CN101568158B

CN101568158B - Method, system and device for plot switching of user equipment

Info

Publication number: CN101568158B
Application number: CN2008100668794A
Authority: CN
Inventors: 王俊伟; 黄曲芳; 谢铂云
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2008-04-24
Filing date: 2008-04-24
Publication date: 2011-07-20
Anticipated expiration: 2028-04-24
Also published as: CN101568158A

Abstract

The invention provides a method for the plot switching of user equipment, which comprises the following steps: a switching command is received, and the information carried by the switching command includes an indication that a target plot does not have an upstream resource; the switching command is reselected or switched into the plot with an upstream resource and covered with the plot without an upstream resource to stay according to the condition whether the RRC connection controlled by a wireless resource is released; and multimedia broadcast multicast service (MBMS) service of the plot without an upstream resource is received in the plot with the upstream resource. The invention also provides a system and a device for the plot switching of the user equipment. The user equipment can stay in the plot with the upstream resource and covered with the plot without an upstream resource to receive the MBMS service of the plot without an upstream resource by the technical scheme provided bythe invention so as to enable the procedure of switching the user equipment to the plot without an upstream resource to be smoothly completed and ensure that the MBMS service is not interrupted in th e switching process.

Description

Method, system and device for switching user equipment cell

Technical Field

The invention relates to the technical field of mobile communication, in particular to a cell switching technology of mobile user equipment.

Background

With the diversified development of the user's demands for mobile communication Service types, the MBMS (multimedia broadcast Multicast Service) Service becomes one of the promising communication services. The MBMS service refers to a network side that simultaneously transmits the same multimedia service data to multiple users in the network, and a user receiving the MBMS service can simultaneously receive one or more MBMS services. Currently, MBMS services mainly include streaming media services, such as video, and background services, such as text download. The user may have other unicast services in progress while receiving the MBMS service.

In an LTE (Long Term Evolution ) system, an eNB (enhanced NodeB) provides implementation of functions of a user plane and a control plane protocol of an E-UTRAN (Evolved Universal Radio access network), and the enbs interact with each other through an interface of X2. In the system, in order to better ensure the quality of receiving the MBMS service by the user, a new transmission mode SFN (Single frequency network) is introduced. An MB SFN (Multimedia Broadcast multicast service single frequency Network) adopts a multi-carrier modulation technology, for a certain specific MBMS service, a specific subcarrier frequency is adopted, and all cells in a certain area use the same carrier frequency, and when a base station sends an MBMS service data radio frame, the base stations of all cells in the area send radio frames with the same MBMS service data content at the same time, so as to ensure that user equipment at the edge of the cell can combine signals of the same MBMS service from different cells, so that the received signal strength is enhanced, and the receiving quality of users is improved. The transmission method corresponding To MBSFN is SC-PTM (Single Cell-Point To Multi-Point ) transmission method.

When a cell or system used by a ue in an RRC (Radio Resource Control) connected state changes, the ue is considered to be handed over. In the prior art, in a normal handover procedure in which a user equipment is handed over from a source eNB cell to a target eNB cell, after the user equipment receives a handover command from the source eNB, the user equipment and the target eNB cell are synchronized, and the user equipment performs RACH (Random Access Channel) uplink operation to Access the target eNB, that is, the user equipment is handed over to the target cell through the handover procedure.

However, if the moving scene is: the mobile subscriber in the RRC connected state moves from an SC-PTM cell of a mixed Carrier, i.e., a cell supporting a unicast service and an MBMS service, to a cell without an uplink resource, e.g., a DC-MBSFN (Dedicated Carrier-Multimedia Broadcast multicast service Single Frequency Network) cell, and since there is no uplink resource in the DC-MBSFN cell, the user equipment cannot perform an uplink operation therein and cannot reside therein, so that the existing handover procedure cannot be completed normally.

Disclosure of Invention

In view of this, embodiments of the present invention provide a method, a system, and a device for a ue to perform cell handover, so that the ue in an RRC connected state can smoothly complete a handover procedure to a cell without uplink resources, and ensure that an MBMS service is not interrupted during a handover procedure.

The method for cell switching by user equipment provided by the embodiment of the invention comprises the following steps: receiving a switching command, wherein information carried by the switching command comprises: an indication that the target cell is a cell without uplink resources; reselecting or switching to a cell with uplink resources and covering the same with the cell without the uplink resources for residence according to whether the radio resource control RRC connection is released or not; and receiving the MBMS service of the cell without the uplink resource in the cell with the uplink resource.

The embodiment of the invention also provides a mobile communication system, which comprises a source evolution base station eNB, a target eNB and user equipment, wherein the user equipment is used for receiving a switching command, reselecting or switching to a cell with uplink resources and covering the same cell without the uplink resources for residence according to the fact that whether the radio resource control RRC connection is released, and receiving the Multimedia Broadcast Multicast Service (MBMS) service of the cell without the uplink resources in the cell with the uplink resources; the information carried by the handover command includes: the target cell is an indication of a cell without uplink resources.

An embodiment of the present invention further provides a user equipment, where the user equipment includes: a receiving unit, configured to receive a handover command, where information carried by the handover command includes: an indication that the target cell is a cell without uplink resources; a control unit, configured to reselect or switch to a cell with uplink resources and covered by the cell without uplink resources for camping in accordance with whether radio resource control RRC connection is released; and a service receiving unit, configured to receive the MBMS service of the cell without the uplink resource in the cell with the uplink resource.

Through the technical scheme provided by the embodiment of the invention, the user equipment is switched or reselected to the cell with the uplink resource and the cell without the uplink resource which is covered with the cell without the uplink resource to reside, and the MBMS service of the cell without the uplink resource is received in the cell with the uplink resource, so that the process of switching the user equipment to the cell without the uplink resource can be smoothly completed, and the MBMS service is ensured not to be interrupted in the switching process.

Drawings

Fig. 1 is a simplified schematic diagram of a flow of a method for performing cell handover by a ue according to an embodiment of the present invention;

fig. 2 is a simplified schematic diagram of a flow of a method for performing cell handover by a ue according to a second embodiment of the present invention;

fig. 3 is a simplified schematic diagram of a flow of a method for performing cell handover by a ue according to a third embodiment of the present invention;

fig. 4 is a simplified schematic diagram of a mobile communication system according to a fourth embodiment of the present invention;

fig. 5 is a simplified schematic diagram of a structure of a ue according to a fifth embodiment of the present invention.

Detailed Description

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

In the following embodiments, the target cell to which the ue is handed over is a cell without uplink resources, that is, a cell without uplink resources, for example, a DC-MBSFN cell. The following embodiments are described by taking the target cell as a DC-MBSFN cell as an example.

Example one

In this embodiment, a User Equipment (hereinafter, referred to as UE) is a dual receiver, the UE receives an MBMS service and also receives a unicast service in a source cell, the source cell is an SC-PTM cell, and a target cell switched by the User Equipment is a DC-MBSFN cell. In this embodiment, the MBMS handover Entity is an MME (Mobility Management Entity), and the handover between different MMEs is taken as an example in this embodiment.

As shown in fig. 1, the specific steps of this embodiment are as follows:

in step 100, the source eNB stores UE context regarding area restrictions when the UE establishes a connection or updates a TA (tracking area).

Step 101, the source eNB sends a measurement control command to the UE according to the area restriction condition. The measurement control command may include MBMS-related information to control the measurement of the MBMS service signal quality of the UE in the cell.

102, after receiving the measurement control command, the UE measures the quality of the MBMS service signal in the cell, and when finding that the quality of the MBMS service signal in the cell is lower than a preset threshold, the UE sends a request for measuring the quality of the MBMS service signal in an adjacent cell to the source eNB, and after receiving the measurement request, the source eNB notifies the UE of the frequency point information of the MBSFN cell supporting the MBMS service in the adjacent cell and the corresponding MBSFN subframe distribution, and according to the obtained frequency point information and the corresponding subframe distribution, the UE measures the signal quality of the adjacent cell and sends a measurement report to the source eNB, where the measurement report includes information such as the corresponding signal quality of the MBMS service list being received by the UE. The measurement report also carries the information that the UE preferentially ensures that the currently received MBMS service and the UE are dual receivers.

Step 103, the source eNB determines whether to switch the UE to the adjacent DC-MBSFN cell by a RRM (Radio resource management) entity according to the measurement report reported by the UE, i.e. whether to let the UE receive the MBMS service of the DC-MBSFN cell, and if it determines to switch the UE to the adjacent DC-MBSFN cell, step 104 is executed.

Step 104, the source eNB sends an MBMS handover request message, e.g. an MBMS ho required, to the source MME, where the message includes information required by the target eNB to prepare resources for the UE, e.g. an MBMS service number that the UE is receiving.

Step 105, the source MME sends the MBMS handover request message to the target MME.

Step 106, the target MME sends an MBMS handover request message to the target eNB, which contains the information content obtained in steps 104 and 105, i.e. the information needed in the target eNB to prepare resources for the UE.

Step 107, the target eNB responds to the target MME with an MBMS handover request response message, for example, an MBMS HO REQ ACK message, which includes indication information indicating that the target cell is a DC-MBSFN cell and configuration information of the MBMS service related to the target cell, such as radio bearer information.

Step 108, the target MME sends the handover request response message to the source MME.

Step 109, the source MME sends a handover command, e.g. handover command, to the source eNB, where the handover command includes the content included in the handover request response message in steps 107 and 108, i.e. the indication information indicating that the target cell is the DC-MBSFN cell and the configuration information of the MBMS service related to the target cell.

Step 110, the source eNB sends the handover command to the UE. And the UE acquires that the target cell is the DC-MBSFN cell according to the indication information which is contained in the switching command and indicates that the target cell is the DC-MBSFN cell.

In addition, it should be noted that, if the target Cell is a DC-MBSFN Cell, the target eNB does not allocate a C-RNTI (Cell Radio Network Temporary Identifier) to the UE, and the UE may also know that the target Cell is the DC-MBSFN Cell according to that the target eNB does not allocate the C-RNTI to the UE. At this time, the information included in the handover request response message and the handover command may further include information indicating that the target eNB does not allocate the C-RNTI to the UE.

Step 111, the UE receives the handover command, and sends a Media Access Control (MAC) layer response message, such as MAC ACK, to the source eNB. And after receiving the MAC layer response message, the source eNB releases the context related to the MBMS service, and releases the entity related to the MBMS and the resources related to the entity.

Step 112, after receiving the handover command, the UE synchronizes with the target eNB.

The steps 111 and 112 have no chronological restriction.

And step 113, because the UE receives the MBMS service and also has the unicast service, the UE does not release the RRC connection, and further, because the RRC connection is not released and the unicast service also needs to be switched, the UE performs a normal procedure of cell switching, selects to be switched to a cell having uplink resources and covering the same as the DC-MBSFN cell for camping according to the RRM algorithm, and receives the MBMS service of the DC-MBSFN cell in the cell.

In the method for cell switching by user equipment according to this embodiment, the UE is switched to the cell with uplink resources, which is covered by the same DC-MBSFN cell, and resides in the cell, and receives the MBMS service in the target DC-MBSFN cell in the cell, so that the process of switching the UE to the DC-MBSFN cell between MMEs can be smoothly completed, and the MBMS service is guaranteed not to be interrupted during the switching process.

Example two

In this embodiment, the UE is a single receiver, and only receives the MBMS service in a source cell, and does not perform the unicast service at the same time, where the source cell is an SC-PTM cell, and a target cell switched by the UE is a DC-MBSFN cell. In this embodiment, the MBMS handover Entity is an MCE (Multi-cell/multicast coordination Entity), and the handover between different MCEs is taken as an example in this embodiment.

Step 200, the source eNB saves the UE context of the relevant area restriction condition when the UE establishes the connection or updates the TA

Step 201, the source eNB sends a measurement control command to the UE according to the area restriction condition. The measurement control command may include MBMS-related information to control the measurement of the MBMS service signal quality of the UE to the local cell and the neighboring MBSFN cell. In this embodiment, the measurement control command includes frequency point information of adjacent MBSFN cells and corresponding MBSFN subframe distribution information.

Step 202, after receiving the measurement control command, the UE measures the MBMS service signal quality of the source cell, measures the MBSFN signal quality of the neighboring cell according to the frequency point information of the neighboring MBSFN cell and the corresponding MBSFN subframe distribution information, and reports a measurement report to the source eNB. The information carried by the measurement report includes information indicating that the UE preferentially guarantees the currently received MBMS service and that the UE is a single receiver.

In step 203, the source eNB determines whether to switch the UE to the neighboring DC-MBSFN cell by the RRM entity according to the measurement report of the UE, that is, the UE is allowed to receive the MBMS service of the neighboring DC-MBSFN cell, and if it determines to switch the UE to the neighboring DC-MBSFN cell, step 204 is executed.

In step 204, the source eNB sends an MBMS handover request message, such as an MBMS ho REQ, to the source MCE, where the message includes information required by the target eNB to prepare resources for the UE, such as an MBMS service number being received by the UE.

In step 205, the source MCE forwards the MBMS handover request message to the target MCE.

In step 206, the target MCE sends an MBMS handover request message to the target eNB, where the message includes the information content obtained in steps 204 and 205, that is, the information needed by the target eNB to prepare resources for the UE.

Step 207, the target eNB sends an MBMS handover request response message, for example, an MBMS HO REQ ACK message, to the target MCE, where the message includes indication information that the target cell is a DC-MBSFN cell, and configuration information of the MBMS service related to the target cell, such as radio bearer information.

Step 208, the target MCE sends the MBMS handover request response message to the source MCE.

In step 209, the source MCE sends a handover COMMAND, e.g. HO COMMAND, to the source eNB, where the handover COMMAND carries information included in the MBMS handover request response messages in steps 207 and 208, i.e. indication information that the target cell is a DC-MBSFN cell, and configuration information of MBMS service related to the target cell.

Step 210, the source eNB sends the handover command to the UE. And the UE knows that the target cell is the DC-MBSFN cell by the fact that the switching command contains the indication information indicating that the target cell is the DC-MBSFN cell.

In addition, it should be noted that, if the target cell is a DC-MBSFN cell, the target eNB does not allocate a C-RNTI to the UE, and the UE may also know that the target cell is the DC-MBSFN cell according to that the target eNB does not allocate the C-RNTI to the UE. At this time, the information included in the handover request response message and the handover command may further include information indicating that the target eNB does not allocate the C-RNTI to the UE.

In step 211, the UE receives the handover command and sends a MAC layer response message, such as MAC ACK, to the source eNB. And after receiving the MAC layer response message, the source eNB releases the context related to the MBMS service, and releases the entity related to the MBMS and the resources related to the entity.

In step 212, the UE synchronizes with the target eNB after receiving the handover command.

The steps 211 and 212 have no sequential limitation.

In step 213, since the UE has no unicast service, the UE releases the RRC connection, and further, since the RRC connection is released, the UE performs a normal process of cell reselection, reselects to a cell with uplink resources and the same coverage as the DC-MBSFN cell to camp on, and receives the MBMS service of the DC-MBSFN cell in the cell.

In the method for cell switching by user equipment provided in this embodiment, the UE reselects to the cell with uplink resources and covering the same as the DC-MBSFN cell to reside in the cell, and receives the MBMS service in the target DC-MBSFN cell in the cell, so that the procedure for switching the UE to the DC-MBSFN cell between MCEs can be smoothly completed, and the MBMS service is ensured not to be interrupted during the switching process.

It should be noted that, in the first embodiment, the MBMS handover entities of the source cell and the target cell are both MMEs, and in the second embodiment, the handover entities of the source cell and the target cell are both MCEs, however, it should be understood by those skilled in the art that the technical solutions provided in the above embodiments can also be implemented by combining the MBMS handover entities according to system requirements, for example, the MBMS handover entity of the source cell is an MCE, and the MBMS handover entity of the target cell is an MME; or the MBMS switching entity of the source cell is MME, and the MBMS switching entity of the target cell is MCE.

EXAMPLE III

Different from the two embodiments, the UE handover in this embodiment is performed under the same MBMS handover entity MME. As shown in fig. 3, the specific steps of this embodiment are as follows:

step 300, the source eNB saves the UE context regarding the area restriction condition when the UE establishes the connection or updates the TA.

Step 301, the source eNB sends a measurement control command to the UE according to the area restriction condition.

Step 302, after receiving the measurement control command, the UE measures the quality of the MBMS service signal of the neighboring MBSFN cell, and sends a measurement report to the source eNB.

If the measurement control command in step 301 does not carry the frequency point information of the adjacent MBSFN cell and the corresponding MBSFN subframe distribution information, step 302 is performed in step 102, and if the measurement control command in step 301 carries the frequency point information of the adjacent MBSFN cell and the corresponding MBSFN subframe distribution information, step 302 is performed in the same step 202, and the specific measurement method is not described herein again.

Step 303, the source eNB determines whether to switch the UE to the neighboring DC-MBSFN cell by the RRM entity according to the measurement report of the UE, that is, the UE is allowed to receive the MBMS service of the DC-MBSFN cell, and if it determines to switch the UE to the neighboring DC-MBSFN cell, step 304 is executed.

Step 304, the source eNB sends a handover request message, such as HO REQ, to the target eNB, where the message includes information needed by the target eNB to prepare resources for the UE, such as the MBMS service number being received by the UE.

Step 305, the target eNB sends a handover request response message, such as HO REQACK, to the source eNB, where the message includes the above allocated security-related configuration parameters in the target eNB; and includes indication information indicating that the target cell is a DC-MBSFN cell and target cell MBMS service related configuration information, such as radio bearer configuration information.

Step 306, the source eNB sends a HANDOVER COMMAND, such as HANDOVER COMMAND, to the UE, where the HANDOVER COMMAND includes configuration information acquired from the target eNB, including configuration parameters related to security, indication information indicating that the target cell is a DC-MBSFN cell, and configuration information related to MBMS service of the target cell.

Step 307, the UE receives the handover command, knows that the target cell is the DC-MBSFN cell, and sends a MAC layer response message, such as MAC ACK, to the source eNB. And after receiving the MAC layer response message, the source eNB releases the context related to the MBMS service, and releases the entity related to the MBMS and the resources related to the entity.

Step 308, after receiving the handover command, the UE synchronizes with the target eNB.

The above steps 307 and 308 have no chronological restriction.

In step 309, if the UE only receives the MBMS service, or the UE is a single receiver, the UE releases the RRC connection, and performs step 310 a. If the UE receives the MBMS service and also has a unicast service, and the UE is a dual receiver, the UE does not release the RRC connection, and performs step 310 b.

In step 310a, since the RRC connection is released and the UE is a dual-receiver, the UE performs a cell reselection operation, reselects to a cell having uplink resources and covering the same as the DC-MBSFN cell for camping, and receives the MBMS service of the DC-MBSFN cell in the cell.

In step 310b, because the RRC connection is not released and the unicast service also needs to be switched, the UE performs the normal procedure of cell switching of unicast, switches to a cell with uplink resources and co-covering with the DC-MBSFN cell for camping, and receives the MBMS service of the DC-MBSFN cell in the cell. If the unicast service does not need to be switched, the switching process is not executed.

In the method for switching the cell by the UE provided in this embodiment, the UE is switched to or reselects to reside in the cell with the uplink resource, which is covered by the same DC-MBSFN cell as the DC-MBSFN cell, and receives the MBMS service in the target DC-MBSFN cell in the cell, so that the process of switching the UE to the DC-MBSFN cell in the same MBMS switching entity MME can be smoothly completed, and the MBMS service is ensured not to be interrupted during the switching process.

Example four

The present embodiment provides a mobile communication system, as shown in fig. 4, the mobile communication system including: a source eNB400, a target eNB401 and user equipment 402.

And the user equipment 402 receives the switching command, synchronizes with the target eNB, reselects or switches to the cell with the uplink resource and covered by the DC-MBSFN cell for residence according to whether the RRC connection is released, and receives the MBMS service of the target DC-MBSFN cell in the cell. The information carried by the up-switch command includes: an indication that the target cell is a DC-MBSFN cell, the indication further comprising indication information indicating that the target cell is the DC-MBSFN cell, and/or information indicating that the target eNB does not allocate a C-RNTI for the UE.

Further, when the user equipment 402 receives the MBMS service and also has a unicast service, the RRC connection is not released; when the user equipment 402 receives only the MBMS service, the RRC connection is released. When the RRC connection is released, cell reselection is executed, and the cell with the uplink resources which is covered by the DC-MBSFN cell is reselected to reside; and when the RRC connection is not released and the unicast service needs to be switched, executing cell switching, and switching to the cell which has the same coverage with the DC-MBSFN cell and has uplink resources for residing.

Further, the source eNB400 sends a measurement control command to the user equipment 402, and the user equipment 402 measures the signal quality of the MBMS service of the neighboring MBSFN cell according to the measurement control command, and reports a measurement report to the source eNB 400. The information carried by the measurement report includes: information indicating whether the user equipment 402 is multi-receiver and/or priority between the unicast service and the MBMS service being received in the user equipment 402.

Further, the mobile communication system further includes an MBMS handover entity 403, where the MBMS handover entity 403 includes a mobility management entity MME and/or a multi-cell multicast coordination entity MCE. The user equipment 402 may be handed over in the same MBMS handover entity 403 or between MBMS handover entities 403.

The source eNB400 sends a handover request message to the target eNB401 or the MBMS handover entity 403, where the handover request message includes MBMS information being received by the user equipment 402; target eNB401 or MBMS handover entity 403 sends a handover request response message to source eNB400, where the handover request response message includes indication information indicating that the target cell is a DC-MBSFN cell, and then source eNB400 learns that the target cell is a DC-MBSFN cell according to the indication information indicating that the target cell is the DC-MBSFN cell or that the target eNB does not allocate a C-RNTI to the user equipment.

In the mobile communication system provided in this embodiment, the UE reselects or switches to the cell with the uplink resource and the same coverage as the DC-MBSFN cell for residence, and receives the MBMS service in the target DC-MBSFN cell in the cell, so that the procedure of switching the UE to the DC-MBSFN cell can be smoothly completed, and the MBMS service is ensured not to be interrupted in the switching process.

EXAMPLE five

The present embodiment provides a user equipment 500, as shown in fig. 5, the user equipment 500 includes: a receiving unit 501, a synchronization unit 502, a control unit 503 and a service receiving unit 506.

The receiving unit 501 receives a handover command, where information carried by the handover command includes: an indication that the target cell is a DC-MBSFN cell; the synchronization unit 502 synchronizes with the target eNB; the control unit 503 reselects or switches to a cell with uplink resources and the same coverage as the DC-MBSFN cell for residence according to whether the radio resource control RRC connection is released; the service receiving unit 506 receives the MBMS service of the DC-MBSFN cell in the cell having the uplink resource.

More specifically, the user equipment 500 further includes an RRC connection management unit 504. When the user equipment 500 receives the MBMS service and there is a unicast service, the RRC connection management unit 504 does not release the RRC connection; when the user equipment 500 receives only the MBMS service, the RRC connection management unit 504 releases the RRC connection. When the RRC connection is released, the control unit 503 performs cell reselection to the cell with uplink resources and covered by the same DC-MBSFN cell for camping; when the RRC connection is not released and the unicast service needs to be switched, the control unit 503 performs cell switching to a cell with uplink resources and the same coverage as the DC-MBSFN cell for camping.

Further, the user equipment 500 further comprises a measurement unit 505. The measurement unit 505 receives the measurement control command, measures the signal quality of the MBMS service in the source cell, measures the signal quality of the MBMS service in the neighboring MBSFN cell according to the measurement control command, and reports a measurement report. Further, the measurement unit 505 carries information indicating whether the ue is a multi-receiver and/or priority information between the unicast service and the MBMS service being received in the ue in the measurement report, and reports the information.

Further, the measurement unit 505 further includes a first measurement module 5051, an acquisition module 5052, and a second measurement module 5053.

The first measurement module 5051 measures the service quality of the cell; when the first measurement module 5051 measures that the service quality of the cell is lower than a preset threshold value, the acquisition module 5052 acquires frequency point information of an adjacent MBSFN cell and MBSFN subframe distribution information, and the second measurement module 5053 measures the MBMS service signal quality of the adjacent MBSFN cell according to the frequency point information of the adjacent MBSFN cell and the MBSFN subframe distribution information, and reports a measurement report. When the measurement control command includes the adjacent MBSFN cell frequency point information and MBSFN subframe distribution information, the second measurement module 5053 directly measures the signal quality of the adjacent MBSFN cell according to the adjacent MBSFN cell frequency point information and MBSFN subframe distribution information included in the measurement control command, and reports a measurement report.

In the UE provided in this embodiment, the UE reselects or switches to a cell with uplink resources and covering the same as the DC-MBSFN cell for residence, and receives the MBMS service in the target DC-MBSFN cell in the cell, so that the procedure of switching to the DC-MBSFN cell can be smoothly completed, and the MBMS service is guaranteed not to be interrupted in the switching process.

Some steps in the embodiments of the present invention may be implemented by software, and the corresponding software program may be stored in a readable storage medium, such as an optical disc or a hard disk.

The above-described embodiments are not intended to limit the present invention, and any modifications, equivalent substitutions, improvements, etc. that may be made by one of ordinary skill in the art without departing from the spirit of the present invention are intended to be included within the scope of the present invention.

Claims

1. A method for a user equipment to perform cell switching is characterized by comprising the following steps:

receiving a switching command, wherein information carried by the switching command comprises: an indication that the target cell is a cell without uplink resources;

reselecting or switching to a cell with uplink resources and covering the same cell without the uplink resources for residence according to whether the radio resource control RRC connection is released or not;

receiving the multimedia broadcast multicast service MBMS service of the cell without the uplink resource in the cell with the uplink resource; wherein,

the reselecting or switching to the cell with the uplink resource and the cell without the uplink resource in the same coverage with the cell without the uplink resource for camping comprises:

when the user equipment only receives the MBMS service in a source cell, releasing the RRC connection, executing cell reselection, and reselecting the cell with the uplink resource which is covered by the cell without the uplink resource to reside in the cell with the uplink resource;

when the user equipment receives the MBMS service in the source cell and simultaneously has a unicast service, and the unicast service needs to be switched, the RRC connection is not released, cell switching is executed, and the user equipment is switched to the cell which has uplink resources and is covered by the cell without the uplink resources to reside in the cell.

2. The method of claim 1, wherein the indication that the target cell is a cell without uplink resources comprises: indicating information indicating that the target cell is a cell without uplink resources, and/or indicating that the target eNB does not allocate the cell radio network temporary identity C-RNTI for the user equipment.

3. The method of claim 1 or 2, wherein the cell without uplink resource is a dedicated carrier multimedia broadcast multicast service single frequency network (DC-MBSFN) cell.

4. The method of claim 1, wherein the receiving the handover command further comprises:

and measuring the quality of the MBMS service signals of the source cell and the adjacent MBSFN cell according to the measurement control command, and reporting a measurement report.

5. The method of cell switching by user equipment according to claim 4, wherein the measurement control command includes the frequency point information of the adjacent MBSFN cells and the distribution information of MBSFN subframes, and the MBMS signal quality of the adjacent MBSFN cells is measured according to the frequency point information of the adjacent MBSFN cells and the distribution information of MBSFN subframes.

6. The method of cell switching by the UE according to claim 4,

when the MBMS signal quality of a source cell is lower than a preset threshold value, acquiring the frequency point information of an adjacent MBSFN cell and the MBSFN subframe distribution information, and measuring the MBMS signal quality of the adjacent MBSFN cell according to the frequency point information of the adjacent MBSFN cell and the MBSFN subframe distribution information.

7. A mobile communication system comprising a source evolved base station eNB, a target eNB and a user equipment,

the user equipment is used for receiving a switching command, reselecting or switching to a cell with uplink resources and covering the cell without the uplink resources for residence according to whether the radio resource control RRC connection is released or not, and receiving the Multimedia Broadcast Multicast Service (MBMS) service of the cell without the uplink resources in the cell with the uplink resources;

the information carried by the handover command includes: an indication that the target cell is a cell without uplink resources; wherein,

the ue is further configured to release the RRC connection, perform cell reselection, and reselect to a cell with uplink resources and covered by the cell without uplink resources to camp on the cell when the ue only receives the MBMS service in a source cell;

the ue is further configured to, when the ue receives an MBMS service in the source cell and also has a unicast service, and the unicast service needs to be switched, not release the RRC connection, and perform cell switching, and switch to the cell with uplink resources and covered by the cell without uplink resources to camp on the cell.

8. The mobile communication system of claim 7, wherein the source eNB is configured to send a measurement control command to the user equipment; then

The user equipment is further configured to measure the quality of the MBMS service signal of the MBSFN cell of the adjacent multimedia broadcast multicast service single frequency network according to the measurement control command, and report a measurement report to the source eNB.

9. The mobile communication system of claim 7, wherein the mobile communication system further comprises an MBMS handover entity.

10. The mobile communication system of claim 9, wherein the MBMS handover entity comprises: a mobility management entity MME, and/or a multi-cell multicast coordination entity MCE.

11. The mobile communication system of claim 9, wherein the target eNB or the MBMS handover entity is further configured to send a handover request response message, and wherein the handover request response message includes an indication that the target cell is a cell without uplink resources.

12. The mobile communication system according to any of claims 7 to 11, wherein the indication that the target cell is a cell without uplink resources comprises: indicating information indicating that the target cell is a cell without uplink resources, and/or indicating that the target eNB does not allocate the cell radio network temporary identity C-RNTI for the user equipment.

13. The communication system of claim 12, the no uplink resource cell is a dedicated carrier multimedia broadcast multicast service single frequency network, DC-MBSFN, cell.

14. A user equipment, the user equipment comprising:

a receiving unit, configured to receive a handover command, where information carried by the handover command includes: an indication that the target cell is a cell without uplink resources;

a control unit, configured to reselect or switch to a cell with uplink resources and covered by the cell without uplink resources for camping in accordance with whether radio resource control RRC connection is released;

a service receiving unit, configured to receive a multimedia broadcast multicast service MBMS service of the cell without the uplink resource in the cell with the uplink resource; wherein,

the control unit is further configured to, when the ue receives only the MBMS service in the source cell, release the RRC connection, perform cell reselection, and reselect to the cell with the uplink resource that is covered by the cell without the uplink resource and camp on the cell;

the control unit is further configured to, when the user equipment receives an MBMS service in the source cell and also has a unicast service, and the unicast service needs to be switched, not release the RRC connection, and perform cell switching, and switch to the cell with uplink resources and co-covering the cell without the uplink resources to camp on the cell.

15. The user equipment as claimed in claim 14, wherein the user equipment further comprises: the RRC connection management unit is used for not releasing the RRC connection when the user equipment receives the MBMS service and simultaneously has a unicast service; when the user equipment only receives the MBMS service, releasing the RRC connection;

the control unit is further configured to, when the RRC connection is released, perform cell reselection to the cell with uplink resources and co-located with the cell without uplink resources; and when the RRC connection is not released and the unicast service needs to be switched, executing cell switching, and switching to the cell which has the uplink resource and is covered by the cell without the uplink resource for residence.

16. The UE of claim 14, wherein the indication that the target cell received by the receiving unit is a cell without uplink resources comprises: indicating information indicating that the target cell is a cell without uplink resources, and/or indicating that the target eNB does not allocate the cell radio network temporary identity C-RNTI for the user equipment.

17. The user equipment as claimed in claim 14, wherein the user equipment further comprises: and the measuring unit is used for receiving the measurement control command, measuring the MBMS service signal quality of the MBSFN cell of the adjacent multimedia broadcast multicast service single frequency network according to the measurement control command and reporting a measurement report.

18. The ue of claim 17, wherein the measuring unit is further configured to measure the signal quality of the MBMS service in the neighboring MBSFN cell according to the neighboring MBSFN cell frequency point information and MBSFN subframe distribution information included in the measurement control command, and report a measurement report.

19. The UE of claim 17, wherein the measurement unit further comprises,

the first measurement module is used for measuring the quality of the MBMS service signal of the cell;

the acquisition module is used for acquiring the frequency point information of an adjacent MBSFN cell and the distribution information of MBSFN subframes when the first measurement module measures that the MBMS quality of the cell is lower than a preset threshold value;

and the second measurement module is used for measuring the signal quality of the MBMS service of the adjacent MBSFN cell according to the frequency point information and the MBSFN subframe distribution information of the adjacent MBSFN cell and reporting a measurement report.

20. The ue of any one of claims 17 to 19, wherein the measurement unit is further configured to carry information indicating whether the ue is a multi-receiver ue and/or priority information between a unicast service and a MBMS service being received in the ue in the measurement report for reporting.

21. The UE of any of claims 14 to 19, wherein the cell without uplink resources is a dedicated carrier MBMS single frequency network DC-MBSFN cell.