CN111629407B

CN111629407B - Method for supporting UE switching

Info

Publication number: CN111629407B
Application number: CN202010208092.8A
Authority: CN
Inventors: 许丽香; 王弘; 范.德.费尔德
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2011-09-30
Filing date: 2012-07-06
Publication date: 2022-08-12
Anticipated expiration: 2032-07-06
Also published as: CN111629407A; CN103037463A; CN103037463B

Abstract

The invention discloses a method for supporting UE switching, which comprises the following steps: filtering the PLMNs broadcasted by the target cell through the UE, and selecting a proper PLMN for the UE from the filtered PLMNs by the source base station to complete the switching process; or the source base station knows the CSG list which can be accessed by the UE and knows all PLMN ID lists broadcasted by the target cell and the rPLMN and ePLMN of the UE, thereby selecting a proper PLMN for the UE and completing the switching process; or after the source base station knows all PLMN ID lists broadcasted by the target cell, the MME is informed of all PLMN ID lists broadcasted by the target cell or the PLMN ID lists which are rPLMN or ePLMN of the UE in all PLMN ID lists broadcasted by the target cell, and the MME selects the PLMN for the UE to complete the switching process; or, after the source base station knows all the PLMN ID lists broadcasted by the target cell, the MME screens the PLMNs, and then the source base station selects the PLMN serving the UE, thereby completing the switching process. The method for supporting UE switching can avoid failure of the switching process and ensure the continuity of the service.

Description

Method for supporting UE switching

The application is a divisional application of an invention patent application with an application date of 2012, 7/6 and an application number of 201210236198.4, and the invention name of the invention is 'a method for supporting UE handover'.

Technical Field

The present invention relates to the field of mobile communication systems, and in particular, to a method for supporting handover of User Equipment (UE).

Background

In a mobile communication system, in order to provide better service to a specific UE group, it is often necessary to group a plurality of radio resource management entities into a Closed Subscriber Group (CSG) for the specific UE group, for example, all UEs within a company or a school are a specific UE group, and the plurality of radio resource management entities are grouped into a CSG for the specific UE group, so as to provide a specific access service.

The case where a plurality of radio resource management entities are CSG formed for a specific UE group is common in a mobile communication system, and in order to illustrate the case more clearly, a Long Term Evolution (LTE) system of System Architecture Evolution (SAE) is taken as an example for explanation.

Fig. 1 is a schematic structural diagram of a conventional LTE system, and as shown in fig. 1, in a radio access network of the LTE system, a radio resource management entity includes a macro base station (eNB)101 and an HeNB 102, and optionally includes a home base station gateway (HeNB GW) 103. The eNBs 101 are connected through an X2 interface, and each eNB 101 is directly connected with a Mobility Management Entity (MME)104 in a core network through an S1 interface; the HeNB 102 can be connected with the HeNB GW103 through an S1 interface, and then the HeNB GW103 is connected with the MME104 through an S1 interface, or directly connected with the MME104 through an S1 interface, or, when the HeNB GW103 is not deployed in the system, the HeNB 102 is directly connected with the MME104 through an S1 interface; and both eNB 101 and HeNB 102 may be connected to multiple MMEs 104 in the core network.

In order to provide richer access services, various types of radio resource management entities are provided, for example, the HeNB 102 in the LTE system shown in fig. 1 includes an open HeNB, a CSG HeNB, and a hybrid HeNB. The open HeNB has no UE with specific access, and any UE can be accessed to the open HeNB; the CSG type HeNB only allows access to UEs in a specific UE group (for convenience of description, a user in the specific UE group is hereinafter referred to as CSG UE); the hybrid HeNB can allow the CSG UE served by the hybrid HeNB to access so as to provide a better access service for the CSG UE, and can also allow other non-CSG UEs to access.

Fig. 2 describes a specific work flow of the UE to handover to the CSG type HeNB or the hybrid HeNB cell by taking S1 handover as an example, and the source base station may be an eNB or an HeNB. As shown in fig. 2, the process includes the following steps:

step 201: the source base station S- (H) eNB configures the UE to transmit a Proximity Indication control (Proximity Indication control).

Step 202: when the UE is close to a CSG type HeNB cell or a hybrid type HeNB cell (the CSG ID of the cell is in an accessible CSG list of the UE), the UE sends an approaching indication of 'entering' to a base station.

In this step, the proximity indication contains Radio Access Technology (RAT) and frequency information of the proximity cell.

Step 203: and when the measurement configuration of the frequency/RAT does not exist, configuring corresponding measurement for the UE by the source base station.

The measurements include measurement gaps, whereby the UE may perform measurements of the RAT and frequency.

Step 204: the UE sends a measurement report to the source base station.

The measurement report includes the PCI of the measuring cell.

Step 205: the source base station configures the UE to perform system information, SI, requests and reports for the particular PCI corresponding cell.

Step 206: the UE acquires the relevant system information of the destination HeNB with the automatic gap.

Step 207: the UE sends a measurement report to the source base station.

The measurement report includes global cell identity (ECGI) of the destination HeNB cell, routing area code (TAC), CSG ID and member.

Step 208: and the source base station sends a switching demand message to the MME.

The handover requirement message includes an ECGI and a CSG ID of the target HeNB cell, and further includes a cell access mode if the target cell is in the hybrid access mode.

Step 209: and the MME performs access control on the UE according to the received CSG ID and the stored subscription CSG information of the UE.

In this step, if the access control fails, the MME sends a handover preparation failure message to the source base station to end the handover procedure, and if the handover request message contains the access mode, the MME determines the member status of the UE and sends it to the destination base station through the handover request message.

Step 210: the MME sends a handover request message to the destination (T) -HeNB.

And under the condition that the HeNB GW is deployed, the MME sends a switching request message to the target base station through the HeNB GW.

The handover request message includes a CSG ID, and if the destination cell is in hybrid access mode, the message also includes a CSG member indication.

Step 211: the destination HeNB verifies whether the CSG ID received in the handover request message is the CSG ID broadcasted by the destination cell.

If the received CSG ID is the CSG ID broadcasted by the target cell, appropriate resources are allocated, and if the CSG member indicates that the UE is a member, the target HeNB can perform a priority principle on the UE.

Step 212: and the target HeNB sends a switching request confirmation message to the MME.

And under the condition that the HeNB GW is deployed, the target HeNB sends a switching request confirmation message to the MME through the HeNB GW.

Step 213: and the MME sends a switching command message to the source base station.

Step 214: the source base station sends a handover command message to the UE.

It should be noted that, in the process of moving the UE to the CSG-type HeNB or the hybrid-type HeNB cell, the access control is performed in two steps, the UE checks whether the UE is a member of the target cell according to the CSG ID of the target cell and the accessible CSG list of the UE stored in the UE, the UE reports that the UE is a member to the network, and the MME further verifies the UE in step 209.

At this point, the existing whole procedure of moving the UE to the HeNB through S1 handover is completed.

Under the condition that a target base station cell (a non-CSG cell or a mixed cell) supports Radio Access Network (RAN) sharing, a source base station selects a Public Land Mobile Network (PLMN) as a UE registration PLMN according to an intersection of the PLMN supported by the target base station cell and the PLMN (registration PLMN or equivalent PLMN) which the UE can access.

Currently, a CSG cell or a hybrid cell broadcasts only one PLMN ID.

When a CSG cell or a hybrid cell supports RAN sharing, how to support handover to a target cell is an unsolved problem.

And if the target base station cell is the CSG cell supporting RAN sharing, the target base station cell broadcasts the CSG ID and a plurality of PLMN identifications. If (PLMN1, broadcasted CSG ID) is in the CSG list allowed to be accessed by the UE, where PLMN1 is the PLMN broadcasted by the cell of the destination base station and PLMN1 is the current UE registered PLMN (rpplmn) or equivalent PLMN (eplmn), then the UE is a member of the CSG cell or hybrid cell, and in the case that the UE is a member of the CSG cell or hybrid cell, the UE reports CGI, TAI, CSG ID and member to the source base station, and after receiving the UE report, the source base station does not know which PLMNs are supported by the destination HeNB cell and does not know which PLMN the UE is a member under which PLMN, so that the destination PLMN cannot be selected, and in the case of improper selection, handover failure may be caused, which affects continuity of UE traffic. See in particular the following examples:

UE rpmn ═ B, ePLMN ═ a, C }, accessible CSG list { (C1, a), (C1, B), (C2, a) }; the candidate handover destination base station cell broadcasts PLMNs { D, a, C, E }, CSG ═ C1.

Because (c1, A) in the accessible CSG list of the UE, PLMN-A is the PLMN broadcasted by the destination cell and is the ePLMN of the UE, the UE sends A member indication to the source base station, but the source base station does not know which PLMNs are supported by the destination base station cell, so that only the first PLMN broadcasted by the destination base station cell, for example, D, is known from the ECGI, but D is not the rPLMN or the ePLMN accessible by the UE, thus causing the source base station to be unable to perform the handover procedure. This situation is also present in case the destination base station cell is a hybrid cell and supports multiple PLMNs.

However, due to the above problems, the source base station may select a hybrid cell under the PLMN of which the UE is not a member for the UE, so that the UE cannot enjoy better quality of service and charging policy.

Further, even if the source base station knows the PLMNs broadcast by the cell of the destination base station, the source base station needs to select a new PLMN registered by the UE from the PLMNs { D, a, C, E } broadcast by the cell of the destination base station and rpmns and ePLMNs PLMN { B, a, C } of the UE, however, the source base station does not know under which PLMN the UE is a member, and if the source base station selects PLMN C, the handover may fail. Under the condition that the target base station cell is a hybrid cell and supports a plurality of PLMNs, the source base station can randomly select one PLMN, so that the original UE can access one PLMN which is a member of the UE, and the source base station switches the UE to the PLMN which is a non-member of the UE, so that the UE cannot enjoy high-quality service quality and a charging strategy.

Disclosure of Invention

In view of this, the present invention provides a method for supporting UE handover, which can avoid failure in the handover process and ensure continuity of service.

In order to achieve the above purpose, the technical solution of the embodiment of the present invention is specifically realized as follows:

a method of supporting handover of a User Equipment (UE), the method comprising:

the UE sends a measurement report to a source base station, wherein the measurement report contains one or more public land mobile network identification (PLMN ID) broadcasted by a target cell;

and the source base station selects the PLMN of the target cell for the UE from the PLMN ID in the received measurement report and then initiates the switching.

When the target cell is a closed subscriber group, CSG, type or hybrid type, the PLMNs of the PLMN ID included in the measurement report are:

the PLMN ID of the destination CSG type home base station cell or the PLMN ID broadcasted by the hybrid home base station cell is included in a CSG list accessible to the UE, or,

the PLMN ID broadcasted by the target CSG type hnb cell or the hybrid hnb cell is the registered PLMN rpplmn or the equivalent PLMN ePLMN of the UE, and the PLMN ID and the CSG ID broadcasted by the target hnb cell are in the CSG list accessible by the UE.

When the target cell is a hybrid type or an open type, the PLMNs of the PLMN ID included in the measurement report are:

a PLMN ID broadcasted by a target hybrid or open type home base station cell, and is a registered PLMN rPLMN of the UE or an equivalent PLMN ePLMN;

or all PLMN IDs broadcast by the destination hybrid or open home base station cell.

When the target home base station cell is a hybrid type and is a CSG type member cell, the PLMNs of the PLMN ID included in the measurement report are: registering PLMN rPLMN or equivalent PLMN ePLMN of the UE, wherein the PLMN ID and the CSG ID broadcasted by the target home base station cell are in a CSG list accessed by the UE;

when the target cell is a hybrid type and non-CSG type member cell or the target femtocell cell is an open type, the PLMNs of the PLMN IDs included in the measurement report are: the registered PLMN rPLMN or equivalent PLMN ePLMN of the UE or all PLMN IDs broadcasted by the destination home base station cell.

The measurement report further includes indication information corresponding to each PLMN ID broadcasted by the target cell, and is used to indicate whether the UE corresponding to each PLMN ID is a target CSG type cell or a hybrid type cell member.

And the source base station selects a PLMN ID serving the UE in the target home base station cell, and the PLMN ID reported by the UE selected by the source base station is one of rPLMN ID or ePLMN ID of the UE.

The method further comprises the following steps: the MME performs access control or CSG membership check for the UE.

In this embodiment, the PLMN broadcasted by the target cell is broadcasted by the UE, the PLMN ID and the CSG ID broadcasted by the target cell are in a CSG list accessible by the UE, or the PLMN broadcasted by the target cell is an rPLMN or an ePLMN of the UE, and the PLMN ID and the CSG ID broadcasted by the target cell are in the CSG list accessible by the UE, or all PLMN IDs broadcasted by the target cell are added with an indication information and broadcasted to the source base station, or the PLMN broadcasted by the target cell is an rPLMN or an ePLMN of the UE, or a PLMN broadcasted by the target cell, and then the source base station selects one of the PLMN IDs to send to the MME, and the MME completes access control on the UE, thereby completing PLMN selection in the handover process.

A method for supporting User Equipment (UE) switching, a target cell is a Closed Subscriber Group (CSG) type or a mixed type, the method comprises the following steps:

a mobile management entity MME sends a CSG list which can be accessed by UE to a source base station;

a source base station obtains a Public Land Mobile Network (PLMN) list broadcasted by a neighboring cell;

and the source base station selects the PLMN of the target cell from the obtained PLMN list and initiates the switching.

The obtaining, by the source base station, a PLMN list broadcasted by the neighboring cell includes:

the UE sends a measurement report to a source base station cell, wherein the measurement report comprises a physical layer cell identity (PCI) of an adjacent cell;

the base station indicates the UE to read the global cell identity (ECGI) of the cell corresponding to the PCI in the measurement report;

after reading the ECGI, the UE sends a measurement report including the read ECGI, routing area code TAC, CSG ID, and broadcast PLMN list of the neighboring cell to the source base station.

the source base station obtains the IP address of the adjacent cell;

the source base station sends an X2 establishment request message to the adjacent base station, wherein the establishment request message comprises information of a cell of the source base station, and the information of the cell comprises a PLMN list broadcasted by the cell;

and the adjacent base station sends an X2 establishment response message to the source base station, wherein the establishment response message contains the information of the adjacent cell, and the information of the cell contains a PLMN list broadcasted by the cell.

The selecting, by the source base station, the PLMN of the destination cell for the UE includes: the source base station selects the PLMN in the PLMN reported by the UE, the rPLMN or ePLMN of the UE, and the { PLMN, the destination cell CSG ID } is the PLMN in the CSG list accessible by the UE.

In this embodiment, the source base station knows the CSG list that the UE can access, and knows all PLMN ID lists broadcast by the destination cell, so as to select the PLMN of the destination cell for the UE, thereby completing the handover procedure.

A method for supporting User Equipment (UE) to switch to a cell, wherein a target cell is a Closed Subscriber Group (CSG) type or a mixed type, and the method comprises the following steps:

the source base station includes the CSG ID and the PLMN ID of the target cell in a switching demand message and sends the switching demand message to a mobile management entity MME, wherein the PLMN ID is the PLMN ID broadcasted by the target cell or a PLMN ID broadcasted by the target cell and is a PLMN ID list of a registered PLMN rPLMN or an equivalent PLMN ePLMN of the UE;

and after the MME selects the PLMN of the target cell for the UE, the switching is initiated.

UE sends a measurement report to a source base station cell, wherein the measurement report comprises a physical layer cell identity (PCI) of an adjacent cell;

the source base station obtains the IP address of the adjacent cell;

The MME selecting the PLMN of the target cell for the UE comprises: the MME selects a PLMN in the PLMN reported by the UE and which is the rPLMN or ePLMN of the UE, and { PLMN, destination cell CSG ID } is in a CSG list accessible by the UE.

In this embodiment, after the source base station knows all PLMN ID lists broadcasted by the destination cell, the MME selects the PLMN of the destination cell for the UE, thereby completing the handover procedure.

A method for supporting User Equipment (UE) handover, a target cell is a Closed Subscriber Group (CSG) type or a hybrid type, the method comprises:

a source base station sends an access selection request message to an MME, wherein the access selection request message comprises CSG IDs (closed subscriber identity) of target cells and a PLMN ID list, and the PLMN ID list is all PLMN IDs broadcasted by the target cells or is the PLMN IDs broadcasted by the target cells and is the PLMN IDs of registered PLMN rPLMN (public land Mobile network) or equivalent PLMN ePLMNN (public land Mobile network) of UE (user equipment);

the MME filters out a registered PLMN rPLMN or an equivalent PLMN ePLMN which is the UE according to the CSG ID and the PLMN ID list provided by the source base station, and the UE is the PLMN ID of a target CSG cell or a mixed cell member under the PLMN;

and the source base station selects the PLMN of the target cell for the UE from the PLMN ID contained in the control response message sent by the MME and initiates the switching.

And the MME filters the PLMN ID list received from the source base station, wherein the PLMN ID and the CSG ID broadcasted by the target cell are in the CSG list accessible to the UE.

the source base station obtains the IP address of the adjacent cell;

The filtering, by the MME, PLMN IDs that the UE can access in the destination cell includes: the MME filters out PLMNs reported by the UE for the UE, and the PLMNs are rPLMN or ePLMN of the UE, and { PLMN, destination cell CSG ID } is the PLMN in the CSG list accessible by the UE.

In this embodiment, after the source base station knows all PLMN ID lists broadcasted by the destination cell, the MME filters out the rPLMN or the ePLMN that is the UE according to the received CSG ID, all PLMN ID lists broadcasted by the destination cell, the rplmns or the ePLMNs of the UE, and the subscription CSG information of the UE stored by the MME, and the UE is the PLMN ID of the destination CSG cell or a member of a mixed cell under the PLMN, and then the source base station completes the handover process after selecting a PLMN serving the UE from the PLMNs screened by the MME.

In summary, the embodiments of the present invention can select a suitable PLMN for the UE to complete the handover process, thereby avoiding the failure of the handover process and ensuring the continuity of the service.

Drawings

Fig. 1 is a schematic structural diagram of a conventional LTE system;

fig. 2 is a flowchart illustrating a conventional UE being handed over to a CSG or a hybrid HeNB through S1;

FIG. 3 is a flowchart illustrating a first embodiment of a method for supporting UE handover according to the present invention;

FIG. 4 is a flowchart illustrating a second embodiment of a method for supporting UE handover according to the present invention;

FIG. 5 is a flowchart illustrating a third embodiment of a method for supporting UE handover according to the present invention;

fig. 6 is a flowchart illustrating a first method for a source base station to obtain a PLMN ID list broadcasted by a neighboring cell;

fig. 7 is a flowchart illustrating a second method for obtaining a PLMN ID list broadcasted by a neighboring cell by a source base station;

FIG. 8 is a flowchart illustrating a fourth exemplary embodiment of a method for supporting UE handover according to the present invention;

fig. 9 is a flowchart of a fifth embodiment of a method for supporting UE handover according to the present invention.

FIG. 10 is a flowchart illustrating a sixth exemplary embodiment of a method for supporting UE handover according to the present invention;

fig. 11 is a flowchart of a seventh embodiment of a method for supporting UE handover according to the present invention.

Detailed Description

In order to solve the problems in the prior art, the invention provides a method for supporting UE switching, which comprises the following steps:

the UE sends a measurement report to a source base station, wherein the measurement report contains one or more public land mobile network identification (PLMN ID) broadcasted by a target cell; after selecting the PLMN of the target cell for the UE from the PLMN ID in the received measurement report, the source base station initiates handover,

or, when the target cell is a Closed Subscriber Group (CSG) type or a mixed type, the MME sends a CSG list which can be accessed by the UE to the source base station; a source base station obtains a Public Land Mobile Network (PLMN) list broadcasted by a neighboring cell; the source base station selects the PLMN of the target cell from the obtained PLMN list, initiates handover,

or when the target cell is a closed subscriber group CSG type or a mixed type, the source base station obtains a public land mobile network PLMN list broadcasted by the adjacent cell; the source base station includes the CSG ID and the PLMN ID of the target cell in a switching demand message and sends the switching demand message to a mobile management entity MME, wherein the PLMN ID is the PLMN ID broadcasted by the target cell or a PLMN ID broadcasted by the target cell and is a PLMN ID list of a registered PLMN rPLMN or an equivalent PLMN ePLMN of the UE; after the MME selects the PLMN of the target cell for the UE, switching is initiated,

or, when the target cell is a closed subscriber group CSG type or a mixed type, the source base station obtains a public land mobile network PLMN list broadcasted by the adjacent cell; a source base station sends an access selection request message to an MME, wherein the access selection request message comprises CSG IDs (closed subscriber identity) of target cells and a PLMN ID list, and the PLMN ID list is all PLMN IDs broadcasted by the target cells or is the PLMN IDs broadcasted by the target cells and is the PLMN IDs of registered PLMN rPLMN (public land Mobile network) or equivalent PLMN ePLMNN (public land Mobile network) of UE (user equipment); the MME filters out a registered PLMN rPLMN or an equivalent PLMN ePLMN which is the UE according to the CSG ID and the PLMN ID list provided by the source base station, and the UE is the PLMN ID of a target CSG cell or a mixed cell member under the PLMN; and the source base station selects the PLMN of the target cell for the UE from the PLMN ID contained in the control response message sent by the MME and initiates the switching.

Before introducing a specific implementation, the following description is required:

in the present invention, whether a UE is a member of a target CSG cell or a hybrid cell under a certain PLMN (e.g., PLMN1) or a UE is a member under a certain PLMN (e.g., PLMN1) means: the CSG ID broadcast by the destination cell and PLMN1 are in the CSG list accessible to the UE, where PLMN1 is the PLMN ID broadcast by the destination CSG cell or the hybrid cell.

Wherein, that the UE is a member in a CSG cell or a hybrid cell means: among PLMNs broadcasted by the CSG cell or the hybrid cell, there are PLMNs such as PLMN1, PLMN1 is a registered PLMN of the UE or an equivalent PLMN, and the CSG ID broadcasted by the destination cell and PLMN1 are in a CSG list accessible by the UE; the PLMN ID accessible by the UE in the destination cell refers to: the PLMN ID (e.g., PLMN ID1) in the PLMN ID broadcasted by the destination cell, the PLMN ID1 is the identity of rPLMN or ePLMN of the UE, and the CSG ID and PLMN ID1 broadcasted by the destination cell are in the CSG list accessible by the UE.

The concept of CSG member cell is the same as defined in 3GPP specification 36.331, that is, for a UE in RRC connected mode, an rPLMN or an ePLMN of the UE exists in a PLMN broadcasted by one cell, and the PLMN ID and the CSG ID broadcasted by the cell are in a CSG list accessible by the UE.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and examples.

The first embodiment,

In this embodiment, after the UE acquires the relevant system information of the target cell, the PLMN identifier of the UE under which PLMN is a member in the PLMNs broadcasted by the target cell, or the rpplmn or ePLMN of the UE in the PLMN broadcasted by the target cell is sent to the source base station, the source base station verifies the access check of the PLMN reported by the UE and selects one PLMN identifier that passes the access verification to send to the MME, and the MME completes the access control or CSG member check on whether the CSG ID broadcasted by the UE at the source base station and the target cell is in the CSG list accessible by the UE, where a specific handover procedure may refer to fig. 3 (a detailed description of a step irrelevant to the present invention is omitted in this figure). As shown in fig. 3, the femto cell of this embodiment is CSG type or hybrid type, and the procedure includes:

step 301: the source base station S- (H) eNB configures the UE to transmit a Proximity Indication control (Proximity Indication control).

Step 302: when the UE is close to a CSG type HeNB cell or a hybrid type HeNB cell (the CSG ID of the cell is in an accessible CSG list of the UE), the UE sends an approaching indication of 'entering' to a base station.

The proximity indication contains RAT and frequency information of the proximity cell.

Step 303: when the measurement configuration of the frequency/RAT does not exist, the source base station configures corresponding measurement for the UE, and the measurement can contain measurement gaps, so that the UE can perform the measurement of the RAT and the frequency.

Step 304: the UE sends a measurement report to the source base station.

The measurement report includes the PCI of the measuring cell.

Step 305: the source base station configures the UE to perform system information, SI, requests and reports for the particular PCI corresponding cell.

Step 306: the UE acquires the relevant system information of the destination HeNB with the automatic gap.

Step 307: the UE sends a measurement report to the source base station.

In this step, the measurement report includes not only the global cell identity (ECGI), routing area code (TAC), CSG ID and member of the destination HeNB cell, but also one or more of PLMN IDs broadcast by the destination cell.

Wherein, the PLMN of the PLMN ID included in the measurement report is: the UE is a target CSG area or a hybrid cell member, or a registered PLMN rPLMN or an equivalent PLMN ePLMN of the UE, and the UE is a target CSG cell or a hybrid cell member under the PLMN. The method specifically comprises the following steps: the PLMN ID is in a PLMN ID broadcasted by a target cell, and the PLMN ID and the CSG ID broadcasted by the target cell are in a CSG list accessible to the UE, and if the UE is a member under multiple PLMNs broadcasted by the target cell, the measurement report may be a PLMN identification list; or, the PLMN ID is a PLMN ID that the UE can access in the destination cell, that is, the PLMN broadcasted by the destination cell is an rPLMN or an ePLMN of the UE, and the CSG ID broadcasted by the destination cell and a PLMN ID in the CSG list that the UE can access corresponding PLMN ID are included in the message, if there are a plurality of PLMN IDs that the UE can access in the destination cell, the message may be a PLMN identification list.

The UE sends the filtered PLMN ID list to the source base station. For the encoding of the information, the UE may transmit the PLMN ID satisfying the above condition to the source base station from the second PLMN ID among the PLMN IDs broadcast by the destination cell. If the primary PLMN ID (the first PLMN ID in the broadcast information) also satisfies the above condition, i.e. is equal to rPLMN or ePLMN, and the PLMN ID and the CSG ID broadcast by the destination cell are in the CSG list accessible to the UE, the UE includes the primary PLMN suitability indication in the measurement report, since the primary PLMN ID is already included in the ECGI and does not need to be included repeatedly.

The source base station verifies the access check of the PLMN IDs reported by the UE and selects one PLMN ID for the UE among the PLMN IDs passing the access check. And the source base station selects the PLMN serving the UE in the target cell from the PLMN IDs which can be accessed by the UE in the target cell in the measurement report. It should be noted that the source base station needs to ensure that the selected PLMN ID is rPLMN or ePLMN of the UE. Because the source base station stores the rPLMN and ePLMN of the UE, the source base station is ensured according to the stored rPLMN and ePLMN of the UE. When the UE initially accesses the base station, the base station receives rPLMN and ePLMN of the UE from the MME. If the first access of the UE to the source base station is switched by the X2, the base station obtains the rPLMN and ePLMN of the UE from the source base station switched last time. How a specific UE obtains the rPLMN and the ePLMN of the UE is not the focus of the present invention, and a detailed description is omitted here.

The method includes that a PLMN ID contained in a corresponding UE measurement report is an rPLMN or ePLMN of a UE in a PLMN broadcasted by a target cell, and a CSG ID broadcasted by the target cell and a PLMN ID corresponding to the PLMN ID are PLMN IDs in a CSG list accessible by the UE, a source base station verifies that the PLMN should be the rPLMN or ePLMN of the UE and selects one PLMN ID which is the rPLMN ID or ePLMN ID of the UE for the UE, and then, the selected PLMN ID is contained in a TAI and sent to an MME through a step 308.

Step 308: and the source base station sends a switching demand message to the MME.

The handover required message not only includes the ECGI and CSG ID of the target cell, but also includes the TAI where the target cell is located, where the TAI includes the selected PLMN identifier.

As in the prior art, if the destination cell is hybrid access mode, the message also contains the cell access mode.

Step 309: and the MME performs access control or CSG member check on the UE according to the received CSG ID, the selected PLMN ID and the stored subscription CSG information of the UE.

The MME obtains the subscription CSG information of the UE from the HSS, and the specific obtaining procedure is not a key point of the present invention, and a detailed technical description is omitted here.

The subscription CSG information of the UE includes a CSG ID identifier list that the UE can access under the registered PLMN and the equivalent PLMN, and the CSG list that the UE can access may be, for example, PLMN1{ CSG1, CSG2, … }, PLMN2{ CSG5, CSG6, … }; the CSG list accessible to the UE may also be { PLMN1, CSG1}, { PLMN2, CSG1}, { PLMN2, CSG3} …, etc.

The invention does not limit the concrete form of the CSG list which can be accessed by the UE, and the MME needs to refer to the selected PLMN and the target cell CSG ID to see whether the UE can be accessed to the target cell when carrying out access control on the UE.

And after the access control fails, the MME sends a switching preparation failure message to the source base station to finish the switching process, if the switching requirement message contains an access mode, the MME determines the member state of the UE and sends the member state to the target base station through a switching request message.

Step 310: the MME sends a handover request message to the destination (T) -HeNB.

And under the condition that the HeNB GW is deployed, the MME sends a switching request message to the target home base station through the HeNB GW, wherein the message contains the CSG ID, and if the target cell is in a hybrid access mode, the message contains the CSG member indication.

Step 311: the destination HeNB verifies whether the CSG ID received in the handover request message is the CSG ID broadcasted by the destination cell.

If the received CSG ID is the CSG ID broadcasted by the target cell, proper resources are allocated, and if the CSG member indicates that the UE is a member, the target HeNB can perform a priority principle on the UE.

Step 312: and the target HeNB sends a switching request confirmation message to the MME.

And under the condition that the HeNB GW is deployed, sending a switching request confirmation message to the MME through the HeNB GW.

Step 313: and the MME sends a switching command message to the source base station.

Step 314: and the source base station sends RRC connection reconfiguration information to the UE. The RRC connection reconfiguration message contains handover command information.

Thus, the whole work flow of the UE handover method of this embodiment is completed.

Example II,

Like the embodiment, in this embodiment, after the UE acquires the system information related to the target cell, the PLMN identifier broadcast by the target cell is sent to the source base station, and then the source base station selects one PLMN identifier to send to the MME, and the MME completes access control on the UE. However, the difference from the first embodiment is that, in the present embodiment, the UE sends all PLMN identifiers broadcasted by the destination cell to the source base station, and adds an indication information for each PLMN identifier while sending each PLMN identifier, so as to indicate whether the UE corresponding to each PLMN identifier is a member under the PLMN or is a PLMN ID accessible by the UE in the destination cell, which may be specifically referred to in fig. 4. As shown in fig. 4, the cell of this embodiment is CSG type or hybrid type, and the procedure includes:

step 401: the UE sends a measurement report to the serving base station cell (i.e., the source base station cell), which contains the PCIs and signal qualities of the neighboring base station cells.

Step 402: and the base station instructs the UE to read the ECGI of the base station cell corresponding to the PCI in the measurement report.

How the UE reads the corresponding information of the neighboring cells in this step is the same as the related art, and a detailed technical description is omitted here.

Step 403: the UE acquires the relevant system information of the destination HeNB with the automatic gap.

Step 404: the UE sends a measurement report to the serving base station, where the measurement report includes the read ECGI, TAC, CSG ID of the destination cell, each PLMN ID broadcasted by the destination cell, and an indication information (used to indicate whether the UE corresponding to each PLMN ID is a member under the PLMN or not or whether the UE is a PLMN ID that the destination cell can access).

It should be noted that the CSG ID is included when the detected destination cell is of a CSG type or a hybrid type.

After receiving the measurement report containing the content, the serving base station adds the cell into the neighboring cell for storage, and stores information of which PLMNs broadcasted by the UE in the destination cell are members or which PLMN IDs are PLMN IDs accessible by the UE in the destination cell, and which PLMNs are non-members or which PLMN IDs are not PLMN IDs accessible by the UE in the destination cell according to the indication information.

Step 405: the UE sends a measurement report to the serving base station, which contains the PCI and signal quality of the destination cell.

It should be noted that the operation of this step is the same as that of step 401, and is not an essential step in the method, and may be omitted.

Step 406: and the source base station sends a switching demand message to the MME.

And the source base station selects a PLMN serving the UE in the target cell from the PLMNs reported by the UE as members under a certain PLMN, wherein the selected PLMN is the rPLMN or ePLMN of the UE. Or the source base station selects the PLMN serving the UE in the target cell from the PLMN IDs which the UE can access in the target cell. It should be noted that the source base station needs to ensure that the selected PLMN ID is rPLMN or ePLMN of the UE. Because the source base station stores the rPLMN and ePLMN of the UE, the source base station is ensured according to the stored rPLMN and ePLMN of the UE. When the UE initially accesses the base station, the base station receives rPLMN and ePLMN of the UE from the MME. If the first access of the UE to the source base station is switched by the X2, the base station obtains the rPLMN and ePLMN of the UE from the source base station switched last time. How a specific UE obtains the rPLMN and the ePLMN of the UE is not the focus of the present invention, and a detailed description is omitted here.

The source base station sends the selected PLMN identification to the MME by including the selected PLMN identification in the TAI, the handover requirement message comprises the ECGI and the CSG ID of the target cell, the TAI where the target cell is located, and the message also comprises the cell access mode if the target cell is in the hybrid access mode.

Step 407-step 412: the operation is the same as steps 309-314 and will not be described in detail here.

Thus, the whole work flow of the UE switching to the femtocell cell in this embodiment is completed.

Example III,

In this embodiment, the source base station knows the CSG list that the UE can access, and knows the PLMN ID list broadcasted by the destination cell, and selects the destination cell as the PLMN served by the UE from the obtained PLMN list to initiate handover, and fig. 5 is a flowchart of a third embodiment of supporting handover in the present invention. Detailed descriptions of steps not related to the present invention are omitted herein. As shown in fig. 5, the cell of this embodiment is CSG type or hybrid type, and the procedure includes:

step 500: and the MME sends the CSG list which can be accessed by the UE to the base station.

In this step, when the UE initially accesses the current serving cell, the MME may send a CSG list to the base station through the initial UE context request message, where the CSG list is accessible to the UE: if the UE initially accesses the current service cell and is switched over through S1, the MME sends a CSG list which can be accessed by the UE to the base station through a switching request message; if the initial access of the UE to the current serving cell is switched over by the X2, the MME sends a CSG list which can be accessed by the UE to the base station through a path switching request confirmation message. Or, the source base station sends the CSG list that the UE can access to the base station through the handover request message.

The MME obtains the CSG list accessible to the UE from the HSS, and the specific steps are not important in the present invention, and detailed technical description is omitted here. The CSG list which can be accessed by the UE comprises a CSG ID identification list which can be accessed by the UE under the registered PLMN and the equivalent PLMN; the CSG list accessible by the UE may be, for example, { CSG1, CSG2, … } under PLMN1, and a CSG list { CSG5, CSG6, … } accessible by PLMN2 UE; the CSG list accessible to the UE may also be { PLMN1, CSG1}, { PLMN2, CSG1}, { PLMN2, CSG3} …, etc.

Step 500 a: the source base station obtains the PLMN ID list broadcasted by the destination cell.

In this step, there are two implementation manners for the source base station to obtain the PLMN ID list broadcasted by the destination cell, that is, the source base station may obtain the PLMN ID list broadcasted by the destination cell from the UE (see fig. 6 for a specific procedure), or establish the PLMN ID list broadcasted by obtaining the destination cell from the destination cell through X2 (see fig. 7 for a specific procedure). There are two ways for the source base station to obtain the PLMN ID list broadcasted by the destination cell from the UE, one way is to obtain the PLMN ID list from the UE through the automatic neighbor relation ANR as described in fig. 6, and when obtaining the ANR, the ANR process is performed before preparing handover, for example, between step 500 and step 501, or between step 503 and step 505 (in this case, step 504 and step 501 are the same, and are performed once, and need not be performed repeatedly), and this embodiment does not limit the sequence and time point of the ANR process. The second is that the UE sends the PLMN ID list broadcasted by the destination cell to the source base station in step 507 (same as the first embodiment). Another way to obtain the PLMN ID list broadcast by the destination cell from the source base station is through operation and maintenance configuration. This method can be applied without affecting the main content of the PLMN selection of the present embodiment.

The PLMN ID list sent by the UE to the source base station may be all PLMN IDs broadcast by the destination cell, or the UE may send to the source base station a part of PLMN IDs filtered from the PLMN IDs broadcast by the destination cell to be the registered PLMN or equivalent PLMN of the UE.

Two methods of obtaining the PLMN ID list broadcast by the destination cell are described below with reference to fig. 6 and 7, and referring first to fig. 6, the process may include:

step 601: the UE sends a measurement report to the serving cell, the measurement report including the PCIs and signal qualities of the neighboring base station cells.

Step 602: and the base station instructs the UE to read the ECGI of the cell corresponding to the PCI in the measurement report.

How the UE reads the corresponding information of the neighboring cell is the same as the prior art, and a detailed technical description is omitted here.

Step 603: and after reading, the UE sends a measurement report to the serving base station, wherein the measurement report comprises the read ECGI, TAC and CSG ID of the neighboring home base station cell and all broadcasted PLMN IDs.

In this step, the CSG ID is included when the detected neighboring cells are of a CSG type or a hybrid type.

And after receiving the measurement report containing the content, the service base station adds the cell into the neighboring cell relationship for storage.

Thus, the whole working process for obtaining the PLMN ID list broadcasted by the target cell adopted by the method is completed.

Referring to fig. 7, a specific procedure for establishing, through X2, a PLMN ID list broadcasted by a destination cell from a destination home base station cell is shown, and as shown in fig. 7, the procedure is described with (H) eNB1 as a source base station and HeNB2 as a destination home base station, and specifically may include:

step 701: (H) the eNB-1 obtains the IP address of the neighbouring base station HeNB-2.

How to obtain the IP of the neighboring base station is not the focus of the present invention, and detailed technical description is omitted here.

Step 702: (H) the eNB-1 sends an X2 establishment request message to the HeNB-2, wherein the establishment request message comprises (H) information of an eNB-1 cell, and the information of the cell comprises all PLMN identifications broadcasted by the cell.

Step 703: the HeNB-2 sends an X2 establishment response message to the (H) eNB-1, wherein the establishment response message comprises information of the HeNB-2 cell, and the information of the cell comprises all PLMN identifications broadcasted by the cell.

Thus, the whole working process of obtaining the PLMN ID list broadcasted by the target cell by the method is completed. Corresponding to the method for obtaining the broadcast PLMN ID of the neighboring cell in the present invention, an X2 interface needs to be established between the source base station and the neighboring cell base station, and when the PLMN ID list broadcast by a neighboring cell is updated, the PLMN ID stored at the opposite end can be updated through the eNB configuration update process.

Steps 501 to 506 are the same as steps 301 to 306, and are not described in detail here.

Step 507: and the UE sends a measurement report to the source base station, wherein the measurement report comprises global cell identity (ECGI) of the target HeNB cell, routing area code (TAC), CSG ID and members.

And a second method for obtaining the PLMN ID list broadcasted by the destination cell from the UE corresponding to the source base station, where the message further includes a PLMN ID list broadcasted by the destination cell, or a part of PLMN ID list which is the registered PLMN or equivalent PLMN of the UE in the PLMN ID broadcasted by the destination cell.

And after receiving the measurement report, the source base station selects the PLMN ID served in the target cell for the UE. It should be noted that, the source base station selects according to the PLMN list broadcasted by the destination cell, the rPLMN or ePLMN of the UE and the CSG list allowed to be accessed by the UE, the source base station needs to determine which PLMNs in the plmnsbroadcasted by the destination cell are in the rPLMN or ePLMN of the UE and the PLMNs, for example PLMNi { PLMNi, CSG ID broadcasted by the destination cell } is in the CSG list accessible by the UE, and if there are multiple PLMNs (PLMN IDs broadcasted by the destination cell and are rPLMN or ePLMN of the UE and { the PLMN ID, destination cell CSG ID } are in the CSG list accessible by the UE), the source base station selects one PLMN ID for the UE among the PLMNs.

For example: UE rpmn { (C1, a), (C1, B), (C1, D), (C2, a) }, candidate HO destination cell broadcast PLMNs { D, a, C, E }, CSG ═ C1, then the PLMN that the UE can access at the destination cell is { a, D } because a, D is in the ePLMN, and a, D are the cells broadcast by the destination cell, and (C1, a), (C1, D) is in the CSG list that the UE can access. The source base station then selects the PLMN serving the UE in the destination cell in a or D.

As another implementation manner of this embodiment, the source base station may find only PLMN IDs in PLMNs reported by the UE, for example, PLMNi { PLMNi, CSG ID broadcasted by the destination cell } in a CSG list accessible to the UE. If there are multiple such PLMNs (the PLMN reported by the UE and { said PLMN ID, destination cell CSG ID } is in the CSG list accessible to the UE), the source base station selects one PLMN ID for the UE among these PLMNs. It should be noted that the source base station needs to ensure that the selected PLMN ID is rPLMN or ePLMN of the UE. Because the source base station stores the rPLMN and ePLMN of the UE, the source base station is ensured according to the stored rPLMN and ePLMN of the UE. When the UE initially accesses the base station, the base station receives rPLMN and ePLMN of the UE from the MME. If the first access of the UE to the source base station is switched by the X2, the base station obtains the rPLMN and ePLMN of the UE from the source base station switched last time. How a specific UE gets the rPLMN and the ePLMN of the UE is not the focus of the present invention, and a detailed description is omitted here.

Thereafter, the source base station includes the selected PLMN identity in the TAI, and sends it to the MME in step 508.

Steps 508 to 514 are the same as steps 308 to 314 and will not be described in detail here.

Example four

As in the third embodiment, in this embodiment, the source base station also needs to know the PLMN ID list broadcast by the destination cell or the part of the PLMN ID list that is the registration PLMN or the equivalent PLMN of the UE in the PLMN ID list broadcast by the destination cell, and how to obtain the PLMN ID list broadcast by the destination cell or the part of the PLMN ID list that is the registration PLMN or the equivalent PLMN of the UE in the PLMN ID list broadcast by the destination cell is the same as the third embodiment, which is not described in detail herein. However, the difference from the third embodiment is that the MME selects a PLMN for the UE in the present embodiment, and the working procedure thereof can refer to fig. 8, and a detailed description of the steps irrelevant to the present invention is omitted here, where the cell in the present embodiment is a CSG type or a hybrid type, and specifically includes:

steps 801 to 807 are the same as steps 501 to 507, and detailed description thereof is omitted.

Step 808: the source base station contains a PLMN ID in the TAI.

In this step, the included PLMN ID may be a PLMN ID broadcasted by the destination cell, or a PLMN ID selected from PLMNs broadcasted by the destination cell and being rpmns of the UE or ePLMN.

Step 809: and the source base station sends a switching demand message to the MME.

In this step, the handover required message includes not only the ECGI and CSG ID of the target cell, but also the TAI of the target cell. If the destination cell is in the hybrid access mode, the handover required message further includes the cell access mode.

Further, the handover requirement message further includes a PLMN ID list, where the PLMN ID list may be all PLMN IDs broadcasted by the destination cell or PLMN IDs of the rPLMN or the ePLMN of the UE in the destination cell broadcast PLMN IDs screened by the source base station or the UE. If the selected PLMN ID of the target cell broadcast PLMN ID of the UE is also the PLMN ID of the rPLMN or the epdmn of the UE, it should be noted that the source base station needs to verify that the PLMN ID is the rPLMN or the epdmn of the UE, and the source base station sends the verified PLMN ID list to the MME. Because the source base station stores the rPLMN and ePLMN of the UE, the source base station is ensured according to the stored rPLMN and ePLMN of the UE. When the UE initially accesses the base station, the base station receives rPLMN and ePLMN of the UE from the MME. If the first access of the UE to the source base station is switched by the X2, the base station obtains the rPLMN and ePLMN of the UE from the source base station switched last time. How a specific UE obtains the rPLMN and the ePLMN of the UE is not the focus of the present invention, and a detailed description is omitted here.

Step 810: and the MME corresponding to all PLMN IDs broadcasted by the target cell and sent by the source base station performs access control on the UE or performs CSG member check on the UE according to the received CSG ID, all PLMN ID lists broadcasted by the target cell, the rPLMN or ePLMNNs of the UE and the subscription CSG information of the UE stored by the MME, and selects the target PLMN.

For example, if the PLMNn is a PLMN broadcasted by the destination cell and is an rplmns or ePLMNs of the UE, if all { PLMNn, destination cell CSG ID } are not in the CSG list accessible by the UE, the access control fails or the CSG member check is performed, and after the access control or the CSG member check fails, the MME sends a handover preparation failure message to the source base station to end the handover process; if the plurality of { PLMNn, destination cell CSG ID } are in the accessible CSG list of the UE, the MME selects a PLMN serving the UE by the destination cell from the plurality of PLMNs. And if the PLMN ID sent by the corresponding source base station is the PLMN ID of the rPLMN or ePLMN of the UE in the target cell broadcast PLMN ID, the MME performs access control or CSG member check on the UE according to the received CSG ID, the received PLMN ID list and the subscription CSG information of the UE stored by the MME, selects the target PLMN, and selects the PLMN { PLMNm, the target cell CSG ID } in the accessible CSG list of the UE from the received PLMN (the PLMNm is the PLMN received from the source base station). If all { PLMNm, destination cell CSG ID } are not in the CSG list that the UE can access, the access control or CSG member check fails, and the MME sends a switching preparation failure message to the source base station after the access control or CSG member check fails to finish the switching process; and if a plurality of { PLMNm, destination home base station cell CSG ID } are in the accessible CSG list of the UE, the MME selects one PLMN from a plurality of PLMNs to serve the PLMN of the UE as the destination cell.

After the selection is made, if the TAI received from the source base station contains the PLMN ID that is not selected, as an implementation of the present invention, the MME may replace the PLMN ID in the TAI with the PLMN ID selected by the MME. If the switching is carried out between different MME, the source MME finds the target MME by the selected PLMN ID and the TAC; if the switching request message sent by the MME to the target cell contains a switching restriction list, the MME gives a registered PLMN and an equivalent PLMN according to the newly selected PLMN, namely the selected PLMN is the registered PLMN, and the original rPLMN and other ePLMNs are ePLMNs; if the handover required message includes the access mode, the MME determines the member status of the UE and transmits the member status to the target base station through the handover request message.

Step 811: the MME sends a handover request message to the destination (T) -HeNB.

And under the condition that the HeNB GW is deployed, the MME sends a switching request message to a target base station through the HeNB GW, wherein the switching request message contains CSG ID, and if the target cell is in a hybrid access mode, the switching request message also contains CSG member indication.

Steps 812 to 815 are the same as steps 311 to 314, and will not be described in detail.

EXAMPLE five

As in the third and fourth embodiments, in this embodiment, the source base station also needs to know the PLMN ID list broadcast by the destination cell or the part of the PLMN ID list that is the registration PLMN or the equivalent PLMN of the UE in the PLMN ID list broadcast by the destination cell, and a method for specifically obtaining the part of the PLMN ID list that is the registration PLMN or the equivalent PLMN of the UE in the PLMN ID list broadcast by the destination cell or the PLMN ID list broadcast by the destination cell is also implemented in the third embodiment, and details are not described here. However, the difference between the third and fourth embodiments is that in the present embodiment, the MME performs access control on the UE according to the received CSG ID, the PLMN ID list broadcasted by the destination cell, or the part of the PLMN ID list which is the registered PLMN or equivalent PLMN of the UE in the PLMN ID list broadcasted by the destination cell, the rplmns or epdlmns of the UE, and the subscription CSG information of the UE stored by the MME, screens PLMNs, and then the source base station selects a PLMN serving the UE from the PLMN IDs screened by the MME. The method comprises the steps that a PLMN ID list broadcasted by a target cell is sent to an MME corresponding to a source base station, the MME filters out a registered PLMN rPLMN or an equivalent PLMN ePLMN which is UE according to a received CSG ID and the PLMN ID list broadcasted by the target cell, the UE is a PLMN ID of a CSG type target cell or a mixed type target cell member under the PLMN, and then the source base station selects a PLMN serving the UE from the PLMN IDs screened out by the MME. The working procedure can refer to fig. 9, where the femto cell in this embodiment is a CSG type or a hybrid type, and specifically includes:

steps 901 to 907 are the same as steps 501 to 507, and are not described in detail here.

Step 908: and the source base station sends an access selection request message to the MME.

The access selection request message includes the CSG ID of the target cell and also includes a PLMN ID list, where the PLMN ID list may be all PLMN IDs broadcasted by the target cell or PLMN IDs of the rPLMN or the ePLMN of the UE in the target cell broadcast PLMN IDs screened by the source base station or the UE.

In this step, if the source base station sends a method corresponding to all PLMN IDs broadcasted by the destination cell, the MME performs access control on the UE according to the received CSG ID, all PLMN ID lists broadcasted by the destination cell, the rplmns or ePLMNs of the UE and subscription CSG information of the UE stored by the MME, screens PLMNs, and screens PLMN IDs that the UE can access in the destination cell.

In the PLMN broadcasted by the target cell, the MME decides which are rPLMN or ePLMNNs of the UE, and { the PLMN ID, the target cell CSG ID } are in a CSG list accessible by the UE, and the MME screens the PLMN ID meeting the condition. For example, PLMNn broadcasted by the destination cell is a registered PLMN or an ePLMN of the UE, if all { PLMNn, destination cell CSG ID } are not in the CSG list accessible by the UE, the access control fails, and after the access control fails, the MME sends an access selection failure message to the source base station to end the process; or the MME sends an access control response to the source base station, the message does not contain any PLMN ID, the source base station knows that no PLMN can be accessed by the UE in the target cell, and the source base station does not initiate a handover process to the target cell.

And the source base station sends a method that the source base station or the selected target cell broadcasts the PLMN ID and the PLMN ID of the rPLMN or ePLMN of the UE, so that the MME performs access control on the UE according to the received CSG ID, the received PLMN ID list and the subscription CSG information of the UE stored by the MME, screens the PLMN, and screens the PLMN ID which can be accessed by the UE in the target cell. And selecting the PLMN { PLMNm, the destination cell CSG ID } in the accessible CSG list of the UE from the PLMNm received from the source base station (the PLMNm is the PLMN received from the source base station). If all { PLMNm, destination cell CSG ID } are not in the CSG list that the UE can access, the access control fails, and the MME sends an access selection failure message to the source base station after the access control fails to finish the process; or the MME sends an access control response to the source base station, the message does not contain any PLMN ID, the source base station knows that no PLMN can be accessed by the UE in the target cell, and the source base station does not initiate a handover process to the target cell.

Step 909: and the MME sends an access selection response message to the source base station, wherein the access selection response message contains a PLMN ID list.

The PLMN ID is the PLMN ID list screened in step 908, that is, the PLMN broadcasted by the destination cell is the rPLMN or the ePLMN of the UE, and { the PLMN ID, the destination cell broadcast CSG ID } is the PLMN ID in the accessible CSG list of the UE, if none of the PLMN IDs satisfies the requirement, the MME also notifies the source base station of the information of the PLMN that does not satisfy the requirement, so that the source base station may not initiate the handover process to the destination cell.

As another implementation method of this step, the access control response message may include the PLMN ID list (selectable PLMN ID list) screened in step 908, and may also include a non-selectable PLMN ID list, that is, the PLMN ID list other than those screened in step 908 is received from the source base station.

Step 910: the source base station selects a PLMN serving the UE in the destination cell among the PLMNs received in step 909.

Step 911: the source base station initiates the existing handover procedure.

This process may be an existing S1 handover or an X2 handover.

Corresponding to an implementation manner of the method, after receiving the switching demand message, the MME does not need to perform access control on the UE again.

Example six,

In this embodiment, after acquiring the relevant system information of the target cell, the UE sends the PLMN ID list broadcasted by the target cell, or, the PLMN ID list of the PLMN IDs broadcasted by the destination cell is the rPLMN ID or the ePLMN ID of the UE, or, the PLMN broadcasted by the destination cell is rPLMN or PLMN of the UE and the PLMN ID and the CSG ID broadcasted by the destination cell are sent to the source base station in the PLMN identifier in the CSG list accessible to the UE, and then the source base station verifies the access check of the PLMN reported by the UE and selects one PLMN identification passing the access verification to send to the MME, and the MME completes access control or CSG member check on whether the CSG ID broadcasted by the UE in the source base station selected PLMN and the destination cell is in the CSG list accessible by the UE, and a specific handover procedure may refer to fig. 10 (detailed description of steps not related to the present invention is omitted in this figure). As shown in fig. 10, the home base station cell of the present embodiment is a hybrid type or an open type, and the process includes:

step 1001: and the UE acquires the relevant system information of the target HeNB.

Step 1002: the UE sends a measurement report to the source base station.

In this step, the measurement report includes not only the global cell identity (ECGI), the routing area code (TAC), the CSG ID and the member of the destination HeNB cell, but also one or more PLMN IDs broadcasted by the destination cell.

Wherein, the PLMN of the PLMN ID included in the measurement report is:

if the target cell is a hybrid cell and is a CSG member cell, the contained PLMN ID is a PLMN ID list which is the rPLMN ID or ePLMN ID of the UE in the PLMN IDs broadcasted by the target cell, and the PLMN ID and the CSG ID broadcasted by the target cell are in a CSG list accessible by the UE;

if the target cell is a hybrid type, not a CSG type cell or an open type cell, the PLMN ID included is a PLMN ID list including the PLMN ID of the UE among the PLMN IDs broadcast by the target cell or the PLMN IDs broadcast by the target cell.

And the UE sends the PLMN ID list to the source base station. For the encoding of the information, the UE may transmit the PLMN ID satisfying the above condition to the source base station from the second PLMN ID among the PLMN IDs broadcast by the destination cell. If the primary PLMN ID (the first PLMN ID in the broadcast information) also satisfies the above conditions, i.e. for a hybrid cell and a CSG member cell, the primary PLMN is equal to rPLMN or ePLMN and the PLMN ID and the CSG ID broadcast by the destination cell are in the CSG list accessible by the UE, or for a hybrid, but not a CSG member cell or an open cell, the primary PLMN is equal to rPLMN or ePLMN, the UE includes a primary PLMN suitability indication in the measurement report, since the ECGI already includes the primary PLMN ID, and does not need to include it repeatedly.

The source base station verifies that the PLMN ID reported by the UE should be the rPLMN or ePLMN of the UE and selects a PLMN ID for the UE that is the rPLMN ID or ePLMN ID of the UE, and then includes the selected PLMN ID in the TAI, and sends it to the MME in step 1003.

Step 1003: and the source base station sends a switching demand message to the MME.

Step 1004: and the MME performs access control or CSG member check on the UE according to the received CSG ID, the selected PLMN ID and the stored subscription CSG information of the UE.

Step 1005: the MME sends a handover request message to the destination (T) -HeNB.

And under the condition that the HeNB GW is deployed, the MME sends a switching request message to a target base station through the HeNB GW, wherein the message contains CSG ID, and if the target cell is in a hybrid access mode, the message contains CSG member indication.

Step 1006: and the target HeNB sends a switching request confirmation message to the MME.

Step 1007: and the MME sends a switching command message to the source base station.

Step 1008: and the source base station sends RRC connection reconfiguration information to the UE. The RRC connection reconfiguration message contains handover command information.

Example seven,

In this embodiment, after obtaining the relevant system information of the target cell by the UE, a PLMN ID list broadcasted by the target cell, or a PLMN ID list in which the PLMN ID broadcasted by the target cell is the rPLMN ID or the ePLMN ID of the UE, is sent to the source base station, and then the source base station performs an access check of the PLMN reported by the UE and selects one PLMN identifier passing the access check to send to the MME, and the MME completes an access control or CSG member check on whether the PLMN selected by the UE at the source base station and the CSG ID broadcasted by the target cell are in the CSG list accessible by the UE, where a specific handover procedure may refer to fig. 11 (a detailed description of a step irrelevant to the present invention is omitted in this figure). As shown in fig. 11, the home base station cell of the present embodiment is a hybrid type or an open type, and the process includes:

step 1101: and the UE acquires the relevant system information of the target HeNB.

Step 1102: the UE sends a measurement report to the source base station.

In this step, the measurement report includes not only the global cell identity (ECGI), the routing area code (TAC), the CSG ID, and the member of the destination HeNB cell, but also one or more PLMN IDs broadcasted by the destination base station cell.

Wherein, the PLMN of the PLMN ID included in the measurement report is:

the PLMN ID list broadcast by the destination cell, or,

the PLMN ID list broadcasted by the destination cell is a PLMN ID list of the registration PLMN rPLMN or equivalent PLMN ePLMN of the UE.

And the UE sends the PLMN ID list to the source base station. For the encoding of the information, the UE may transmit the PLMN ID satisfying the above condition to the source base station from the second PLMN ID among the PLMN IDs broadcast by the destination cell. If the UE reports the PLMN ID, which is the rpplmn or ePLMN ID of the UE, in the PLMN ID broadcast by the destination cell to the base station, and the primary PLMN ID (the first PLMN ID in the broadcast information) also satisfies the above condition, that is, the primary PLMN is equal to the rpplmn or ePLMN, the UE includes the primary PLMN suitability indication in the measurement report, because the primary PLMN ID is already included in the ECGI, and the inclusion does not need to be repeated.

The source base station verifies the access check of the PLMN IDs reported by the UE and selects one PLMN ID for the UE among the PLMN IDs passing the access check. And the source base station selects a PLMN serving the UE in the destination cell for the UE from the PLMN IDs contained in the measurement report, wherein the selected PLMN ID is the rPLMN ID or ePLMN ID of the UE. It should be noted that the source base station needs to ensure that the selected PLMN ID is rPLMN or ePLMN of the UE. Because the source base station stores the rPLMN and ePLMN of the UE, the source base station is ensured according to the stored rPLMN and ePLMN of the UE. When the UE initially accesses the base station, the base station receives rPLMN and ePLMN of the UE from the MME. If the first access of the UE to the source base station is switched by the X2, the base station obtains the rPLMN and ePLMN of the UE from the source base station switched last time. How a specific UE obtains the rPLMN and the ePLMN of the UE is not the focus of the present invention, and a detailed description is omitted here.

The source base station verifies that the PLMN ID reported by the UE should be the rPLMN or the ePLMN of the UE and selects a PLMN ID for the UE that is the rPLMN ID or the ePLMN ID of the UE, and then includes the selected PLMN ID in the TAI, and sends it to the MME in step 1103.

Step 1103: and the source base station sends a switching demand message to the MME.

Step 1104: and the MME performs access control or CSG member check on the UE according to the received CSG ID, the selected PLMN ID and the stored subscription CSG information of the UE.

Step 1105: the MME sends a handover request message to the destination (T) -HeNB.

Step 1106: and the target HeNB sends a switching request confirmation message to the MME.

Step 1107: and the MME sends a switching command message to the source base station.

Step 1108: and the source base station sends RRC connection reconfiguration information to the UE. The RRC connection reconfiguration message includes handover command information.

It should be noted that the sixth embodiment and the seventh embodiment are described by taking a hybrid cell as an example, and the method of the present embodiment is also applicable to the case of moving to the HeNB cell in the start mode.

The objects, technical solutions and advantages of the present invention have been described in further detail with reference to the preferred embodiments, it should be understood that the above description is only illustrative of the preferred embodiments of the present invention, and should not be construed as limiting the present invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A method performed by a source base station in a communication system, the method comprising:

the source base station receives a measurement report from the UE, wherein the measurement report contains one or more PLMN IDs broadcasted by the destination cell and checked by a public land mobile network identification (PLMN ID); and

and the source base station selects the PLMN ID of the target cell for switching for the UE from the PLMN IDs in the measurement report, wherein the source base station selects the PLMN ID serving the UE in the target cell, and the PLMN ID selected by the source base station is one of the PLMN IDs reported by the UE, which is the rPLMN ID or ePLMN ID of the UE.

2. The method of claim 1, wherein:

when the target cell is a closed subscriber group, CSG, type or hybrid type, the PLMN ID included in the measurement report is:

the PLMN ID broadcasted by the destination CSG cell or the hybrid cell is the PLMN ID of the registration PLMN rPLMN of the UE or the PLMN ID of the equivalent PLMN ePLMN, and the PLMN ID and the CSG ID broadcasted by the destination cell are in the CSG list accessible by the UE.

3. The method of claim 1, wherein:

and if a plurality of PLMN IDs satisfy the condition, the PLMN IDs include the PLMN IDs which satisfy the condition from a second PLMN ID broadcasted by the destination cell.

4. The method of claim 1, wherein when the destination cell is a hybrid type or an open type, the PLMNs of the PLMN ID included in the measurement report are:

a PLMN ID broadcasted by a target hybrid or open cell, and is a registered PLMN rPLMN of the UE or an equivalent PLMN ePLMN;

or all PLMN IDs broadcast by the intended hybrid or open cell.

5. The method of claim 1,

when the target cell is a hybrid type and is a CSG member cell, the PLMNs of the PLMN ID included in the measurement report are: the PLMN ID broadcasted by the target cell is a registered PLMN rPLMN of the UE or an equivalent PLMN ePLMN, and the PLMN ID and the CSG ID broadcasted by the target cell are in a CSG list accessed by the UE;

when the target cell is a hybrid type and is not a CSG member cell, or the target cell is an open type, the PLMNs of the PLMN IDs included in the measurement report are: the PLMN IDs broadcasted by the destination cell are all PLMN IDs broadcasted by the registration PLMN rPLMN or equivalent PLMN ePLMN of the UE or the destination cell.

6. The method of claim 1, wherein the measurement report further comprises a global cell identity and a CSG ID.

7. The method of claim 1, wherein the source base station sends the selected PLMN ID and the CSG ID broadcast by the destination cell to the mobility management entity.

8. The method of claim 7, wherein the selected PLMN ID and the CSG ID are used for access control or CSG membership check of the UE by the mobile management entity together with saved subscription CSG information of the UE.

9. The method according to any one of claims 1 to 6, wherein:

the source base station verifies the access check of the PLMN IDs reported by the UE and selects one PLMN ID for the UE among the PLMN IDs passing the access check.

10. A method performed by a User Equipment (UE) in a communication system, the method comprising:

transmitting a measurement report to the source base station, the measurement report containing one or more of the PLMN IDs broadcast by the destination cell checked by the public land Mobile network identity PLMN ID,

the PLMN ID in the measurement report is used for the source base station to select a PLMN ID of a target cell initiating handover for the UE, wherein the source base station selects a PLMN ID serving the UE in the target cell, and the PLMN ID selected by the source base station is one of PLMN IDs reported by the UE, which is an rPLMN ID or an ePLMN ID of the UE.

11. The method of claim 10,

12. The method of claim 10, wherein:

13. The method of claim 10, wherein when the destination cell is a hybrid type or an open type, the PLMNs of the PLMN ID included in the measurement report are:

or all PLMN IDs broadcast by the intended hybrid or open cell.

14. The method of claim 10,

15. The method of claim 10, wherein the measurement report further comprises a global cell identity and a CSGID.

16. The method of claim 10, wherein the source base station sends the selected PLMN ID and the CSG ID broadcast by the destination cell to the mobility management entity.

17. The method of claim 16, wherein the selected PLMN ID and the CSG ID are used for access control or CSG membership check of the UE by the mobility management entity together with saved subscription CSG information of the UE.

18. The method according to any one of claims 11 to 15, wherein:

19. A source base station in a communication system, comprising:

means for receiving a measurement report from the UE containing one or more of the PLMN IDs broadcast by the destination cell checked by public land Mobile network identification (PLMN ID); and

means for selecting a PLMN ID of a destination cell initiating handover for the UE from the PLMN IDs in the measurement report, wherein the source base station selects a PLMN ID serving the UE in the destination cell, and the PLMN ID selected by the source base station is one of the PLMN IDs reported by the UE, which is an rPLMN ID or an ePLMN ID of the UE.

20. The source base station of claim 19, wherein:

21. The source base station of claim 19, wherein:

22. The source base station of claim 19, wherein when the destination cell is a hybrid type or an open type, the PLMNs of the PLMN ID included in the measurement report are:

or all PLMN IDs broadcast by the intended hybrid or open cell.

23. The source base station of claim 19,

24. The source base station of claim 19, wherein the measurement report further comprises a global cell identity and a CSG ID.

25. The source base station of claim 19, further comprising: means for sending the selected PLMN ID and the CSG ID broadcast by the destination cell to a mobility management entity.

26. The source base station of claim 25, wherein the selected PLMN ID and the CSG ID are used for the mobility management entity to perform access control or CSG membership check on the UE together with the saved subscription CSG information of the UE.

27. The source base station according to any of claims 19 to 24, further comprising:

means for verifying an access check of the PLMN ID reported by the UE, and

the means for selecting selects one PLMN ID among the PLMN IDs passing the access check for the UE.

28. A user equipment, UE, in a communication system, the UE comprising:

means for sending a measurement report to the source base station, the measurement report containing one or more of the PLMN IDs broadcast by the cell checked by public land Mobile network identity, PLMN ID,

29. The UE of claim 28,

30. The UE of claim 28, wherein:

31. The UE of claim 28, wherein when the destination cell is a hybrid type or an open type, the PLMNs of the PLMN ID included in the measurement report are:

or all PLMN IDs broadcast by the intended hybrid or open cell.

32. The UE of claim 28,

33. The UE of claim 28, wherein the measurement report further comprises a global cell identity and a CSG ID.

34. The UE of claim 28, wherein the source base station sends the selected PLMN ID and the CSG ID broadcast by the destination cell to the mobility management entity.

35. The UE of claim 34, wherein the selected PLMN ID and the CSG ID are used for access control or CSG membership check of the UE by the mobility management entity together with saved subscription CSG information of the UE.

36. The UE of any of claims 28 to 33, wherein: