CN102598786A

CN102598786A - Switching method between base stations, base stations and communication system

Info

Publication number: CN102598786A
Application number: CN2011800026222A
Authority: CN
Inventors: 李婧媛
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2011-11-11
Filing date: 2011-11-11
Publication date: 2012-07-18
Anticipated expiration: 2031-11-11
Also published as: CN102598786B; WO2012167547A1

Abstract

This invention provides a switching method between base stations, base stations and a communication system. The method includes: sending switching-request information from a source base station to a target base station to switch user equipments to which the said source base stations provides service to cells of the target base stations. According to S1 link state information among the target base stations and a mobile management entity which provides service to the source base stations and has the UE residing in, the source base stations confirm and perform either X2 link switching or S1 link switching. This invention also provides a base station and a communication system. This invention can select the most suitable switching method between X2 link switching and S1 link switching to successfully switch source eNBs to target eNBs.

Description

Changing method between the base station, base station and communication system

Technical field

The embodiment of the invention relates to the mobile communication technology field, relates in particular to a kind of technical scheme of switching between the base station of being used to realize.

Background technology

3GPP Long Term Evolution (Long Term Evolution; Hereinafter to be referred as LTE) system is very promising GSM; It comes from traditional UMTS (Universal Mobile Telecommunications System; UMTS) network can provide higher wireless access rate and better business support.

With the LTE system is example, and it adopts flat wireless access network (Radio Access Network is called for short RAN) structure, has cancelled radio network controller (Radio Network Control is called for short RNC).As shown in Figure 1, the LTE system comprises that evolution base station (evolved-NodeB is called for short eNB) and Evolved Packet Core (Evolved Packer Core Network is called for short EPC) constitute.Be connected through X2 interface between the eNB, be connected through the S1 interface between eNB and the EPC.EPC comprises mobile management entity (Mobility Management Entity is called for short MME) and System Architecture Evolution gateway (SAE GateWay is called for short SGW).For example, MME is responsible for the mobile management of chain of command as the chain of command part, comprises the management of user's context and mobile status, distributing user temporary identity sign etc.Through agency (proxy) function of S1 interface, realize the transmission of chain of command signaling between eNB and MME between eNB and the MME.And for example, SGW is that downlink data is initiated paging under the responsible idle condition as the user plane part, and Internet Protocol (Internet Protocol is called for short IP) bearing parameter and the interior routing iinformation of network etc. are preserved in management.Through agency (proxy) function of S1 interface, realize the transmission of user plane signaling between eNB and SGW between eNB and the SGW.

In wireless telecommunication system, switching is the fundamental characteristics that keeps business continuance, through improving handover success rate, can guarantee the business continuance at terminal.The so-called switching; Be meant when sub-district under the eNB in communication process, terminal and move to the sub-district under another eNB; When perhaps causing the terminal call quality to descend owing to external interference; Need to change the original voice channel in terminal and be transferred on the new idle voice channel, to continue the process of maintenance conversation.

In the wireless telecommunication system based on LTE technology, above-mentioned switching can be divided into S1 link switchover and the X2 link switchover between eNB between eNB and EPC.The eNB that initiates to switch can be called source eNB, and the eNB that receives handoff request can be called target eNB.

At present, industry is expected the changing method between a kind of eNB, when source eNB when target eNB is initiated handoff request, can in X2 link switchover and S1 link switchover, select suitable changing method, successfully to carry out the switching of source eNB to target eNB.

Summary of the invention

The embodiment of the invention provides changing method, base station and the communication system between a kind of base station, how is used for solving the problem of selecting suitable changing method in X2 link switchover and S1 link switchover.

One side of the present invention provides the changing method between a kind of base station, comprising:

Source base station sends handoff request message to target BS, is used for providing the subscriber equipment User Equipment (UE) of service to switch to the sub-district under the said target BS said source base station;

Said source base station according to said target BS, and serve the S1 link-state information between the resident mobile management entity Mobile Management Entity (MME) of said source base station and said UE, confirm to carry out X2 link switchover or S1 link switchover.

Another aspect of the present invention provides the changing method between a kind of base station, comprising:

The handoff request message that send target BS reception sources base station is used for providing the subscriber equipment User Equipment (UE) of service to switch to the sub-district under the said target BS said source base station;

Said target BS sends said target BS, and serves the S1 link-state information between the resident mobile management entity Mobile Management Entity (MME) of said source base station and said UE to said source base station, is used for said source base station and confirms to carry out X2 link switchover or S1 link switchover.

Another aspect of the present invention provides a kind of base station, comprising:

Transmitting element is used for sending handoff request message to target BS, so that provide the subscriber equipment User Equipment (UE) of service to switch in the sub-district under the said target BS said base station;

Processing unit is used for according to said target BS, and serves the S1 link-state information between the resident mobile management entity Mobile Management Entity (MME) of said base station and said UE, confirms to carry out X2 link switchover or S1 link switchover.

One side more of the present invention provides a kind of base station, comprising:

Receiving element is used for the handoff request message that send the reception sources base station, so that provide the subscriber equipment User Equipment (UE) of service to switch in the sub-district under the said base station said source base station;

Transmitting element; Be used for sending said base station, and serving the S1 link-state information between the resident mobile management entity Mobile Management Entity (MME) of said source base station and said UE, so that said source base station confirms to carry out X2 link switchover or S1 link switchover to said source base station.

One side more of the present invention provides a kind of communication system, comprising:

One source base station, an and target BS;

Said source base station is used for sending handoff request message to target BS, so that provide the subscriber equipment User Equipment (UE) of service to switch in the sub-district under the said target BS said base station; And according to said target BS, and serve the S1 link-state information between the resident mobile management entity Mobile Management Entity (MME) of said source base station and said UE, carry out X2 link switchover or S1 link switchover;

Said target BS is used for the handoff request message that send the reception sources base station; And send said target BS, and serve the S1 link-state information between the resident MME of said source base station and said UE to said source base station.

Changing method between base station of the present invention, base station and communication system; Be used for guaranteeing selecting suitable changing method in X2 link switchover and S1 link switchover; Successfully to carry out the switching of source eNB, realize that the terminal switches to the sub-district under the target eNB from the sub-district under the eNB of source to target eNB.

Description of drawings

Fig. 1 is the configuration diagram of LTE system in the prior art;

Fig. 2 is the flow chart of the changing method between the base station of one embodiment of the invention;

Fig. 3 is the flow chart of the changing method between the base station of another embodiment of the present invention;

Fig. 4 is the flow chart of the changing method between the base station of another embodiment of the present invention;

Fig. 5 is the flow chart of the changing method between the base station of another embodiment of the present invention;

Fig. 6 is the architecture of base station sketch map of another embodiment of the present invention;

Fig. 7 is the architecture of base station sketch map of another embodiment of the present invention.

Embodiment

For the purpose, technical scheme and the advantage that make the embodiment of the invention clearer; To combine the accompanying drawing in the embodiment of the invention below; Technical scheme in the embodiment of the invention is carried out clear, intactly description; Obviously, described embodiment is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, the every other embodiment that those of ordinary skills are obtained under the prerequisite of not making creative work belongs to the scope that the present invention protects.

It will be appreciated by those skilled in the art that accompanying drawing is the sketch map of a preferred embodiment, module in the accompanying drawing or flow process might not be that embodiment of the present invention is necessary.

Combine terminal and/or base station to describe various aspects among this paper.

The terminal refers to the equipment that voice and/or data connectivity are provided to the user, comprises wireless terminal or catv terminal.Wireless terminal can be other treatment facilities that have the portable equipment of wireless connections function or be connected to radio modem; The portable terminal that communicates through wireless access network (Radio Access Network, be called for short RAN) and one or more core net.For example, wireless terminal can be mobile phone (or being called " honeycomb " phone) and the computer with portable terminal.And for example, wireless terminal also can be portable, pocket, hand-hold type, built-in computer or vehicle-mounted mobile device.For another example; Wireless terminal can also be PCS (Personal Communication Service; Abbreviation PCS) phone, cordless telephone, Session initiation Protocol (Session Initiated Protocol; Being called for short SIP) phone, WLL (Wireless Local Loop is called for short WLL) stands, personal digital assistant equipment such as (Personal Digital Assistant, abbreviation PDA).For another example; Wireless terminal also can be called system, subscriber unit (Subscriber Unit), subscriber station (Subscriber Station); Mobile radio station (Mobile Station), travelling carriage (Mobile), distant station (Remote Station), access point (Access Point), remote terminal (Remote Terminal), access terminal (Access Terminal), user terminal (User Terminal), user agent (User Agent), subscriber equipment (User Device) or subscriber's installation (User Equipment is called for short UE).

The base station, refer to finger network in the equipment through one or more sub-districts and wireless terminal communications on the interface aloft.The base station can be used for air frame of receiving and Internet protocol (Internel Protocol is called for short IP) are divided into groups to change each other, and as the router between the remainder of wireless terminal and Access Network, wherein the remainder of Access Network can comprise IP network.The base station is the attribute management of tunable air interface also.For example; The base station can be base station (the Base Transceiver Station among GSM or the CDMA; Be called for short BTS), also can be the base station (NodeB) among the WCDMA, can also be evolved base station (the evolutional Node B among the LTE; Be called for short NodeB or eNB or e-NodeB), the present invention does not do qualification to this.

In addition, among this paper term " system " and " network " in this article often by interchangeable use.Term among this paper " and/or ", only be a kind of incidence relation of describing affiliated partner, can there be three kinds of relations in expression, for example, and A and/or B, can represent: individualism A exists A and B, these three kinds of situation of individualism B.In addition, character "/" among this paper, generally represent forward-backward correlation to as if a kind of " or " relation.

Different embodiments of the invention, the X2 link switchover refers to the mobile management that does not relate to the EPC reorientation.For example, when UE moves in a MME group or switches in when carrying out in the same MME, handoff procedure does not relate to MME and SGW, by source base station directly and target BS carry out carrying out the X2 link switchover alternately through X2 interface.The S1 link switchover refers to the mobile management that relates to the EPC reorientation.When UE moves, or do not have X2 interface between source base station and target BS in two MME groups, or target BS with serve source base station and MME that UE is resident between when not having the S1 interface, need execution MME reorientation, carry out the S1 link switchover.

Wherein, the handoff procedure of X2 link comprises:

201:UE is to the source base station reporting measurement reports.

202: source base station sends X2 link switchover request message to target BS.

Comprise in the above-mentioned X2 link switchover request message that target BS is switch to prepare the necessary information of resource, like the signaling context reference information of UE in source base station, the S1 signaling context reference information of UE, the sign of Target cell etc.

203: target BS sends X2 link switchover request acknowledge message to source base station.

204: source base station is realized the synchronous of source base station and target BS to the target BS state information that transmits Sequence Number.

205: source base station sends Radio Resource control (Radio Resource Control is called for short RRC) to UE and connects reconfiguration message.

206:UE sends the RRC connection to target BS and reshuffles completion message.

207: target BS is to MME transmit path handoff request message (Path Switch Request).

Carry the indication of target BS in the handoff request of above-mentioned path to MME acquisition request UE user profile.

208:MME is to target BS transmit path switch acknowledgment message (Path Switch Acknowledge).

The user profile of carrying UE in the switch acknowledgment message of above-mentioned path.

209: target BS sends to source base station and discharges the UE context message.

In normal X2 link switchover process; MME carries UE in the path switch acknowledgment message that target BS sends user profile, subsequently, target BS sends to source base station and discharges the UE context message; The X2 link switchover of notification source base station is accomplished smoothly, can discharge the resource that originally took.

But, when target BS and serve source base station and MME that UE is resident between the S1 link unusual when unavailable, MME just can't obtain the user profile of above-mentioned UE.Though target BS can through in the MME of target side group, search out and target BS between the S1 link be MME1 good for use, and send to MME1 to path handoff request message.But among the non-resident MME1, so there is not the user profile of UE among the MME1, MME1 does not handle above-mentioned path handoff request message because UE resides among the MME, causes target BS to wait for that the path switch acknowledgment message is overtime, X2 link switchover failure.

Different embodiments of the invention; Can according to target BS and serve source base station and MME that UE is resident between the S1 link-state information; Indicate said target BS and serve said source base station and MME that said UE is resident between the S1 link whether normal; Carry out S1 link switchover or X2 link switchover with judgement source base station and target BS, successfully carry out the switching of source base station, realize that UE switches to the sub-district under the target BS from the sub-district under the source base station to target BS.

Below, in conjunction with accompanying drawing each specific embodiment is elaborated.

One embodiment of the invention provides the changing method between a kind of base station, and is as shown in Figure 2, comprising:

301: source base station sends handoff request message to target BS, is used for providing the subscriber equipment User Equipment (UE) of service to switch to the sub-district under the said target BS said source base station.

302: said source base station according to said target BS, and serve the S1 link-state information between the resident mobile management entity Mobile Management Entity (MME) of said source base station and said UE, confirm to carry out X2 link switchover or S1 link switchover.

In 301; The MME group that confirms to serve said source base station when said source base station and the MME group that serves said target BS have identical MME group identification (being called for short MME Group ID), and said source base station and said target BS between the X2 link just often, said source base station is to said target BS transmission X2 link switchover request message.At this moment; Source base station default sources base station and target BS provide service by same MME, and the X2 link can use, so; Switching between source base station and target BS need not the S1 link through MME, can directly accomplish change action through the X2 link between source base station and target BS.

In the present embodiment, can MME of unique identification through two identifiers, above-mentioned identifier is respectively MME Group ID and MME key (being called for short MME Code).Source base station can be through self obtaining the MME Group ID that the MME group of service is provided to it.For example, when source base station and the MME group that serves source base station set up the S1 link and be connected, source base station can obtain the MME Group ID of the MME group that serves source base station.And, provide each MME in the MME group of service to have identical MME Group ID to source base station, and different MME Code.Equally, target BS also can be through self obtaining the MME Group ID that the MME group of service is provided to it.And, provide each MME in the MME group of service to have identical MME Group ID to target BS, and different MME Code.

In the present embodiment, source base station can learn whether the X2 link between source base station and target BS is normal through dominant mode or stealthy mode.For example, dominant mode is that source base station can obtain the state of X2 link through the status indicator of source base station side.Above-mentioned status indicator is represented three kinds of states of X2 link respectively, comprising: break off, busy, and normal.For example, when status indicator with the status indication of X2 link when breaking off, the physical layer of the X2 link between expression source base station and target BS does not also configure, the X2 link is unavailable.And for example, when status indicator when being busy with the status indication of X2 link, the physical layer of the X2 link between expression source base station and target BS is connected, but can't transmit data via the X2 link, and the X2 link is unavailable.For another example, when status indicator with the status indication of X2 link for just often, the physical layer of the X2 link between expression source base station and target BS is connected, and can transmit data via the X2 link, the X2 link is good for use.And for example, stealthy mode is that (opposite end of source base station is a target BS, and same, the opposite end of target BS is a source base station to the opposite end for source base station or target BS.) transmit data, if the opposite end receives above-mentioned data, show that then the X2 link between source base station and target BS is good for use.Those skilled in the art will appreciate that through additive method and can learn also whether the X2 link between source base station and target BS is normal, repeats no more at this.

In the present embodiment, when triggering the A3 incident, source base station sends handoff request message to target BS.Above-mentioned A3 incident refers to service quality when the adjacent area than the high threshold value of Serving cell.For example, the service quality of the sub-district under the target BS is during than the high threshold value of the service quality of the sub-district under the current source base station that adheres to of UE, and source base station sends handoff request message to target BS, is used for UE is switched to the sub-district under the target BS.The definition that those skilled in the art will appreciate that above-mentioned threshold value can be for a concrete numerical value, also can be a number range, and the present invention does not do qualification to this.

In 302, serve the resident MME of source base station and subscriber equipment (User Equipment is called for short UE) and remain with the user profile of UE.For example, the user profile of above-mentioned UE can be the security context relevant with UE, roaming restriction, UE ability information etc.

In the present embodiment, the target BS that sends of source base station receiving target base station and serve source base station and MME that UE is resident between the S1 link-state information.When said target BS and serve said source base station and MME that said UE is resident between the S1 link-state information indicate said target BS and serve said source base station and MME that said UE is resident between S1 link when unusual; Source base station stops the X2 link switchover with said target BS, then carries out the S1 link switchover.When said target BS and serve said source base station and MME that said UE is resident between the S1 link-state information indicate said target BS and serve said source base station and MME that said UE is resident between the S1 link just often, said source base station and said target BS normally carry out the X2 link switchover.Perhaps; When source base station do not receive the target BS that target BS sends and serve source base station and MME that UE is resident between the S1 link-state information; And target BS sends switch acknowledgment message to source base station; Source base station give tacit consent to said target BS according to switch acknowledgment message and serve said source base station and MME that said UE is resident between the S1 link normal, source base station and target BS normally carry out the X2 link switchover.

In the present embodiment, the said target BS of above-mentioned indication and serve said source base station and MME that said UE is resident between the unusual S1 link-state information of S1 link can be carried at target BS and prepare in the failed message (HANDOVER PREPARATION FAILURE) to the switching that source base station sends.For example; Increase a cause value in transport network layer cause value (the Transport Network Layer cause) cell in switch preparing failed message, above-mentioned cause value represent target BS and serve said source base station and MME that said UE is resident between the S1 link cannot use unusually.After source base station receives above-mentioned cause value, can adjudicate the X2 link switchover that to carry out between source base station and target BS, need to stop the X2 link switchover, then carry out the S1 link switchover.

So; Present embodiment can according to target BS to target BS that source base station sends and serve source base station and MME that UE is resident between the S1 link-state information; Indicate said target BS and serve said source base station and MME that said UE is resident between the S1 link whether normal; Carry out S1 link switchover or X2 link switchover with judgement source base station and target BS, successfully carry out the switching of source base station, realize that UE switches to the sub-district under the target BS from the sub-district under the source base station to target BS.

Another embodiment of the present invention provides the changing method between a kind of base station, and is as shown in Figure 3, comprising:

401: source base station obtains the MME key MME Code that serves the resident MME of said source base station and said UE.

402: said source base station receives the MME Code set of the MME group that serves said target BS of said target BS transmission, and the MME and the S1 link between said target BS of the MME Code representative in the said MME Code set are normal.

403: source base station sends handoff request message to target BS, is used for providing the subscriber equipment User Equipment (UE) of service to switch to the sub-district under the said target BS said source base station.

404: said source base station according to said target BS, and serve the S1 link-state information between the resident mobile management entity Mobile Management Entity (MME) of said source base station and said UE, confirm to carry out X2 link switchover or S1 link switchover.

In 401, when setting up the S1 link between source base station and the MME group that serves source base station and be connected, source base station can obtain MME Group ID and the MME Code of the MME in the above-mentioned MME group.When UE prepared to insert source base station, source base station was selected resident EPC according to the user profile of UE, and according to the cell load balance, for UE selects the suitable MME in the MME group among the EPC, let UE be able to reside among the above-mentioned MME.At this moment, source base station can obtain the MME Code that serves the resident MME of source base station and UE.

In 402; When said source base station and said target BS connect; Said source base station receives the X2 link connection of said target BS transmission and sets up request message (X2 Setup Request) or X2 link connection establishment response message (X2 Setup Response), and request message is set up in said X2 link connection or said X2 link connection establishment response message can comprise that the MME Code of the MME group that serves said target BS gathers.It will be appreciated by those skilled in the art that; In the process that source base station and target BS connect; When source base station at first initiates to connect demand; Source base station sends the connection of X2 link to target BS and sets up request message, and target BS sends X2 link connection establishment response message to source base station, to confirm connection.When target BS at first initiated to connect demand, target BS sent the connection of X2 link to source base station and sets up request message, and source base station sends X2 link connection establishment response message to target BS, to confirm connection.

When reconfiguring between said source base station and said target BS when being connected; Said source base station receives configuration update message (Configuration Update) or the config update acknowledge message (Configuration Update Acknowledge) that said target BS sends, and said configuration update message or said config update acknowledge message can comprise the MME Code set of the MME group that serves said target BS.For example, after connecting between source base station and target BS, when the relevant information of source base station or target BS changes (when changing like the number of cells under source base station or the target BS), corresponding renewal is done in notice base station, opposite end.It will be appreciated by those skilled in the art that; In the process that source base station and target BS connect, when source base station at first initiated to reconfigure demand, source base station sent configuration update message to target BS; Target BS sends the config update acknowledge message to source base station, to confirm to reshuffle connection.When target BS at first initiated to reconfigure demand, target BS sent configuration update message to source base station, and source base station sends the config update acknowledge message to target BS, to confirm to reshuffle connection.

403 of present embodiment can repeat no more at this with reference to the associated description among the last embodiment 301.

In 404, source base station judges whether the MMECode serve the resident MME of said source base station and said UE is identical with MME Code in the said MME Code set, and the X2 that carries out between source base station and target BS according to judged result switches or the S1 switching.For example; When the MME Code that serves the resident MME of said source base station and said UE is identical with a MME Code in the said MME Code set; Source base station confirm target BS and serve said source base station and MME that said UE is resident between the S1 link good for use; Need not to carry out the mobile management that EPC is redirected, source base station and said target BS carry out the X2 link switchover.And for example; When the said MME Code that serves the resident MME of said source base station and said UE and any MME Code in the said MME Code set are all inequality; Source base station confirm target BS and serve said source base station and MME that said UE is resident between the S1 link unavailable unusually; Need carry out the mobile management that EPC is redirected, said source base station and said target BS carry out the S1 link switchover.

So; Present embodiment can be according to target BS to target BS that source base station sends and serve the S1 link-state information between the MME of target BS; Indicate said target BS and serve said source base station and MME that said UE is resident between the S1 link whether normal; Carry out S1 link switchover or X2 link switchover with judgement source base station and target BS, successfully carry out the switching of source base station, realize that UE switches to the sub-district under the target BS from the sub-district under the source base station to target BS.

Another embodiment of the present invention provides the changing method between a kind of base station, and is as shown in Figure 4, comprising:

A MME key (the being called for short MME Code) set of the MME group that serves said first base station is sent to second base station in 501: the first base stations, and the MME and the S1 link between said first base station of the MME Code representative in the said MME Code set are normal.

502: said first base station receives the 2nd MME Code set of the MME group that serves said second base station that sends said second base station, and the MME and the S1 link between said second base station of the MME Code representative in said the 2nd MME Code set are normal.

503: when first base station/second base station when handoff request message is sent in second base station/first base station; Said first base station/second base station according to said second base station/first base station, and serve the S1 link-state information between the resident mobile management entity Mobile Management Entity (MME) of said first base station/second base station and said UE, confirm to carry out X2 link switchover or S1 link switchover.

In 501,502, first base station obtain MME Code set, and second base station method of obtaining the 2nd MME Code set can repeat no more at this with reference to 401 associated description among the last embodiment.

503; When first base station/second base station has a MME Code and the 2nd MMECode respectively; No matter which base station UE will reside in, and the resident base station of above-mentioned UE all can obtain the S1 link-state information between the resident MME of base station, opposite end and UE when initiating handoff request.

For example, when UE resided in first base station, first base station can obtain the MME Code of the resident MME of UE through MME Code set.Simultaneously, first base station receives the 2nd MME Code set of sending second base station.When first base station when handoff request message is sent in second base station, whether the MME Code of the resident MME of said UE is compared in first base station identical with MME Code during said the 2nd MME Code gathers.Identical, then said first base station learn said second base station and serve said first base station and MME that said UE is resident between the S1 link normal, carry out the X2 link switchover.Difference, then said first base station learn said second base station and serve said first base station and MME that said UE is resident between the S1 link unusual, carry out the S1 link switchover.

And for example, when UE resided in second base station, second base station can obtain the MME Code of the resident MME of UE through the 2nd MME Code set.Simultaneously, second base station receives the MME Code that send first base station.When second base station when handoff request message is sent in first base station, whether the MME Code of the resident MME of said UE is compared in second base station identical with MME Code during a said MME Code gathers.Identical, then said second base station learn said first base station and serve said second base station and MME that said UE is resident between the S1 link normal, carry out the X2 link switchover.Difference, then said second base station learn said first base station and serve said second base station and MME that said UE is resident between the S1 link unusual, carry out the S1 link switchover.

Those skilled in the art will appreciate that in the present embodiment first base station/second base station of initiating handoff request message is a source base station, first base station/second base station that receives handoff request is a target BS.

Another embodiment of the present invention provides the changing method between a kind of base station, and is as shown in Figure 5, comprising:

601: the handoff request message that send target BS reception sources base station is used for providing the subscriber equipment User Equipment (UE) of service to switch to the sub-district under the said target BS said source base station.

602: said target BS sends said target BS, and serves the S1 link-state information between the resident mobile management entity Mobile Management Entity (MME) of said source base station and said UE to said source base station, is used for said source base station and confirms to carry out X2 link switchover or S1 link switchover.

601 and 602 of present embodiment can repeat no more at this with reference to the associated description in the changing method between above-mentioned other embodiment base stations.

The all or part of flow process that it will be appreciated by those skilled in the art that realization said method embodiment can be accomplished through the relevant hardware of program command; Aforesaid program can be stored in the computer read/write memory medium; Said procedure the flow process that comprises said method embodiment when carrying out; And aforesaid storage medium comprises: various media that can be program code stored such as ROM, RAM, magnetic disc or CD.

Another embodiment of the present invention provides a kind of base station, and its primary structure can comprise with reference to shown in Figure 6:

Transmitting element 701 is used for sending handoff request message to target BS, so that provide the subscriber equipment User Equipment (UE) of service to switch in the sub-district under the said target BS said base station;

Processing unit 702 is used for according to said target BS, and serves the S1 link-state information between the resident mobile management entity Mobile Management Entity (MME) of said base station and said UE, confirms to carry out X2 link switchover or S1 link switchover.

Wherein, Said base station also comprises confirmation unit; The MME group that is used to confirm to serve said base station and the MME group that serves said target BS have identical MME group identification MMEGroup ID, and said base station and said target BS between the X2 link normal so that said base station and said target BS carry out the X2 link switchover.

Wherein, Said base station also comprises first receiving element; Be used to receive the said target BS that said target BS sends and serve said base station and MME that said UE is resident between the S1 link-state information; With the said target BS of box lunch and serve said base station and MME that said UE is resident between the S1 link-state information indicate said target BS and serve said base station and MME that said UE is resident between S1 link when unusual; X2 link switchover between termination of said base station and said target BS, then carry out the S1 link switchover.

Wherein, said first receiving element also is used to receive the switching that said target BS sends and prepares failed message, said switching prepare failed message comprise said target BS and serve said base station and MME that said UE is resident between the S1 link-state information.

Wherein, said base station also comprises acquiring unit, is used to obtain the MME key MME Code that serves the resident MME of said base station and said UE; And second receiving element, being used to receive the MME Code set of the MME group that serves said target BS that said target BS sends, the MME and the S1 link between said target BS of the MME Code representative in the said MME Code set are normal.

Wherein, Said base station also comprises judging unit; Be used for a MME Code when the said MME Code that serves the resident MME of said base station and said UE and said MME Code set when identical; Judge said target BS and serve said base station and MME that said UE is resident between the S1 link normal, said base station and said target BS carry out the X2 link switchover; And when the said MME Code that serves the resident MME of said base station and said UE and any MME Code in the said MME Code set are all inequality; Judge said target BS and serve said base station and MME that said UE is resident between the S1 link unusual, said base station and said target BS carry out the S1 link switchover.

Wherein, Said second receiving element; Also be used for when said base station and said target BS connect; Request message or connection establishment response message are set up in the connection that receives said target BS transmission, and request message is set up in said connection or said connection establishment response message comprises that the MME Code of the MME group that serves said target BS gathers.

Wherein, Said second receiving element; Also be used for when reconfiguring between said base station and said target BS when being connected; Said base station receives configuration update message or the config update acknowledge message that said target BS sends, and said configuration update message or said config update acknowledge message comprise the MME Code set of the MME group that serves said target BS.

The base station of present embodiment is used for realizing the performed action of source base station of the changing method between above-mentioned base station.For example, above-mentioned transmitting element 701 is used for carrying out the action of the changing method 301 between an embodiment base station, and above-mentioned processing unit 702 is used for carrying out the action of the changing method 302 between an embodiment base station.

Another embodiment of the present invention provides a kind of base station, and its primary structure can comprise with reference to shown in Figure 7:

Receiving element 801 is used for the handoff request message that send the reception sources base station, so that provide the subscriber equipment User Equipment (UE) of service to switch in the sub-district under the said base station said source base station;

Transmitting element 802; Be used for sending said base station, and serving the S1 link-state information between the resident mobile management entity Mobile Management Entity (MME) of said source base station and said UE, so that said source base station confirms to carry out X2 link switchover or S1 link switchover to said source base station.

Wherein, Said base station also comprises indicating member; Be used for via said base station and serve said source base station and MME that said UE is resident between the S1 link-state information to said source base station indicate said base station, and the S1 link of serving between the resident MME of said source base station and said UE unusual; Be used for the X2 link switchover between said source base station termination and said base station, then carry out the S1 link switchover.

Wherein, said transmitting element 802 also is used for sending to switch to said source base station preparing failed message, said switching prepare failed message comprise said base station and serve said source base station and MME that said UE is resident between the S1 link-state information.

Wherein, said transmitting element 802 also is used for sending to said source base station the MME Code set of the MME group that serves said base station, and the MME and the S1 link between said base station of the MME Code representative in the said MME Code set are normal.

The base station of present embodiment is used for realizing the performed action of target BS of the changing method between other embodiment base stations.For example, above-mentioned receiving element 801 can be used for carrying out 601 the action of an embodiment, and above-mentioned transmitting element 802 can be used for carrying out 602 the action of an embodiment.

Another embodiment of the present invention provides a kind of communication system, and its primary structure comprises:

One source base station, an and target BS;

One embodiment of the invention provides the changing method between a kind of base station, comprising:

31: the X2 link switchover request message that send target BS reception sources base station is used for providing the subscriber equipment User Equipment (UE) of service to switch to the sub-district under the said target BS said source base station.

32: said target BS via first mobile management entity Mobility Management Entity (MME) Connection Service of serving said target BS in said source base station and the 2nd resident MME of said UE.

33: said target BS and said source base station carry out the X2 link switchover.

In 31; The MME group that confirms to serve said source base station when said source base station and the MME group that serves said target BS have identical MME group identification (being called for short MME Group ID), and said source base station and said target BS between the X2 link just often, said source base station is to said target BS transmission X2 link switchover request message.At this moment; Source base station default sources base station and target BS provide service by same MME, and the X2 link can use, so; Switching between source base station and target BS need not the S1 link through MME, can directly accomplish change action through the X2 link between source base station and target BS.

In 32, when said target BS and serve said source base station and the 2nd MME that said UE is resident between S1 Link State when unusual, said target BS connects said the 2nd MME via a MME.

In the present embodiment, because UE resides among the 2nd MME, so target BS need obtain the user profile of UE from the 2nd MME after, could accomplish normal X2 link switchover between source base station and target BS.And when the S1 Link State between target BS and the 2nd MME is unusual, can't carry out normal data communication between target BS and the 2nd MME, then target BS can't directly obtain the user profile of UE from the 2nd MME.Connect between the one MME and the 2nd MME, refer between a MME and the 2nd MME and can set up being connected of S10 link through the S10 interface.Through normal S1 Link State between a target BS and a MME, and normal S10 Link State between a MME and the 2nd MME, said target BS can obtain the user profile of the said UE among the 2nd MME indirectly through a MME.

In the present embodiment, the user profile of above-mentioned UE can be the security context relevant with UE, roaming restriction, UE ability information etc.

In 33; The one MME carries UE in the path switch acknowledgment message that target BS sends user profile, subsequently, target BS sends to source base station and discharges the UE context message; The X2 link switchover of notification source base station is accomplished smoothly, can discharge the resource that originally took.

So; Present embodiment can target BS and serve source base station and MME that UE is resident between S1 Link State when unusual; Obtain the user profile of UE indirectly, successfully carry out source base station, realize that UE switches to the sub-district under the target BS from the sub-district under the source base station to the X2 of target BS link switchover.

Another embodiment of the present invention provides the changing method between a kind of base station, comprising:

41: source base station sends X2 link switchover request message to target BS, is used for providing the subscriber equipment User Equipment (UE) of service to switch to the sub-district under the said target BS said source base station.

42: when serving the 2nd resident MME of source base station and UE and the S1 link between said target BS when unusual, said target BS sends the indication of the user profile of obtaining said UE to a MME who serves said target BS.

43: connect between a said MME and said the 2nd MME.

44: the indication that a said MME will obtain the user profile of said UE is sent to said the 2nd MME.

45: said the 2nd MME sends the user profile of said UE to a said MME.

46: said target BS receives the user profile of the said UE of said MME forwarding.

47: said target BS sends to said source base station and discharges the UE context message, is used to accomplish the X2 link switchover between source base station and target BS.

41 of present embodiment can repeat no more at this with reference to the associated description of a last embodiment 31.

In 42 and 43, when setting up the S1 link between target BS and the MME group that serves target BS and be connected, target BS can obtain the MME Group ID of the MME in the above-mentioned MME group.Equally, when setting up the S1 link between source base station and the MME group that serves source base station and be connected, source base station also can obtain the MME Group ID of the MME in the above-mentioned MME group.When UE prepared to insert source base station, source base station was selected resident EPC according to the user profile of UE, and according to the cell load balance, for UE selects the suitable MME in the MME group among the EPC, let UE be able to reside among the above-mentioned MME.At this moment, source base station can obtain the MME Group ID that serves the resident MME of source base station and UE.

In the present embodiment, when a MME and the 2nd MME were positioned at same MME group, a MME had identical MME Group ID with the 2nd MME.When target BS finds the 2nd MME through identical MME Group ID but can't carry out data communication with it in MME group; Target BS can find a MME who is fit to carry out with it data communication through identical MME Group ID equally in above-mentioned MME group; And, obtain the user profile of the UE among the MME indirectly through normal S10 link between a MME and the 2nd MME.

In the present embodiment, said target BS can transmit path handoff request message (Path Switch Request) to a said MME, said path handoff request message contains said indication of obtaining the user profile of said UE.

In 44, a MME is to the 2nd MME transmit path handoff request message, and said path handoff request message carries said indication of obtaining the user profile of said UE.

In 45,,, and the user profile of above-mentioned UE is sent to a MME through the S10 link so the 2nd MME can be through self obtaining the user profile of UE because UE itself just resides among the 2nd MME.

In the present embodiment, said the 2nd MME is to a said MME transmit path switch acknowledgment message, and said path switch acknowledgment message comprises the user profile of said UE.

In 46, target BS receives the path switch acknowledgment message that a MME transmits, and said path switch acknowledgment message comprises the user profile of said UE.

51: serve the 2nd resident MME Connection Service of source base station and UE in a MME of target BS.

52: said the 2nd MME connects said target BS via a said MME, in order to when said source base station when said target BS sends X2 link switchover request message, said target BS and said source base station carry out the X2 link switchover.

51 and 52 of present embodiment can repeat no more at this with reference to the associated description in the changing method between above-mentioned other embodiment base stations.

Another embodiment of the present invention provides a kind of base station, comprising:

Receiving element 61 is used for the X2 link switchover request message that send the reception sources base station, so that provide the subscriber equipment User Equipment (UE) of service to switch in the sub-district under the said base station said source base station;

Linkage unit 62 is used for via a MME Connection Service of serving said base station in said source base station and the 2nd resident MME of said UE; And

Switch unit is used for carrying out the X2 link switchover with said source base station.

The base station of present embodiment is used for realizing the performed action of target BS of the changing method between above-mentioned base station.For example, above-mentioned receiving element 61 is used for carrying out the action of the changing method 31 between an embodiment base station, and above-mentioned linkage unit 62 is used for carrying out the action of the changing method 32 between an embodiment base station.

Another embodiment of the present invention provides a kind of mobile management entity MME, comprising:

Linkage unit 71; Be used for Connection Service in a MME of target BS and serve source base station and MME that said UE is resident; So that said MME connects said target BS via a said MME; In order to when said source base station when said target BS sends X2 link switchover request message, said target BS and said source base station carry out the X2 link switchover.

The mobile management entity of present embodiment, be used for realizing between the foregoing description base station changing method serve source base station and the resident performed action of the 2nd MME of UE.For example, above-mentioned linkage unit 71 can be used for carrying out 51 the action of an embodiment.

Another embodiment of the present invention provides a kind of Element management system, comprising:

One serve target BS a MME, and one serve source base station and the 2nd resident MME of said UE;

A said MME is used to connect said the 2nd MME;

Said the 2nd MME; Be used to connect a said MME; So that said the 2nd MME connects said target BS via a said MME, in order to when said source base station when said target BS sends X2 link switchover request message, said target BS and said source base station carry out the X2 link switchover.

In several embodiment that the application provided, should be understood that, the system that is disclosed, apparatus and method can realize through other mode.For example, device embodiment described above only is schematically, for example; The division of said unit; Only be that a kind of logic function is divided, during actual the realization other dividing mode can be arranged, for example a plurality of unit or assembly can combine or can be integrated into another system; Or some characteristics can ignore, or do not carry out.Another point, the coupling each other that shows or discuss or directly coupling or communication to connect can be through some interfaces, the INDIRECT COUPLING of device or unit or communication connect, and can be electrically, machinery or other form.

Said unit as separating component explanation can or can not be physically to separate also, and the parts that show as the unit can be or can not be physical locations also, promptly can be positioned at a place, perhaps also can be distributed on a plurality of NEs.Can realize the purpose of present embodiment scheme according to the needs selection some or all of unit wherein of reality.

In addition, each functional unit in each embodiment of the present invention can be integrated in the processing unit, also can be that the independent physics in each unit exists, and also can be integrated in the unit two or more unit.Above-mentioned integrated unit both can adopt the form of hardware to realize, also can adopt the form of SFU software functional unit to realize.

If said integrated unit is realized with the form of SFU software functional unit and during as independently production marketing or use, can be stored in the computer read/write memory medium.Based on such understanding; Part or all or part of of this technical scheme that technical scheme of the present invention contributes to prior art in essence in other words can come out with the embodied of software product; This computer software product is stored in the storage medium; Comprise some instructions with so that computer equipment (can be personal computer, server, the perhaps network equipment etc.) carry out all or part of step of the said method of each embodiment of the present invention.And aforesaid storage medium comprises: various media that can be program code stored such as USB flash disk, portable hard drive, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disc or CD.

It will be appreciated by those skilled in the art that the module in the device among the embodiment can be distributed in the device of embodiment according to the embodiment description, also can carry out respective change and be arranged in the one or more devices that are different from present embodiment.The module of the foregoing description can be merged into a module, also can further split into a plurality of submodules.

It will be understood by those skilled in the art that the function that is divided into of apparatus module is divided in the embodiment of the invention, actual concrete structure can be the fractionation or the merging of above-mentioned functions module.

The sequence number of above embodiment is not represented the quality of embodiment just to description.

The scheme of the content record of claim also is the protection range of the embodiment of the invention.

What should explain at last is: above embodiment is only in order to explaining technical scheme of the present invention, but not to its restriction; Although with reference to previous embodiment the present invention has been carried out detailed explanation, those of ordinary skill in the art is to be understood that: it still can be made amendment to the technical scheme that aforementioned each embodiment put down in writing, and perhaps part technical characterictic wherein is equal to replacement; And these are revised or replacement, do not make the spirit and the scope of the essence disengaging various embodiments of the present invention technical scheme of relevant art scheme.

Claims

1. the changing method between the base station is characterized in that, comprising:

2. the method for claim 1 is characterized in that, said source base station sends handoff request message to target BS, is used for providing the subscriber equipment User Equipment (UE) of service to switch to the sub-district under the said target BS said source base station, comprising:

The MME group that said source base station confirms to serve said source base station and the MME group that serves said target BS have identical MME group identification MME Group ID, and said source base station and said target BS between the X2 link normal;

Said source base station sends X2 link switchover request message to said target BS, is used for said source base station and said target BS carries out the X2 link switchover.

3. method as claimed in claim 2; It is characterized in that; Said source base station according to said target BS and serve said source base station and mobile management entity Mobile Management Entity (MME) that said UE is resident between the S1 link-state information; Confirm to carry out X2 link switchover or S1 link switchover, comprising:

Said source base station receive the said target BS that said target BS sends and serve said source base station and MME that said UE is resident between the S1 link-state information;

When said target BS and serve said source base station and MME that said UE is resident between the S1 link-state information indicate said target BS and serve said source base station and MME that said UE is resident between S1 link when unusual; Said source base station stops the X2 link switchover with said target BS, then carries out the S1 link switchover.

4. method as claimed in claim 3 is characterized in that, said source base station receive said target BS send said target BS and serve said source base station and MME that said UE is resident between the S1 link-state information, comprising:

Said source base station receives the switching that said target BS sends and prepares failed message, said switching prepare failed message comprise said target BS and serve said source base station and MME that said UE is resident between the S1 link-state information.

5. the method for claim 1 is characterized in that, said source base station sends handoff request message to target BS, before the subscriber equipment User Equipment (UE) that is used for that said source base station is provided switches to the sub-district under the said target BS, comprising:

Said source base station obtains the MME key MME Code that serves the resident MME of said source base station and said UE;

Said source base station receives the MME Code set of the MME group that serves said target BS of said target BS transmission, and the MME and the S1 link between said target BS of the MME Code representative in the said MME Code set are normal.

6. method as claimed in claim 5; It is characterized in that; Said source base station according to said target BS and serve said source base station and mobile management entity Mobile Management Entity (MME) that said UE is resident between the S1 link-state information; Confirm to carry out X2 link switchover or S1 link switchover, comprising:

As the said MME Code of the resident MME of said source base station and said UE that serves when identical with a MME Code in the said MME Code set; Said source base station learn said target BS and serve said source base station and MME that said UE is resident between the S1 link normal, said source base station and said target BS carry out the X2 link switchover;

When the said MME Code that serves the resident MME of said source base station and said UE and any MME Code in the said MME Code set are all inequality; Said source base station learn said target BS and serve said source base station and MME that said UE is resident between the S1 link unusual, said source base station and said target BS carry out the S1 link switchover.

7. like claim 5 or 6 described methods; It is characterized in that; Said source base station receives the MME Code set of the MME group that serves said target BS of said target BS transmission; The MME and the S1 link between said target BS of the MME Code representative in the said MME Code set are normal, comprising:

When said source base station and said target BS connect; Said source base station receives the X2 link connection of said target BS transmission and sets up request message or X2 link connection establishment response message, and request message is set up in said X2 link connection or said X2 link connection establishment response message comprises that the MME Code of the MME group that serves said target BS gathers.

8. like claim 5 or 6 described methods; It is characterized in that; Said source base station receives the MME Code set of the MME group that serves said target BS of said target BS transmission; The MME and the S1 link between said target BS of the MME Code representative in the said MME Code set are normal, comprising:

When reconfiguring between said source base station and said target BS when being connected; Said source base station receives configuration update message or the config update acknowledge message that said target BS sends, and said configuration update message or said config update acknowledge message comprise the MME Code set of the MME group that serves said target BS.

9. the changing method between a base station is characterized in that, comprising:

10. method as claimed in claim 9 is characterized in that, also comprises:

Said target BS via said target BS and serve said source base station and MME that said UE is resident between the S1 link-state information to said source base station indicate said target BS and serve said source base station and MME that said UE is resident between the S1 link unusual; Be used for the X2 link switchover of said source base station termination and said target BS, then carry out the S1 link switchover.

11. like claim 9 or 10 described methods; It is characterized in that; Said target BS sends said target BS, and serves the S1 link-state information between the resident mobile management entity Mobile Management Entity (MME) of said source base station and said UE to said source base station, comprising:

Said target BS sends to switch to said source base station prepares failed message, said switching prepare failed message comprise said target BS and serve said source base station and MME that said UE is resident between the S1 link-state information.

12. method as claimed in claim 9; It is characterized in that; Said target BS sends said target BS, and serves the S1 link-state information between the resident mobile management entity Mobile Management Entity (MME) of said source base station and said UE to said source base station; Be used for said source base station and confirm to carry out X2 link switchover or S1 link switchover, comprising:

Said target BS is gathered to the MME Code that said source base station sends the MME group that serves said target BS, and the MME and the S1 link between said target BS of the MME Code representative in the said MME Code set are normal.

13. method as claimed in claim 12 is characterized in that, also comprises:

As the said MME Code of the resident MME of said source base station and said UE that serves when identical with a MME Code in the said MME Code set; Said target BS and serve said source base station and MME that said UE is resident between the S1 link normal, said target BS and said source base station carry out the X2 link switchover;

When the said MME Code that serves the resident MME of said source base station and said UE and any MME Code in the said MME Code set are all inequality; Said target BS and serve said source base station and MME that said UE is resident between the S1 link unusual, said target BS and said source base station carry out the S1 link switchover.

14. like claim 12 or 13 described methods; It is characterized in that; Said target BS sends the MME Code set of the MME group that serves said target BS to said source base station; The MME and the S1 link between said target BS of the MME Code representative in the said MME Code set are normal, comprising:

When said source base station and said target BS connect,

Said target BS sends the connection of X2 link to said source base station and sets up request message or X2 link connection establishment response message, and request message is set up in said X2 link connection or said X2 link connection establishment response message comprises that the MME Code of the MME group that serves said target BS gathers.

15. like claim 12 or 13 described methods; It is characterized in that; Said target BS sends the MME Code set of the MME group that serves said target BS to said source base station; The MME and the S1 link between said target BS of the MME Code representative in the said MME Code set are normal, comprising:

When need reconfiguring between said source base station and said target BS when being connected,

Said target BS sends configuration update message or config update acknowledge message to said source base station,

Said configuration update message or said config update acknowledge message comprise the MME Code set of the MME group that serves said target BS.

16. a base station is characterized in that, comprising:

17. base station as claimed in claim 16 is characterized in that, also comprises:

Confirmation unit; The MME group that is used to confirm to serve said base station and the MME group that serves said target BS have identical MME group identification MME Group ID, and said base station and said target BS between the X2 link normal so that said base station and said target BS carry out the X2 link switchover.

18. base station as claimed in claim 17 is characterized in that, also comprises:

First receiving element; Be used to receive the said target BS that said target BS sends and serve said base station and MME that said UE is resident between the S1 link-state information; With the said target BS of box lunch and serve said base station and MME that said UE is resident between the S1 link-state information indicate said target BS and serve said base station and MME that said UE is resident between S1 link when unusual; X2 link switchover between termination of said base station and said target BS, then carry out the S1 link switchover.

19. base station as claimed in claim 18 is characterized in that:

Said first receiving element also is used to receive the switching that said target BS sends and prepares failed message, said switching prepare failed message comprise said target BS and serve said base station and MME that said UE is resident between the S1 link-state information.

20. base station as claimed in claim 16 is characterized in that, also comprises:

Acquiring unit is used to obtain the MME key MME Code that serves the resident MME of said base station and said UE; And

Second receiving element is used to receive the MME Code set of the MME group that serves said target BS that said target BS sends, and the MME and the S1 link between said target BS of the MME Code representative in the said MME Code set are normal.

21. base station as claimed in claim 20 is characterized in that, also comprises:

Judging unit is used for:

As the said MME Code of the resident MME of said base station and said UE that serves when identical with a MME Code in the said MME Code set; Judge said target BS and serve said base station and MME that said UE is resident between the S1 link normal, said base station and said target BS carry out the X2 link switchover; And

When the said MME Code that serves the resident MME of said base station and said UE and any MME Code in the said MME Code set are all inequality; Judge said target BS and serve said base station and MME that said UE is resident between the S1 link unusual, said base station and said target BS carry out the S1 link switchover.

22., it is characterized in that like claim 20 or 21 described base stations:

Said second receiving element; Also be used for when said base station and said target BS connect; Request message or connection establishment response message are set up in the connection that receives said target BS transmission, and request message is set up in said connection or said connection establishment response message comprises that the MME Code of the MME group that serves said target BS gathers.

23., it is characterized in that like each described base station of claim 20-22:

Said second receiving element; Also be used for when reconfiguring between said base station and said target BS when being connected; Said base station receives configuration update message or the config update acknowledge message that said target BS sends, and said configuration update message or said config update acknowledge message comprise the MME Code set of the MME group that serves said target BS.

24. a base station is characterized in that, comprising:

25. base station as claimed in claim 24 is characterized in that, also comprises:

Indicating member; Be used for via said base station and serve said source base station and MME that said UE is resident between the S1 link-state information to said source base station indicate said base station, and the S1 link of serving between the resident MME of said source base station and said UE unusual; Be used for the X2 link switchover between said source base station termination and said base station, then carry out the S1 link switchover.

26. base station as claimed in claim 25 is characterized in that:

Said transmitting element also is used for sending to switch to said source base station preparing failed message, said switching prepare failed message comprise said base station and serve said source base station and MME that said UE is resident between the S1 link-state information.

27. base station as claimed in claim 24 is characterized in that:

Said transmitting element also is used for sending to said source base station the MME Code set of the MME group that serves said base station, and the MME and the S1 link between said base station of the MME Code representative in the said MME Code set are normal.

28. a communication system is characterized in that, comprising:

One source base station, an and target BS;

29. communication system as claimed in claim 28 is characterized in that:

Said source base station, the MME group that also is used to confirm to serve said source base station and the MME group that serves said target BS have identical MME group identification MME Group ID, and said base station and said target BS between the X2 link normal.

30. communication system as claimed in claim 29 is characterized in that:

Said source base station; Also be used to receive the said target BS that said target BS sends and serve said source base station and MME that said UE is resident between the S1 link-state information; With the said target BS of box lunch and serve said source base station and MME that said UE is resident between the S1 link-state information indicate said target BS and serve said source base station and MME that said UE is resident between S1 link when unusual; X2 link switchover between termination and said target BS, then carry out the S1 link switchover.

31. communication system as claimed in claim 28 is characterized in that:

Said source base station also is used to receive the MME Code set of the MME group that serves said target BS that said target BS sends, and the MME and the S1 link between said target BS of the MME Code representative in the said MME Code set are normal.

32. communication system as claimed in claim 31 is characterized in that:

Said source base station; Also be used for a MME Code when the said MME Code that serves the resident MME of said source base station and said UE and said MME Code set when identical; Judge said target BS and serve said source base station and MME that said UE is resident between the S1 link normal, carry out the X2 link switchover with said target BS; And

When the said MME Code that serves the resident MME of said source base station and said UE and any MME Code in the said MME Code set are all inequality; Judge said target BS and serve said source base station and MME that said UE is resident between the S1 link unusual, carry out the S1 link switchover with said target BS.

33., it is characterized in that like each described communication system of claim 28-30:

Said target BS; Also be used for via said target BS and serve said source base station and MME that said UE is resident between the S1 link-state information to said source base station indicate said target BS and serve said source base station and MME that said UE is resident between the S1 link unusual; Be used for said source base station and end at the X2 link switchover between said target BS, then carry out the S1 link switchover.