CN110351790A

CN110351790A - Communication handover method and device based on dual link

Info

Publication number: CN110351790A
Application number: CN201810300052.9A
Authority: CN
Inventors: 骆亚铭; 陈翔; 招溢利
Original assignee: Huizhou TCL Mobile Communication Co Ltd
Current assignee: Huizhou TCL Mobile Communication Co Ltd
Priority date: 2018-04-04
Filing date: 2018-04-04
Publication date: 2019-10-18
Also published as: WO2019192150A1

Abstract

The invention discloses a kind of communication handover methods based on dual link, this method comprises: source base station assists user equipment to enter dual link state, user equipment under dual link state connects source base station and target BS simultaneously, and wherein source base station is as host node, and target BS is as auxiliary node；Source base station assists user equipment to switch to the single connection state of a linking objective base station from dual link state, the process can the communication between source base station and user equipment start when breaking down.The invention also discloses a kind of communication switching devices based on dual link.Occur a possibility that ping-pong/reduction handoff procedure complexity by the above-mentioned means, the present invention can reduce and reduce signaling overheads.

Description

Communication handover method and device based on dual link

Technical field

The present invention relates to the communications fields, more particularly to a kind of communication handover method and device based on dual link.

Background technique

Switching (Handover, HO) is one of most basic and most important process in mobile management.In the prior art, The mobile management of wireless heterogeneous networks (Radio Resource Control, RRC) state is network controlled, i.e. network Determine the connection relationship between user equipment and cell.

Under normal circumstances, user equipment first disconnects the connection between source base station during network-control switching, then with Target BS is attached.However, establishing the company with target BS after the connection that user equipment disconnects between source base station Before connecing, without connection relationship between user equipment and source base station, user equipment and target BS, user can not be transmitted at this time The user face data of equipment is (including sending downlink user face data to user equipment and/or receiving the uplink from user equipment User face data), cause in handoff procedure there are the mobility of the user plane data transfer of long period interrupt (abbreviation mobility It interrupts).

For the duration for shortening mobility interruption, the switching based on dual link (Dual Connectivity, DC) is proposed, It specifically includes: 1) adding target BS using source base station as host node as auxiliary node；2) source base station starts Counterchange roles, role Source base station is as auxiliary node after the completion of transformation, and target BS is as host node；3) auxiliary node (i.e. source base station) is discharged.

Relative to conventional handover procedure, in the handoff procedure based on DC step 1) generally the communications status of source base station more It is executed when stablizing.If may result in table tennis if execution or even the two merge execution after step 2) followed by step 1) Effect, especially in the junctional area of two cells.

In addition, the application of high-frequency and multi-beam leads to more frequent signal matter newly eating dishes without rice or wine in (New Radio, NR) Amount variation, the communication between user equipment and base station more frequently can more suddenly break down.If executing step 2) executes it Occur between preceding user equipment and source base station radio jink failure (Radio Link Failure, RLF), no matter secondary cell How is signal quality, and user equipment can all start wireless heterogeneous networks (Radio Resource Control, RRC) connection reconstruction Process, the process include that all configured auxiliary nodes of release interrupt so as to cause the mobility of some time.

Summary of the invention

The invention mainly solves the technical problem of providing a kind of communication handover method and device based on dual link, can Solve the problems, such as that the handoff procedure based on DC will lead to ping-pong in the prior art.

In order to solve the above-mentioned technical problems, the present invention provides a kind of communication handover method based on dual link, this method Include: source base station assist user equipment enter dual link state, the user equipment under dual link state connect simultaneously source base station and Target BS, wherein source base station is as host node, and target BS is as auxiliary node；Communication between source base station and user equipment goes out When existing failure, source base station assistance user equipment switches to the single connection state of a linking objective base station from dual link state.

In order to solve the above-mentioned technical problems, the present invention provides a kind of communication handover method based on dual link, this method It include: that target BS with the user equipment connecting with source base station is remain establishes connection, target BS is as under dual link state User equipment auxiliary node, source base station is as host node；When communication between source base station and user equipment is broken down, target Base station assistance user equipment switches to the single connection state of a linking objective base station from dual link state.

In order to solve the above-mentioned technical problems, the present invention provides a kind of communication handover method based on dual link, this method It include: that user equipment establishes the connection with target BS in the case where keeping the connection with source base station to enter dual link state, doubly-linked Connect that source base station is as host node under state and target BS is as auxiliary node；There is event in communication between source base station and user equipment When barrier, user equipment switches to the single connection state of a linking objective base station from dual link state.

In order to solve the above-mentioned technical problems, the present invention provides a kind of communication handover method based on dual link, this method Include: source base station assist user equipment enter dual link state, the user equipment under dual link state connect simultaneously source base station and Target BS, wherein source base station is as host node, and target BS is as auxiliary node；Source base station assists user equipment from dual link shape State is directly switch into the single connection state of a linking objective base station.

In order to solve the above-mentioned technical problems, the present invention provides a kind of communication handover method based on dual link, this method It include: that target BS with the user equipment connecting with source base station is remain establishes connection, target BS is as under dual link state User equipment auxiliary node, source base station is as host node；Target BS assists user equipment directly to switch from dual link state To the single connection state of only linking objective base station.

In order to solve the above-mentioned technical problems, the present invention provides a kind of communication handover method based on dual link, this method It include: that user equipment establishes the connection with target BS in the case where keeping the connection with source base station to enter dual link state, doubly-linked Connect that source base station is as host node under state and target BS is as auxiliary node；User equipment is received from target BS or source base The direct switching command stood；The direct switching command of user device responsive is directly switch into a linking objective base station from dual link state Single connection state.

In order to solve the above-mentioned technical problems, the present invention provides a kind of communication switching device based on dual link, the devices Including processor and telecommunication circuit, processor connection communication circuit, processor is above-mentioned any one to realize for executing instruction Kind method.

In order to solve the above-mentioned technical problems, the present invention provides a kind of communication switching device based on dual link, the communications Switching device is stored with instruction, and instruction, which is performed, realizes any one method above-mentioned.

The beneficial effects of the present invention are: when being broken down by the communication between source base station and user equipment, source base station/ Target BS assists user equipment to switch to the single connection state of a linking objective base station from dual link state, and in the prior art By target BS add supplemented by Counterchange roles carried out after node at once compare, postponed the time for initiating Counterchange roles, reduced There is a possibility that ping-pong.It is executed in addition, Counterchange roles and the release of auxiliary node are merged, i.e. user equipment is from source base station As host node and target BS is directly switch into the single connection shape of a linking objective base station as the dual link state of auxiliary node State can reduce the complexity of handoff procedure and reduce signaling overheads.

Detailed description of the invention

Fig. 1 is the flow diagram of the communication handover method first embodiment the present invention is based on dual link；

Fig. 2 is the flow diagram of the communication handover method second embodiment the present invention is based on dual link；

Fig. 3 is the idiographic flow schematic diagram of S121 in Fig. 2；

Fig. 4 is the flow diagram of the communication handover method 3rd embodiment the present invention is based on dual link；

Fig. 5 is the flow diagram of the communication handover method fourth embodiment the present invention is based on dual link；

Fig. 6 is the flow diagram of the 5th embodiment of communication handover method the present invention is based on dual link；

Fig. 7 is the flow diagram of the communication handover method sixth embodiment the present invention is based on dual link；

Fig. 8 is the idiographic flow schematic diagram of S221 in Fig. 7；

Fig. 9 is the flow diagram of the 7th embodiment of communication handover method the present invention is based on dual link；

Figure 10 is the flow diagram of the 8th embodiment of communication handover method the present invention is based on dual link；

Figure 11 is the flow diagram of the 9th embodiment of communication handover method the present invention is based on dual link；

Figure 12 is the flow diagram of the tenth embodiment of communication handover method the present invention is based on dual link；

Figure 13 is the flow diagram of the 11st embodiment of communication handover method the present invention is based on dual link；

Figure 14 is that fault condition is RLF and by target base in one embodiment of communication handover method the present invention is based on dual link Stand initiate merge direct handoff procedure in the case of overall handoff procedure schematic diagram；

It is BLF and by source base that Figure 15, which is the present invention is based on fault condition in another embodiment of the communication handover method of dual link, The overall handoff procedure schematic diagram stood under initiation Counterchange roles and auxiliary node release process condition；

Figure 16 is the flow diagram of the 12nd embodiment of communication handover method the present invention is based on dual link；

Figure 17 is the idiographic flow schematic diagram of S42 in Figure 16；

Figure 18 is the flow diagram of the 13rd embodiment of communication handover method the present invention is based on dual link；

Figure 19 is the idiographic flow schematic diagram of S52 in Figure 18；

Figure 20 is the flow diagram of the 14th embodiment of communication handover method the present invention is based on dual link；

Figure 21 is the structural schematic diagram of the communication switching device first embodiment the present invention is based on dual link；

Figure 22 is the structural schematic diagram of the communication switching device second embodiment the present invention is based on dual link；

Figure 23 is the structural schematic diagram of the communication switching device 3rd embodiment the present invention is based on dual link；

Figure 24 is the structural schematic diagram of the communication switching device fourth embodiment the present invention is based on dual link.

Specific embodiment

The present invention is described in detail with reference to the accompanying drawings and examples.What is do not conflicted in following embodiment can phase Mutually combine.

It is base station the present invention is based on the executing subject of the communication handover method first embodiment of dual link, and the base station is being cut As source base station during changing, i.e. the base station that currently connects of user equipment (User Equipment, UE).Base station connects core net And carried out wireless communication with UE, communication overlay is provided for corresponding geographic area.Base station can be macro base station, micro- (micro) base It stands, the pico- base station (pico) or Home eNodeB (femtocell).In some embodiments, base station can also be referred to as wireless base It stands, access point, B node, evolved B node (eNodeB, eNB), gNB or other suitable terms.As shown in Figure 1, this implementation Example include:

S11: source base station assists user equipment to enter dual link state.

User equipment under dual link state connects source base station and target BS simultaneously, and wherein source base station is as host node, Target BS is as auxiliary node.

This step may include the part that source base station is responsible in auxiliary node adding procedure in existing doubly-linked connection technology.At this Before step, source base station can be that user equipment confirms target BS according to the measurement report of user equipment to report.

User equipment needs to establish connection with target BS in the case where keeping the connection with source base station to enter doubly-linked State is connect, this process may bring certain time-delay, especially need to carry out random access in user equipment to be synchronized to mesh In the case where marking base station, delay is can not to be ignored.If before delay terminates, i.e., user equipment not yet and target BS When establishing connection, radio link deterioration between source base station and user equipment is to can not continue as user equipment service, Yong Hushe It is standby to cannot be introduced into dual link state, in some instances it may even be possible to enter radio jink failure (Radio Link Failure, RLF) and hold Row RRC is re-established, and mobility is caused to be interrupted.For the generation for reducing this case, when starting auxiliary node adding procedure, user equipment Source cell signal quality start than in the prior art switching when it is more preferable.If completed in the auxiliary node adding procedure of this step Afterwards, subsequent process is directly initiated, serious ping-pong may be brought.

Whole wireless heterogeneous networks (Radio Resource needed for user equipment into dual link state Control, RRC) signaling message and function, such as common radio resources configuration, dedicated radio resources configuration, measurement and mobility pipe Reason etc. can be only managed by host node.In the case, only host node has RRC entity, signal resource carrying (Signal Resource Bearer, SRB) is direct main plot group (the serving cell group of MCG, i.e. host node control) mode Or clastotype.

For the user equipment of dual link state, can be used two RRC entities, one in host node, another Auxiliary node, allow so auxiliary node manage independently in some aspects user equipment and make certain mobile management decision and nothing Need the participation of host node.In the case, host node and auxiliary node control face data with user device transmissions, and SRB can be Clastotype.

Furthermore, it is possible to the control face data of the user equipment of dual link state only be managed by auxiliary node, due to auxiliary node Being made that after mobile management determines may not need by host node and directly sends corresponding control signaling to user equipment, subtract Signaling overheads on small interface between host node and auxiliary node (such as Xn interface).In the case, only auxiliary node with User device transmissions control face data, and SRB is direct secondary cell group (SCG, i.e., the serving cell group of auxiliary node control) mode.

It is similar, the user face data of the user equipment of dual link state can only by host node transmission, by host node and Auxiliary node-node transmission or only by auxiliary node-node transmission, corresponding data resource carrying (Data Resource Bearer, DRB) can be with For direct MCG mode, clastotype or SCG mode.

S12: when the communication between source base station and user equipment is broken down, source base station assists user equipment from dual link shape State switches to the single connection state of a linking objective base station.

When communication is broken down, source base station or user equipment can not receive certain information of other side or receive difficult, use It is worse when the signal quality of family equipment source cell is completed than auxiliary node adding procedure.Failure can be radio jink failure (Beam Link Failure, BLF may be referred to simply as wave beam event for (Radio Link Failure, RLF), beam link failure Barrier), the signal quality of user equipment source cell is lower than certain threshold value etc..Can by source base station or user equipment to determine whether Meet fault condition to decide whether to start later handover processes (including Counterchange roles and the release of auxiliary node).

Target BS can be become host node with executive role conversion process source base station is become auxiliary node by source base station. After the completion of Counterchange roles process, the target BS as host node can assist user equipment to discharge auxiliary node (i.e. source base station), Become the single connection state of a linking objective base station from dual link state.Alternatively, Counterchange roles and the release of auxiliary node can be closed And execute, i.e., user equipment is directly switch into from dual link state (for source base station as host node, target BS is as auxiliary node) The single connection state of linking objective base station.

By the implementation of the present embodiment, when the communication between source base station and user equipment is broken down, source base station is assisted User equipment switches to the single connection state of a linking objective base station from dual link state, and in the prior art adds target BS Adding as auxiliary node, progress Counterchange roles are compared at once later, have postponed the time for initiating Counterchange roles, are reduced appearance table tennis and are imitated A possibility that answering.

It is the present invention is based on doubly-linkeds as shown in Fig. 2, the present invention is based on the communication handover method second embodiment of dual link On the basis of the communication handover method first embodiment connect, S12 includes:

S121: Counterchange roles are carried out between source base station and target BS.

Counterchange roles are used to source base station becoming auxiliary node, and target BS is become host node.Counterchange roles can be by source Base station or target BS are initiated.

As shown in figure 3, S121 can be specifically included:

S1211: source base station and target BS are completed Counterchange roles and are negotiated.

If source base station judgement, which meets, initiates Counterchange roles after fault condition, it includes source base station to mesh that Counterchange roles, which are negotiated, It marks base station and sends Counterchange roles request, then target BS sends Counterchange roles confirmation message to source base station.If user equipment Judgement meets fault condition, and user equipment can send failure indication information to target BS and initiate angle to notify target BS Colour change, Counterchange roles are negotiated to include that target BS is requested to source base station transmission Counterchange roles in this case, then source base station Counterchange roles confirmation message is sent to target BS.

S1212: source base station sends Counterchange roles to user equipment directly or by target BS and instructs.

It is host node that Counterchange roles instruction, which is used to indicate user equipment modification target BS, modifies node supplemented by source base station. Counterchange roles instruction can be RRC signaling, such as RRC Connection Reconfiguration.

Source base station/target BS can be according to the SRB mode of communications status and/or user equipment between user equipment To determine how to send Counterchange roles instruction.If source base station determines that its communication between user equipment remains to support downlink letter The transmission of order then directly can send Counterchange roles instruction to user equipment；If source base station determines that communication can not support downlink Can the transmission of signaling, or uncertain communication be supported, then Counterchange roles instruction can be sent to target BS, then by target base It stands and forwards the Counterchange roles to instruct to user equipment, or Counterchange roles instruction is directly sent to user equipment from target BS. If the SRB of user equipment is direct SCG mode, Counterchange roles directly can be sent to user equipment from target BS and referred to It enables；If the SRB of user equipment be clastotype or direct MCG mode, can be by source base station directly or by target base It stands and sends Counterchange roles instruction to user equipment.

The instruction of user device responsive Counterchange roles carries out RRC connection reconfiguration and sets to modify target BS as host node, modifies Node supplemented by source base station.After user equipment completes Counterchange roles, Counterchange roles are sent to target BS and complete message.Counterchange roles Completing message can be RRCConnection Reconfiguration Complete.

S1213: source base station sends First ray number (Sequence Number, SN) state Transfer Message to target BS.

Serial-number-state Transfer Message is for transmitting Packet Data Convergence Protocol (Packet Data Convergence Protocol, PDCP) sequence number, to notify the data transmission state of target BS source base station.

Subsequent target BS can complete first path switching with core net, complete Counterchange roles process.This certain step It can also execute, or be performed simultaneously after first path switching.

S122: source base station is released.

Source base station is released as auxiliary node, so that user equipment becomes single connection state.This step may include existing Doubly-linked connection technology in the responsible part of source base station during the release of auxiliary node.Auxiliary section can be initiated by source base station or target BS Point release process.

Negotiate specifically, source base station and target BS complete auxiliary node release.Similar, if initiating auxiliary section by source base station Point release, then source base station sends auxiliary node release request to target BS, and then target BS sends auxiliary node to source base station and releases Put confirmation message；If initiating auxiliary node by target BS to discharge, target BS sends auxiliary node release request to source base station, Then source base station sends auxiliary node release confirmation message to target BS.Then target BS sends auxiliary node to user equipment and releases Instruction is put to discharge entire SCG configuration (user face and control plane) with notifying user equipment and disconnect the connection with source base station.User Equipment completes the rear of release and sends auxiliary node Release complete to target BS.Source base station sends third sequence to target BS Number state Transfer Message, source base station, target BS and core net complete the switching of third path.In other embodiments, third sequence The execution sequence of the transmission of row number state Transfer Message and the switching of third path can be exchanged or is performed simultaneously.Target BS to Source base station sends the notice of release customer equipment context, and source base station discharges the resource of user equipment (including the upper of user equipment Hereafter and relevant source base station be user equipment distribution resource).

In the present embodiment, the later handover processes after auxiliary node addition include that Counterchange roles and auxiliary node discharge two mistakes Journey.

It is the present invention is based on doubly-linkeds as shown in figure 4, the present invention is based on the communication handover method 3rd embodiment of dual link On the basis of the communication handover method first embodiment connect, S12 includes:

S125: source base station and target BS are completed Counterchange roles and are negotiated.

The main distinction of the present embodiment and previous embodiment is that Counterchange roles and the release of auxiliary node merge execution, Allow user equipment from source base station as host node and target BS is directly switch to as the dual link state of auxiliary node The single connection state of linking objective base station, can reduce the complexity of handoff procedure and reduce signaling overheads.

S126: source base station sends direct switching command to user equipment directly or by target BS.

Direct switching command is used to indicate user equipment and is directly switch into a list for linking objective base station from dual link state Connection status.Direct switching command is that the Counterchange roles instruction and auxiliary node in previous embodiment during Counterchange roles discharged The merging version that auxiliary node releases order in journey.Source base station/target BS can be according to logical between user equipment and source base station Letter state and/or the SRB mode of user equipment determine how to send direct switching command, and particular content can refer to previous implementation The associated description of example.

Direct switching command can be RRC signaling, such as RRC Connection Reconfiguration.User equipment Respond the single connection state that the direct switching command is directly switch into a linking objective base station from dual link state, and to target base It stands and sends direct handoff completion message.

S127: source base station sends the second serial-number-state Transfer Message to target BS.

Second serial-number-state Transfer Message is that the First ray state in previous embodiment during Counterchange roles turns The merging version of third serial-number-state Transfer Message during shifting message and the release of auxiliary node.

S128: source base station and target BS and core net complete the switching of the second path.

The switching of second path is that the first path switching and auxiliary node in previous embodiment during Counterchange roles discharged The merging version that third path switches in journey.Subsequent target BS sends the notice of release customer equipment context to source base station.

There is no restriction for execution sequence between this step and S127, with reversed order or can be performed simultaneously.

S129: the resource of source base station release user equipment.

The resource of user equipment includes the context of user equipment and the money that relevant source base station distributes for user equipment Source.

The conjunction of Counterchange roles and the release of auxiliary node is not mechanical merging, but needs not move through role in traditional scheme Transformed transition state, i.e. source base station are as auxiliary node and target BS is as host node.Specifically, for source base station, Not needing first becomes auxiliary node from host node discharges again, but directly becomes to discharge from host node, needs not move through source base station work Supplemented by node this transition state.For target BS, also do not need to first pass through becomes exclusive node as host node again, but Directly become exclusive node from auxiliary node.During whole operation, it is related to tradition inside the merging version of signaling and step The part of transition state can remove from scheme.

It is the present invention is based on doubly-linkeds as shown in figure 5, the present invention is based on the communication handover method fourth embodiment of dual link On the basis of the communication handover method first embodiment connect, further comprise before S12 after S11:

S13: source base station judges whether to meet fault condition.

Fault condition can be specified condition, can also be based only on the condition of practical application, sentence as long as can be used as The appropriate measurement of communication performance deterioration condition between disconnected user equipment and source base station.

Fault condition may include that source base station fails to receive the number of the confirmation message from user equipment and is greater than the The number that one threshold value, source base station receive the wave beam fault recovery request from user equipment is greater than second threshold, Yong Hushe The standby measurement report reported meets at least one of switching condition.First threshold/second threshold can be for more than or equal to 0 Integer.

Wherein, due to the use of beamforming technique, user equipment is possible to be consecutively detected before detecting RLF more Secondary wave beam failure (i.e. beam link failure, BLF).User equipment can send wave beam fault recovery to base station after detecting BLF Request, that is to say, that source base station, which receives wave beam fault recovery request, means that user equipment has had been detected by BLF.

Direct switching condition may include the host node that measurement obtains wave beam/cell signal quality less than the 6th threshold value, Wave beam/cell signal quality of host node is less than wave beam/cell signal quality of auxiliary node and the absolute value of the difference of the two is greater than 7th threshold value, host node wave beam/cell signal quality be greater than less than wave beam/cell signal quality of the 8th threshold value and auxiliary node One of 9th threshold value.

If meeting fault condition, source base station can star subsequent switching flow.

As shown in fig. 6, be base station the present invention is based on the executing subject of the 5th embodiment of communication handover method of dual link, and The base station is used as target BS in handoff procedure.The present embodiment includes:

S21: target BS establishes connection with the user equipment connecting with source base station is remain.

It is above-mentioned establish connection (also referred to as auxiliary node addition) during, user equipment can by with target base It stands and carries out random access to complete to synchronize.User equipment and target BS are established after connection, can transmit data between the two, User equipment enters dual link state, auxiliary node of the target BS as the user equipment under dual link state, source base station conduct Host node.The SRB/DRB of user equipment under dual link state can be direct MCG mode, clastotype or SCG mode.

S22: when the communication between source base station and user equipment is broken down, target BS assists user equipment from dual link State switches to the single connection state of a linking objective base station.

When communication is broken down, source base station or user equipment can not receive certain information of other side or receive difficult, use It is worse when the signal quality of family equipment source cell is completed than auxiliary node adding procedure.Failure can be RLF, BLF, user equipment The signal quality of source cell is lower than certain threshold value etc..It can be by source base station or user equipment to determine whether meeting fault condition To decide whether to start later handover processes.

Target BS can be become main section with executive role conversion process source base station is become auxiliary node by target BS Point.After the completion of Counterchange roles process, the target BS as host node can assist user equipment to discharge auxiliary node (i.e. source base Stand), become the single connection state of a linking objective base station from dual link state.Alternatively, Counterchange roles and auxiliary node can be released It puts merging to execute, i.e., user equipment is directly cut from dual link state (for source base station as host node, target BS is as auxiliary node) Shift to the single connection state of a linking objective base station.

By the implementation of the present embodiment, when the communication between source base station and user equipment is broken down, target BS association User equipment is helped to switch to the single connection state of a linking objective base station from dual link state, and in the prior art by target BS It carries out Counterchange roles supplemented by addition after node at once to compare, has postponed the time for initiating Counterchange roles, reduced and rattle A possibility that effect.

It is the present invention is based on doubly-linkeds as shown in fig. 7, the present invention is based on the communication handover method sixth embodiment of dual link On the basis of the 5th embodiment of communication handover method connect, S22 includes:

S221: Counterchange roles are carried out between target BS and source base station.

As shown in figure 8, S221 can be specifically included:

S2211: target BS and source base station are completed Counterchange roles and are negotiated.

If source base station judgement, which meets, initiates Counterchange roles after fault condition, it includes source base station to mesh that Counterchange roles, which are negotiated, It marks base station and sends Counterchange roles request, then target BS sends Counterchange roles confirmation message to source base station.If user equipment Judgement meets fault condition, and user equipment can send failure indication information to target BS and initiate angle to notify target BS Colour change, Counterchange roles are negotiated to include that target BS responds failure indication information to source base station transmission Counterchange roles in this case Request, then source base station sends Counterchange roles confirmation message to target BS.

S2212: target BS receives the Counterchange roles instruction from source base station.

Source base station/target BS can be according to the SRB mode of communications status and/or user equipment between user equipment It is instructed to determine how to send Counterchange roles, particular content can refer to the second reality of communication handover method the present invention is based on dual link Apply the associated description of example.If target BS is the Counterchange roles instruction for voluntarily sending rather than forwarding from source base station, this Step can be removed.

S2213: target BS sends Counterchange roles instruction to user equipment.

S2214: target BS receives the Counterchange roles completion message from user equipment.

S2215: target BS receives the First ray state Transfer Message from source base station.

S2216: target BS and core net complete first path switching.

There is no restriction for execution sequence between this step and S2215, can exchange sequencing or be performed simultaneously.This step Counterchange roles process is completed after after rapid and S2215 is complete.

S222: target BS assists the release of user equipment of auxiliary node.

Source base station is released as auxiliary node, so that user equipment becomes single connection state.This step may include existing Doubly-linked connection technology in the responsible part of source base station during the release of auxiliary node.Auxiliary section can be initiated by source base station or target BS Point release process, particular content can refer to the associated description of the communication handover method second embodiment the present invention is based on dual link.

It is the present invention is based on doubly-linkeds as shown in figure 9, the present invention is based on the 7th embodiment of communication handover method of dual link On the basis of the 5th embodiment of communication handover method connect, S22 includes:

S224: target BS and source base station are completed Counterchange roles and are negotiated.

The main distinction of the present embodiment and previous embodiment is that Counterchange roles and the release of auxiliary node merge execution, Allow user equipment from source base station as host node and target BS is directly switch to as the dual link state of auxiliary node The single connection state of linking objective base station, can reduce the complexity of handoff procedure and reduce signaling overheads.Counterchange roles Conjunction with the release of auxiliary node is not mechanical merging, but needs not move through the transition shape in traditional scheme after Counterchange roles State.

S225: target BS receives the direct switching command from source base station.

Direct switching command is used to indicate user equipment and is directly switch into a list for linking objective base station from dual link state Connection status.Direct switching command can be RRC signaling, such as RRC Connection Reconfiguration.

Direct switching command is that the Counterchange roles instruction and auxiliary node in previous embodiment during Counterchange roles discharged The merging version that auxiliary node releases order in journey.Source base station/target BS can be according to logical between user equipment and source base station Letter state and/or the SRB mode of user equipment determine how to send direct switching command, and particular content can refer to base of the present invention In the associated description of the communication handover method second embodiment of dual link.If target BS is voluntarily to send rather than forward From in the direct switching command of source base station, this step can be removed.

S226: target BS sends direct switching command to user equipment.

S227: target BS receives the direct handoff completion message from user equipment；

S228: target BS receives the second serial-number-state Transfer Message from source base station.

Similar, the second serial-number-state Transfer Message is the First ray number in previous embodiment during Counterchange roles The merging version of third serial-number-state Transfer Message during state Transfer Message and the release of auxiliary node.

S229: target BS and core net and source base station complete the switching of the second path.

The switching of second path is that the first path switching and auxiliary node in previous embodiment during Counterchange roles discharged The merging version that third path switches in journey.There is no restriction for execution sequence between this step and S228, can exchange successively suitable Sequence is performed simultaneously.Target BS sends the logical of release customer equipment context to source base station after the completion of this step and S228 Know.

It is user equipment (User the present invention is based on the executing subject of the 8th embodiment of communication handover method of dual link Equipment, UE), UE can be fixed is also possible to it is mobile, can for cellular phone, personal digital assistant (PDA), Radio modem, tablet computer, laptop, wireless phone etc..As shown in Figure 10, the present embodiment includes:

S31: user equipment establishes the connection with target BS in the case where keeping the connection with source base station to enter dual link shape State.

S32: when the communication between source base station and user equipment is broken down, user equipment switches to only from dual link state The single connection state of linking objective base station.

When communication is broken down, source base station or user equipment can not receive certain information of other side or receive difficult, use It is worse when the signal quality of family equipment source cell is completed than auxiliary node adding procedure.Failure can be RLF, BLF, user equipment The signal quality of source cell is lower than certain threshold value etc..It can be by source base station or user equipment to determine whether meeting fault condition To decide whether to start later handover processes.Counterchange roles and the release of auxiliary node can be executed successively, can also merge execution.

By the implementation of the present embodiment, when communication between source base station and user equipment is broken down, user equipment from Dual link state switches to the single connection state of a linking objective base station, in the prior art by target BS add supplemented by node It carries out Counterchange roles at once later to compare, has postponed the time for initiating Counterchange roles, reduced and a possibility that ping-pong occur.

It as shown in figure 11, is the present invention is based on double the present invention is based on the 9th embodiment of the communication handover method of dual link On the basis of the 8th embodiment of communication handover method of connection, S32 includes:

S321: user equipment is received to be instructed from the Counterchange roles of target BS or source base station.

Source base station/target BS can be according to the SRB mode of communications status and/or user equipment between user equipment To determine how to send Counterchange roles instruction.

S322: source base station will be become auxiliary node by the instruction of user device responsive Counterchange roles, and target BS is become main section Point.

S323: user equipment sends Counterchange roles to target BS and completes message.

After user equipment completes Counterchange roles, Counterchange roles are sent to target BS and complete message.Counterchange roles completion disappears Breath can be RRCConnection Reconfiguration Complete.

S324: user equipment of auxiliary node release.

Particular content can refer to the associated description of the communication handover method second embodiment the present invention is based on dual link.

It as shown in figure 12, is the present invention is based on double the present invention is based on the tenth embodiment of the communication handover method of dual link On the basis of the 8th embodiment of communication handover method of connection, S32 includes:

S326: user equipment is received from target BS or the direct switching command of source base station.

Direct switching command is that the Counterchange roles instruction and auxiliary node in previous embodiment during Counterchange roles discharged The merging version that auxiliary node releases order in journey.Source base station/target BS can be according to logical between user equipment and source base station Letter state and/or the SRB mode of user equipment determine how to send direct switching command.

S327: the direct switching command of user device responsive is directly switch into a list for linking objective base station from dual link state Connection status.

S328: user equipment sends direct handoff completion message to target BS.

As shown in figure 13, the present invention is based on the 11st embodiment of the communication handover method of dual link, be the present invention is based on On the basis of the 8th embodiment of communication handover method of dual link, further comprise before S32:

S33: user equipment judges whether to meet fault condition.

Fault condition may include: to detect RLF, wave beam fault recovery failure, the wave beam number of stoppages be greater than third threshold value, Measurement report meets at least one of switching condition, starting timer T310 or T312.The entry condition of timer T310 is It detects the physical layer problem of main plot, such as continuously receives the step-out instruction from low layer.The trip bar of timer T310 Part is the measurement report (such as A2) that triggering has the measurement mark being pre-configured in T310 timer operational process.Timer T310 Or T312 expires and may mean that and detect RLF.Third threshold value can be the integer more than or equal to 0.

If meeting fault condition, S34 is jumped to.

S34: user equipment sends failure indication information to target BS.

In the prior art, if detecting the RLF of host node, user equipment will start the RRC connection re-establishment of main plot Process, in this process, SCG configuration are released.That is, if there is RLF in host node, even if auxiliary node is still in good Good state, user equipment will not bring prolonged mobility to interrupt by auxiliary node and core network communications.

In the case where user equipment judgement meets fault condition (not including RLF), due to user equipment and source base station it Between the wireless environment that deteriorates, user equipment possibly can not success notification source base station, if source base station can not voluntarily initiate role's change It changes, then wireless environment continuous worsening may go down until there is the RLF of host node.And in the present embodiment, determine in user equipment In the case where meeting fault condition (regardless of whether including RLF), user equipment can send failure indication information to target BS To indicate that target BS initiates Counterchange roles, to reduce unnecessary RRC connection re-establishment process, shortens mobility and interrupt simultaneously Reduce signaling overheads.

The specific handoff procedure under different situations is illustrated with reference to the accompanying drawing, wherein portion identical with previous embodiment Divide and is not repeated.

As shown in figure 14, in an embodiment of the present invention, fault condition is RLF and initiates to merge by target BS direct Handoff procedure, overall handoff procedure specifically include:

S101: user equipment, source base station and target BS complete auxiliary node addition.

User equipment enters dual link state after the completion of auxiliary node addition, and wherein source base station is as host node, target BS As auxiliary node.

S102: user equipment detects the RLF of source base station.

User equipment judgement meets fault condition.

S103: user equipment sends failure indication information to target BS.

S104: target BS sends Counterchange roles request to source base station.

S105: source base station sends Counterchange roles confirmation message to target BS.

S106: target BS sends RRC Connection Reconfiguration to user equipment.

The RRC Connection Reconfiguration is as direct switching command.The SRB of user equipment in this example For direct SCG mode.The user device responsive direct switching command is directly switch into a linking objective base station from dual link state Single connection state.

S107: user equipment sends RRC Connection Reconfiguration Complete to target BS.

The RRC Connection Reconfiguration Complete is as direct handoff completion message.

S108: source base station sends the second serial-number-state Transfer Message to target BS.

S109: source base station, target BS and core net complete the switching of the second path.

S110: target BS notifies the context of source base station release user equipment.

S111: the resource of source base station release user equipment.

As shown in figure 15, in an alternative embodiment of the invention, fault condition be BLF and by source base station initiate Counterchange roles and Auxiliary node discharges process, and overall handoff procedure specifically includes:

S201: user equipment, source base station and target BS complete auxiliary node addition.

S202: the number that source base station receives the BLF recovery request from user equipment is greater than second threshold.

Source base station judgement meets fault condition.

S203: source base station sends Counterchange roles request to target BS.

S204: target BS sends Counterchange roles confirmation message to source base station.

S205: source base station sends RRC Connection Reconfiguration to target BS.

The RRC Connection Reconfiguration is instructed as Counterchange roles.The SRB of user equipment in this example For clastotype.

S206: target BS forwards RRC Connection Reconfiguration to user equipment.

The user device responsive Counterchange roles instruction modification target BS is host node, modifies node supplemented by source base station.

S207: user equipment sends RRC Connection Reconfiguration Complete to target BS.

The RRC Connection Reconfiguration Complete completes message as Counterchange roles.

S208: source base station sends First ray state Transfer Message to target BS.

S209: target BS and core net complete first path switching.

S210: source base station sends auxiliary node release request to target BS.

S211: target BS sends auxiliary node to source base station and discharges confirmation message.

S212: target BS sends RRC Connection Reconfiguration to user equipment.

The RRC Connection Reconfiguration releases order as auxiliary node.

S213: user equipment sends RRC Connection Reconfiguration Complete to target BS.

The RRC Connection Reconfiguration Complete is as auxiliary node Release complete.

S214: source base station sends third serial-number-state Transfer Message to target BS.

S215: source base station, target BS and core net complete the switching of third path.

S216: target BS notifies the context of source base station release user equipment.

S217: the resource of source base station release user equipment.

It is base station the present invention is based on the executing subject of the 12nd embodiment of communication handover method of dual link, and the base station exists Source base station is used as in handoff procedure.As shown in figure 16, the present embodiment includes:

S41: source base station assists user equipment to enter dual link state.

Source base station can execute auxiliary node adding procedure, by target BS add supplemented by node.Use under dual link state Family equipment connects source base station and target BS simultaneously, and wherein source base station is as host node, and target BS is as auxiliary node.In this step Before rapid, source base station can be that user equipment confirms target BS according to the measurement report of user equipment to report.Dual link state Under the SRB/DRB of user equipment can be direct MCG mode, clastotype or SCG mode.

S42: source base station assistance user equipment is directly switch into the single connection shape of a linking objective base station from dual link state State.

As shown in figure 17, S42 can be specifically included:

S421: source base station sends direct switching command to user equipment directly or by target BS.

Direct switching command is that the Counterchange roles instruction during Counterchange roles and auxiliary node discharge process in the prior art In the merging version that releases order of auxiliary node, be used to indicate user equipment from dual link state and be directly switch into a linking objective base The single connection state stood.Direct switching command can be RRC signaling, such as RRC Connection Reconfiguration.

S422: source base station transmits Sequence Number state Transfer Message to target BS.

Serial-number-state Transfer Message be in the prior art Counterchange roles process and auxiliary node release during sequence number shape The merging version of state Transfer Message.

S423: source base station and core net and target BS complete path switching.

Path switching be in the prior art Counterchange roles process and auxiliary node release during path switch merging version. There is no restriction for execution sequence between this step and S422, can exchange sequencing or be performed simultaneously.

S424: the resource of source base station release user equipment.

By the implementation of the present embodiment, Counterchange roles and the release of auxiliary node are merged and is executed, is i.e. user equipment is from source base station As host node and target BS is directly switch into the single connection shape of a linking objective base station as the dual link state of auxiliary node State can reduce the complexity of handoff procedure and reduce signaling overheads.The conjunction of Counterchange roles and the release of auxiliary node is not machine The merging of tool, but need not move through the transition state in traditional scheme after Counterchange roles.

It is base station the present invention is based on the executing subject of the 13rd embodiment of communication handover method of dual link, and the base station exists Target BS is used as in handoff procedure.As shown in figure 18, the present embodiment includes:

S51: target BS establishes connection with the user equipment connecting with source base station is remain.

S52: target BS assists user equipment to be directly switch into a single connection for linking objective base station from dual link state State.

As shown in figure 19, S52 can be specifically included:

S520: target BS receives the direct switching command from source base station.

If target BS is voluntarily to send rather than forward direct switching command, this step can be saved.

S521: target BS sends direct switching command to user equipment.

S522: target BS receives the direct handoff completion message from user equipment.

S523: target BS receives the serial-number-state Transfer Message from source base station.

S524: target BS and source base station and core net complete path switching.

Path switching be in the prior art Counterchange roles process and auxiliary node release during path switch merging version. There is no restriction for execution sequence between this step and S523, can exchange sequencing or be performed simultaneously.

It is user equipment the present invention is based on the executing subject of the 14th embodiment of communication handover method of dual link.Such as Figure 20 Shown, the present embodiment includes:

S61: user equipment establishes the connection with target BS in the case where keeping the connection with source base station to enter dual link shape State.

S62: user equipment is received from target BS or the direct switching command of source base station.

Direct switching command is used to indicate user equipment and is directly switch into a list for linking objective base station from dual link state Connection status.Direct switching command can be RRC signaling, such as RRCConnection Reconfiguration.

S63: the direct switching command of user device responsive is directly switch into a list for linking objective base station from dual link state Connection status.

It as shown in figure 21, the present invention is based on the communication switching device first embodiment of dual link include: processor 110 and logical Believe circuit 120,110 connection communication circuit 120 of processor.

Telecommunication circuit 120 is that communication switching device is led to other communication equipments for sending and receiving user data The interface of letter.

Processor 110 controls the operation of communication switching device, and processor 110 can also be known as CPU (Central Processing Unit, central processing unit).Processor 110 may be a kind of IC chip, the processing with signal Ability.Processor 110 can also be general processor, digital signal processor (DSP), specific integrated circuit (ASIC), ready-made Programmable gate array (FPGA) either other programmable logic device, discrete gate or transistor logic, discrete hardware group Part.General processor can be microprocessor or the processor is also possible to any conventional processor etc..

Processor 110 for execute instruction with realize the present invention is based on the communication handover method first to the 7th of dual link, 12nd, any of the 13rd embodiment and arbitrarily method provided by the combination that does not conflict.

Communication switching device in the present embodiment can be base station, be also possible to the individual components that can be integrated in base station, Such as baseband board.

It as shown in figure 22, the present invention is based on the communication switching device second embodiment of dual link include: processor 210 and logical Believe circuit 220,210 connection communication circuit 220 of processor.

Telecommunication circuit 220 is that communication switching device is led to other communication equipments for sending and receiving user data The interface of letter.

Processor 210 controls the operation of communication switching device, and processor 110 can also be known as CPU (Central Processing Unit, central processing unit).Processor 110 may be a kind of IC chip, the processing with signal Ability.Processor 110 can also be general processor, digital signal processor (DSP), specific integrated circuit (ASIC), ready-made Programmable gate array (FPGA) either other programmable logic device, discrete gate or transistor logic, discrete hardware group Part.General processor can be microprocessor or the processor is also possible to any conventional processor etc..

Processor 210 realizes that the present invention is based on the communication handover methods the 8th to the tenth of dual link for executing instruction One, any of the 14th embodiment and arbitrarily method provided by the combination that does not conflict.

Communication switching device in the present embodiment can be user equipment, be also possible to be integrated in only in user equipment Vertical component, such as baseband chip.

It as shown in figure 23, include memory 310 the present invention is based on the communication switching device 3rd embodiment of dual link, storage Device 310 is stored with instruction, which is performed realization, and the present invention is based on the communication handover methods first of dual link to the 7th, the Method provided by any of 12, the 13rd embodiment and the combination not conflicted arbitrarily.

Memory 310 may include read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), flash memory (Flash Memory), hard disk, CD etc..

It as shown in figure 24, include memory 410 the present invention is based on the communication switching device fourth embodiment of dual link, storage Device 410 is stored with instruction, the instruction be performed realization the present invention is based on the communication handover method the 8th to the 11st of dual link, Method provided by any of 14th embodiment and the combination not conflicted arbitrarily.

Memory 410 may include read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), flash memory (Flash Memory), hard disk, CD etc..

In several embodiments provided by the present invention, it should be understood that disclosed method and apparatus can pass through it Its mode is realized.For example, device embodiments described above are only schematical, for example, the module or unit Division, only a kind of logical function partition, there may be another division manner in actual implementation, such as multiple units or group Part can be combined or can be integrated into another system, or some features can be ignored or not executed.Another point, it is shown Or the mutual coupling, direct-coupling or communication connection discussed can be through some interfaces, device or unit it is indirect Coupling or communication connection can be electrical property, mechanical or other forms.

The unit as illustrated by the separation member may or may not be physically separated, aobvious as unit The component shown may or may not be physical unit, it can and it is in one place, or may be distributed over multiple In network unit.Some or all of unit therein can be selected to realize present embodiment scheme according to the actual needs Purpose.

It, can also be in addition, the functional units in various embodiments of the present invention may be integrated into one processing unit It is that each unit physically exists alone, can also be integrated in one unit with two or more units.Above-mentioned integrated list Member both can take the form of hardware realization, can also realize in the form of software functional units.

If the integrated unit is realized in the form of SFU software functional unit and sells or use as independent product When, it can store in a computer readable storage medium.Based on this understanding, technical solution of the present invention is substantially The all or part of the part that contributes to existing technology or the technical solution can be in the form of software products in other words It embodies, which is stored in a storage medium, including some instructions are used so that a computer It is each that equipment (can be personal computer, server or the network equipment etc.) or processor (processor) execute the present invention The all or part of the steps of embodiment the method.And storage medium above-mentioned includes: USB flash disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic or disk Etc. the various media that can store program code.

Mode the above is only the implementation of the present invention is not intended to limit the scope of the invention, all to utilize this Equivalent structure or equivalent flow shift made by description of the invention and accompanying drawing content, it is relevant to be applied directly or indirectly in other Technical field is included within the scope of the present invention.

Claims

1. a kind of communication handover method based on dual link characterized by comprising

Source base station assists user equipment to enter dual link state, and the user equipment under the dual link state connects institute simultaneously Source base station and target BS are stated, wherein the source base station is as host node, the target BS is as auxiliary node；

When communication between the source base station and the user equipment is broken down, the source base station assist the user equipment from The dual link state switches to the single connection state for only connecting the target BS.

2. the method according to claim 1, wherein

The source base station assists the user equipment to switch to the list for only connecting the target BS based on the dual link state Connection status includes:

Counterchange roles are carried out between the source base station and the target BS, the Counterchange roles are for becoming the source base station The target BS is become the host node by the auxiliary node；

The source base station is released.

3. according to the method described in claim 2, it is characterized in that,

Counterchange roles are carried out between the source base station and the target BS includes:

The source base station and the target BS are completed Counterchange roles and are negotiated；

The source base station sends Counterchange roles instruction to the user equipment directly or by the target BS；

The source base station sends First ray state Transfer Message to the target BS.

4. the method according to claim 1, wherein

The source base station sends direct switching command to the user equipment directly or by the target BS, described directly to cut Instruction is changed to be used to indicate the user equipment and be directly switch into the Dan Lian for only connecting the target BS from the dual link state Connect state；

The source base station sends the second serial-number-state Transfer Message to the target BS；

The source base station and the target BS and core net complete the switching of the second path；

The source base station discharges the resource of the user equipment.

5. the method according to claim 3 or 4, which is characterized in that

The source base station completes Counterchange roles negotiation with the target BS

The source base station sends Counterchange roles request to the target BS；

The source base station receives the Counterchange roles confirmation message from the target BS.

6. the method according to claim 3 or 4, which is characterized in that

The source base station receives the Counterchange roles request from the target BS, and the Counterchange roles request is the target Base station in response from the user equipment failure indication information and send；

The source base station sends Counterchange roles confirmation message to the target BS.

7. method according to any of claims 1-4, which is characterized in that

The source base station assists the user equipment to switch to the list for only connecting the target BS based on the dual link state Further comprise before connection status:

The source base station judges whether to meet fault condition.

8. the method according to the description of claim 7 is characterized in that

The fault condition include the source base station fail to receive it is big from the number of the confirmation message of the user equipment It is greater than second in the number that first threshold, the source base station receive the wave beam fault recovery request from the user equipment Threshold value, the measurement report of the user equipment to report meet at least one of switching condition.

9. a kind of communication handover method based on dual link characterized by comprising

Target BS establishes connection with the user equipment connecting with source base station is remain, and the target BS is as dual link state Under the user equipment auxiliary node, the source base station is as host node；

When communication between the source base station and the user equipment is broken down, the target BS assists the user equipment The single connection state for only connecting the target BS is switched to from the dual link state.

10. according to the method described in claim 9, it is characterized in that,

The target BS assists the user equipment to switch to the list for only connecting the target BS from the dual link state Connection status includes:

Counterchange roles are carried out between the target BS and the source base station, the Counterchange roles are for becoming the source base station The target BS is become the host node by the auxiliary node；

The target BS assists the user equipment to discharge the source base station.

11. according to the method described in claim 10, it is characterized in that,

Counterchange roles are carried out between the target BS and the source base station includes:

The target BS and the source base station are completed Counterchange roles and are negotiated；

The target BS sends Counterchange roles instruction to the user equipment；

The target BS receives the Counterchange roles completion message from the user equipment；

The target BS receives the First ray state Transfer Message from the source base station；

The target BS and core net complete first path switching.

12. according to the method for claim 11, which is characterized in that

The target BS further comprises before sending Counterchange roles instruction to the user equipment:

The target BS receives the Counterchange roles instruction from the source base station.

13. according to the method described in claim 9, it is characterized in that,

The target BS is assisted the user equipment to be switched to based on the dual link state and only connects the target BS Single connection state includes:

The target BS sends direct switching command to the user equipment, and the direct switching command is used to indicate the use Family equipment is directly switch into the single connection state for only connecting the target BS from the dual link state；

The target BS receives the direct handoff completion message from the user equipment；

The target BS receives the second serial-number-state Transfer Message from the source base station；

The target BS and core net and the source base station complete the switching of the second path.

14. according to the method for claim 13, which is characterized in that

The target BS further comprises before sending direct switching command to the user equipment:

The target BS receives the direct switching command from the source base station.

15. method described in any one of 1-14 according to claim 1, which is characterized in that

The target BS completes Counterchange roles negotiation with the source base station

The target BS responds the failure indication information and sends Counterchange roles request to the source base station；

The target BS receives the Counterchange roles confirmation message from the source base station.

16. method described in any one of 1-14 according to claim 1, which is characterized in that

The target BS receives the Counterchange roles request from the source base station；

The target BS sends Counterchange roles confirmation message to the source base station.

17. the method according to any one of claim 9-14, which is characterized in that

The target BS assists the user equipment to switch to the list for only connecting the target BS from the dual link state Further comprise before connection status:

The target BS receives the failure indication information from the user equipment.

18. a kind of communication handover method based on dual link, which is characterized in that

User equipment is established in the case where keeping the connection with source base station and the connection of target BS is to enter dual link state, described double The source base station is as host node under connection status and the target BS is as auxiliary node；

When communication between the source base station and the user equipment is broken down, the user equipment is from the dual link state Switch to the single connection state for only connecting the target BS.

19. according to the method for claim 18, which is characterized in that

The user equipment is switched to from the dual link state only to be connected the single connection state of the target BS and includes:

The user equipment is received to be instructed from the Counterchange roles of the target BS or the source base station；

The source base station will be become the auxiliary node by the instruction of Counterchange roles described in the user device responsive, by the target base Station becomes the host node；

The user equipment sends Counterchange roles to the target BS and completes message；

The user equipment discharges the source base station.

20. according to the method for claim 18, which is characterized in that

The user equipment is received from the target BS or the direct switching command of the source base station；

Direct switching command is directly switch into from the dual link state described in the user device responsive only connects the target The single connection state of base station；

The user equipment sends direct handoff completion message to the target BS.

21. method described in any one of 8-20 according to claim 1, which is characterized in that

The user equipment switches to the advance one for only connecting the single connection state of the target BS from the dual link state Step includes:

The user equipment judges whether to meet fault condition；

If satisfied, then the user equipment to the target BS send failure indication information.

22. according to the method for claim 21, which is characterized in that

The fault condition includes: to detect radio jink failure, and wave beam fault recovery failure, the wave beam number of stoppages are greater than third Threshold value, measurement report meet at least one of switching condition, starting timer T310 or T312.

23. a kind of communication handover method based on dual link characterized by comprising

The source base station assists the user equipment to be directly switch into from the dual link state and only connects the target BS Single connection state.

24. according to the method for claim 23, which is characterized in that

The source base station assists the user equipment to be directly switch into from the dual link state and only connects the target BS Single connection state includes:

The source base station transmits Sequence Number state Transfer Message to the target BS；

The source base station and core net and the target BS complete path switching；

The source base station discharges the resource of the user equipment.

25. a kind of communication handover method based on dual link characterized by comprising

The target BS assists the user equipment to be directly switch into from the dual link state and only connects the target BS Single connection state.

26. according to the method for claim 25, which is characterized in that

The target BS receives the serial-number-state Transfer Message from the source base station；

The target BS and core net and the source base station complete path switching.

27. according to the method for claim 26, which is characterized in that

28. a kind of communication handover method based on dual link characterized by comprising

Direct switching command is directly switch into from the dual link state described in the user device responsive only connects the target The single connection state of base station.

29. a kind of communication switching device based on dual link, which is characterized in that including processor and telecommunication circuit, the processing Device connects the telecommunication circuit；

The processor is for executing instruction to realize such as any one of claim 1-28 the method.

30. a kind of communication switching device based on dual link, is stored with instruction, which is characterized in that described instruction is performed reality The now method as described in any one of claim 1-28.