, and a time-frequency resource corresponding to CoMP transmission of the CoMP UE is released (if the information of the time-frequency resource is carried in the message, the corresponding time-frequency resource is released according to the information of the time-frequency resource, and if the information of the time-frequency resource is not carried, the time-frequency resource is determined in other manners, for example, the time-frequency resource information is locally stored, or the time-frequency resource information is separately acquired from the serving base station or the CCN, and the like). If the precoding matrix is restricted from being used when CoMP transmission is performed on the CoMP UE, the other cooperative base stations may also release the restriction on the precoding matrix. And if the message also carries the information of the deactivation reason, other cooperative base stations also store the information of the deactivation reason so as to be analyzed and used in the future. For data for the CoMP UE that has not been transmitted, other cooperating base stations may be discarded without interaction to the serving base station.

For the second architecture, taking the example of the X2 handover of the CoMP UE from the serving base station supporting CoMP transmission to the target base station not supporting CoMP transmission, a handover process and a CoMP transmission control method in the handover process may refer to the processing flow of fig. 4.

However, after the CCN receives the message indicating to deactivate CoMP transmission sent by the serving base station, if there is data that is not transmitted to the CoMP UE or that is not received ACK of the CoMP UE, the CCN sends, to the serving base station, identification information of the CoMP UE, data that is not transmitted to the CoMP UE and/or that is not received ACK of the CoMP UE (the data is composed of a plurality of RBs), information such as a data end (data end) identifier corresponding to each RB, and a data start (data start) identifier corresponding to each RB.

And the service base station stores the identification information of the CoMP UE, the data, and the data end identification and the data start identification corresponding to each RB in a correlation manner.

For data sent by the CCN, the serving base station may schedule the data according to uncooperative multipoint transmission before receiving the handover request response. These data may also be notified to the target base station along with the data to be transmitted during the handover execution.

And after receiving the release instruction, the service base station triggers a connection release process of an interface corresponding to the CoMP UE between the service base station and the CCN.

For the second architecture, taking an example of X2 handover of CoMP UE from a serving base station supporting CoMP transmission to a target base station under the same CCN, as shown in fig. 5, a CoMP transmission control method in the handover process and the handover process includes:

step 500, the serving base station determines to perform cell handover for the CoMP UE.

Step 510a, the serving base station sends a handover request message to each candidate target base station.

Step 520a, allowing the candidate target base station receiving the CoMP UE to send a handover request response to the serving base station.

Step 530a, after receiving the handover request response message sent by the candidate target base station, the serving base station sends a handover command to the CoMP UE, stops receiving and sending data of the CoMP UE on the local base station, and interacts untransmitted or unacknowledged data with the target base station.

And 540a, after performing uplink and downlink synchronization with the target base station, the CoMP UE switches to the cell of the target base station.

After the synchronization is completed, the CoMP UE returns a handover complete message (RRC reconfiguration complete message) to the target base station. And after receiving the message, the target base station returns an ACK message of the RLC and starts to transmit downlink data at the same time. And after receiving the path switching confirmation, the target base station informs the serving base station to release the old bearer and the UE context. And after receiving the ACK of the RRC reconfiguration completion message, the CoMP UE transmits uplink data with the target base station target.

Step 530b, the serving base station determines, according to the information indicating whether CoMP transmission is supported and the information of the supported CoMP transmission mode and the CCN information to which the target base station belongs, that the target base station supports CoMP transmission for the CoMP UE and belongs to the same CCN, which are carried in the handover request response.

It should be noted that, if the serving base station learns in advance whether the target base station supports CoMP transmission and the supported CoMP transmission mode and the CCN information to which the target base station belongs by other means (such as the second to fourth embodiments described in the above embodiment), it may be determined that the target base station supports CoMP transmission for the CoMP UE at any time after determining to perform cell handover.

It should be noted that step 510a and step 510b may be executed in parallel, and there is no sequential limitation in timing.

Step 540b, the serving base station sends a handover notification message to the CCN.

The switching notification message sent to the CCN carries identification information of the CoMP UE, identification information of the target base station, and coordinated multi-point transmission maintenance indication information.

Step 550b, after receiving the handover notification message, the CCN determines the CoMP UE according to the identification information of the CoMP, determines the target base station according to the identification information of the target base station, and determines that the CoMP UE is handed over to the target base station and then continues coordinated multi-point transmission according to the coordinated multi-point transmission maintenance indication information.

And step 560b, the CCN suspends scheduling control of the coordinated multi-point transmission of the terminal, and judges whether the CCN of the coordinated set of the target base station is the CCN according to the identification information of the CCN of the coordinated set of the target base station.

If so, step 570b is performed, otherwise, the operation ends.

Step 570b, after the CCN confirms that the CoMP UE is switched to the target base station, the path switching process is not initiated to the core network node, and the scheduling control of the coordinated multi-point transmission is continued for the terminal.

The CCN may confirm that the CoMP UE is handed over to the target base station through a process triggered by the target base station and establishing connection with the CoMP UE. Specifically, in the process, the target base station notifies the CCN of the identification information of the target base station (optionally, the identification information of the access cell after handover), the identification information of the UE allocated to the CoMP UE in the handover process, and the like, and the CCN notifies the target base station of the identification information of the UE finally configured for the CoMP UE; or the target base station notifies the CCN of the identification information of the target base station (optionally, the identification information of the access cell after handover), the identification information of the UE allocated to the CoMP UE during handover, and the like, and the CCN does not reallocate the identification information of the UE, but identifies different UEs from different base stations by using the UE identification notified by the target base station and the identification of the base station. Then, the target base station notifies the CCN of a handover complete message, which includes: a handover complete indication, a UE identity and a base station identity. The CCN determines that the corresponding comp ue is handed over to the target base station according to the received message, and may start data transmission and scheduling control without triggering a path switch request (pathswitch request) procedure.

The CCN may also confirm that the CoMP UE is handed over to the target base station through a path switchrequest procedure initiated by the target base station. Specifically, the target base station notifies the CCN of the path change through the path switch request process, and the CCN confirms that the CoMP UE is switched to the target base station according to the notification. And according to the fact that the target base station is under the CCN, the CCN informs the target base station of path switching request acknowledgement (path switching request ack) without initiating a path switching request process to the MME.

In addition, if some bearer target base stations cannot be admitted, the MME can be notified to modify the bearer by adopting an E-RAB Release INDICATION process subsequently.

In the embodiment of the present invention, the base station identifier and the UE identifier notified by the target base station to each CCN may be the following: the target base station identifier, the UE identifier and the IMSI which are distributed between the CCN and the target base station and used for identifying the CoMP UE; or target base station identification, UE identification allocated between the CCN and the target base station, serving base station identification, UE identification under the source cell (Old enb UE X2AP ID); or the target base station identifier, the UE identifier which is distributed between the CCN and the target base station and used for identifying the CoMP UE, the serving base station identifier, the CCN and the UE identifier which is distributed by the serving base station and used for identifying the CoMP UE. The serving base station may inform the target base station of the CCN and the UE identity or IMSI or Old eNB UE X2AP ID assigned by the serving base station to identify the CoMP UE in a handover request message.

If the CCN determines that the CCN of the cooperating set where the target base station is located is not the CCN, the serving base station may also be notified to send a handover notification message to the target base station, so that the target base station sends the handover notification message to the CCN of the cooperating set where the target base station is located, and the CCN in the cooperating set where the target base station is located performs coordinated multi-point transmission control. The specific operation can be referred to from step 550b to step 570 b. Of course, the serving base station may also determine whether the target base station belongs to the same CCN as the base station before sending the handover notification message to the CCN, and if so, send the handover notification message to the CCN, otherwise, send the handover notification message to the target base station.

It should be noted that if the target base station is not under the same CCN as the serving base station. The target base station informs the core network of changing the data transmission path into SGW < - > CCN < - > target base station through the pathswitch request process.

Based on the same inventive concept as the method, an embodiment of the present invention provides a base station, as shown in fig. 6, including:

a cell switching decision module 601, configured to determine to perform cell switching on a terminal;

a message receiving and sending module 602, configured to send a handover request message to a target base station after the cell handover decision module 601 determines to perform cell handover on the terminal; after receiving a switching request response message sent by the target base station, sending a switching command to the terminal to indicate the terminal to switch to a cell of the target base station, wherein the terminal is a terminal for executing coordinated multi-point transmission;

a coordinated multi-point transmission control module 603, configured to determine whether the target base station supports coordinated multi-point transmission for the terminal after the cell handover decision module 601 determines to perform cell handover for the terminal; if the target base station supports the coordinated multi-point transmission of the terminal, sending a switching notification message to other access network nodes in a coordinated set participating in the coordinated multi-point transmission of the terminal, wherein the switching notification message carries identification information of the terminal, identification information of the target base station and coordinated multi-point transmission maintaining indication information; and if the target base station does not support the coordinated multi-point transmission of the terminal, deactivating the coordinated multi-point transmission of the terminal, and sending a message for indicating to deactivate the coordinated multi-point transmission to other access network nodes in a coordinated set participating in the coordinated multi-point transmission of the terminal, wherein the message for indicating to deactivate the multi-point transmission carries the identification information of the terminal and the indication information for deactivating the coordinated multi-point transmission.

Preferably, when determining whether the target base station supports coordinated multi-point transmission to the terminal, the coordinated multi-point transmission control module 603 is specifically configured to:

Based on the above preferred embodiment, after the cell handover determining module determines to perform cell handover on the terminal, before the coordinated multi-point transmission control module determines whether the target base station supports coordinated multi-point transmission for the terminal, the coordinated multi-point transmission control module 603 may further be configured to:

Based on any of the foregoing embodiments of the base station, preferably, if the coordinated set participating in the coordinated multi-point transmission of the terminal includes a central coordinated point, when the coordinated multi-point transmission control module 603 sends a message indicating to deactivate coordinated multi-point transmission to other access network nodes in the coordinated set participating in the coordinated multi-point transmission of the terminal, the method is specifically configured to:

On this basis, preferably, if the coordinated set participating in the coordinated multi-point transmission of the terminal further includes other coordinated base stations except the base station, the coordinated multi-point transmission control module 703 is further configured to, when sending a message indicating to deactivate coordinated multi-point transmission to other access network nodes participating in the coordinated set participating in the coordinated multi-point transmission of the terminal:

Based on any of the foregoing embodiments of the base station, preferably, if the cooperation set participating in the coordinated multi-point transmission of the terminal includes other cooperation base stations except the base station but does not include a central cooperation point, the coordinated multi-point transmission control module 603 is configured to, when sending a message indicating to deactivate coordinated multi-point transmission to other access network nodes participating in the cooperation set participating in the coordinated multi-point transmission of the terminal, specifically:

Based on the same inventive concept as the method, an embodiment of the present invention provides an access network node, where the access network node is an access network node that participates in coordinated multipoint transmission of a terminal, except for a terminal service base station in a coordinated set, as shown in fig. 7, the access network node includes:

a coordinated multi-point transmission indication receiving module 701, configured to receive a message indicating to deactivate coordinated multi-point transmission, where the message indicating to deactivate multi-point transmission carries identification information of the terminal and indication information for deactivating coordinated multi-point transmission; or receiving a handover notification message, where the handover notification message carries the identifier information of the terminal, the identifier information of the target base station, and the coordinated multi-point transmission maintenance indication information;

a coordinated multipoint transmission deactivation module 702, configured to, when the coordinated multipoint transmission indication receiving module 701 receives a message indicating deactivation of coordinated multipoint transmission, determine the terminal according to the identifier information of the terminal, and deactivate coordinated multipoint transmission of the terminal according to the indication of the indication information for deactivating coordinated multipoint transmission;

a coordinated multi-point transmission maintaining module 703, configured to, when the coordinated multi-point transmission indication receiving module 701 receives the handover notification message, determine the terminal according to the identifier information of the terminal, determine the target base station according to the identifier information of the target base station, and determine that the terminal continues coordinated multi-point transmission after being handed over to the target base station according to the coordinated multi-point transmission maintaining indication message.

Based on any of the foregoing embodiments of the access network node, preferably, after the coordinated multi-point transmission maintaining module 703 determines that the terminal continues to perform coordinated multi-point transmission after being switched to the target base station, the coordinated multi-point transmission maintaining module is further configured to:

Based on any of the above embodiments of the access network node, preferably, if the access network node is a central cooperating point, the access network node further includes a first data sending module;

if the access network node is other cooperative base stations except the service base station, the access network node also comprises a second data sending module;

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A coordinated multi-point transmission control method in a cell switching process, the cell switching process comprising: the method comprises the steps that a service base station sends a switching request message to a target base station after determining to perform cell switching on a terminal, and sends a switching command to the terminal after receiving a switching request response message sent by the target base station so as to indicate the terminal to be switched to a cell of the target base station, wherein the terminal is a terminal for executing coordinated multi-point transmission; the coordinated multi-point transmission control method is characterized by comprising the following steps:

after determining to perform cell switching on the terminal, the serving base station judges whether the target base station supports coordinated multi-point transmission on the terminal;

if the target base station does not support the coordinated multi-point transmission of the terminal, the service base station deactivates the coordinated multi-point transmission of the terminal and sends a message indicating to deactivate the coordinated multi-point transmission to other access network nodes in a coordinated set participating in the coordinated multi-point transmission of the terminal, wherein the message indicating to deactivate the multi-point transmission carries the identification information of the terminal and the indication information of deactivating the coordinated multi-point transmission.

2. The method of claim 1, wherein:

the serving base station judges whether the target base station supports the coordinated multi-point transmission of the terminal or not according to the indication information of whether the target base station supports the coordinated multi-point transmission of the terminal or not, wherein the indication information is carried in the switching request response message; or,

the service base station judges whether the target base station supports the coordinated multi-point transmission of the terminal according to indication information which is sent by an Operation Administration and Maintenance (OAM) in advance and indicates whether each base station supports the coordinated multi-point transmission of the terminal; or,

the service base station judges whether the target base station supports the coordinated multi-point transmission of the terminal according to the indication information whether the base stations support the coordinated multi-point transmission of the terminal or not, which is interacted in advance; or,

and the service base station judges whether the target base station supports the coordinated multi-point transmission of the terminal or not according to the indication information which is sent by the central coordination point in the coordination set in advance and is used for judging whether each base station supports the coordinated multi-point transmission of the terminal or not.

3. The method of claim 2, wherein the determining whether the target base station supports coordinated multi-point transmission to the terminal comprises:

if the indication information indicating whether the target base station supports the coordinated multi-point transmission for the terminal indicates that the target base station does not support the coordinated multi-point transmission, the serving base station judges that the target base station does not support the coordinated multi-point transmission for the terminal;

if the indication information indicating whether the target base station supports the coordinated multi-point transmission of the terminal indicates that the target base station does not support the coordinated multi-point transmission of a central scheduling mode, but the coordinated multi-point transmission of the terminal is in the central scheduling mode, the serving base station judges that the target base station does not support the coordinated multi-point transmission of the terminal;

if the indication information indicating whether the target base station supports the coordinated multi-point transmission of the terminal indicates that the target base station supports the coordinated multi-point transmission of the central scheduling mode and the coordinated multi-point transmission of the terminal is in the central scheduling mode, the serving base station judges that the target base station supports the coordinated multi-point transmission of the terminal; and if the indication information of whether the target base station supports the coordinated multi-point transmission of the terminal indicates that the target base station supports the coordinated multi-point transmission of the central scheduling mode, the indication information of whether the target base station supports the coordinated multi-point transmission of the terminal also indicates the identification information of the central coordinated point of the coordinated set where the target base station is located.

4. The method of claim 3, wherein if the indication information indicating whether the target base station supports the coordinated multi-point transmission for the terminal indicates that the target base station supports the coordinated multi-point transmission in the central scheduling mode and the identification information of the central coordinated point in the coordinated set where the target base station is located, and the coordinated multi-point transmission for the terminal is in the central scheduling mode, the serving base station sends the handover notification message to other access network nodes in the coordinated set participating in the coordinated multi-point transmission for the terminal, the method comprises:

and the service base station sends a switching notification message to a central cooperation point in a cooperation set participating in the cooperative multi-point transmission of the terminal, wherein the switching notification message also carries identification information of the central cooperation point of the cooperation set where the target base station is located.

5. The method of claim 4, wherein before the serving base station sends the handover notification message to a central cooperating point in a cooperating set participating in the coordinated multi-point transmission of the terminal, the method further comprises:

the service base station judges whether the target base station and the service base station belong to the same central cooperation point according to the identification information of the central cooperation point of the cooperation set where the target base station is located;

the serving base station sends a handover notification message to a central cooperating point in a cooperating set participating in the coordinated multi-point transmission of the terminal, including:

and if the target base station and the service base station belong to the same central cooperation point, the service base station sends a switching notification message to the central cooperation point in the cooperation set participating in the cooperative multipoint transmission of the terminal.

6. The method of claim 2, wherein the serving base station determines whether the target base station supports coordinated multi-point transmission for the terminal after determining to perform cell handover for the terminal, and the method further comprises:

and if the serving base station determines that the cell is switched to S1, deactivating coordinated multi-point transmission to the terminal, and sending a message indicating deactivation of coordinated multi-point transmission to other access network nodes in a coordinated set participating in coordinated multi-point transmission of the terminal, wherein the message indicating deactivation of multi-point transmission carries identification information of the terminal and indication information of deactivation of coordinated multi-point transmission.

7. The method according to any of claims 1 to 6, wherein if the coordinated set participating in the coordinated multi-point transmission of the terminal includes a central coordinated point, the sending the message indicating to deactivate coordinated multi-point transmission to other access network nodes in the coordinated set participating in the coordinated multi-point transmission of the terminal comprises:

after sending a message indicating to deactivate coordinated multipoint transmission to the central coordination point, the method further comprises:

the service base station receives the identification information of the terminal sent by the central cooperation point, data which is not transmitted to the terminal or received the correct confirmation of the terminal, the start position information of the data and the end position information of the data;

and the service base station stores the identification information of the terminal, the data, the start position information of the data and the end position information of the data in a related manner.

8. The method according to claim 7, wherein if the cooperative set participating in the coordinated multi-point transmission of the terminal further includes other cooperative base stations except the serving base station, the sending the message indicating to deactivate the coordinated multi-point transmission to other access network nodes participating in the cooperative set participating in the coordinated multi-point transmission of the terminal further includes:

9. The method according to any of claims 1 to 6, wherein if the cooperative set participating in the coordinated multi-point transmission of the terminal includes other cooperative base stations except the serving base station but does not include a central cooperative point, the sending the message indicating to deactivate the coordinated multi-point transmission to other access network nodes participating in the cooperative multi-point transmission of the terminal comprises:

after sending a message indicating deactivation of coordinated multipoint transmission to other coordinated base stations in the coordinated set, the method further includes:

the service base station receives the identification information of the terminal, the data which is not transmitted to the terminal or received the correct confirmation of the terminal, the starting position information of the data and the ending position information of the data, which are sent by other cooperative base stations;

10. A coordinated multi-point transmission control method in a cell switching process is characterized by comprising the following steps:

an access network node except the terminal service base station in a coordinated set participating in coordinated multi-point transmission of a terminal receives a message indicating to deactivate coordinated multi-point transmission, wherein the message indicating to deactivate multi-point transmission carries identification information of the terminal and indication information for deactivating coordinated multi-point transmission; the access network node determines the terminal according to the identification information of the terminal and deactivates the coordinated multi-point transmission of the terminal according to the indication of the indication information for deactivating the coordinated multi-point transmission; or,

the access network node receives a switching notification message, wherein the switching notification message carries the identification information of the terminal, the identification information of the target base station and the coordinated multi-point transmission maintenance indication information; and the access network node determines the terminal according to the identification information of the terminal, determines the target base station according to the identification information of the target base station, and determines that the terminal is switched to the target base station and then continues coordinated multi-point transmission according to the coordinated multi-point transmission maintaining indication information.

11. The method according to claim 10, wherein if the access network node is a central cooperating point, the handover notification message further carries identification information of the central cooperating point of the cooperating set where the target base station is located.

12. The method according to claim 10 or 11, wherein if the access network node is a central cooperating point, after determining that the terminal continues coordinated multipoint transmission after switching to the target base station, the method further comprises:

13. The method of claim 10, wherein if the access network node is a central cooperating point, after the access network node receives a message indicating deactivation of coordinated multipoint transmission sent by a serving base station of a terminal, the method further comprises:

the central cooperation point sends the identification information of the terminal, the data which is not transmitted to the terminal or received the correct confirmation of the terminal, the start position information of the data and the end position information of the data to a service base station of the terminal;

if the access network node is a cooperative base station other than the serving base station, and after the access network node receives a message indicating deactivation of cooperative multipoint transmission sent by the serving base station of the terminal, the method further comprises:

the other cooperative base stations send the identification information of the terminal and the data which is not transmitted to the terminal or received the correct confirmation of the terminal to a service base station of the terminal; or, the other cooperative base stations send the identification information of the terminal, the data which is not transmitted to the terminal or received the correct confirmation of the terminal, the start position information of the data and the end position information of the data to the serving base station of the terminal.

14. The method of claim 13, wherein if the access network node is a central cooperating point, after the central cooperating point receives a message indicating to deactivate coordinated multipoint transmission sent by a serving base station of a terminal, the method further comprises:

the central cooperative point sends a message indicating to deactivate cooperative multi-point transmission to other cooperative base stations except the service base station in the cooperative set of the cooperative multi-point transmission of the participating terminal, and the message indicating to deactivate cooperative multi-point transmission sent to the other cooperative base stations carries the identification information of the terminal and the indication information for deactivating cooperative multi-point transmission.

15. A base station, the base station comprising:

characterized in that, the base station further comprises:

16. The base station of claim 15, wherein when determining whether the target base station supports coordinated multi-point transmission to the terminal, the coordinated multi-point transmission control module is specifically configured to:

17. The base station of claim 16, wherein when determining whether the target base station supports coordinated multi-point transmission to the terminal, the coordinated multi-point transmission control module is specifically configured to:

18. The base station of claim 17, wherein if the indication information indicating whether the target base station supports the coordinated multi-point transmission for the terminal indicates that the target base station supports the coordinated multi-point transmission in the central scheduling mode and the identification information of the central coordination point in the coordination set where the target base station is located, and the coordinated multi-point transmission for the terminal is in the central scheduling mode, the coordinated multi-point transmission control module is specifically configured to, when sending the handover notification message to other access network nodes in the coordination set that participate in the coordinated multi-point transmission for the terminal:

19. The base station of claim 18, wherein when sending the handover notification message to a central cooperating point in a cooperating set participating in the coordinated multi-point transmission of the terminal, the coordinated multi-point transmission control module is specifically configured to:

judging whether the target base station and the base station belong to the same central cooperation point or not according to the identification information of the central cooperation point of the cooperation set where the target base station is located;

20. The base station of claim 17, wherein after the cell handover determining module determines to perform cell handover on the terminal, before the coordinated multi-point transmission control module determines whether the target base station supports coordinated multi-point transmission for the terminal, the coordinated multi-point transmission control module is further configured to:

21. The base station according to any one of claims 16 to 20, wherein if the coordinated set participating in the coordinated multi-point transmission of the terminal includes a central coordinated point, the coordinated multi-point transmission control module is specifically configured to, when sending a message indicating deactivation of coordinated multi-point transmission to other access network nodes participating in the coordinated set participating in the coordinated multi-point transmission of the terminal:

22. The base station of claim 21, wherein if the coordinated set participating in the coordinated multi-point transmission of the terminal further includes other coordinated base stations except the base station, the coordinated multi-point transmission control module is further configured to, when sending a message indicating to deactivate coordinated multi-point transmission to other access network nodes participating in the coordinated set participating in the coordinated multi-point transmission of the terminal, further:

23. The base station according to any of claims 16 to 20, wherein if the coordinated set participating in the coordinated multi-point transmission of the terminal includes other coordinated base stations except the base station but does not include a central coordinated point, the coordinated multi-point transmission specifically is configured to, when sending a message indicating deactivation of coordinated multi-point transmission to other access network nodes in the coordinated set participating in the coordinated multi-point transmission of the terminal:

24. An access network node, wherein the access network node is an access network node outside a serving base station of a terminal in a cooperating set participating in a coordinated multipoint transmission of the terminal, the access network node comprising:

25. The access network node according to claim 24, wherein if the access network node is a central cooperating point, the handover notification message further carries identification information of the central cooperating point of the cooperating set where the target base station is located.

26. The access network node according to claim 24 or 25, wherein if the access network node is a central cooperating point, after the coordinated multi-point transmission maintaining module determines that the terminal continues coordinated multi-point transmission after switching to the target base station, the coordinated multi-point transmission maintaining module is further configured to:

27. The access network node of claim 24, further comprising a first data transmission module if the access network node is a central cooperating point;

28. The access network node of claim 27, further comprising a coordinated multi-point transmission indication sending module if the access network node is a central coordinated point;