WO2012122816A1

WO2012122816A1 - Method and system for determining switchover target cell for user equipment

Info

Publication number: WO2012122816A1
Application number: PCT/CN2011/082371
Authority: WO
Inventors: 杜晓; 马子江; 王斌; 褚丽; 许辉; 苟伟
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-03-17
Filing date: 2011-11-17
Publication date: 2012-09-20
Also published as: CN102685682A

Abstract

Disclosed is a method for determining a switchover target cell for a user equipment (UE). A control network element of a source cell where the UE is located transmits a multimedia broadcast multicast service (MBMS) information request to the control network element of one or a plurality of adjacent cells; the control network element of the adjacent cell transmits MBMS information of the adjacent cell to the control network element of the source cell; and the control network element of the source cell selects a switchover target cell for the UE on the basis of the MBMS information received. Also disclosed is a system for determining the switchover target cell for the UE. Employment of the method and system ensures to the greatest extent the reception continuity of the MBMS for the UE.

Description

Method and system for determining target cell for user equipment handover

The present invention relates to the field of mobile multimedia communications, and more particularly to a method and system for determining a target cell for user equipment handover. Background technique

With the rapid development of the Internet and the popularity of large-screen multi-function mobile terminals, a large number of mobile data multimedia services and various high-bandwidth multimedia services have emerged, such as: video conferencing, television broadcasting, video on demand, advertising, online education, Interactive games, etc., on the one hand, satisfy the rich and diverse needs of mobile users, and bring new business growth points to mobile operators. These mobile data multimedia services require multiple users to receive the same data at the same time. Compared with general data services, they have the characteristics of large data volume, long duration, and delay sensitivity.

In order to effectively utilize mobile network resources, the 3rd Generation Partnership Project (3GPP) proposes a Multimedia Broadcast Multicast Service (MBMS) service, which is a data source. The technology for transmitting data by multiple target mobile terminals realizes the sharing of resources of the core network and the access network in the network, and improves the utilization of network resources, especially the utilization of air interface resources. The MBMS service defined by 3GPP can not only realize plain text low-rate message class multicast and broadcast, but also realize high-speed multimedia service broadcast and multicast, and provide a variety of rich video, audio and multimedia services, which undoubtedly conforms to the future. The trend of mobile data development provides a better business prospect for the development of 3G.

A user equipment (UE, or terminal) that normally receives an MBMS service can be in two states: One is a Radio Resource Control (RRC) connection state (referred to as a connection) The state is RRC idle state (referred to as idle state). According to whether the UE is receiving the unicast service, it can be determined whether the UE that is receiving the MBMS service is in the connected state or in the idle state. When the UE is receiving the unicast service, the UE is in the connected state. The UE in the idle state does not establish an RRC connection with the network side, and the UE in the connected state establishes an RRC connection with the network side.

In the process of the mobile, the UE in the idle state generally enters the target cell according to the cell reselection procedure, and the UE in the connected state generally uses the cell handover procedure to enter the target cell. The handover of the connected UE can be divided into several phases: First, it is the handover preparation phase. At this stage, the current cell control UE in which the UE is located controls the neighboring cell, that is, controls the list of neighboring cells to be measured configured by the evolved Node B (eNB) of the current cell.

After the UE measures, the cell list that meets the measurement requirements is reported to the current cell. The current cell (ie, the eNB that controls the current cell, or the eNB or the source cell, which is simply referred to as the source cell) is comprehensively considered according to the signal quality and load status of the cell that the UE reports to meet the measurement requirements, and selects a suitable cell as the target cell of the UE. . Second, it is the switching phase. At this stage, the source cell sends a handover request to the target cell, and the target cell performs access control, and feeds back some parameters of the target cell to the source cell. After receiving the information, the source cell sends an RRC connection reconfiguration message to the UE. After the UE accesses the target cell according to the message and obtains the uplink resource allocation and the tracking area of the target cell, the UE sends an RRC connection reconfiguration complete message to the target cell. Finally, it is the post-completion phase. At this stage, the core network completes the path switching work, and the core network switches the data sent by the source cell to the target cell, and finally the target cell notifies the source cell to release the relevant resources. It should be specially stated that this process can be simplified if the source cell and the target cell are under the control of the same eNB. In the present invention, it is specifically analyzed for the case where two cells belong to different eNBs.

Currently, the handover of the connected UE is mainly based on ensuring the continuity of the unicast service, that is, the unicast service such as the voice call of the UE cannot be interrupted when the user switches from one cell to another. However, in the current LTE network, in addition to the unicast service, the MBMS service transmitted by the multicast mode can also be simultaneously used. When the UE switches from the source cell to the target cell, there are two situations, one The source cell and the neighboring cell (generally referred to as the neighboring cell before being determined as the handover target cell) belong to the same eNB. At this time, the eNB where the source d and the zone are located can know the MBMS service information of the neighboring cell, that is, The cell is using information of all MBMS services played in the multicast single frequency network (MBSFN) mode. In another case, the source cell and the neighboring cell belong to different eNBs, and the eNB where the source cell is located does not know the neighbors. MBMS service information of the cell eNB. FIG. 1 is a schematic diagram of distribution of neighboring cells and their eNBs when UE is handed over. As shown in FIG. 1, cells 1, 2, 3, 4, and 5 are all controlled by eNB1; cells 6, 7, 8, and 9 are all controlled by eNB2; Cells 10, 11, 12, 13, 14, and 15 all belong to eNB3 control. When the UE that needs to be handed over is located in the cell 4, since the cells 2, 3, and 5 belong to the same eNB as the cell 4, the eNB1 is responsible for forwarding the MBMS service information of the cells 2, 3, and 5; and for the cells 7, 9 and 10, Since the cell 4 does not belong to the same eNB, the eNB1 where the cell 4 is located does not know the MBMS service information of the cells 7, 9, and 10. However, the criterion for determining the target cell of the UE handover by the source cell is determined according to the signal quality and the load condition of the cell unicast service, and the target cell to which the handover is performed cannot guarantee the MBMS service, and the target cell cannot be guaranteed even if the MBMS service is provided. The same MBMS service as the source cell can be provided. Therefore, according to the current unicast criterion, when the source cell controls the UE handover, there is no guarantee that the target cell to which the UE is handed over can provide the MBMS service that is receiving or interested. After the UE switching of the MBMS service being received, the MBMS service that it is receiving may be interrupted, and thus cannot be continuously received. Summary of the invention

In view of the above, the main object of the present invention is to provide a method and a system for determining a target cell for user equipment handover, which can solve the problem that the target cell cannot be guaranteed to be receiving or interested in the target cell when the source cell controls the UE handover. The problem of the MBMS business.

In order to achieve the above object, the technical solution of the present invention is achieved as follows:

The present invention provides a method for determining a target cell for user equipment handover, and the method includes: The control network element of the source cell where the UE is located sends an MBMS service information request to the control network element of one or more neighboring cells;

The control network element of the neighboring cell sends the MBMS service information of the neighboring cell to the control network element of the source cell;

The control network element of the source cell selects the target cell for handover according to the received MBMS service information.

The control network element includes: an evolved base station (eNB), or a multi-cell/multicast cooperative entity (MCE), or a mobility management entity (MME).

The selecting the target cell to be handed over includes: selecting a neighboring cell that can provide the UE with the same MBMS service as the source cell, and having the best signal quality and load status as the target cell of the handover.

The MBMS service information includes: an MBSFN area ID of the neighboring cell, and further includes one or more of the following information: an identifier list of the MBMS service sent by the neighboring cell, and the neighboring cell sends The frequency of the MBMS service, the MBMS service identifier list that the neighboring cell has stopped transmitting, and the MBMS service identifier list that the neighboring cell plans to send.

The MBMS service information request or the MBMS service information includes: adding a new information element (IE) to an existing message, or creating a new message as an MBMS service information request or MBMS service information;

The sending the MBMS service information request or the sending the MBMS service information includes: sending, by using an X2 interface between the source cell and the eNB of the neighboring cell, or by using the M2 between the source cell and the MCE to which the eNB of the neighboring cell belongs. The interface sends or sends it through the MME.

The present invention further provides a system for determining a target cell of a user equipment handover, where the system includes: a control network element of a source cell and a control network element of a neighboring cell, where The control network element of the source cell is configured to send to a control network element of one or more neighboring cells

The MBMS service information request, according to the received MBMS service information, select a target cell for handover for the UE in the source cell;

The control network element of the neighboring cell is configured to send the MBMS service information of the neighboring cell to the control network element of the source cell after receiving the MBMS service information request.

The control network element of the source cell and the control network element of the neighboring cell include: an eNB, or an MCE, or an MME.

The control network element of the source cell selects the target cell to be handed over, and includes: the control network element of the source cell selects a neighboring cell that can provide the UE with the same MBMS service as the source cell and has the best signal quality and load status. As the target cell for handover.

The MBMS service information sent by the control network element of the neighboring cell includes: an MBSFN area ID of the neighboring cell, and further includes one or more of the following information: an MBMS service sent by the neighboring cell An identifier list, a frequency point of the MBMS service that the neighboring cell sends, an identifier list of the MBMS service that the neighboring cell has stopped transmitting, and an identifier list of the MBMS service that the neighboring cell plans to send.

The MBMS service information request sent by the control network element of the source cell or the MBMS service information sent by the control network element of the neighboring cell includes: adding a new IE to an existing message, or creating a new message as an MBMS Service information request or MBMS service information;

The MBMS service information request sent by the control network element of the source cell or the MBMS service information sent by the control network element of the neighboring cell includes: sending, by the X2 interface between the source cell and the eNB of the neighboring cell, or by The M2 interface between the source cell and the MCE to which the eNB of the neighboring cell belongs is sent or transmitted by the MME.

The method and system for determining a target cell for user equipment handover provided by the present invention, the MBM service information request is sent to the control network element of one or more neighboring cells by the control network element of the source cell where the UE is located; The network element sends the neighboring cell to the control network element of the source cell The MBMS service information of the source cell; the control network element of the source cell selects the target cell for handover according to the received MBMS service information. The source eNB of the UE obtains the MBMS service information of the cell that meets the UE measurement condition, and ensures that the cell that can continuously receive the MBMS service is used as the target cell, so as to ensure the unicast continuity of the UE. The continuity of the MBMS service received by the UE is guaranteed to the greatest extent. DRAWINGS

FIG. 1 is a schematic diagram of distribution of neighboring cells and their eNBs when a UE switches;

2 is a schematic flowchart of a method for determining a target cell of a user equipment handover according to the present invention; FIG. 3 is a schematic flowchart of a method for determining a target cell of a user equipment handover according to the present invention;

4 is a schematic flow chart of a method for determining a target cell of a user equipment handover according to the present invention;

FIG. 5 is a schematic structural diagram of a system for determining a target cell for user equipment handover according to the present invention. detailed description

The basic idea of the present invention is that the control network element of the source cell where the UE is located sends an MBMS service information request to the control network element of one or more neighboring cells; the control network element of the neighboring cell sends the control network element to the control cell of the source cell. The MBMS service information of the neighboring cell; the control network element of the source cell selects the target cell for handover according to the received MBMS service information, combining the signal quality and the load condition for the UE.

The technical solutions of the present invention are further elaborated below in conjunction with the accompanying drawings and specific embodiments. FIG. 2 is a schematic flowchart of a method for determining a target cell for user equipment handover according to the present invention. As shown in FIG. 2, the method specifically includes:

Step 201: The control network element of the source cell where the UE is located sends an MBMS service information request to the control network element of one or more neighboring cells. Specifically, the control network element includes: an eNB, or a Multi-cell/Multicast Coordination Entity (MCE), or a Mobility Management Entity (MME). When the source cell and the neighboring cell of the UE belong to the same eNB, and the source eNB and the new eNB belong to the same network element, the network element can also know the MBMS service information of the adjacent d and the area, so that the source network does not need to be sent. The MBMS service information request. If the source cell and the neighboring cell in which the UE is located do not belong to the same eNB, the eNB of the current cell in which the UE is located (hereinafter referred to as the current eNB, that is, the source eNB) receives the neighbor cell list that satisfies the measurement condition sent by the UE. And querying the neighbor cell list of the neighboring cell, when the MBMS service information of the neighboring cell is not included, sending to the eNB of one or more of the neighboring cells by using a point-to-point (PTP) or a multicast (PTM) The MBMS service information request, the eNB of the neighboring cell is required to feed back the MBMS service information to the current eNB, for example, whether the cell provides the MBMS service, which MBSFN area belongs, which MBMS services and the like are provided.

The MBMS service information request is configured by: adding a new information element (IE) to the existing message, or using the new message as the MBMS service information request or the MBMS service information. The sending the MBMS service information request includes: sending by using an X2 interface between the eNBs, or by using an M2 interface between the MCEs to which the eNB belongs, or by using the MME to forward. The manner of the forwarding specifically includes: when there is no direct X2 interface between the current eNB and the eNB of the neighboring cell, the eNB of the current cell sends the request to the neighbor by using the MME and the S1 interface. The eNB of the cell is first sent to the eNB through the X2 port of the other eNB, and then sent to the eNB of the neighboring cell through the X2 port between the eNB and the eNB of the neighboring cell; or sent through the M2 interface first. To the MME, and then sent by the MME to the eNB of the neighboring cell through the M2 interface; or when there is no M2 interface between the current eNB and the MCE, the eNB is sent to the eNB of the other cell through the X2 interface with the other eNB, and then The request information and the like are further transmitted by the eNB of the other cell and the M2 interface of the MCE of the target neighboring cell. Of course, other network elements can also be used. To forward, or forward multiple times between multiple network elements.

It is to be noted that, in the eNB of the neighboring cell that meets the UE measurement condition, the eNB that sends the MBMS service information request to the UE is directed to all the eNBs that are not in the same eNB as the current cell and are in the current cell. In the neighbor cell list, the eNB of the neighboring cell that does not include the MBMS service information of the cell transmits an MBMS service information request. If the neighboring cell belongs to the same eNB as the current cell, it is not in the cell that sends the MBMS service information request. The neighboring cell that receives the MBMS service information request or sends the MBMS service information mentioned below, unless otherwise stated, has the same meaning here, that is, does not belong to the same eNB as the current cell, and the eNB of the current cell The neighboring cell of the MBMS service information of the target neighboring cell is not included in the neighbor cell list.

Step 202: The control network element of the neighboring cell sends the MBMS service information of the neighboring 'j, the area to the control network element of the source cell;

Specifically, the MBMS service information includes: adding a new IE to an existing message, or creating a new message as an MBMS service information request or MBMS service information; and sending the MBMS service information, including: The X2 interface between the eNBs of the neighboring cells is sent, or is sent by the M2 interface between the source and the MCE to which the eNB of the neighboring cell belongs, or is sent by the MME. The MBMS service information includes at least: an MBSFN area ID of the neighboring cell. In addition, one or more of the following information may be included: an identifier list of the MBMS service sent by the neighboring cell, a frequency point of the MBMS service sent by the neighboring cell, and an MBMS service that the neighboring cell has stopped transmitting. The identifier list, the identifier list of the MBMS service that the neighboring cell plans to send. Specifically, the identifier list of the MBMS service may be one or more of the following information: MBMS Service ID, MBMS Session ID, TMGI (Temporary Mobile Group Identity), LCID (Logical Channel Identity, Logic) Channel number). After the eNB of the neighboring cell receives the MBMS service information request sent by the eNB of the source cell, the eNB of the neighboring cell will The MBMS service information of the neighboring cell under control is sent to the eNB of the source cell. The MBMS service information is preferably an MBSFN area ID of a neighboring cell. In addition, it is also possible to feed back the identification list of the MBMS services provided by the cell, and/or the frequency of providing these MBMS services, and other information that can identify the MBSFN area of the cell and the provided MBMS service. If the neighboring cell cannot provide the MBMS service, the MBMS service information is fed back or not fed back. When the eNB of the current source cell receives the null feedback or does not receive the feedback, the eNB may consider that the neighboring cell cannot provide the MBMS service.

Further, in the specific implementation, the MBMS service information of the source cell may be sent in the MBMS service request, and the eNB of the neighboring cell receives the same MBMS service information after receiving the same, and then feeds back a positive indicator; The same, feedback a negative indicator or no feedback.

It is to be noted that, when the sending of the MBMS service information request is performed by the MCE, that is, when the MCE is the receiver of the MBMS service information request, the MCE receives the MBMS service information sent by the eNB of the source cell. After the request, the MBMS service information of the neighboring cell may be queried, and may be an MBSFN area ID or other MBSFN area that can identify the cell and information for providing an MBMS service, and then send the information to the eNB of the source cell. If the neighboring cell and the source cell belong to the same MBSFN area, the MBMS service information can be obtained by direct query. If it does not belong to the same MBSFN area, the MCE must be queried by the MCE. In fact, if the MBMS service area does not belong to the same MBSFN area, the MBMS service information of the neighboring cell may be fed back or not, so that the source cell can know that the target neighboring cell is not in the same MBSFN area as itself. Further, the MCE may also search whether the neighboring cell belongs to the same MBSFN area as the source cell, and if yes, feed back a positive indicator, such as 1; if not, feedback 0 or no feedback. Further, an index or a bitmap indication corresponding to a neighboring cell of the same MBSFN of the source cell may be directly fed back according to the neighbor cell list sent by the source cell. Of course, the specific feedback depends on the The contents of the MBMS service information request, the general engineering staff can easily construct a variety of methods, and will not be described here.

Step 203: The control network element of the source cell selects a target cell for handover according to the received MBMS service information.

Specifically, the target cell that is selected for the handover is specifically: comprehensively considering the signal quality, the load status, and the MBMS service information of the neighboring cell, selecting to provide the UE with the same MBMS service as the source cell, and the signal quality and the group status. The best neighboring cell seat switching target cell.

Preferably, the target cell of the handover refers to a cell selected according to the following principle: Step 203a, comprehensively considering the signal quality and load level of the neighboring cell, and performing sorting; specifically, the principle of the sorting is : Preference is given to cells with good neighboring cell signals and good load.

Step 203b: On the basis of the foregoing sorting, preferentially select a cell that is consistent with the source cell MBMS service information of the UE as the target cell of the handover.

Specifically, the information is consistent, that is, the MBSFN area of the neighboring cell is the same as the MBSFN area of the source cell, or the multiple MBSFN areas of the neighboring cell include the MBSFN area of the source cell, or the MBSFN area of the neighboring cell. The same as the MBSFN area in which the source cell provides the MBMS service for the UE; or the neighboring cell provides the same service as the MBMS service received by the UE in the source cell.

Further, the foregoing principle may be extended to: select a cell with a good signal quality and a good load degree in a neighboring cell to form a new cell list; and preferentially select a cell from the cell list that is consistent with the current cell MBMS service information of the UE. The cell is used as the target cell; when there are multiple cells that meet the condition, one of the cells may be selected as the target cell according to the existing unicast handover condition. Although the principle of selecting the target cell to be switched has been described above, the present invention is not limited thereto. The basic principle is to ensure that unicast continuity is maintained. Authenticate the continuity of the MBMS business.

FIG. 3 is a schematic flowchart of a method for determining a target cell of a user equipment handover according to the present invention. As shown in FIG. 3, the method includes:

Step 301: The source eNB controls UE measurement, and the UE reports all neighbor cell lists that meet the UE measurement threshold.

Specifically, the UE measurement threshold requirement is performed according to the provisions of the existing protocol. All cells that meet the UE measurement threshold can be used as candidate targets for UE handover. The source eNB refers to an eNB that controls a source cell where the UE is currently located.

Step 302: The source eNB of the UE sends an MBMS service information request to an eNB of a neighboring cell that meets the measurement threshold requirement.

Specifically, the neighboring cell that meets the measurement threshold requirement refers to a cell in the neighbor cell list that is reported by the UE after measurement. When the eNB of the neighboring cell and the eNB of the source cell belong to the same eNB, that is, the same network element, or the neighboring cell list of the source eNB of the UE includes the MBMS service information of the neighboring cell, only the eNB needs to pass the MBMS service information of the neighboring cell. The source eNB can learn the MBMS service information of the neighboring cell, and therefore does not need to use the present invention to send the MBMS service information request. If the neighboring cell does not belong to the same eNB as the current cell, and the neighboring cell list of the source eNB does not include the MBMS service information of the cell, the MBMS service information needs to be sent only to the eNB of the neighboring cell. request.

The source eNB may send the service information request by using signaling on the X2 interface. In a specific implementation, a new IE may be added to the existing signaling, or the new signaling may be used to send the service information request. . This embodiment preferably uses the new signaling to send the MBMS service information request, such as an MBMS Status Request message, and may use a message with feedback or no feedback. This embodiment preferably has a feedback message, and the feedback information may be an MBMS Status Request Acknowledge message. Specifically, the MBMS service information request may not include MBMS service information of the current cell, and only all neighbor cells satisfying the condition are indicated. The eNB feeds back the MBMS service information of the neighboring cell, and may also include its own MBMS service information, indicating whether the eNB feedback of all the neighboring cells satisfying the condition is consistent with the MBMS service information of the current cell, and if yes, the feedback is positive. For example, "1", otherwise the indicator of negative feedback, such as "0"; may further include information about the MBMS service that the UE that needs to switch is receiving, for example: the MBSFN area ID to which it belongs, the MBMS service ID, And/or other information that can identify the MBMS service of the cell, and the like. If the MBMS service information of the neighboring cell is consistent with the information in the MBMS service information request of the source cell, a positive indicator is fed back, otherwise a negative indicator is fed back. Of course, the foregoing methods are only some preferred methods, and the requests may be sent in other forms in the MBMS service information request, and the requested neighboring cells are required to be fed back in a corresponding manner.

In addition, if there is no direct X2 interface between the source eNB and the eNB of the neighboring cell, the request may be sent in a forwarding manner. The forwarding mode includes: the source eNB sends the request to the eNB of the neighboring cell through the MME and the S1 interface; or sends the eNB to the other eNB through the X2 port of the other eNB, and then passes the eNB and the eNB of the neighboring cell. The X2 port is sent to the eNB of the neighboring cell; or is sent to the MME and the multicast gateway through the M2 and M3 interfaces, and then sent to the eNB of the neighboring cell. Further, other network elements may be used for forwarding, or may be forwarded multiple times between multiple network entities. Similarly, these requests can be sent using the signaling in the above interface, either by adding a new IE to the existing signaling or by sending a new signaling.

Step 303: The eNB of the neighboring cell that meets the measurement threshold requirement sends the MBMS service information of the neighboring cell to the source eNB of the UE.

The MBMS service information refers to an MBSFN area ID to which a neighboring cell belongs. In addition, one or more of the following information may be included: an identifier list of the MBMS service sent by the cell, a frequency point of sending the MBMS service, an identifier list of the MBMS service that has been sent but is now stopped, and an identifier of the MBMS service to be sent. List, etc. In addition, according to the needs, Send other information related to the MBMS service. Of course, as described in step 302, corresponding feedback may be used to describe its own MBMS service information according to different transmission requests.

Similarly, the eNB of the neighboring cell that meets the threshold requirement transmits its own MBMS service information on the same channel or interface as the MBMS service information request. Specifically, the MBMS service information is sent through the X2 interface or forwarding mode. Specifically, the forwarding mode includes: the eNB of the neighboring cell that meets the threshold requirement sends the MBMS service information of the cell to the source eNB of the UE through the MME and the S1 interface; or the eNB of the neighboring cell that meets the threshold requirement The MBMS service information of the cell is sent to other neighboring eNBs through the X2 interface, and the neighboring eNB sends the information to the source eNB of the UE through the X2 interface. Alternatively, the eNB of the neighboring cell that meets the threshold requirement may also pass the MCE and The M2 and M3 interfaces on the MBMS gateway send their own MBMS service information to the source eNB of the UE. Of course, the above is only a preferred method, and the neighboring cell MBMS service information may be sent to the source eNB of the UE through other network elements or interfaces.

Specifically, the MBMS service information may be sent to the current cell of the UE by using the signaling on the interface in the X2 interface or the forwarding mode. The signaling may be existing signaling in which new IE information is added; it may also be new signaling. The specific interface or sending mode, and the signaling carrying the information, are determined according to the interface or sending mode of the MBMS service information request and its bearer signaling.

Step 304: The source eNB of the UE selects a cell with a suitable condition from the neighboring cell as a target cell for UE handover.

Preferably, the cell with the appropriate condition refers to a cell selected according to the following principles: comprehensively considering the signal quality and load level of the neighboring cell, and performing sorting; on the basis of the above sorting, preferentially selecting the current cell MBMS with the UE A cell with the same service information is used as the cell with the appropriate conditions. Of course, the above principle can be further extended as follows: selecting a cell with good signal quality and good load in a neighboring cell to form a new cell list; prioritizing from the cell list A cell that is consistent with the current cell MBMS service information of the UE is selected as the cell with the appropriate condition.

For a case where the MBSFN area of the neighboring cell exceeds one, as long as the MBSFN area of the current cell of the UE is included, the cell is considered to be consistent with the current cell MBMS service information of the UE. For the case where the MBSFN area of the current cell of the UE exceeds one, only the MBSFN area of the neighboring cell is the same as the MBSFN area of the MBMS service received by the UE in the current cell, and the cell is considered to be consistent with the current cell MBMS service information of the UE.

Although a suitable cell has been described above, it is not limited thereto. The basic principle is to ensure the continuity of the MBMS service on the basis of ensuring unicast continuity. In addition, some neighboring cells that can provide MBMS service continuity may be selected first, and then the appropriate cell is selected as the target cell according to the processing mode of the unicast cell. In this case, when there are fewer neighboring cells that can provide MBMS service continuity, there may be a discontinuity in the unicast service. Therefore, this mode is not the most preferred mode of the present invention, but is only a possible implementation.

Further, after step 304, the source eNB controls the UE to initiate a handover procedure to the target cell, switches to the target cell, and continues to receive the MBMS service in the target cell. The advantages of using the above method are as follows: The continuity of the MBMS service of the UE can be improved as much as possible, and the user experience is improved. In addition, in general, the X2 interface between the eNBs of each cell exists, and the MBMS service information of the neighboring cell is transmitted through the X2 interface, which is relatively easy to implement, and the resources on the X2 port are relatively abundant. In addition, the method of the embodiment is used to improve the continuity of the MBMS service, and does not affect the continuous reception of the unicast service of the cell, and has good standardization and practical value.

FIG. 4 is a schematic flowchart of a method for determining a target cell of a user equipment handover according to the present invention. As shown in FIG. 4, the method includes:

Step 401: The network side controls the UE to measure, and the UE reports all neighbor cell lists that meet the UE measurement threshold.

The measurement threshold of the UE is determined according to the provisions of the current specification. UE measurement, including configuration Measurement interval measurement and measurement without measurement interval, the specific configuration depends on the configuration of the network. The network refers to a network element that controls measurement by the UE. Specifically, it may be an eNB that controls a current cell of the UE, that is, a source eNB. It may also be an MCE or MME that controls the source eNB of the UE.

Step 402: The source eNB of the UE sends the MBMS service information request of the neighbor cell to the MCE.

Specifically, the neighboring cell refers to a neighboring cell that is reported by the UE and meets a measurement threshold. Further, the neighboring cell does not belong to the same eNB as the current source cell, and/or the neighboring cell list of the source eNB of the UE does not include the MBMS service information of the neighboring cell.

Preferably, the MBMS service information refers to an MBSFN area ID of a neighboring cell. Further, the MBMS service information may further include one or more of the following information: an identifier list of the MBMS service sent by the neighboring cell, a frequency point of sending the MBMS service, and an identifier of the MBMS service that has been sent but is now stopped to be sent. The list, the list of identifiers of the MBMS service to be sent, and the like can identify the information of the MBMS service.

After receiving the neighboring list and the area list reported by the UE, the source eNB of the UE sends the MBMS service information request to the MCE through the signaling on the M2 interface. Specifically, the MBMS service information request may be sent by adding an IE to the original signaling, or by using a new signaling. In addition, if there is no direct M2 interface between the current cell and the MCE, the MBMS service information request may be sent in a forwarding manner. Specifically, the current cell may send the MBMS service information request to other eNBs, and the other eNB forwards the information to the MCE through the M2 interface. Of course, the MBMS service information request may also be sent to the MCE by using other network elements or interfaces. At this time, the MBMS service information request is transmitted by using the signaling on the interface involved in the forwarding mode, and the MBMS service information may be sent by adding an IE to the existing signaling or by using new signaling. request.

Specifically, the MBMS service information request may include only the list of the neighboring cells, and the MCE feeds back the MBMS service information of the neighboring cell according to the list. Of course, it can also be The MBMS service information of the previous cell and the neighbor cell list are sent to the MCE, and the MCE queries which cells are consistent with the MBMS service information of the current cell, and then feeds the cell information to the current cell. Further, as long as the source eNB of the UE can learn the MBMS service information of the neighboring cell, other agreed manners can also be adopted.

Step 403: The MCE sends the MBMS service information of the neighboring cell to the source eNB of the UE according to the request.

Specifically, after receiving the MBMS service information request sent by the source eNB of the UE, the MCE directly searches for the MBMS service information of the neighboring cell, and sends the information to the source eNB of the UE through the signaling on the M2 interface; The MBMS gateway queries the MBMS service information of the neighboring cell, and sends the signaling on the M2 interface to the eNB of the current cell of the UE. In fact, if the neighboring cell and the current cell belong to the same MBSFN area, that is, the MBSFN area ID of the neighboring cell is the same as the MBSFN area ID of the current cell, the MBMS service capability of the cell can be queried in the MCE of the current cell; If the information of the neighboring cell is not queried in the MCE of the current cell, the cell may not belong to the MBSFN area where the current cell is located.

The MCE may feed back the MBMS service information of the neighboring cell to the current cell in a corresponding manner according to the MBMS service information request sent by the source eNB. For example, the eNB of the current cell sends the neighboring d, the area list to the MCE in the MBMS service information request, and the MCE feeds back the MBMS service information of the neighboring cell to the eNB of the current cell. If some neighboring cells in the list cannot be found in the MCE, the feedback may be null or no feedback, and other MCE or MBMS entities may be queried before being fed back. When querying other MCE or MBMS entities, you need to set the corresponding timer. If the timeout is exceeded, the cell cannot be considered to provide MBMS services. Of course, the MCE can also feed back only the neighbor cell list to the MBSFN area where the current cell is located. In this case, only one indicator can be fed back. In general, the same MBMS service is sent only in one MBSFN area, but not in multiple MBSFN areas. Therefore, only the MCE where the eNB of the current cell is located can be found. For transmissions that may be spread across multiple MBSFN areas For the MBMS service, it may be necessary to query the MBMS service information of the neighboring cells of other MCEs. Certainly, the MBMS service information fed back by the specific MCE needs to be determined according to the content of the MBMS service information request sent by the current cell, and the engineering technician can construct a lot of medium forms without creative labor, and details are not described herein again. The signaling for carrying the MBMS service information may be either existing signaling or new signaling. Specifically, it is determined according to the signaling form adopted by the MBMS service information request in step 402. When the MBMS service information request uses an existing signaling bearer, the MBMS service information is also carried on the corresponding existing signaling; when the MBMS service information request adopts new signaling, the MBMS service information is used. It is also carried on the corresponding new signaling. The network element and interface used for the transmission are the same as those in step 402. When the signaling on the M2 or M3 interface is used in step 402, the MBMS service information also uses signaling on the same interface. When the forwarding mode is adopted in step 402, the MBMS service information also adopts a forwarding mode.

Step 404: The source eNB of the UE selects an appropriate cell as the target cell for UE handover according to the signal quality, the load status, and the MBMS service information of the neighboring cell.

Preferably, the cell with the appropriate condition refers to a cell selected according to the following principles: comprehensively considering the signal quality and load level of the neighboring cell, and performing sorting; on the basis of the above sorting, preferentially selecting the current cell MBMS with the UE A cell with the same service information is used as the cell with the appropriate conditions.

Certainly, the foregoing principle may be further extended as follows: selecting a cell with a good signal quality and a good load degree in a neighboring cell to form a new cell list; and preferentially selecting, from the cell list, a message consistent with the current cell MBMS service information of the UE. The cell serves as a suitable cell for the condition.

If the MBSFN area of the neighboring cell exceeds one, as long as the MBSFN area of the current cell of the UE is included, the cell is considered to be consistent with the current cell MBMS service information of the UE. For the case where the MBSFN area of the current cell of the UE exceeds one, only the MBSFN area of the neighboring cell and the MBSFN of the MBMS service received by the UE in the current cell are available. The area is the same, and the cell is considered to be consistent with the current cell MBMS service information of the UE.

Although a suitable cell has been described above, it is not limited thereto. The basic principle is to ensure the continuity of the MBMS service on the basis of ensuring unicast continuity. In addition, some neighboring cells that can provide MBMS service continuity may be selected first, and then a suitable cell is selected as the target cell according to the processing mode of the single cell. In this case, when there are fewer neighboring cells that can provide MBMS service continuity, there is a possibility that the unicast service is discontinuous. Therefore, this approach is not preferred as a preferred embodiment of the present invention.

Further, after the step 304, the source eNB may control the UE to initiate a handover to the target cell, so that after the UE enters the target cell, the UE can continue to receive the MBMS service of interest, thereby ensuring the continuity of the user service reception. The advantage of this embodiment is: by querying the MBMS service information of the neighboring cell that satisfies the UE measurement condition from the MCE, and preferentially selecting the neighboring cell that can provide the continuity of the MBMS service as the UE handover for the UE on the basis of ensuring the continuity of the unicast service. The target cell improves the continuity of the UE when receiving the MBMS service. In addition, the current cell only needs to send signaling to the MCE to obtain the MBMS service information of the required neighboring cell, which reduces the signaling burden of the system and has good practical value.

FIG. 5 is a schematic flowchart of a system for determining a target cell for user equipment handover according to the present invention. As shown in FIG. 5, the system includes: a control network element 51 of a source cell and a control network element 52 of a neighboring cell, where

The control network element 51 of the source cell is configured to send an MBMS service information request to the control network element 52 of one or more neighboring cells, and select a target cell to be handed over for the UE in the source cell according to the received MBMS service information. ;

Specifically, the control network element 51 of the source cell includes: an eNB, or an MCE, or an MME. The control network element 51 of the source cell selects the target cell to be handed over to the UE in the source cell, and includes: the control network element 51 of the source cell selects to provide the same MBMS service as the source cell, and the signal quality and the group are in the The target cell of the best neighboring cell seat handover. The MBMS The service information request includes: adding a new IE to the existing message, or using the new message as the MBMS service information request; the MBMS service information request, including: sending by using an X2 interface between the eNBs, or by the eNB The M2 interface between the MCEs is sent by means of MME forwarding.

The control network element 51 of the source cell where the UE is located, that is, the source eNB, after receiving the neighbor cell list that is sent by the UE and satisfying the measurement condition, queries the neighbor cell list, and when the MBMS service information of the neighboring cell is not included therein, And transmitting, by the eNB of the one or more neighboring cells, the MBMS service information request by using the PTP or the PTM, requesting the eNB of the neighboring cell to feed back the MBMS service information to the current eNB, for example, whether the cell provides the MBMS service. Which MBSFN area belongs to, which MBMS services and other information are provided. The sending manner of the MBMS service information request includes: sending by using an X2 interface between the eNBs, or by using an M2 interface between the MCEs to which the eNB belongs, or by using a forwarding manner. The manner of the forwarding specifically includes: when there is no direct X2 interface between the current eNB and the eNB of the neighboring cell, the eNB of the current cell sends the request to the phase by using the MME and the S1 interface. The eNB of the neighboring cell is first sent to the eNB through the X2 port of the other eNB, and then sent to the eNB of the neighboring cell through the X2 port between the eNB and the eNB of the neighboring cell; or first through the M2 interface And sent to the MME, and then sent by the MME to the eNB of the neighboring cell through the M2 interface; or when the M2 interface does not exist between the current eNB and the MCE, the eNB is sent to the eNB of the other cell through the X2 interface with other eNBs. Then, the request information and the like are transmitted through the M2 interface of the MCE of the other cell and the MCE of the target neighboring cell. Of course, other network elements may also be used for forwarding, or may be forwarded multiple times between multiple network elements.

The control network element 52 of the neighboring cell is configured to send the MBMS service information of the neighboring cell to the control network element 51 of the source cell after receiving the MBMS service information request.

Specifically, the control network element 52 of the neighboring cell includes: an eNB, or an MCE, or an MME. The MBMS service information sent by the control network element 52 of the neighboring cell includes: the neighboring cell MBSFN area ID. In addition, one or more of the following information may be included: an identifier list of the MBMS service sent by the neighboring cell, a frequency point of the MBMS service sent by the neighboring cell, and an MBMS service that the neighboring cell has stopped transmitting. The identifier list, the identifier list of the MBMS service that the neighboring cell plans to send. The MBMS service information includes: adding a new IE to an existing message, or adding a new message as the MBMS service information; the sending manner of the MBMS service information includes: sending by using an X2 interface between the eNBs, or by using an eNB The M2 interface between the MCEs to which the MCE belongs, or sent by the MME.

After the control network element 52 of the neighboring cell receives the MBMS service information request sent by the eNB of the source cell, the eNB of the neighboring cell sends the MBMS service information of the neighboring cell under the control to the eNB. The eNB of the source cell. The MBMS service information is preferably the MBSFN area ID of the neighboring cell. In addition, it is also possible to feed back the list of identifiers of the MBMS services provided by the cell, and/or the frequency of providing these MBMS services, and other information that can identify the MBSFN area of the cell and the MBMS service provided. If the neighboring cell cannot provide the MBMS service, the MBMS service information is fed back or not fed back. When the eNB of the current source cell receives null feedback or does not receive feedback, it can be considered that the neighboring cell cannot provide the MBMS service.

It is to be noted that, when the sending of the MBMS service information request is performed by the MCE, that is, when the MCE is the receiver of the MBMS service information request, the MCE receives the MBMS service information sent by the eNB of the source cell. After the request, querying the MBMS service information of the neighboring cell may be an MBSFN area ID or other information indicating an MBSFN area of the cell and providing an MBMS service, and then transmitting the information to the source cell. eNB. If the neighboring cell and the source cell belong to the same MBSFN area, the MBMS service information can be obtained by direct query. If it does not belong to the same MBSFN area, the MCE must be queried by the MCE. In fact, if the MBMS service area does not belong to the same MBSFN area, the MBMS service information of the neighboring cell may be fed back or not, so that the source cell can know that the target neighboring cell is not in the same MBSFN area as itself. Further, the MCE may also search whether the neighboring cell belongs to the same MBSFN area as the source cell, and if yes, feed back a positive indicator, such as 1; if not, feedback 0 or no feedback. Further, an index or a bitmap indication corresponding to a neighboring cell of the same MBSFN of the source cell may be directly fed back according to the neighbor cell list sent by the source cell. Certainly, the specific feedback content depends on the content of the MBMS service information request, and a general engineering staff can easily construct a plurality of methods, which are not described herein.

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

Claim

A method for determining a target cell of a user equipment (UE) handover, the method, comprising:

The control network element of the source cell where the UE is located sends a multimedia broadcast multicast service (MBMS) service information request to the control network element of one or more neighboring cells;

The method according to claim 1, wherein the control network element comprises: an evolved base station (eNB), or a multi-cell/multicast cooperative entity (MCE), or a mobility management entity

( MME I

The method according to claim 1 or 2, wherein the selecting the target cell to be handed over comprises: selecting a neighbor that can provide the UE with the same MBMS service as the source cell and having the best signal quality and load status. The cell serves as the target cell for handover.

The method according to claim 1 or 2, wherein the MBMS service information includes: a multicast single frequency network (MBSFN) area ID of the neighboring cell, and further includes one of the following information Or a plurality of: an identifier list of the MBMS service sent by the neighboring cell, a frequency point of the MBMS service sent by the neighboring cell, an MBMS service identifier list that the neighboring cell has stopped transmitting, and the neighboring cell plans to send A list of MBMS service identifiers.

The method according to claim 1 or 2, wherein the MBMS service information request or the MBMS service information comprises: adding a new information element (IE) to an existing message, or creating a new message. As MBMS service information request or MBMS service information;

The sending the MBMS service information request or the sending the MBMS service information includes: sending by using an X2 interface between a source cell and an eNB of a neighboring cell, or by using a source cell and a phase The M2 interface between the MCEs to which the eNB of the neighboring cell belongs is sent or transmitted by the MME.

A system for determining a target cell for user equipment handover, wherein the system includes: a control network element of a source cell and a control network element of a neighboring cell, where

The control network element of the source cell is configured to send to a control network element of one or more neighboring cells

The system according to claim 6, wherein the control network element of the source cell or the control network element of the neighboring cell includes: an eNB, or an MCE, or an MME.

The system according to claim 6 or 7, wherein the control network element of the source cell selects the target cell to be handed over, the method includes: the control network element selection of the source cell can provide the same as the source cell The MBMS service, and the neighboring cell with the best signal quality and load condition is the target cell for handover.

The system according to claim 6 or 7, wherein the MBMS service information sent by the control network element of the neighboring cell includes: an MBSFN area ID of the neighboring cell, and further includes the following information. One or more types: an identifier list of the MBMS service sent by the neighboring cell, a frequency point of the MBMS service sent by the neighboring cell, an identifier list of the MBMS service that the neighboring cell has stopped transmitting, and the neighboring A list of identifiers of MBMS services that the cell plans to send.

The system according to claim 6 or 7, wherein the MBMS service information request sent by the control network element of the source cell or the MBMS service information sent by the control network element of the neighboring cell includes: Add a new IE to the existing message, or create a new message as an MBMS service information request or MBMS service information; The control network element of the source cell sends the MBMS service information request or the control network element of the neighboring cell sends the MBMS service information, including: sending by using the X2 interface between the source cell and the eNB of the neighboring cell, or by using the source cell It is sent by the M2 interface between the MCEs to which the eNBs of the neighboring cells belong, or by the MME.