CN102215485B

CN102215485B - Method for guaranteeing safety of multi-carrier switching or reconstructing in multi-carrier communication system

Info

Publication number: CN102215485B
Application number: CN201010162560.9A
Authority: CN
Inventors: 黄亚达
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2010-04-04
Filing date: 2010-04-04
Publication date: 2015-07-22
Anticipated expiration: 2030-04-04
Also published as: CN102215485A

Abstract

The invention discloses a method for guaranteeing safety of multi-carrier switching or reconstructing in a multi-carrier communication system, and the method comprises the following steps: a terminal or a source base station or a switching target base station selects one from a plurality of target cells to serve as a switched main carrier cell or a switching target cell during a switching process, and the terminal uses a parameter of the switched main carrier cell or the switching target cell to compute a terminal safety key; the source base station or the switching target base station uses the parameter of the switched main carrier area or the switching target cell to compute the safety key of the switching target base station, wherein the safety key is corresponding to the terminal; during reconstruction, the terminal and a network side reconstructing target base station respectively compute an authentication code for intercepting the short message integrality; and the authentication code for intercepting the short message integrality at the terminal is in match with that at the reconstructing target base station, and the reconstructing target base station determines the context corresponding to the terminal so as to continue the reconstructing process. The method provided by the invention is simple in configuration and reliable, and can be used for effectively guaranteeing the safety in switching and reconstructing.

Description

Ensure in multi-carrier communications systems that multicarrier switches or rebuilds the method for fail safe

Technical field

The present invention relates to mobile communication technology field, particularly relate in multi-carrier communications systems and ensure that multicarrier switches or rebuilds the method for safety.

Background technology

As shown in Figure 1, Long Term Evolution (LTE, Long Term Evolution) network is by evolution Universal Terrestrial Radio Access Network (E-UTRAN, Evolved Universal Terrestrial Radio AccessNetwork) and evolution packet switching center (EPC, Evolved Packet Core) composition, network presents flattening.EUTRAN is connected with EPC by S1 interface.Wherein, EUTRAN is made up of multiple interconnective evolution base station (eNB, Evolved NodeB), is connected between each eNB by X2 interface; EPC is made up of Mobility Management Entity (MME, Mobility Management Entity) and service gateway entity (S-GW, Serving Gateway).

In LTE network system, due to subscriber equipment (UE, User Equipment) move at network's coverage area, the change of the Serving cell of UE may be caused, in order to keep the business continuance of UE, network assistance UE is needed to switch between each community, the current switching in LTE inside mainly can be divided into switching (intra-eNB) in base station eNB according to flow process, S1 switches and X2 switches, the initiator wherein switched is referred to as source, and the destination party of switching is referred to as target side.

Terminal UE is after access network, and base station can indicate UE to start safety (security), after safety (security) starts, just can proceed follow-up business and set up, the flow processs such as switching.Safety is used to ensure that UE connects the integrality of transmitting data and encryption, intercepts and captures or distort to prevent other people.In order to ensure UE in the handover, the fail safe of business after handover, after handoff procedure, UE can enable new key and carries out safeguard protection, and its key derivation structure as shown in Figure 2, is mainly reflected in the maintenance of access layer secret key KeNB Access Layer of eating dishes without rice or wine.

From UE, in each handoff procedure, UE can generate a safe key KeNB*, and it can adopt two kinds of derivation modes, that is:

(1) level derivation mode: KeNB* can by the physical-layer cell identifier of Target cell (PhysicalCell Identity, PCI), the downstream frequency (E-UTRA Absolute RadioFrequency Channel Number-Down Link, EARFCN-DL) of Target cell and the access layer secret key KeNB of use before switching derive from.Or,

(2) vertically derive from mode: KeNB* can by the PCI of Target cell, the EARFCN-DL of Target cell, and down hop key (NHNext Hop, NH) derives from, after deriving from, KeNB* uses as new KeNB.

UE derives from KeNB* by level derivation mode or vertical derivation mode, depend on down hop counting (the Next hop Chaining Counter in switching command, NCC), when NCC does not increase, UE usage level derives from mode and derives from KeNB*; When NCC increases, UE uses vertical derivation mode to derive from KeNB*.Derive from chain as shown in Figure 2, down hop NH and down hop counting NCC is paired relation, and according to down hop counting NCC, terminal UE can be understood and derive from KeNB* by level or vertical direction.

In base station side, as shown in Figure 3, the handoff procedure in LTE system in base station eNB is shown.Terminal UE is operated in base station eNB 1, UE and measures adjacent cell, after meeting measurement event, to base station eNB 1 reporting measurement reports.According to measurement report, base station eNB 1 judges that UE needs the community CELL2 be switched under base station eNB 1, control because CELL1 and CELL2 belongs to eNB1, base station eNB 1 sends RRC (wireless heterogeneous networks to terminal UE in CELL1, Radio ResourceControl) reconfiguration message, after terminal has eated dishes without rice or wine to reshuffle, in CELL2, send switch acknowledgment message to base station eNB 1, complete terminal UE from community CELL1 to the CELL2 handoff procedure a base station.Wherein have one group in eNB {, the aforementioned vertical derivation mode stated can not selected to carry out the derivation of KeNB*, and NCC corresponding for this NH is sent to UE by switching command when NH, NCC} couple by the down hop that uses and down hop counting; Otherwise untapped { when NH, NCC} couple, usage level derives from mode and carries out the derivation of KeNB*, and down hop corresponding for the down hop NH being used for deriving former KeNB counting NCC is sent to UE by switching command not having.After UE derives from according to level derivation mode or vertical derivation mode, derivative for UE safe key KeNB* uses as new KeNB by eNB.

In base station side, as shown in Figure 4, the switching flow of X2 mouth is shown.Terminal UE is operated in base station eNB 1, UE and measures adjacent cell, after meeting measurement event, to base station eNB 1 reporting measurement reports.According to measurement report, base station eNB 1 judges that UE needs the community CELL2 be switched under base station eNB 2, then send handover request message to eNB2.Base station eNB 2 returns switching request response to base station eNB 1, base station eNB 1 sends RRC reconfiguration message to terminal UE, terminal sends switch acknowledgment message to base station eNB 2, after base station eNB 2 receives switch acknowledgment message, to MME transmit path handover request, can be that SGW switches downlink data transmission path after MME receives, be switched to base station eNB 2 from base station eNB 1, after completing, MME transmit path handover acknowledge is to base station eNB 2, completes handoff procedure.

Wherein whether according to having, untapped { NH, NCC} use vertical derivation mode or level derives from mode to deciding it for KeNB* that target BS derives to source base station.Then source base station by derivative safe key and down hop counting right, namely { KeNB*, NCC} couple send to target BS by handover request message.Target BS will directly use KeNB* to use as new KeNB.The NCC received is included in switching command by target BS, replies to source base station by the transparent vessel in switching request response, and the switching command in container is transmitted to UE by source base station.UE selects corresponding derived method to carry out the derivation of KeNB according to the NCC received.And in above-mentioned path handoff procedure MME can new calculate a pair NH, NCC} to target BS, target BS receives rear deletion, and other is untapped NH, NCC} couple, preserve and up-to-dately to receive NH, NCC} be after switching use.

In base station side, as shown in Figure 5, the handoff procedure of S1 mouth is shown.Terminal UE is operated in base station eNB 1, UE and measures adjacent cell, after meeting measurement event, to base station eNB 1 reporting measurement reports.According to measurement report, base station eNB 1 judges that UE needs the community CELL2 be switched under base station eNB 2, send to switch to prepare message to Mobility Management Entity MME, and MME sends handover request message to eNB2.Base station eNB 2 returns switching request response and sends switching command to Mobility Management Entity MME, MME to base station eNB 1, and base station eNB 1 sends RRC reconfiguration message to terminal UE, and terminal sends switch acknowledgment message to base station eNB 2, completes handoff procedure.In S1 handoff procedure, source base station can not send any key to target BS, and MME will calculate a pair, and new { NH, NCC} couple send to target BS by handover request message.Target BS receives, and { NH, NCC}, to rear, use vertical derivation mode to carry out the derivation of KeNB*, and it can be used as new KeNB to use.The NCC received is included in switching command by target BS, and reply to MME by the transparent vessel in switching request response, MME is transmitted to source base station again, and switching command is finally transmitted to UE by source base station.UE selects corresponding derived method to carry out the derivation of KeNB according to the NCC received.

As shown in Figure 6, due to wireless environment or subscriber equipment (UE in LTE, User Equipment) in the factor such as the movement impact of network's coverage area, the connection of UE may be caused to occur abnormal, in order to keep the business continuance of UE, UE can initiate RRC (Radio Resource Control, wireless heterogeneous networks) connection reconstruction request (RRCConnectionReestablishment Request) again to re-establish RRC connection.Terminal sends the request of RRC connection reconstruction to network side EUTRAN, and network side returns RRC connection re-establishment message to terminal, and after having re-established, terminal UE returns RRC connection re-establishment to network side and completes message.Be defined in UE in following several situation in current LTE protocol can initiate to rebuild: detect RLF (Radio Link Failure, Radio Link Failure), handoff failure, failure when moving toward different system from LTE, bottom be when integrity protection inspection failure or RRC reconfiguration failure being detected.

The another one prerequisite initiating RRC connection reconstruction is that the safety of Access Layer must be activated, if now the fail safe of Access Layer is not activated, then UE can not carry out above-mentioned RRC connection reconstruction, directly enters Idle state.Receive the RRC connection reconstruction message of UE in the base station eNB of network side after, the brachymemma message integrity authentication code (short MAC-I) carried by message confirms that whether this message is from reliable UE.Short MAC-I is by using the tegrity protection key that uses before reconstruction of UE and protection algorithm integrallty; use and rebuild message, rebuild Cell Radio Network Temporary Identifier/Identity, Cell-RNTI (the Cell Radio Network Temporary Indentity of the PCI of front community, the front UE use of reconstruction; and rebuild the integrality authentication code that the cell ID of community calculates 32 C-RNTI); UE intercepts wherein 16 as brachymemma message integrity authentication code short MAC-I; short MAC-I is carried at and rebuilds in message, sends to the base station rebuild belonging to community.

In LTE, TDD (time division duplex) community only provides a carrier wave to be used as downstream transmission, and FDD (Frequency Division Duplexing (FDD)) community only provides a pair carrier wave (a up and descending carrier) as downstream transmission.In order to meet the demand of people to more high bandwidth, third generation cooperative programme (3GPP, 3rd Generation Partnership Project) new enhancing function is proposed to LTE system, be referred to as LTE Advance, be called for short LTE-A, carrier aggregation (CA is proposed in LTE Advance, Carrier Aggregation) method realizes the object of more large bandwidth, now a community is made up of multiple continuous or discrete carrier wave, each carrier wave is called component carrier (CC, Component Carrier), can simultaneously for UE provides the service of multicarrier.Component carrier can adopt the carrier wave of compatible LTE system, and this carrier wave is called backward compatibility carrier wave (Backwards compatible carrier); Component carrier also can adopt the carrier wave of incompatible existing LTE system, this carrier wave is called non-backward compatible carrier waves (Non-backwards compatible carrier), this carrier wave can only be LTE Advance UE and more highest version UE use; Component carrier can also be expansion carrier wave (Extension carrier), and this carrier wave can not be used alone, and needs to use together with other carrier waves that can independently use.

From above-mentioned, in carrier aggregation subdistrict, UE can use several up-link carriers and descending carrier simultaneously, and based on current agreement discussion, if target side is carrier aggregation subdistrict in the handover, UE can support to switch toward multiple component carrier CC of community, target side simultaneously.In key derivation, the relevant parameter (PCI and EARFCN-DL) inputting Target cell is needed for the calculating of KeNB*, the calculating of brachymemma message integrity authentication code short MAC-I is needed to the relevant parameter (PCI and C-RNTI) of input source community in process of reconstruction, and above-mentioned parameter comes from same community in LTE, namely switching target small area and the former community of reconstruction after switching are identical.In the switching of lte-a system, cell-of-origin and Target cell may have several, now how should select suitable calculation of parameter KeNB* and short MAC-I brachymemma message integrity authentication code, the former community whether requirement is rebuild and the Target cell switched before are same communities, as shown in Figure 7, the problem that need solve is become.

In multiple communities of UE configuration, select a community as the output parameter of security parameter, in discussions in 3 gpp, this community is called as particular cell (special cell), simultaneously in order to transmit conveniently, in turn define main carrier PCC (primary component carrier) community, PCC is in state of activation always.Based on existing LTE-A framework, 2 schemes are probably had to solve above-mentioned safety problem:

Scheme (one): separate configurations particular cell (special cell), uses particular cell as the input community of security parameter when UE initially accesses.It can be gathered independent of the operational cell of UE configuration, or a community in the operational cell set of UE configuration.When X2 switching occurs UE, target BS needs the special cell under intended target base station, for source base station computationally secure key K eNB*.Its benefit is in eNB, the configuration of special cell can be comparatively independent, decrease the reconstitution process that special cell change needs to recalculate security parameter, but this process directly can cause the temporary interruption of user face data, has a certain impact to business continuance.Its shortcoming is that UE needs to safeguard separately the configuration of special cell, and the configuration reconfiguration operation that network needs the new special of establishment cell to be correlated with, thus causes the behavior of protocol definition comparatively complicated.

Scheme (two): not separate configurations special cell, using main carrier community PCC namely as specialcell, provides corresponding security parameter, when each PCC occurs to change, needs to upgrade security parameter by handoff procedure.The benefit of this scheme simplifies configuration and the definition to agreement behavior, but change scene frequently for PCC, and the user face of likely repeatedly causing the amendment due to security parameter to cause is interrupted.

Therefore, how easy in view of such scheme, to there is configuration complicated, can cause the defects such as user face interruption, guarantee that multicarrier in multi-carrier communications systems switches or fail safe in process of reconstruction becomes a technical problem to be solved reliably.

Summary of the invention

Technical problem to be solved by this invention is, there is provided in multi-carrier communications systems and ensure that multicarrier switches or rebuilds the method for fail safe, when switching in order to solve or rebuild, security configuration is complicated and easily cause the problems such as user's face rings, fail safe when simple and reliable guarantee switches or rebuilds.

In order to solve the problem, the present invention proposes a kind of method ensureing multicarrier switch safety in multi-carrier communications systems, comprising:

When source base station judges that terminal needs to be switched to the one or more Target cell supporting the handover-target base station of carrier aggregation administrative, from one or more Target cell, one is selected as the main carrier community after switching or switching target small area, in the process switching to this main carrier community or switching target small area by terminal or source base station or handover-target base station:

The key that main carrier community after terminal utilizes this switching or the parameter of switching target small area calculate according to key schedule as input parameter, as terminal security key;

The source base station of network side or handover-target base station utilize the parameter of the main carrier community after this switching or switching target small area, calculate the safe key corresponding with this terminal as handover-target base station according to the key schedule identical with terminal; Or using the parameter of the main carrier community after all possible one or more switching or switching target small area as input parameter, from the key calculated according to the key schedule identical with terminal, a selected safe key corresponding with this terminal as handover-target base station.

Further, described terminal, source base station or handover-target base station also comprise according to input parameter during identical key schedule computation key: the safe key that under source base station, terminal is corresponding or down hop NH;

Describedly to comprise as the parameter of main carrier community or switching target small area after the switching of input parameter: Physical Cell Identifier, descending carrier frequency.

When described handoff procedure to occur in same base station between different districts, described source base station and described handover-target base station are same base station, are namely all source base station self;

Source base station specifies one as switching target or main carrier community from multiple Target cell, and according to key schedule, the safe key corresponding with terminal under source base station or down hop NH, safe key corresponding with terminal under the Physical Cell Identifier of switching target small area and descending carrier frequency calculate source base station as input parameter; The switching target small area that source base station notification terminal in switching command is specified or main carrier cell information and down hop count information;

Terminal is according to key schedule, determine to use according to down hop count information the safe key or down hop NH that terminal is corresponding under source base station, and the Physical Cell Identifier of the switching target small area of specifying, base station or main carrier community and descending carrier frequency calculate the safe key of terminal as input parameter.

Source base station calculates corresponding safe key respectively for multiple Target cell, according to key schedule, the safe key corresponding with terminal under source base station or down hop NH, the safe key that under the Physical Cell Identifier of each Target cell and descending carrier frequency calculate source base station as input parameter, each Target cell is corresponding with terminal; Or source base station specifies a community to be switching target small area, according to key schedule, the safe key corresponding with terminal under source base station or down hop NH, the Physical Cell Identifier of this Target cell and descending carrier frequency calculate the safe key corresponding with terminal of this Target cell under source base station as input parameter;

The Target cell of the multiple candidate of source base station notification terminal in switching command or main carrier cell information, and down hop count information;

Terminal selects one as switching target small area or main carrier community from target complete community, according to key schedule, according to down hop count information, the safe key corresponding with terminal under source base station or down hop NH, and the Physical Cell Identifier of selected switching target small area or main carrier community and descending carrier frequency calculate the safe key of terminal as input parameter;

Terminal accesses successfully, send switching in switching target small area or main carrier community and complete order, source base station selects the safe key corresponding with switching target small area or main carrier community from safe key corresponding to target complete community, as the safe key corresponding with terminal of base station.

Further, when described handoff procedure is occurred between the different districts between different base station by X2 mouth, source base station specifies one as the Target cell after switching or main carrier community from the administrative multiple Target cells of handover-target base station, and according to key schedule, the safe key corresponding with terminal under source base station or down hop NH, safe key corresponding with terminal under the Physical Cell Identifier of switching target small area and descending carrier frequency calculate handover-target base station as input parameter; The Target cell of this being specified or main carrier community and corresponding safe key, also have down hop count information to be carried in handover request message and send to handover-target base station;

Handover-target base station using the safe key corresponding to main carrier community as safe key corresponding to itself and terminal, in the switching command returning to source base station, carry this Target cell or main carrier cell information and next count information, again switching command is sent to terminal by source base station;

Terminal receives switching command, according to key schedule, according to down hop count information, to determine to use the safe key or down hop NH that terminal is corresponding under source base station, and the Physical Cell Identifier of the Target cell of specifying or main carrier community and descending carrier frequency calculate the safe key of terminal as input parameter.

Further, when described handoff procedure is occurred between the different districts between different base station by X2 mouth, source base station is each in the administrative multiple Target cells of handover-target base station, according to key schedule, the safe key corresponding with terminal under source base station or down hop NH, the Physical Cell Identifier of each Target cell and descending carrier frequency calculate the safe key corresponding with terminal of each Target cell under handover-target base station as input parameter; By the information of target complete community and corresponding safe key, also have down hop count information to be carried in handover request message and send to handover-target base station;

Handover-target base station is according to received target complete cell information, therefrom specify one as Target cell or main carrier community, using the safe key corresponding to Target cell or main carrier community as safe key corresponding to itself and terminal, in the switching command returning to source base station, carry this main carrier cell information and next count information, again switching command is sent to terminal by source base station;

Terminal receives switching command, according to key schedule, according to down hop count information, the safe key corresponding with terminal under source base station or down hop NH, and the Physical Cell Identifier of described Target cell of specifying or main carrier community and descending carrier frequency calculate the safe key of terminal as input parameter.

Received target complete cell information and next count information are carried in switching command and return to source base station by handover-target base station, then are transmitted to terminal by source base station;

Terminal selects one as Target cell or main carrier community from target complete community, according to key schedule, according to down hop count information, the safe key corresponding with terminal under source base station or down hop NH, and the Physical Cell Identifier of selected Target cell or main carrier community and descending carrier frequency calculate the safe key of terminal as input parameter;

Terminal accesses successfully, main carrier community after handover sends switching and completes order, handover-target base station selects the safe key corresponding with this main carrier community from safe key corresponding to target complete community, as the safe key corresponding with terminal of handover-target base station.

Further, when described handoff procedure is occurred between the different districts between different base station by S1 mouth, source base station will specify one as the Target cell after switching or main carrier community in multiple Target cells administrative for handover-target base station, Mobility Management Entity is informed by switching preparation message, Mobility Management Entity sends handover request message, and this main carrier cell information and down hop NH are sent to handover-target base station;

Handover-target base station according to key schedule, with down hop NH, safe key corresponding to terminal under also having the Physical Cell Identifier of described Target cell of specifying or main carrier community and descending carrier frequency to calculate this base station as input parameter;

Target cell or main carrier cell information and down hop count information are configured in switching command by handover-target base station, are transmitted to terminal through Mobility Management Entity, source base station;

Terminal receives switching command, and according to key schedule, according to down hop count information, with down hop NH, and the Physical Cell Identifier of described Target cell of specifying or main carrier community and descending carrier frequency calculate the safe key of terminal as input parameter.

Further, when described handoff procedure is occurred between the different districts between different base station by S1 mouth, source base station, by target complete cell information administrative for handover-target base station, informs Mobility Management Entity by switching preparation message; Mobility Management Entity sends handover request message, and target complete cell information and down hop NH are sent to handover-target base station;

Handover-target base station is for each Target cell, according to key schedule, with down hop NH, safe key corresponding to terminal under also having the Physical Cell Identifier of each Target cell and descending carrier frequency to calculate this base station of each Target cell corresponding as input parameter;

Handover-target base station specifies one as Target cell or main carrier community from target complete community, is configured in switching command, is transmitted to terminal through Mobility Management Entity, source base station by Target cell or main carrier cell information and down hop count information;

Target complete cell information and down hop count information are configured in switching command by handover-target base station, are transmitted to terminal through Mobility Management Entity, source base station;

Terminal receives switching command, one is selected as Target cell or main carrier community from received target complete community, according to key schedule, according to down hop count information, with down hop NH, the Physical Cell Identifier of described selected Target cell or main carrier community and descending carrier frequency is also had to calculate the safe key of terminal as input parameter;

The main carrier community of terminal after selected switching sends switching to handover-target base station and completes order, handover-target base station then selects the safe key corresponding to main carrier community as safe key corresponding with terminal under this base station.

Further, described method comprises the steps: further after completing switching

Described terminal, after completing switching, when being under the handover-target base station supporting carrier aggregation, if only main carrier community is revised, then in the modification process of main carrier community, keeps amendment front original base station safe key.

The present invention also provides in a kind of multi-carrier communications systems and ensures that multicarrier rebuilds the method for fail safe, comprising:

When supporting that the main carrier Zone of the source base station of carrier aggregation needs wireless heterogeneous networks to rebuild, terminal starts Cell searching, finds the reconstructed object community supporting that the reconstructed object base station of carrier aggregation is administrative;

Terminal is according to the safe key of source base station, the Physical Cell Identifier of the main carrier community before reconstruction and Cell Radio Network Temporary Identifier/Identity, Cell-RNTI, and the cell ID of reconstructed object community calculates the brachymemma message integrity authentication code of terminal, after Stochastic accessing, the wireless heterogeneous networks sent to reconstructed object base station rebuilds Physical Cell Identifier and the Cell Radio Network Temporary Identifier/Identity, Cell-RNTI of carried terminal brachymemma message integrity authentication code and source base station main carrier community in request message;

Reconstructed object base station confirms the context that terminal is corresponding, continues process of reconstruction after judging terminal brachymemma message integrity authentication code coupling.

Wherein, reconstructed object base station judges that the concrete steps of terminal brachymemma message integrity authentication code coupling comprise:

Reconstructed object base station receives wireless heterogeneous networks and rebuilds request message, obtain the brachymemma message integrity authentication code of terminal, the Physical Cell Identifier of source base station main carrier community and Cell Radio Network Temporary Identifier/Identity, Cell-RNTI, the brachymemma message integrity authentication code of each terminal corresponding with the Physical Cell Identifier of described source base station main carrier community is calculated according to the algorithm identical with terminal, if wherein have the authentication code mated with received terminal brachymemma message integrity authentication code, then reconstructed object base station confirms the context that terminal is corresponding, continues process of reconstruction.

Described source base station and reconstructed object base station are same base stations, also can be different base stations.

What the switching under the multicarrier system that the present invention proposes or the method for guarantee fail safe of reconstruction defined Target cell or target main carrier community PCC chooses mode, and the generation rule of security parameter, farthest can reduce on the one hand the renewal of security parameter thus the impact on the transmission of user face caused, will be restricted to minimum to the amendment of agreement behavior on the other hand.Compared with prior art, main thought is that special cell is incorporated into PCC, do not re-use the concept of special cell, and use produce switch into first PCC for produce KeNB parameter is provided, after this change of PCC need not revise security parameter, when the follow-up generation of UE is rebuild, use last PCC to provide the calculating parameter of short-MACI, and the former PCC producing KeNB need not be used.

Accompanying drawing explanation

Fig. 1 is the E-UTRAN configuration diagram of LTE system;

Safe key when Fig. 2 is terminal switch in LTE system derives from schematic diagram;

Fig. 3 switches process schematic in base station in LTE system;

Fig. 4 is X2 handoff procedure schematic diagram in LTE system;

Fig. 5 is S1 handoff procedure schematic diagram in LTE system;

Fig. 6 is RRC process of reconstruction schematic diagram in LTE system;

Fig. 7 is the schematic diagram that lte-a system rebuilds community selection;

Fig. 8 is that in lte-a system, main carrier community PCC changes schematic diagram;

Fig. 9 is that before rebuilding selected reconstruction in lte-a system, last PCC carries out the schematic diagram rebuild.

Embodiment

For making the object, technical solutions and advantages of the present invention clearly, below in conjunction with accompanying drawing, the present invention is described in further detail.

For in existing lte-a system, switch or rebuild time guarantee fail safe time, there is configuration complexity and easily the problem impacted transmitted to user face, propose in multi-carrier communications systems the method ensureing multicarrier switch safety, terminal is when being switched to the Target cell supporting the handover-target base station of carrier aggregation administrative, from multiple Target cell, one is selected as the main carrier community after switching or switching target small area, in the process switching to this main carrier community or switching target small area by terminal or source base station or handover-target base station:

The source base station of network side or handover-target base station utilize the main carrier community after the parameter of the main carrier community after this switching or switching target small area or all possible one or more switching or switching target small area as input parameter, according to the key that the key schedule identical with terminal calculates, a selected safe key corresponding with this terminal as handover-target base station.

Wherein, the computational methods of safe key are consistent with existing LTE system, and described terminal, source base station or handover-target base station also comprise according to input parameter during identical key schedule computation key: the safe key that under source base station, terminal is corresponding or down hop NH; Describedly to comprise as the parameter of main carrier community or switching target small area after the switching of input parameter: Physical Cell Identifier, descending carrier frequency.

Described handoff procedure can to occur in same base station between different districts, occur between the different districts between different base station by X2 mouth, is occurred between the different districts between different base station by S1 mouth.

Described terminal, after completing switching, when being under the handover-target base station supporting carrier aggregation, if main carrier community is revised, then in the modification process of main carrier community, keeps amendment front original base station safe key.

Also proposed in multi-carrier communications systems and ensure that multicarrier rebuilds the method for fail safe, when needing wireless heterogeneous networks to rebuild, terminal starts Cell searching, finds the reconstructed object community supporting that the reconstructed object base station of carrier aggregation is administrative;

Terminal is according to the safe key of source base station, the Physical Cell Identifier of source base station main carrier community and Cell Radio Network Temporary Identifier/Identity, Cell-RNTI, and the cell ID of reconstructed object community calculates the brachymemma message integrity authentication code of terminal, after Stochastic accessing, the wireless heterogeneous networks sent to reconstructed object base station rebuilds carried terminal brachymemma message integrity authentication code in request message, and the Physical Cell Identifier of source base station main carrier community and Cell Radio Network Temporary Identifier/Identity, Cell-RNTI;

Process of reconstruction also can occur in the different districts under same base station, and now described source base station and reconstructed object base station are same base stations.

In the specific embodiment of the present invention, the main scene describing the switching/reconstruction of UE under carrier aggregation subdistrict.

Terminal UE switches the community of anteposition under source base station covers, and source base station S-eNB is the evolution eNB of LTE-Advance, and namely S-eNB is the base station supporting carrier aggregation, and its administrative support carrier aggregation subdistrict is S-Cell1 and S-Cell2.Handover-target base station T-eNB is the evolution eNB of LTE-Advance, namely T-eNB is the base station supporting carrier aggregation, community T-Cell1 and T-Cell2 is the community of administrative the used carrier aggregation of T-eNB, T-Cell1 and T-Cell2 also can be called as member carrier when being polymerized.Reconstructed object base station R-eNB is the evolution eNB of LTE-Advance, and namely R-eNB supports the base station of carrier aggregation, and community R-Cell1 and R-Cell2 is the community of administrative the used carrier aggregation of R-eNB.

Below for the situation of 2 cell aggregation, under switching or re-construct, how to guarantee that fail safe is described in detail.With reference to the execution mode of 2 communities, the scene of carrier aggregation is carried out in multiple communities that also can derive source and target side further.

Embodiment 1: handover between cells scene in base station

Under terminal UE is operated in the source base station S-eNB supporting carrier aggregation, and to be configured administrative community S-Cell1 and S-Cell2 of source base station be carrier aggregation subdistrict, and its small area S-Cell1 is as main carrier community PCC.Separately have S-Cell3 and S-Cell4 to be carrier aggregation subdistrict under same base, and with S-Cell1 and S-Cell2 adjacent area each other.

Step 101, UE measures adjacent cell, and after meeting measurement event, UE reporting measurement reports is to source base station S-eNB;

Step 102, according to measurement report, source base station S-eNB judges that terminal UE needs community S-Cell3 or S-Cell4 be switched under handover-target base station S-eNB to go.In such cases, handover-target base station and source base station S-eNB are same base station, are namely all base station S-eNB.

Step 103, now S-eNB can have 2 kinds of selections for Target cell:

A. PCC is specified in base station

Target main carrier community PCC after specifying UE to switch in the switching command sending to terminal is community S-Cell3 or S-Cell4.Can be appointment that is explicit or implicit expression, described implicit expression can be first component carrier CC of configuration be acquiescence main carrier community PCC.

B. terminal selectes PCC

Not intended target main carrier community PCC in the switching command sending to terminal, notice UE community S-Cell3 and S-Cell4 can be called main carrier community PCC, and UE can oneself select one of them as target main carrier community PCC.

The key derivation in a and b is selected for above-mentioned two kinds, whether base station has untapped down hop and next counting { NH according to current base station, which kind of derived method NCC} uses to deciding, if there is no untapped { NH, NCC} couple, then adopt level to derive from mode derivative key, if there is untapped { NH, NCC} couple, then adopt vertical derivation mode derivative key.For the Target cell parameter PCI in derivation history and EARFCN-DL, provided by Target cell or target P CC.

For a, base station only can calculate the Target cell and target P CC chosen, to choose community S-Cell3, when level derives from:

KeNB*＝KeNB* _S-Cell3＝KDF(KeNB _S-eNB，PCI _S-Cell3，EARFCN-DL _S-Cell3)；

During vertical derivation:

KeNB*＝KeNB* _S-Cell3＝KDF(NH，PCI _S-Cell3，EARFCN-DL _S-Cell3)；

Wherein, KDF is key schedule; KeNB _s-eNBbe the UE key that uses of source base station S-eNB before the handover, its NCC correspondence generates KeNB _s-eNBtime down hop counting NCC, work as KeNB _s-eNBwhen being initial safe Procedure Acquisition, NCC is 0; Down hop NH be preserve in the S-eNB of base station not by { the NH value of NH, NCC} centering used.

For b, base station S-eNB can calculate a key for possible Target cell or target P CC, is namely respectively community S-Cell3 and S-Cell4 computation key KeNB* _s-Cell3and KeNB* _s-Cell4.The method of derivative key is consistent with the derivation mode in above-mentioned a selection.

After base station S-eNB completes configuration, send switching command to UE, wherein carry the down hop counting NCC that above-mentioned community is corresponding.

Step 104, after terminal UE receives switching command, be no matter to be specified by base station or UE oneself selects, final UE carries out Stochastic accessing under determining a Target cell or target P CC, Bing Gai community, completes order access successfully transmission switching afterwards.

For security parameter configuration, UE, according to the NCC in switching command, contrasts the key K eNB before switching _uE(KeNB _uE=KeNB _s-eNB) corresponding NCC, if NCC is identical, then UE adopts horizontal derived method derivative key, otherwise uses vertical derived method derivative key, and the derived method of key is selected with LTE system consistent.In key derivation, the parameter PCI of Target cell and EARFCN-DL comes from UE and sends the community having switched order place.KeNB* is generated by KDF algorithm _uE, and as the KeNB after switching, bring into use new security parameter having switched order.

Step 105, base station when the switching receiving UE completes order,

If that select in step 103 is a, base station uses the KeNB* that generated as the new KeNB of UE, after carrying out security setting, uses new security configuration to complete order to switching and carries out security process (comprising integrity protection and deciphering).

If that select in step 103 is b, two key K eNB* that base station can generate _s-Cell3and KeNB* _s-Cell4the KeNB* that middle selection receives the community that switched order corresponding is the KeNB that UE is new, and complete order as UE in this example selects S-Cell4 to send switching, KeNB* is then selected in base station _s-Cell4the KeNB that the UE used for this base station is new, then uses new security configuration to complete order to switching and carries out security process.

Embodiment 2: X2 handoff scenario between base station

Under terminal UE is operated in the source base station S-eNB supporting carrier aggregation, and to be configured administrative community S-Cell1 and S-Cell2 of source base station be carrier aggregation subdistrict, and its small area S-Cell1 is as main carrier community PCC.

Step 201, UE measures adjacent cell, and after meeting measurement event, UE reporting measurement reports is to source base station S-eNB;

Step 202, according to measurement report, source base station S-eNB judges that terminal UE needs to be switched in the community under handover-target base station T-eNB, when Target cell may have multiple (such as community T-Cell1 or T-Cell2), S-eNB can have 2 kinds of selections for Target cell:

C., in handover request message, notice handover-target base station, intended target community or target P CC are T-Cell1 or T-Cell2.

D., in handover request message, Target cell or the target P CC of notice handover-target base station can select in T-Cell1 or T-Cell2.

Wherein the derivation of key level can be derived from or vertically derive from.Such as according to selection c, when source base station specifies T-Cell1 to be the main carrier community PCC after switching:

When level derives from:

KeNB*＝KeNB* _T-Cell1＝KDF(KeNB _S-eNB，PCI _T-Cell1，EARFCN-DL _T-Cell1)；

During vertical derivation:

KeNB*＝KeNB* _T-Cell1＝KDF(NH，PCI _T-Cell1，EARFCN-DL _T-Cell1)；

For selection c, during source base station derivative key, derive from KeNB* according to the Target cell of specifying or target P CC, afterwards, the Target cell of specifying or target P CC, the KeNB* of derivation and the NCC of correspondence are carried in handover request message and send to handover-target base station.

For selection d, source base station is all possible Target cell or target P CC derivative key, calculates the safe key KeNB* that each Target cell is corresponding _t-Cell1and KeNB* _t-Cell2, and the down hop of Liang Ge community and each self-corresponding key and correspondence counting NCC is carried in handover request message is sent to handover-target base station; Or key and the corresponding NCC of one of them community and its derivation are sent by handover request message, other community and its key derived from can be placed in the RRC transparent vessel in handover request message and send to T-eNB.

Step 203, handover-target base station T-eNB is for above-mentioned selection c, can as selected the mode as described in a in step 103, the community that just target BS chooses source base station to specify herein is Target cell, for in community T-Cell1 or T-Cell2 selecting d that it can be selected administrative as the main carrier community PCC after switching, as selected the mode as described in a in step 103, target BS chooses a Target cell or target P CC, preserve corresponding KeNB*, the switching command configured carries NCC.Also can as selected the mode as described in b in step 103 for selection d, T-eNB, by UE oneself select target community or target P CC, preserve all KeNB*, the switching command configured carries NCC.

Switching command is carried in switching request response by RRC container and returns to source base station S-eNB, and sends to terminal UE by source base station S-eNB.

Step 204, UE process is identical with step 104.Calculating the safe key KeNB* obtaining terminal _uEafterwards, terminal UE is by this KeNB* of use _uEas its key under handover-target base station T-eNB, according to the security algorithm in switching command, enable new security parameter, in Target cell or target P CC community, if this example can be that T-Cell1 sends handoff completion message.

Step 205; after handover-target base station T-eNB receives the handoff completion message of terminal; if that select in step 203 is a; base station uses the KeNB* preserved as the new KeNB of UE; after carrying out security setting, use new security configuration to complete order to switching and carry out security process (comprising integrity protection and deciphering).If that select is b, safe key KeNB* is cut by what send at the source base station preserved before in this base station _t-Cell1and KeNB* _t-Cell2the KeNB* that middle selection receives the community that switched order corresponding is the KeNB that UE is new, and UE sends switching and completes order on T-Cell1 in step 203, so T-eNB selects KeNB* _t-Cell1for the KeNB that UE is new, then use new security configuration to complete order to switching and carry out security process.

Step 206, T-eNB successfully solves after switching completes order, and T-eNB is by transmit path handover request message to MME, and downlink data is switched to T-eNB from S-eNB by S-GW to allow MME notify.T-eNB transmit path switching response message is given after MME completes.

Step 207, in T-eNB storing path switching response message { NH, NCC}, to for not using, use as next key derivation.

Embodiment 3: S1 handoff scenario between base station

Step 301, UE measures adjacent cell, and after meeting measurement event, UE reporting measurement reports is to source base station S-eNB;

Step 302, according to measurement report, source base station S-eNB judges that terminal UE needs to be switched in the community under handover-target base station T-eNB, when Target cell may have multiple, S-eNB can have 2 kinds of selections for Target cell:

E., in handover request message, notification target base station, intended target community or target P CC are T-Cell1 or T-Cell2.

F., in handover request message, Target cell, notification target base station or target P CC can select in T-Cell1 or T-Cell2.

Owing to being S1 switching, so the KeNB* of the not responsible generation handover-target base station of source base station.

For selection e, source base station, by the Target cell of specifying or target P CC, as T-Cell1, prepares to send to handover-target base station in message in switching.

For selection f, two possible Target cells are all carried to switch and prepare to be sent to handover-target base station in message by source base station, or one of them community prepares message transmission by switching, and other community can be placed in the RRC transparent vessel switching and prepare in message and send to MME.

Step 303, MME sends handover request message to handover-target base station after receiving and switching preparation message, and carries vertical new { NH, the NCC} couple that derive from.

Step 304, after target BS T-eNB receives handover request message, then generates KeNB* according to vertical derivation mode by NH, the entering to join PCI and EARFCN-DL and can be of its Target cell:

If that the selection in step 302 is e, so T-eNB selects to switch the Target cell prepared in message and provides PCI and EARFCN-DL, and that select in this example is T-Cell1.Produce KeNB* and preserve together with NH after selected, and the switching command configured carries the NCC that MME sends.

If that the selection in step 302 is f, so T-eNB can select in T-Cell1 or T-Cell2 one to provide key derivation parameter PCI and EARFCN-DL.By the mode as selected in step 103 as described in a, that preserves correspondence derives KeNB*, and the switching command configured carries the NCC that MME sends.

If the selection in step 302 is that f, T-eNB also by the mode as selected in step 103 as described in b, by UE oneself select target community or target P CC, can preserve all KeNB*, as KeNB* _t-Cell1and KeNB* _t-Cell2, the switching command configured carries the NCC that MME sends.

T-eNB sends switching response message to MME, and wherein carry the switching command configured in RRC container, switching command is transmitted to S-eNB by MME, and sends to UE by S-eNB.

Step 305, UE process is identical with step 204.

Step 306, after the switching that handover-target base station T-eNB receives terminal completes information,

If when selecting f in step 304; have employed as the mode a in step 103 further; handover-target base station uses the KeNB* preserved as the new KeNB of UE; after carrying out security setting, use new security configuration to complete order to switching and carry out security process (comprising integrity protection and deciphering).

If when selecting f in step 304, have employed as the mode b in step 103 further, the safe key KeNB* that handover-target base station will preserved before _t-Cell1and KeNB* _t-Cell2the KeNB* that middle selection receives the community that switched order corresponding is the KeNB that UE is new, and in step 305, if UE sends switching on T-Cell1 complete order, T-eNB then selects KeNB* _t-Cell1for the KeNB that UE is new, then use new security configuration to complete order to switching and carry out security process.

Step 307, T-eNB successfully solves after switching completes order, and T-eNB will send handoff notification message to MME, complete switching.

Embodiment 4: the scene of main carrier community PCC change after switching

When terminal is under the base station supporting carrier aggregation, due to the reason such as signal intensity or load variations, main carrier community PCC can modify, and in PCC modification process, base station can be selected not revise original base station safe key, thus can avoid because security parameter changes the service disconnection caused.

Such as, after terminal is switched to handover-target base station T-eNB from source base station S-eNB, main carrier community time initial is T-Cell1, due to signal intensity or load variations, main carrier community PCC can be there is revise, such as revising main carrier community is T-Cell2, in PCC modification process, does not need to revise original KeNB _t-eNB, as shown in Figure 8.

RRC re-construct:

When terminal UE generation Radio Link Failure, handoff failure or other failure (as reasons such as configuration parameter mistakes) time, UE can initiate radio resource control RRC process of reconstruction.If there is the contextual information of UE reconstructed object base station, so UE can rebuild successfully.RRC rebuilds the shortMAC-I=shortINTEGRITY (KeNB carried in request command _{source eNB}, PCI _{source cell}, C-RNTI _{source cell}, CellID _{target cell}), when UE carries out carrier aggregation before reconstruction, select the PCC before reconstruction to provide PCI and C-RNTI, shortMAC-I=shortINTEGRITY (KeNB _{source eNB}, PCI _{pCC prior to failure}, C-RNTI _{pCC prior to failure}, Cell ID _{taret cell}), wherein shortINTEGRITY is protection algorithm integrallty, as shown in Figure 9.

Embodiment 5: the scene that in base station, RCC rebuilds

Step 501, UE starts Cell searching, finds reconstructed object community, and reconstruction community is the S-Cell3 under S-eNB.

Step 502, UE after completing random access procedure, can send RRC and rebuilds request message.According to the formula of above-mentioned shortMAC-I, UE is when the RRC sent rebuilds request message, and the shortMAC-I carried is calculated as:

ShortMAC-I _uE=shortINTEGRITY (KeNB _s-eNB, PCI _s-Cell1, C-RNTI _s-Cell1, CellID _s-Cell3), RRC rebuilds request message and also can carry PCI simultaneously _s-Cell1and C-RNTI _s-Cell1.

Step 503, base station S-eNB receives the RRC reconstruction request message that UE sends.According to above-mentioned shortMAC-I _uEformula, can rebuild request message and obtains the shortMAC-I that this UE reports by RRC _uE, and the PCI carried _s-Cell1and C-RNTI _s-Cell1information.But because identical PCI can use over different frequencies, so multiple UE all mated with PCI and C-RNTI may be there is.Thus, the KeNB that S-eNB is corresponding according to each UE _s-eNBcalculate the shortMAC-I that each UE is corresponding respectively _s-eNB=shortINTEGRITY (KeNB _s-eNB, PCI _s-Cell1, C-RNTI _s-Cell1, Cell ID _s-Cell3).As one of them shortMAC-I _s-eNBthe shortMAC-I that energy and UE report _uEduring coupling, S-eNB can confirm the context that this UE is corresponding, can continue follow-up process of reconstruction.

Embodiment 6: the scene that between base station, RCC rebuilds

When there is the reconstruction between base station, source base station needs in advance the context of UE to be sent to possibility Target cell to prepare.Because S-eNB cannot confirm which community UE finally can rebuild to before reconstruction, so to all possible reconstructed object community, source base station S-eNB can calculate a shortMAC-I.S-eNB uses the parameter of current main carrier community PCC and possible reconstructed object cell parameter to calculate brachymemma message integrity authentication code shortMAC-I.

Under supposing that terminal UE is operated in the source base station S-eNB supporting carrier aggregation, and to be configured administrative community S-Cell1 and S-Cell2 of source base station be carrier aggregation subdistrict, and its small area S-Cell1 is as main carrier community PCC.Reconstructed object base station R-eNB supports the base station of carrier aggregation, and community R-Cell1 and R-Cell2 is the community of administrative the used carrier aggregation of R-eNB.Source base station Yao Wei community R-Cell1 and R-Cell2 calculates shortMAC-I respectively:

shortMAC-I _R-cell1＝shortINTEGRITY(KeNB _S-eNB，PCI _S-cell1，C-RNTI _S-cell1，Cell ID _R-cell1)，

shortMAC-I _R-cell2＝shortINTEGRITY(KeNB _S-eNB，PCI _S-cell1，C-RNTI _S-cell1，Cell ID _R-cell2)；

Wherein, KeNB _s-eNBbe the key that UE uses in source base station S-eNB, R-Cell1 and R-Cell2 is possible reconstructed object community.S-eNB completes to rebuild by above-mentioned flow process and prepares, and rebuilds to prepare parameter and comprise C-RNTI corresponding to the main carrier community of source base station _{source PCC}, PCI _{source PCC}with the short MAC-I for multiple reconstructed object community, the reconstructed object community that each short MAC-I correspondence one is possible.

Step 601, UE starts Cell searching, finds reconstructed object community, and reconstruction community is the R-Cell1 under R-eNB.

Step 602, and step 502 is similar, UE can after R-Cell1 completes random access procedure, and send RRC and rebuild request message to reconstructed object base station R-eNB, UE when the RRC sent rebuilds request message, the short MAC-I carried is calculated as:

ShortMAC-I _uE=shortINTEGRITY (KeNB _s-eNB, PCI _s-Cell1, C-RNTI _s-Cell1, CellID _r-Cell1), RRC rebuilds the PCI that request message can carry current main carrier community S-Cell1 simultaneously _s-Cell1and C-RNTI _s-Cell1.

Step 603, reconstructed object base station R-eNB receives the RRC reconstruction request message that UE sends.R-eNB is according to above-mentioned shortMAC-I _uEformula, can rebuild request message from RRC and obtain the shortMAC-I that this UE reports _uE, and the PCI carried _s-Cell1and C-RNTI _s-Cell1information.Because identical PCI can use over different frequencies, so the UE that multiple PCI and C-RNTI mate may be there is.R-eNB is according to the PCI carried in UE message _s-Cell1and C-RNTI _s-Cell1, calculate the shortMAC-I that each UE is corresponding _r-cell1.The shortMAC-I that R-eNB is corresponding according to each UE _r-cell1with the shortMAC-I that UE reports _uEmate.Because have multiple UE to meet the identical condition of PCI with C-RNTI, then compare shortMAC-I _r-cell1and shortMAC-I _uEwhether identical confirm which UE UE context is, when a coupling is found, R-eNB can confirm the context that this UE is corresponding, can continue follow-up process of reconstruction.

In above-described embodiment 1-6, define the generation rule of security parameter when switching and/or rebuild, farthest can reduce on the one hand the renewal of security parameter thus the impact on the transmission of user face caused, will be restricted to minimum to the amendment of agreement behavior on the other hand.Thus, the present invention has easy reliable feature, can ensure fail safe when switching and/or rebuild.

The foregoing is only embodiments of the invention, be not limited to the present invention, for a person skilled in the art, the present invention can have various modifications and variations.Within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within right of the present invention.

Claims

1. ensure a method for multicarrier switch safety in multi-carrier communications systems, it is characterized in that, comprising:

The source base station of network side or handover-target base station utilize the parameter of the main carrier community after this switching or switching target small area, calculate the safe key corresponding with this terminal as handover-target base station according to the key schedule identical with terminal; Or using the parameter of the main carrier community after all possible one or more switching or switching target small area as input parameter, from the key calculated according to the key schedule identical with terminal, a selected safe key corresponding with this terminal as handover-target base station;

Described method comprises the steps: further after completing switching

2. the method for claim 1, is characterized in that,

Described terminal, source base station or handover-target base station also comprise according to input parameter during identical key schedule computation key: the safe key that under source base station, terminal is corresponding or down hop NH;

3. method as claimed in claim 1 or 2, is characterized in that, when described handoff procedure to occur in same base station between different districts, described source base station and described handover-target base station are same base station, are namely all source base station self;

4. method as claimed in claim 1 or 2, is characterized in that, when described handoff procedure to occur in same base station between different districts, described source base station and described handover-target base station are same base station, are namely all source base station self;

5. method as claimed in claim 1 or 2, is characterized in that, when described handoff procedure is occurred between the different districts between different base station by X2 mouth,

Source base station specifies one as the Target cell after switching or main carrier community from the administrative multiple Target cells of handover-target base station, and according to key schedule, the safe key corresponding with terminal under source base station or down hop NH, safe key corresponding with terminal under the Physical Cell Identifier of switching target small area and descending carrier frequency calculate handover-target base station as input parameter; The Target cell of this being specified or main carrier community and corresponding safe key, also have down hop count information to be carried in handover request message and send to handover-target base station;

6. method as claimed in claim 1 or 2, is characterized in that, when described handoff procedure is occurred between the different districts between different base station by X2 mouth,

Source base station is each in the administrative multiple Target cells of handover-target base station, according to key schedule, the safe key corresponding with terminal under source base station or down hop NH, the Physical Cell Identifier of each Target cell and descending carrier frequency calculate the safe key corresponding with terminal of each Target cell under handover-target base station as input parameter; By the information of target complete community and corresponding safe key, also have down hop count information to be carried in handover request message and send to handover-target base station;

7. method as claimed in claim 1 or 2, is characterized in that, when described handoff procedure is occurred between the different districts between different base station by X2 mouth,

8. method as claimed in claim 1 or 2, is characterized in that, when described handoff procedure is occurred between the different districts between different base station by S1 mouth,

Source base station will specify one as the Target cell after switching or main carrier community in multiple Target cells administrative for handover-target base station, Mobility Management Entity is informed by switching preparation message, Mobility Management Entity sends handover request message, and this main carrier cell information and down hop NH are sent to handover-target base station;

9. method as claimed in claim 1 or 2, is characterized in that, when described handoff procedure is occurred between the different districts between different base station by S1 mouth,

Source base station, by target complete cell information administrative for handover-target base station, informs Mobility Management Entity by switching preparation message; Mobility Management Entity sends handover request message, and target complete cell information and down hop NH are sent to handover-target base station;

10. method as claimed in claim 1 or 2, is characterized in that, when described handoff procedure is occurred between the different districts between different base station by S1 mouth,