WO2012093281A2

WO2012093281A2 - Method for handing over mbms ue in an enb in wireless telecommunication network

Info

Publication number: WO2012093281A2
Application number: PCT/IB2011/003218
Authority: WO
Inventors: He Wang; Philippe Godin
Original assignee: Alcatel Lucent
Priority date: 2011-01-04
Filing date: 2011-11-08
Publication date: 2012-07-12
Also published as: TW201234888A; CN102595326B; TWI488515B; CN102595326A; WO2012093281A3

Abstract

The invention relates to a method, in an eNB in wireless telecommunication network, for handing over UE, wherein the method comprises: A. determining a MBSFN area corresponding to the first neighboring cell of the at least one neighboring cell; B. determining a second MBMS service set supported by the first neighboring cell, according to the MBMS services supported by the at least one MBSFN area respectively; C. selecting the first neighboring cell as the handover target cell, if the first MBMS service set and the second MBMS service set have the largest intersection, for the first neighboring cell in the at least one neighboring cell. With the technical solution, the MBMS service continuity which is received in the source cell is kept to the largest extent when the UE is handover to the neighboring cell.

Description

METHOD FOR HANDING OVER MBMS UE IN AN

ENB IN WIRELESS TELECOMMUNICATION

NETWORK

Field of the Invention

The present invention relates to wireless telecommunication network, more particularly, to a method for handing over MBMS UE in an eNB in wireless telecommunication network.

Background of the Invention

In mobile telecommunication, there's a challenging task of how to provide multimedia service to wireless user in an efficient way. More particularly, efficient here means using the scarce and expensive wireless telecommunication resource allocated to network (e.g. frequency band) efficiently, thereby users and different kinds of services as more as possible can be served in parallel in wireless telecommunication frequency band. Although the existing 2^nd generation of wireless telecommunication network supports voice service in an efficient way, the aim of the 3^rd generation system and the wireless telecommunication network based on packet is to provide the optimal services to data communication and packet in the most efficient way.

By using unicast or broadcast/multicast transmission technology according to the kind of services, the network capacity and investment can be optimized. Broadcast/multicast technology can be used when (multimedia) data needs to be provided in parallel from a source to a large number of receivers. Unicast technology can be used when data needs to be exchanged between different telecommunication entities or data needs to be distributed to one or a small number of receivers (e.g. on-demand multimedia content). One presumptive transmission manner is SFN (single frequency network) operation, wherein all cells in MBSFN (MBMS Single Frequency Network) area transmit the same contents in synchronization mode with the same wireless telecommunication resources; thereby allowing reception UE to combine received signals on physical layer. This requires each session serving MBMS user to configure wireless telecommunication resources (e.g. wireless resource block, TTI ...) and physical layer's parameter (e.g. MCS, modulation and coding scheme) in the same way in all the cells. Here, MCE (Multicell/Multicast coordination Entity) can be used. Such kind of MCE can control cells belonging to one or more eNBs. But if SFN area is chosen in the manner that SFN area exceeds the area controlled by a single MCE, coordination is required among the MCEs.

Of course, when UE is receiving one or more MBMS, cell handover happens on eNB side because of UE's moving or other reasons, it is better that one or more MBMS received by the UE keeps good service continuity.

Summary of the Invention

While discovered in experimental process, when UE is receiving one or more MBMS, and handover procedure happens under the control of the eNB which the UE belongs to, usually the one or more MBMS received by the UE cannot continue.

Based on the findings above and a further analysis, the reason why some MBMS reception users cannot keep service continuity in handover usually is, one or more MBMS supported by handover target cell is not the same as one or more MBMS supported by source cell, even one or more MBMS supported by handover target cell is less than the MBMS supported by source cell, or target cell cannot support MBMS service sending.

Therefore, it would be advantageous if a method is provided ,in an eNB in wireless telecommunication network, to control UE's handover, to enable the UE keep its received MBMS service continuity at most.

According to an embodiment of the present invention, there provides a method for handing over UE in an eNB in wireless telecommunication network, wherein the source cell of UE is served by a BS and has at least one neighboring cell, and the UE is used to receive the first MBMS service set, wherein the method comprises:

A. determining at least a MBSFN area corresponding to the first neighboring cell of at least one neighboring cell;

B. determining the second MBMS service set supported by the first neighboring cell, according to MBMS services supported by at least one MBSFN area respectively;

C. selecting the first neighboring cell as the handover target cell, if the first MBMS service set and the second MBMS service set have the largest intersection, for the first neighboring cell in the at least one neighboring cell.

According to another embodiment of the present invention, there provides a apparatus for handing over UE in an eNB in wireless telecommunication network, wherein the source cell of the UE is served by a BS and has at least one neighboring cell; the UE is used to receive the first MBMS service set, wherein the apparatus comprises:

- a MBSFN area determination means, for determining a MBSFN area corresponding to a first neighboring cell of the at least one neighboring cell;

- a second MBMS service set determination means, for determining a second MBMS service set supported by the first cell, according to the MBMS service supported by the at least one MBSFN area respectively;

- handover target cell determination means, for selecting the first neighboring cell as the target cell in the at least one neighboring cell, if the first MBMS service set and the second MBMS service set have the largest intersection, for the at least one first neighboring cell.

Wherein the first MBMS service set is the set of UE's one or more receiving or receivable MBMS service in the source cell, and the second MBMS service set is the set of UE's one or more receivable MBMS service in the first cell of the handover candidate cell for handing over. In the technology solution above, the first neighboring cell is one of the at least one neighboring cell of the UE's source cell, via at least one MBSFN area determination step, at least one MBSFN area that covers the first neighboring cell can be obtained; further, the second MBMS service set supported by the first cell can be determined, if the at least one neighboring cell of the UE's source cell only comprises one cell, that is the first neighboring cell, and the UE can be handed over to the first neighboring cell directly; if it comprises several cells, and if the second MBMS service set receivable in the first neighboring cell and the first MBMS service set above have the largest intersection in all of the neighboring cells, then handing over UE to the first neighboring cell. If the intersection corresponding to the first neighboring cell is not the largest, then repeating the process of the present solution until one neighboring cell with the largest intersection is determined, and handing over UE to the neighboring cell with the largest intersection. Therefore, with the above steps, it ensures that in all neighboring cells, UE can be handed over to a cell with the largest intersection and keeps service continuity at most in UE's MBMS service reception.

Brief Description of Drawings

With reference to the following detailed description of the non-restrictive embodiments, other features, objects and advantages of the present invention will be more apparent.

FIG.l shows a method flowchart of one embodiment of the present invention, for handing over MBMS UE, in an eNB in wireless telecommunication network;

FIG.2 shows a flowchart of MBSFN area determination sub-steps of another embodiment of the present invention, for handing over MBMS UE, in an eNB in wireless telecommunication network;

FIG.3 shows a flowchart of MBSFN area determination sub-steps of yet another embodiment of the present invention, for handing over MBMS UE, in an eNB in wireless telecommunication network; FIG.4 shows a schematic diagram of one embodiment of the present invention, for handing over MBMS UE, in an eNB in wireless telecommunication network;

Wherein same or similar reference numerals refer to same or similar apparatuses (modules) or steps.

Detailed Description of Embodiments

FIG.l shows a method flowchart of one embodiment of the present invention, for handing over MBMS UE in an eNB in wireless telecommunication network. The UE's source cell is served by a BS and has at least one neighboring cell, e.g. NCell_l, NCell_2, NCell_3, and NCell_4; while UE is used for receiving the first MBMS service set, e.g. {MBMS_Service_l, MBMS_Service_3, MBMS_Service_4}, as shown in the drawing, wherein the method comprises step S l l , S 12 and S 13.

In step Sl l, eNB 11 determines at least one MBSFN corresponding to the first neighboring cell in at least one neighboring cell, e.g. NCell_2.

In step SI 2, eNB 11 determines the second MBMS service set supported by the first cell, according to the MBMS service supported by at least one MBSFN area respectively;

In step SI 3, eNB 11 selects the first neighboring cell NCell_2 as the handover target cell if for the first neighboring cell NCell_2, the first MBMS service set (e.g. MBMS_Service_l , MBMS_Service_3, MBMS_Service_4) and the second MBMS service set have the largest intersection, in at least one neighboring cell.

Wherein, the first MBMS service set (e.g. MBMS_Service_l, MBMS_Service_3, MBMS_Service_4) is the set of UE's one or more receiving or receivable MBMS in the source cell, and the second MBMS service set is the set of UE's one or more receivable MBMS service set in the first cell which may be selected as the handover candidate cell.

In some embodiments, at least one neighboring cell of the above cells which can be selected by eNB 11 as the UE's handover candidate cell, is preferably satisfied with handover measurement report criteria of the UE. Correspondingly, the method above further comprises steps: determining at least one neighboring cell based on handover measurement report criteria reported by the UE.

In some embodiments, if the first neighboring cell NCell_2 is served by eNB l l, then alternatively, in step SI 1, at least one MBSFN area, e.g. MBSFN_Area_l and MBSFN_Area_2, corresponding to the first neighboring cell NCell_2 can be obtained from MCE, via M2 interface setup procedure of M2 interface Application Protocol from the MCE 20.

While in other embodiments, if the first neighboring cell NCell_2 is served by eNB 12, thereby in step SI 1, indication information of at least one MBSFN area (e.g. MBSFN_Area_l and MBSFN_Area_2) corresponding to the first neighboring cell NCell_2 can be obtained from MCE.

Alternatively, it can be considered not to centralized store all information of MBSFN corresponding to all cells served by all the BS into MCE20, but share the information in each eNB and update in real time. Then alternatively, in step S l l , O&M (Operation and Management) information can be synchronized between MCE20 and eNB l l, the O&M information comprises the indication information of at least one MBSFN area (e.g. MBSFN_Area_l and MBSFN_Area_2) corresponding to the first neighboring cell NCell_2, or preferably also comprise the neighboring relationship of the UE's source cell and at least one neighboring cell. Via the step, eNB l l can obtain the one or more MBSFN information corresponding to the first neighboring cell NCell_2 above from the MCE 20.

Alternatively, in another embodiment, at least one MBSFN area. e.g. MBSFN_Area_l and MBSFN_Area_2) can be obtained from the response to the message from eNB 12, via sending request message to MCE20, in step S l l . Specifically, step S l l may further comprise the sub-step of "sending at least one MBSFN area indication information update request to MCE" and the sub-step of "determining at least one MBSFN area according to the update request acknowledgement". FIG.2 shows a flowchart of MBSFN area determination sub-steps of another embodiment of the present invention, for handing over MBMS UE, in an eNB in wireless telecommunication network. In the embodiment, the sub-step of "sending at least one MBSFN area indication information update request to MCE", specifically, may further comprises S l l l l and SI 112.

In step Sl l l l , eNB 11 sends at least one MBSFN area indication information update request to MCE20. Wherein at least one MBSFN area is corresponding to the first neighboring cell NCell_2 which is selected as a handover candidate cell.

In step SI 112, eNB 11 determines at least one MBSFN area, e.g. MBSFN_Area_l and MBSFN_Area_2, according to the update request acknowledgement from MCE20.

Specifically, "at least one MBSFN area indication information update request" sent in step S l l l l, may be implemented based on present M2AP procedure by adding an "update request field" for MBSFN area in the present message of M2AP protocol. Thereby in step S l l l l, eNB 11 may further send M2 interface configuration update message to MCE, via M2AP protocol, wherein the configuration message comprises at least one MBSFN area indication information update request. Correspondingly, in step SI 112, eNB 11 may further determine at least one MBSFN area according to M2 interface configuration update request response from MCE.

In the embodiments above, the M2 interface configuration update request and response can use, but not limited to the message format shown in Tab.l , wherein the message is sent to MCE20 by eNB 11 and it indicates that application layer configuration data has changed in the eNB.

Tab. l : M2 INTERFACE CONFIGURATION UPDATE message ( "ENB

CONFIGURATION UPDATE ) (eNB 11 -> MCE20) IE/Group Name Presence Range IE type Criticality Assigned and Criticality reference

Message Type M 9.2.1 .1 YES reject

Global eNB I D O 9.2.1 .10 YES reject eNB Name O Printable YES ignore

String

(1 ..150,...)

eNB MBMS 0..1 YES reject

Configuration data per

cell

>eNB MBMS 1 to <maxnoofCells> EACH reject Configuration data

Item lEs

»CHOICE eNB ID M

»>eNB MBMS 9.2.1 .12

Configuration data

Item

»>E-UTRAN CGI 9.2.1 .1 1

>»lntra Frequency 1 to <maxnooflntraFreqNCell EACH ignore Neighbouring Cell >

List l Es

»»EUTRAN M 9.2.1 .1 1 - - CGI

»>lnter Frequency 1 to <maxnooflnterFreqNCell EACH ignore Neighbouring Cell >

List l Es

»»EUTRAN M 9.2.1 .1 1 - - CGI

Wherein, intra frequency neighboring cell list, inter frequency neighboring cell list, and corresponding "EUTRANCGI" are newly defined IE in message. The meaning of some items in Tab.l shows as following:

Correspondingly, in M2 interface configuration UPDATE message "ENB CONFIGURATION UPDATE ACKNOWLEDGE" message, MCE20 needs to feedback the MBSFN area id information of the requested intra/inter frequency neighboring cells to the eNB 11.

For the M2 interface configuration UPDATE message of ENB CONFIGURATION UPDATE ACKNOWLEDGE message, in the embodiment of the present invention, neighboring cell MSBFN area info is added as one part of the IE "MCCH related BCCH Configuration Item" in ENB CONFIGURATION UPDATE ACKNOWLEDGE message. Then a new IE definition of "NCell MBSFN Area Info Item" is also needed to be defined.

In the embodiment, the detailed modification of IE "MCCH related BCCH Configuration Item" are listed, but not limited to Tab.2:

Tab.2 IE that provides MCCH related BCCH configuration information to the eNB 11.

Wherein, "Intra frequency Ncell MBSFN area information list", "Inter frequency Ncell MBSFN area information list", and corresponding "Ncell MBSFN area information item" are newly defined IE in the message.

Specially, the new added IE definition "NCell MBSFN Area Info Item" is listed but not limited to Tab.3. The "NCell MBSFN Area Info Item" IE provides the id information about the neighboring cell MBSFN area.

Tab.3: NCell MBSFN Area Info Item

Alternatively, in another embodiment of the present invention, "at least one MBSFN area indication information update request" sent in step Sl l l l may be implemented by newly defined message interface in existing M2 interface, that is, eNB l l may send eNB 's MBMS configuration information request message to MCE, wherein the configuration information request message is newly added in M2AP and comprises at least one MBSFN area indication information update request. Correspondingly, in step SI 112, eNB l l may determine at least one MBSFN area, according to MCE's configuration information response.

Those skilled in the art can understand, the specific forms of the request and response newly defined in M2AP used to request neighboring cell's MBSFN area indication information from MCE20 by eNB l l can refer to the IE definition in the Tab.l to Tab.3 above. The specific definitions do not restrict the present invention.

Of course, those skilled in the art can understand, the sub-step of "obtaining at least one MBSFN area indication information from MCE" in step S l l , is not limited to obtaining at least one MBSFN area indication information according to MCE 20's response via "sending at least one MBSFN area indication information update request". Of course, the method may comprise other forms of obtaining sub-steps, e.g. MCE20 may send message of at least one MBSFN area indication information corresponding to the first neighboring cell NCell_2 periodically, correspondingly, the first eNB 11 receives the message according to the information periodically, and obtains the above at least one MBSFN area indication information.

Alternatively, in another embodiment of the present invention, eNB 11 may obtain the at least one corresponding MBSFN area information from the first neighboring cell NCell_2 as well as from the MCE20.

FIG.3 shows a flowchart of MBSFN area determination sub-steps of yet another embodiment of the present invention, for handing over MBMS UE, in an eNB in wireless telecommunication network, wherein it comprises X2 interface setup request message sending step S I 121 and X2 interface setup acknowledge message receiving step S I 122.

In the step S I 121 and SI 122 above, X2 interface setup procedure is used to exchange MBSFN subframe information corresponding to each cell served by BSs, in a plurality of eNBs in the network including eNB 11 and eNB 12. Therefore, the embodiment of the present invention exchanges MBSFN area indication information corresponding to each cell served by eNB 11 and eNB 12 respectively during the X2 interface setup procedure. That is, eNB 11 receives eNB 12's X2 interface setup request message via X2AP protocol in step S I 122, or vice versa, eNB 11 sends X2 interface setup request message to the second eNB in step SI 121 and receives the second eNB's X2 interface setup acknowledge message in step SI 122, wherein the X2 interface setup request message and X2 interface setup acknowledge message both comprise at least one cell's MBSFN area (e.g. MBSFN_Area_l and MBSFN_Area_2) indication information corresponding to the second eNB 12.

Of course, alternatively, eNB 11 may receives eNB 12's "eNB configuration update message" via X2AP protocol, or sends "eNB configuration update message" to eNB 12 and receives eNB 12's acknowledge message of "eNB configuration update message", wherein the configuration update message and its acknowledge message both comprise indication information IE of MBSFN area (e.g. MBSFN_Area_l and MBSFN_Area_2) of at least one cell served b y the second eNB 12.

According to the definitions of X2 SETUP REQUEST, X2 SETUP RESPONSE and ENB CONFIGURATION UPDATE in the present X2AP signaling, in some embodiments of the present invention, MBSFN area information can be added to the definition of "Served Cell Information" of each cell served by eNB 11 in the network, in the signaling message above. Of course,here, preferably, the improvement of signaling message is based on the form of the signaling/message in TS36.423 V9.4.0. Specifically, the form of IE added e.g. "MBSFN area indication" may be the same or different as the changed form in Tab. l to Tab.3 above, therefore it won't be repeated here. The specific modification to forms of signaling/message won't restrict the present invention.

Suppose, UE receivable MBMS set and corresponding MBSFN area is shown in Tab.4 as following:

Meanwhile, suppose MBSFN area indication information of source cell's all neighboring cell is shown in the following Tab.5:

NCell4 MBSFN Area 2

According to the determination of UE's handover measurement report criteria, the first neighboring cell NCell2, may be selected as the handover candidate cell. After the steps of the embodiments above, eNB l l may obtain the MBSFN area (e.g. MBSFN_Area_l and MB SFN_Area_2) indication information of a neighboring cell of the source cell, e.g. the first neighboring cell NCell2. In step SI 2, eNB l l may determine the second MBMS service set supported by the first neighboring cell NCell2, according to the MBMS service set supported by the MBSFN area MBSFN_Area_l and MBSFN_Area_2 respectively. E.g. suppose the MBMS services supported by MBSFN_Area_l is MBMS_Service_land MBMS_Service_3, while the MBMS services supported by MBSFN_Area_2 is MBMS_Service_4, then eNB l l may determine the second MBMS service set supported by the first neighboring cell NCell2 is {MBMS_Service_l , MBMS_Service_3 , MBMS_Service_4} . The first MBMS service set {MBMS_Service_l , MBMS_Service_3 , MBMS_Service_4} and the second MBMS service set {MBMS_Service_l , MBMS_Service_3 , MBMS_Service_4 } have the largest intersection, for the first neighboring cell NCell2, in the neighboring cell NCelll , NCell2 , NCell3 and NCell4, because the two sets overlap with each other, then the first neighboring cell NCell2 may be determined as the UE's handover target cell.

Further, step S 13 further comprises sub- step: in at least one neighboring cell of source cell, if the first MBMS service set of the embodiment is e.g. {MBMS_Service_l , MBMS_Service_3 , MBMS_Service_4 }, while the second MBMS service sets supported by the first neighboring cell NCell2 and the second neighboring cell NCell4 both are e.g. {MBMS_Service_l , MBMS_Service_3 , MBMS_Service_4 } respectively, that is, for the first neighboring cell NCell2 and the second neighboring cell NCell4, their corresponding second MBMS service sets supported respectively and the first MBMS service set corresponding to the UE have the largest intersection, that is {MBMS_Service_l , MBMS_Service_3 , MBMS_Service_4, here, the first neighboring cell NCell2 and the second neighboring cell NCell4 can both be selected as the handover target cell, and support all the UE receivable service continuity in source cell. Meanwhile, eNB l l may select the cell with better channel quality as the handover target cell between the first neighboring cell and the second neighboring cell according to the channel information reported by the UE.

Here, as shown in Tab.5, MBSFN_Area_l and MBSFN_Area_2 overlap and cover the first neighboring cell NCell2. Remarkable, even the at least one MBSFN corresponding to the first neighboring cell NCell_2 do not have any overlap, that is, the first neighboring cell NCell_2 corresponds to only one of MBSFN_Area_l and MBSFN_Area_2, here the second MBMS service set corresponding to NCell_2 is { MBMS_Service_l , MBMS_Service_3 } or { MBMS_Service_4 } . Then, in step S I 3, the neighboring cell with the largest intersection of the first MBMS service set and the second MBMS service set in source cell's neighboring cells NCell_l , NCell_2, NCell_3 and NCell_4 will still be selected as handover target cell in step SI 3. Now, although some part of the MBMS UE receiving service may be interrupted, but one or more MBMS received by UE can keep service continuity at max, via the method of the embodiment.

As is shown in FIG.1 , go to step Sl l after step S 13, keep on determining in the other neighboring cells of source cell, whether the first MBMS service set and the second MBMS service set have the largest intersection for the neighboring cell in the source cell's neighboring cells.

Of course, the neighboring cell in the embodiment above, e.g. the first neighboring cell NCell2 or the second neighboring cell NCell4 etc, can be inter/intra frequency neighboring cell to the source cell.

FIG.4 shows a schematic diagram of apparatus 100, according to one embodiment of the present invention, for handing over MBMS UE in an eNB in wireless telecommunication network. MBSFN area determination means 101, the second MBMS service set determination means 102 and handover target cell determination means 103.

Apparatus 100 above, for handing over MBMS UE, is usually set in eNB 11, for eNB 11 handing over UE served by itself. Wherein MBSFN area determination means 101 , is used to determine at least one MBSFN area corresponding to a first neighboring cell of at least one neighboring cell. The second MBMS service set determination v 102, is used to determine the second MBMS service set supported by the first neighboring cell, according to the MBMS service supported respectively by at least one MBSFN area. Handover target cell determination means 103, is used to select the first neighboring cell as the handover target cell, if the first MBMS service set and the second MBMS service set have the largest intersection, for the first neighboring cell, in the at least one neighboring cell.

In another embodiment of the present invention, MBSFN area determination means 101 further comprises, indication information eNB obtaining module, or indication information MCE obtaining module (not shown), wherein indication information eNB obtaining module is used to obtain at least one MBSFN area indication information from the second eNB ; the indication information MCE obtaining module is used to obtain at least one MBSFN area from MCE via M2AP setup procedure, if the first neighboring cell is served by the eNB.

The above is the description of the embodiments of the present invention. However, the present invention is not limited to specific embodiment. Those skilled in the art may carry out various modification or variation in the scope of the appended claims. The technical solution of the present invention can be implemented with software or hardware.

Claims

1. A method, in an eNB in wireless telecommunication network, for handing over UE, wherein the source cell of the UE is served by a BS and has at least one neighboring cell, and the UE is used for receiving the first MBMS service set, wherein the method comprises:

A. determining a MBSFN area corresponding to the first neighboring cell of the at least one neighboring cell;

B. determining a second MBMS service set supported by the first neighboring cell, according to the MBMS services supported by the at least one MBSFN area respectively;

2. A method according to claim 1, wherein before the step A, the method further comprises:

- determining the at least one neighboring cell, according to handover measurement report criteria reported by the UE .

3. A method according to claim 1 , wherein the step A further comprises:

- obtaining the at least one MBSFN area from MCE via M2AP setup procedure, if the first neighboring cell is served by the eNB.

4. A method according to claim 1 , wherein the step A further comprises: Al . obtaining indication information of the at least one MBSFN area from the MCE, if the first neighboring cell is served by a second eNB,.

5. A method according to claim 4, wherein the step of obtaining in the step A comprises:

- synchronizing operation and management configuration between MCE and the eNB, wherein the operation and management configuration comprises the neighboring relationship of the source cell and the at least one neighboring cell, and indication information of the at least one MBSFN area.

6. A method according to claim 4, wherein the obtaining step of the step Al comprises:

Al l . sending the indication information update request of the at least one MBSFN area to the MCE;

A12. determining the at least one MBSFN area, according to acknowledgement for the update request.

7. A method according to claim 6, wherein the step Al l comprises:

- sending M2 interface configuration update request via M2AP to the MCE, wherein the configuration update request comprises the indication information update request of the at least one MBSFN area;

- determining the at least one MBSFN area, according to response for the M2 interface configuration update request .

8. A method according to claim 6, wherein the step Al l further comprises:

- sending configuration information request message of the eNB to the MCE, wherein the configuration information request message is the additional message of M2AP and comprises the indication information update request of the at least one MBSFN area.

- determining the at least one MBSFN area, according to the response for the configuration information request message from the MCE.

9. A method according to claim 1 , wherein the step A comprises:

A2. obtaining the at least one MBSFN indication information from the second eNB.

10. A method according to claim 9, wherein the step A2 further comprises:

- receiving the X2 interface setup request message or X2 interface setup response message from the second eNB via X2AP, wherein the X2 interface setup request message or the X2 interface setup response message comprises the MBSFN area indication information of the at least one cell served by the second eNB respectively.

11. A method according to claim 9, wherein the step A2 further comprises: - receiving the configuration update message from the second eNB via X2AP, wherein the configuration update message comprises the MBSFN area indication information of the at least one cell served by the second eNB.

12. A method according to claim 1 , wherein the step C further comprises:

selecting the cell with better quality as the handover target cell between the first neighboring cell and the second neighboring cell in the at least one neighboring cell, if the first neighboring cell and the second neighboring cell have the largest intersection with the same number of elements between the first MBMS service set and the second MBMS service set respectively.

13. A method according to any one of claims 1 to 12, wherein the at least one neighboring cell is an intra/inter frequency cell with the source cell.

14. An apparatus, in a base station in wireless telecommunication network, for handing over UE, wherein the source cell of the UE is controlled by the eNB and has a neighboring cell; the UE is used for receiving the first MBMS service set. Wherein the apparatus comprises:

15. An apparatus according to claim 14, wherein the MBSFN area determination means further comprises, indication information eNB obtaining module or indication information MCE obtaining module; wherein the indication information eNB obtaining module is used for obtaining the at least one MBSFN area indication information from the second eNB; the indication information MCE obtaining module is used for obtaining the at least one MBSFN area from MCE via M2AP setup procedure, if the first neighboring cell is served by the eNB.