CN106900015A - A kind for the treatment of method and apparatus re-established in across base station handoff procedure - Google Patents

Abstract

The invention provides a processing method and device for re-establishment in the process of handover between base stations. Wherein, the method includes: when the target base station receives a radio resource control (RRC) connection re-establishment request of the user equipment (UE) in the handover preparation phase, the target base station suspends the handover preparation process and executes the RRC connection re-establishment process; when the target When the base station receives the UE's RRC connection re-establishment complete message, the target base station activates the handover preparation process, sends an RRC connection reconfiguration message to the UE, and sends a handover confirmation message carrying an extended cause value to the mobility management entity (MME) or the source base station. Through the present invention, the processing strategy of the target base station receiving the RRC connection re-establishment request in the cross-base station handover preparation stage is proposed, which reduces the occurrence rate of UE call drop caused by RRC connection re-establishment failure in the handover preparation process, and improves handover stability and user experience.

Description

A processing method and device for re-establishment during inter-base station handover

technical field

The present invention relates to the field of communications, in particular to a processing method and device for re-establishment during handover between base stations.

Background technique

In a Long Term Evolution (LTE for short) system, the state of a user equipment (User Equipment, UE for short) is divided into two types: a connected state (RRC_CONNECTED) and an idle state (RRC_IDLE). When the UE in the RRC_CONNECTED state moves from the serving cell to another cell, a handover (HandOver) will be triggered to ensure uninterrupted service. When a UE is handed over from a cell of an evolved base station (Evolved Node B, eNB for short, ie, LTE base station) to another cell of an eNB, a handover across base stations will be triggered. If there is an X2 interface (X2Interface) between the handover source base station and the handover target base station and they are connected to the same Mobility Management Entity (MME for short), according to the existing technology (3rd Generation Partnership Project (3rd Generation Partnership Project) Project, referred to as 3GPP) protocol, 23.401 protocol), the source eNB will initiate a handover through the X2 interface (X2Interface Handover), otherwise it will initiate a handover through the S1 interface (S1InterfaceHandover). For these two handovers, according to the different stages of handover, they are divided into two stages: preparation and execution. The preparation phase includes the following steps:

In the first step, the handover source side eNB sends a handover request (Handover Request)

In the second step, according to the received handover request, the eNB on the handover target side replies with a handover request acknowledgment (Handover Request Ack) message after the radio resources are accepted and the service bearer is established, which carries the radio resource control (Radio Resource Control (referred to as RRC for short) reconfiguration message, enters the handover execution phase.

Step 3: After entering the handover execution stage, the handover source eNB configures the UE according to the RRC connection reconfiguration message generated by the handover target eNB, and then the UE accesses the target base station to complete the handover.

In the S1/X2 handover preparation stage, due to radio link failure (Radio Link Failure, referred to as RLF for short) and other air interface quality reasons, the UE that is in the security activation state in the RRC connection state is re-established to the handover target side base station. For the handover target base station, the context information of the UE is included and the access stratum (AS for short) has been safely activated. According to the 36.331 protocol, this re-establishment meets the conditions for successful re-establishment.

When the handover target base station receives the RRC connection re-establishment request message in the handover preparation phase, according to the prior art, the following two hypothetical processing schemes are proposed:

Assumption 1: The base station on the handover target side replies the handover preparation failure message to the base station on the handover source side, which will inevitably cause the base station on the handover source side to initiate the next handover to other base stations or cells or release the UE. In fact, the UE has lost RRC with the handover source base station. In this way, the base station on the handover target side can only reject the re-establishment of the RRC connection.

Hypothesis 2: The base station on the handover target side replies a handover confirmation message to the base station on the handover source side. In fact, the UE has lost the RRC connection with the handover source base station, but the handover source base station still sends an RRC connection reconfiguration message for the handover command to the UE, resulting in The wireless resources of the base station on the handover source side are wasted.

Therefore, no matter which hypothetical solution above, it cannot reasonably and effectively solve the problem that the handover target base station receives a re-establishment request in the handover preparation stage, which causes the UE to drop the call due to the failure of the re-establishment.

Contents of the invention

The present invention provides a method and device for processing re-establishment during cross-base station handover, so as to at least solve the problem in the related art that the target base station receives an RRC connection re-establishment request in the preparation stage of cross-base station handover, which causes re-establishment failure and causes UE call drop question.

According to one aspect of the present invention, a method for processing re-establishment during inter-base station handover is provided, including: when the target base station receives the UE's RRC connection re-establishment request during the handover preparation phase, the target base station suspends the handover preparation The process is to execute the RRC connection re-establishment process; when the target base station receives the RRC connection re-establishment completion message of the UE, the target base station activates the handover preparation process and sends an RRC connection reconfiguration message to the UE, And send a handover confirmation message carrying an extended cause value to the MME or the source base station.

Optionally, the target base station sending the handover acknowledgment message carrying the extended cause value includes: when the handover type is S1 handover, the target base station sending the handover confirmation message carrying the extended cause value Acknowledging a message to the MME, wherein the extended cause value is used to instruct the MME to send a handover command carrying the extended cause value to the source base station, and to instruct the source base station not to send an RRC connection reconnection command to the UE. with news.

Optionally, the sending by the target base station of the handover confirmation message carrying the extended cause value includes: when the handover type is X2 handover, the target base station sending the handover confirmation message carrying the extended cause value To the source base station, wherein the extended cause value is used to instruct the source base station not to send an RRC connection reconfiguration message to the UE.

Optionally, after the target base station sends the RRC connection reconfiguration message to the UE, the method further includes: starting an RRC connection reconfiguration completion timer; when the RRC connection reconfiguration completion timer expires When receiving the RRC connection reconfiguration complete message, the target base station confirms that the UE successfully completes the handover.

Optionally, after the target base station confirms that the UE has successfully completed the handover, the method further includes: the target base station sending a path switch request message or a handover notification message to the MME, wherein the path switch request message Or the handover notification message is used to indicate that the UE has successfully completed the handover.

Optionally, when the RRC connection reconfiguration complete timer expires and the RRC connection reconfiguration complete message is not received, the method further includes: the target base station performing RRC connection resource release of the UE process.

Optionally, after the target base station suspends the handover preparation process, the method further includes: when the handover type is S1 handover, and the target base station has not received the RRC connection re-establishment completion of the UE message, the target base station receives the UE context release command sent by the MME; the target base station sends an RRC connection re-establishment rejection message to the UE according to the UE context release command, and sends a UE context release complete message to the MME.

Optionally, after the target base station suspends the handover preparation process, the method further includes: when the handover type is X2 handover, and the target base station has not received the RRC connection re-establishment completion of the UE message, the target base station receives the handover cancel message sent by the source base station; the target base station sends an RRC connection re-establishment rejection message to the UE according to the handover cancel message.

According to another aspect of the present invention, there is also provided a processing device for re-establishment in the process of cross-base station handover, which is applied to a base station, including: a first processing module, used to receive When the RRC connection re-establishment request of the UE is requested, the handover preparation process is suspended, and the RRC connection re-establishment process is executed; the second processing module is configured to activate the handover preparation process when receiving the RRC connection re-establishment completion message of the UE , sending an RRC connection reconfiguration message to the UE, and sending a handover confirmation message carrying an extended cause value to the MME or the source base station.

Optionally, the second processing module is configured to: when the handover type is S1 handover, send a handover confirmation message carrying the extended cause value to the MME, where the extended cause value is used to indicate The MME sends a handover command carrying the extended cause value to the source base station, and instructs the source base station not to send an RRC connection reconfiguration message to the UE.

Optionally, the second processing module is configured to: when the handover type is X2 handover, send a handover confirmation message carrying the extended cause value to the source base station, where the extended cause value is used for Instructing the source base station not to send an RRC connection reconfiguration message to the UE.

Optionally, the device further includes: a starting module, configured to start an RRC connection reconfiguration completion timer; a confirmation module, configured to receive the RRC connection reconfiguration before the RRC connection reconfiguration completion timer expires When the message is completed, it is confirmed that the UE completes the handover successfully.

Optionally, the device further includes: a first sending module, configured to send a path switching request message or a handover notification message to the MME, where the path switching request message or the switching notification message is used to indicate the The UE has successfully completed the handover.

Optionally, the device further includes: an executing module, configured to execute the RRC connection resource of the UE when the RRC connection reconfiguration completion timer expires and the RRC connection reconfiguration completion message is not received. release process.

Optionally, the device further includes: a first receiving module, configured to receive the message sent by the MME when the handover type is S1 handover and the RRC connection re-establishment completion message of the UE has not been received. UE context release command; a second sending module, configured to send an RRC connection re-establishment rejection message to the UE according to the UE context release command, and send a UE context release complete message to the MME.

Optionally, the device further includes: a second receiving module, configured to receive the handover message sent by the source base station when the handover type is X2 handover and the RRC connection re-establishment completion message of the UE has not been received. Cancel message; a third sending module, configured to send an RRC connection re-establishment rejection message to the UE according to the handover cancel message.

Through the present invention, when the target base station receives the RRC connection re-establishment request of the UE in the handover preparation phase, the target base station suspends the handover preparation process and executes the RRC connection re-establishment process; when the target base station receives the RRC connection re-establishment request of the UE When the connection re-establishment complete message is received, the target base station activates the handover preparation process, sends an RRC connection reconfiguration message to the UE, and sends a handover confirmation message carrying an extended cause value, which solves the problem of cross-base station in the related art. In the handover preparation stage, the target base station receives the RRC connection re-establishment request and the re-establishment failure causes the UE to drop the call, which improves the stability of the handover and the user experience.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention and constitute a part of the application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations to the present invention. In the attached picture:

FIG. 1 is a flow chart of a processing method for re-establishment in a cross-base station handover process according to an embodiment of the present invention;

Fig. 2 is a structural block diagram of a processing device for re-establishment in a cross-base station handover process according to an embodiment of the present invention;

FIG. 3 is an optional structural block diagram 1 of a processing device for re-establishment in a cross-base station handover process according to an embodiment of the present invention;

FIG. 4 is an optional structural block diagram 2 of a processing device for re-establishment in a cross-base station handover process according to an embodiment of the present invention;

FIG. 5 is an optional structural block diagram 3 of a processing device for re-establishment in a cross-base station handover process according to an embodiment of the present invention;

FIG. 6 is an optional structural block diagram 4 of a processing device for re-establishment in a cross-base station handover process according to an embodiment of the present invention;

FIG. 7 is an optional structural block diagram 5 of a processing device for re-establishment in a cross-base station handover process according to an embodiment of the present invention;

FIG. 8 is a flow chart of a processing method for re-establishment during inter-base station handover according to optional embodiment 1 of the present invention;

FIG. 9 is a flow chart of a processing method for re-establishment during inter-base station handover according to an optional embodiment 2 of the present invention;

FIG. 10 is a flow chart of a processing method for re-establishment during inter-base station handover according to optional embodiment 3 of the present invention;

FIG. 11 is a flow chart of a processing method for re-establishment during inter-base station handover according to optional embodiment 4 of the present invention;

12 is a flow chart of a processing method for re-establishment during inter-base station handover according to optional embodiment 5 of the present invention;

FIG. 13 is a flow chart of a method for canceling inter-base station handover according to optional embodiment six of the present invention;

Fig. 14 is a flow chart of a method for canceling inter-base station handover according to optional embodiment 7 of the present invention.

detailed description

Hereinafter, the present invention will be described in detail with reference to the drawings and examples. It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

It should be noted that the terms "first" and "second" in the description and claims of the present invention and the above drawings are used to distinguish similar objects, but not necessarily used to describe a specific sequence or sequence.

In this embodiment, a processing method for re-establishment during cross-base station handover is provided. FIG. 1 is a flow chart of a processing method for re-establishment during cross-base station handover according to an embodiment of the present invention, as shown in FIG. 1 , the process includes the following steps:

Step S102, when the target base station receives the UE's RRC connection re-establishment request during the handover preparation phase, the target base station suspends the handover preparation process and executes the RRC connection re-establishment process;

Step S104, when the target base station receives the UE's RRC connection re-establishment completion message, the target base station activates the handover preparation process, sends an RRC connection reconfiguration message to the UE, and sends a handover confirmation message carrying an extended cause value to the MME or the source base station .

Through the above steps, when the target base station receives the UE's RRC connection re-establishment request during the handover preparation phase, the target base station suspends the ongoing handover preparation process, and first re-establishes the RRC connection with the UE by sending an RRC connection re-establishment message to the UE , when the target base station receives the UE's RRC connection re-establishment complete message, activates the pending handover preparation process, sends an RRC connection reconfiguration message to the UE, and sends a handover confirmation message carrying an extended cause value. It can be seen that by adopting the above steps, the problem of UE call drop caused by the target base station receiving the RRC connection re-establishment request in the cross-base station handover preparation phase is solved, and the occurrence of UE call drop caused by RRC connection re-establishment failure in the handover preparation process is reduced. rate, improving the switching stability and user experience.

Optionally, since the target base station sends the RRC connection reconfiguration message to the UE, after the source base station receives the handover confirmation message carrying the extended cause value, it does not need to send the RRC connection reconfiguration message to the UE according to the indication of the extended cause value. When the handover type is S1 handover, the target base station can send the handover confirmation message carrying the extended cause value used to instruct the source base station not to send the RRC connection reconfiguration message to the MME, and then the MME sends the handover command to the source base station Carrying the above cause value indicates that the source base station does not send the RRC connection reconfiguration message to the UE.

For example: in the above step S104, when the handover type is S1 handover, the target base station can send a handover confirmation message carrying an extended cause value to the MME, where the extended cause value is used to instruct the MME to send a handover confirmation message carrying an extended cause value. A handover command is sent to the source base station, and the source base station is instructed not to send an RRC connection reconfiguration message to the UE. Through the above steps, the target base station informs the source base station not to send the RRC connection reconfiguration message to the UE through the MME, which can avoid the waste of RRC connection resources. At the same time, when the source base station has disconnected the RRC connection with the UE, the UE cannot receive the source The message sent by the base station, which leads to the failure of RRC connection reconfiguration, the target base station instructs the UE to perform RRC connection reconfiguration, and instructs the source base station not to send the RRC connection reconfiguration message, reducing the failure of RRC connection re-establishment during the handover preparation process This reduces the occurrence rate of UE call drops, and improves handover stability and user experience.

Optionally, since the target base station sends the RRC connection reconfiguration message to the UE, after the source base station receives the handover confirmation message carrying the extended cause value, it does not need to send the RRC connection reconfiguration message to the UE according to the indication of the extended cause value. When the handover type is X2 handover, the target base station can send a handover confirmation message carrying an extended cause value for instructing the source base station not to send an RRC connection reconfiguration message to the source base station to instruct the source base station not to send an RRC connection reconfiguration message to the UE information.

For example: in the above step S104, when the handover type is X2 handover, the target base station can send a handover confirmation message carrying an extended cause value to the source base station, where the extended cause value is used to instruct the source base station not to send RRC to the UE Connection reconfiguration message. Through the above steps, the target base station notifies the source base station not to send the RRC connection reconfiguration message to the UE, which can avoid the waste of RRC connection resources. At the same time, when the source base station has disconnected the RRC connection with the UE, the UE cannot receive the message, which leads to the failure of RRC connection reconfiguration, the target base station instructs the UE to perform RRC connection reconfiguration, and instructs the source base station not to send the RRC connection reconfiguration message, reducing the RRC connection re-establishment failure during the handover preparation process. The occurrence rate of dropped calls improves the stability of switching and user experience.

Optionally, after the above step S104, the target base station may start the RRC connection reconfiguration completion timer to control the RRC connection reconfiguration process, and, when receiving the RRC connection reconfiguration timer before the RRC connection reconfiguration completion timer expires When the message is completed, the target base station can confirm that the UE has successfully completed the handover.

Optionally, when the target base station confirms that the UE has successfully completed the handover, the target base station may send a path switch request message or a handover notification message to the MME to notify the MME that the UE has successfully completed the handover. Afterwards, the MME can notify the source base station to release the context resource of the UE, or the MME can reply a path conversion request confirmation message to the target base station, and then the target base station notifies the source base station to release the context resource of the UE.

Optionally, after the target base station starts the RRC connection reconfiguration complete timer, the target base station can also execute the UE's RRC connection resource release process.

Optionally, when the handover type is S1 handover, and the target base station has not received the RRC connection re-establishment completion message of the UE, after the above step S102, the target base station may receive the UE context release command sent by the MME, at this time , the target base station can send an RRC connection re-establishment rejection message to the UE according to the UE context release command, and send a UE context release complete message to the MME. Or, when the handover type is X2 handover, and the target base station has not received the RRC connection re-establishment completion message of the UE, after the above step S102, the target base station may receive the handover cancel message sent by the source base station. At this time, the target base station The base station may send an RRC connection re-establishment reject message to the UE according to the handover cancel message.

Through the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiments can be implemented by means of software plus a necessary general-purpose hardware platform, and of course also by hardware, but in many cases the former is better implementation. Based on such an understanding, the essence of the technical solution of the present invention or the part that contributes to the prior art can be embodied in the form of software products, and the computer software products are stored in a storage medium (such as ROM/RAM, disk, CD) contains several instructions to make a terminal device (which may be a mobile phone, a computer, a server, or a network device, etc.) execute the method of each embodiment of the present invention.

This embodiment also provides a processing device for re-establishment during inter-base station handover, which is applied to a base station. The device is used to implement the above embodiments and optional implementation modes, and those that have been explained will not be repeated. As used below, the term "module" may be a combination of software and/or hardware that realizes a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementations in hardware, or a combination of software and hardware are also possible and contemplated.

Fig. 2 is a structural block diagram of a processing device for re-establishment in a cross-base station handover process according to an embodiment of the present invention. As shown in Fig. 2 , the device includes: a first processing module 22 and a second processing module 24, wherein the first A processing module 22, used to suspend the handover preparation process and execute the RRC connection re-establishment process when the base station receives the RRC connection re-establishment request of the UE in the handover preparation phase as the target base station; the second processing module 24 is coupled to the first The processing module 22 is configured to activate the handover preparation process when receiving the RRC connection re-establishment completion message from the UE, send an RRC connection reconfiguration message to the UE, and send a handover confirmation message carrying an extended cause value to the MME or the source base station.

Optionally, the above-mentioned second processing module 24 is configured to: when the handover type is S1 handover, send a handover confirmation message carrying an extended cause value to the MME, where the extended cause value is used to instruct the MME to send a handover confirmation message carrying an extended cause value. value handover command to the source base station, and instruct the source base station not to send the RRC connection reconfiguration message to the UE.

Optionally, the above-mentioned second processing module 24 is configured to: when the handover type is X2 handover, send a handover acknowledgment message carrying an extended cause value to the source base station, where the extended cause value is used to indicate that the source base station does not send a message to the UE Send an RRC connection reconfiguration message.

FIG. 3 is an optional structural block diagram 1 of a processing device for re-establishment in a cross-base station handover process according to an embodiment of the present invention. As shown in FIG. 3 , optionally, the above device further includes: a starting module 32 and a confirmation module 34 , wherein, the startup module 32 is coupled to the second processing module 24, and is used to start the RRC connection reconfiguration completion timer; the confirmation module 34 is coupled to the startup module 32, and is used to receive When the RRC connection reconfiguration complete message is sent, it is confirmed that the UE has successfully completed the handover.

Fig. 4 is an optional structural block diagram II of a processing device for re-establishment in a cross-base station handover process according to an embodiment of the present invention. As shown in Fig. 4, optionally, the above-mentioned device further includes: a first sending module 42, coupled To the confirmation module 34, configured to send a path conversion request message or a handover notification message to the MME, wherein the path conversion request message or the handover notification message is used to indicate that the UE has successfully completed the handover.

FIG. 5 is an optional structural block diagram 3 of a processing device for re-establishment in a cross-base station handover process according to an embodiment of the present invention. As shown in FIG. Module 32, configured to execute the UE's RRC connection resource release process when the RRC connection reconfiguration completion timer expires and the RRC connection reconfiguration completion message is not received.

Fig. 6 is an optional structural block diagram 4 of a processing device for re-establishment in a cross-base station handover process according to an embodiment of the present invention. As shown in Fig. 6, optionally, the above-mentioned device further includes: a first receiving module 62 and a second Two sending module 64, wherein, the first receiving module 62 is coupled to the second processing module 24, and is used to receive the message sent by the MME when the handover type is the S1 handover type and the RRC connection re-establishment completion message of the UE has not been received. The UE context release command; the second sending module 64, coupled to the first receiving module 62, is used to send the RRC connection re-establishment rejection message to the UE according to the UE context release command, and send the UE context release complete message to the MME.

Fig. 7 is an optional structural block diagram 5 of a processing device for re-establishment in a cross-base station handover process according to an embodiment of the present invention. As shown in Fig. 7 , optionally, the above-mentioned device further includes: a second receiving module 72 and a second Three sending modules 74, wherein the second receiving module 72 is coupled to the second processing module 24, and is used to receive the message sent by the source base station when the handover type is X2 handover and the RRC connection re-establishment completion message of the UE has not been received. The handover cancel message; the third sending module 74, coupled to the second receiving module 72, is used to send an RRC connection re-establishment rejection message to the UE according to the handover cancel message.

It should be noted that each of the above-mentioned modules can be implemented by software or hardware. For the latter, it can be implemented in the following manner, but not limited to this: the above-mentioned modules are all located in the same processor; or, the above-mentioned modules are respectively located in multiple in the processor.

Embodiments of the present invention also provide software, which is used to execute the technical solutions described in the foregoing embodiments and optional implementation manners.

The embodiment of the invention also provides a storage medium. In this embodiment, the above-mentioned storage medium may be configured to store program codes for performing the following steps:

Step S102, when the target base station receives the UE's RRC connection re-establishment request during the handover preparation phase, the target base station suspends the handover preparation process and executes the RRC connection re-establishment process;

Step S104, when the target base station receives the UE's RRC connection re-establishment completion message, the target base station activates the handover preparation process, sends an RRC connection reconfiguration message to the UE, and sends a handover confirmation message carrying an extended cause value to the MME or the source base station .

Optionally, in this embodiment, the above-mentioned storage medium may include but not limited to: U disk, read-only memory (Read-Only Memory, ROM for short), random access memory (Random Access Memory, RAM for short), Various media that can store program codes such as removable hard disks, magnetic disks, or optical disks.

In order to make the description of the embodiments of the present invention clearer, the following describes and illustrates in conjunction with optional embodiments.

For the scenario where the base station on the handover target side receives a re-establishment request when it is in the handover preparation stage, according to the existing technology, there are the following two hypothetical solutions:

Assumption 1: The base station on the handover target side replies the handover preparation failure message to the base station on the handover source side, which will inevitably cause the base station on the handover source side to initiate the next handover to other base stations or cells or release the UE. In fact, the UE has lost RRC with the handover source base station. In this way, the base station on the handover target side will reject the RRC connection re-establishment of the UE.

Hypothesis 2: The base station on the handover target side replies a handover confirmation message to the base station on the handover source side. In fact, the UE has lost the RRC connection with the handover source base station, but the handover source base station will still send a reconfiguration message for the handover command to the UE, resulting in handover The wireless resources of the base station on the source side are wasted.

Therefore, no matter which hypothetical solution above, it cannot reasonably and effectively solve the problem that the handover target base station receives a re-establishment request in the handover preparation stage, which causes the UE to drop the call due to the failure of the re-establishment.

An optional embodiment of the present invention relates to an LTE mobile communication system, and proposes a processing method and device for re-establishment during inter-base station handover. Through the processing strategy of the target base station receiving the RRC connection re-establishment request in the cross-base station handover preparation stage provided by the optional embodiment of the present invention, it can overcome the existing inter-station S1/X2 handover in the prior art. The problem and defect of UE call drop caused by re-establishment failure caused by RRC connection re-establishment request message reduces the occurrence rate of UE call drop caused by RRC connection re-establishment failure during the handover preparation process, and improves handover stability and user experience .

The switching method provided by an optional embodiment of the present invention includes the following five steps:

Step 1: The base station on the handover target side receives the RRC connection re-establishment request message of the UE in the preparation phase.

Step 2: The base station on the handover target side first suspends the handover preparation process, executes the RRC connection re-establishment process first, and sends an RRC connection re-establishment message.

Step 3: After the target base station receives the RRC connection re-establishment completion message sent by the UE, the target base station sends the RRC connection reconfiguration message to the UE, and at the same time starts the timer for waiting for the RRC connection reconfiguration completion, and activates the pending handover, and then Determine the type of pending inter-base station handover (S1 handover or X2 handover).

Step 4: If the previously suspended inter-base station handover type is S1 handover:

<a> Reply handover confirmation to the MME and carry the extended cause value. When the S1 handover source side base station receives the handover command with the extended cause value sent by the MME, it will not send the handover command to the UE according to the extended cause value instruction to reconfigure messages, and others are processed according to the normal S1 handover process.

<b>If the target base station receives the RRC connection reconfiguration complete message before waiting for the RRC connection reconfiguration completion timer to expire, the target base station will reply the handover notification message to the MME to notify that the S1 handover is successful.

<c>If the target base station has not received the RRC connection reconfiguration completion message after waiting for the RRC connection reconfiguration completion timer to expire, the target base station will directly execute the RRC release process.

Step 5: If the previously suspended inter-base station handover type is X2 handover:

<a> Send a handover confirmation message to the eNB on the handover source side, and carry the extended cause value. After receiving the handover confirmation message, the base station on the handover source side will not send a handover command reconfiguration message to the UE according to the indication of the extended cause value, and the rest will follow normal The X2 switching process is handled.

<b>If the target base station receives the RRC connection reconfiguration complete message before waiting for the RRC connection reconfiguration completion timer to expire, the target base station will reply to the MME with a path conversion request message, notifying that the X2 handover is successful.

<c>If the target base station has not received the RRC connection reconfiguration complete message after waiting for the RRC connection reconfiguration completion timer to expire, the target base station will directly execute the UE context release process.

Optional embodiments of the present invention will be described below in conjunction with the accompanying drawings.

Optional embodiment one

The first optional embodiment of the present invention provides a handover processing method when an RRC connection re-establishment request is received during the handover process. FIG. 8 is a flow chart of a processing method for re-establishment in a cross-base station handover process according to an optional embodiment 1 of the present invention. As shown in FIG. 8 , the process includes the following steps:

In step S802, the base station on the handover target side receives an RRC connection re-establishment request message from the UE during the preparation phase.

In step S804, the target base station first suspends the handover preparation process, executes the RRC connection re-establishment process first, and sends an RRC connection re-establishment message.

Step S806, after the target base station receives the completion of RRC connection re-establishment, then the target base station sends an RRC connection reconfiguration message to the UE, and at the same time starts the timer for waiting for RRC connection reconfiguration completion, activates the pending handover, and determines the corresponding handover type (S1 switching or X2 switching), execute the subsequent process.

Step S808, if the previously suspended cross-base station handover type is S1 handover:

<a> Reply handover confirmation to MME with extended cause value: Receive reestablishment request (Receive reestablishment during HO Prepare) during handover preparation phase, when the S1 handover source base station receives the handover command sent by MME with the above cause value Afterwards, according to the indication of the cause value, the handover command reconfiguration message is not sent to the UE, and the other processes are handled according to the normal S1 handover process.

<b>When the base station receives the RRC connection reconfiguration complete message before waiting for the RRC connection reconfiguration completion timer to expire, the target base station replies a handover notification message to the MME, notifying that the S1 handover is successful.

<c> After waiting for the RRC connection reconfiguration completion timer to expire and not receiving the RRC connection reconfiguration completion message, the target base station directly executes the RRC connection release process.

Step S810, if the previously suspended cross-base station handover type is X2 handover:

<a> The target base station sends a handover confirmation message to the handover source base station and carries an extended cause value: Receivereestablishment during HO Prepare. After receiving the handover confirmation message, the handover source base station does not issue a handover command to the UE according to the cause value indication messages, and others are processed according to the normal X2 switching process.

<b>Before waiting for the RRC connection reconfiguration completion timer to expire, the base station receives the RRC connection reconfiguration completion message, and the target base station replies to the MME with a path conversion request message, notifying that the X2 handover is successful.

<c> After waiting for the RRC connection reconfiguration completion timer to expire and not receiving the RRC connection reconfiguration completion message, the target base station directly executes the UE context release process.

Optional embodiment two:

The second optional embodiment of the present invention provides a handover processing method for receiving an RRC connection re-establishment request during the X2 handover preparation phase. FIG. 9 is a flow chart of a processing method for re-establishment in a cross-base station handover process according to an optional embodiment 2 of the present invention. As shown in FIG. 9, the process includes the following steps:

In step S902, the base station receives the measurement report message sent by the UE. The base station, as the handover source side, decides to perform X2 handover, and sends an X2 handover request message to the target side base station.

In step S904, after receiving the X2 handover request message from the handover source base station, the handover target base station executes a handover preparation process.

In step S906, due to reasons such as the radio environment, the UE starts to perform an RRC connection re-establishment process after radio link failure occurs, and initiates an RRC connection re-establishment request message.

Step S908, after receiving the RRC connection re-establishment request message, the target base station first suspends the handover being performed, performs re-establishment, and sends an RRC connection re-establishment message to the UE.

Step S910, after receiving the RRC connection re-establishment completion message, the target base station activates the pending handover procedure, and sends an RRC connection reconfiguration message to the UE, starts a timer for waiting for RRC connection reconfiguration completion, and at the same time replies to the handover source base station A handover confirmation message carrying an extended reason value (Receive reestablishment during HO Prepare).

Step S912: After receiving the handover command from the handover target base station, the source base station does not send the reconfiguration message of the handover command to the UE according to the extended cause value carried in the handover command, and performs operations such as data reverse transmission.

Step S914, after receiving the RRC connection reconfiguration complete message, the target base station stops the RRC connection reconfiguration complete wait timer, and sends a path switching request message (PathSwitchRequst) to the MME.

Step S916, the target base station receives the path switching request confirmation message (PathSwitchRequstAcknowledge) returned by the MME, indicating that the X2 handover is successful, and sends a UE context release message (UeContextRelease) to the handover source base station to release information such as radio resources of the source base station.

Optional embodiment three

The third optional embodiment of the present invention provides a handover processing method for receiving an RRC connection re-establishment request during the S1 handover preparation phase. Fig. 10 is a flow chart of a processing method for re-establishment in a cross-base station handover process according to an optional embodiment 3 of the present invention. As shown in Fig. 10 , the process includes the following steps:

In step S1002, the base station receives the measurement report message sent by the UE, and the base station, as the handover source side, decides to perform S1 handover, and sends an S1 handover request message to the MME.

Step S1004, after receiving the S1 handover request message from the MME, the base station at the handover target side executes a handover preparation process.

In step S1006, due to reasons such as the radio environment, the UE has a radio link failure, starts an RRC connection re-establishment process, and initiates an RRC connection re-establishment request message.

Step S1008, after receiving the RRC connection re-establishment request message, the target base station first suspends the handover being executed, executes the RRC connection re-establishment, and sends an RRC connection re-establishment message to the UE.

Step S1010, after receiving the RRC connection re-establishment completion message, the base station activates the pending handover process, and sends an RRC connection reconfiguration message to the UE, starts a timer for waiting for the RRC connection reconfiguration completion, and at the same time replies to the MME with a handover confirmation message carrying Extended reason value: Receive reestablishment during HO Prepare.

Step S1012, after receiving the handover command message, the source base station does not send the RRC connection reconfiguration message of the handover command according to the extended cause value carried in the handover command, and performs data reverse transmission and other operations.

Step S1014, after receiving the RRC connection reconfiguration completion message, the target base station stops the RRC connection reconfiguration completion waiting timer, and returns a handover notification message (HandoverNotify) to the MME.

Optional Embodiment Four

Optional Embodiment 4 of the present invention provides a handover processing method for failing to reconfigure UE successfully after receiving an RRC connection re-establishment request at the X2 handover preparation stage. Fig. 11 is a flow chart of a processing method for re-establishment during inter-base station handover according to optional embodiment 4 of the present invention. As shown in Fig. 11 , the process includes the following steps:

In step S1102, the base station receives the measurement report message sent by the UE, and the base station, as the handover source side, decides to perform X2 handover, and sends an X2 handover request message to the target base station.

Step S1104, after receiving the X2 handover request from the handover source base station, the handover target base station executes a handover preparation process.

In step S1106 , due to reasons such as the radio environment, the UE has a radio link failure, starts an RRC connection re-establishment process, and initiates an RRC connection re-establishment request message.

Step S1108, after receiving the RRC connection re-establishment request message, the target base station first suspends the handover being executed, executes the RRC connection re-establishment, and sends an RRC connection re-establishment message to the UE.

Step S1110, after receiving the RRC connection re-establishment completion message, the target base station activates the pending handover process, and sends an RRC connection reconfiguration message to the UE, starts the timer for waiting for RRC connection reconfiguration completion, and at the same time replies to the handover source base station A handover confirmation message carrying an extended reason value (Receive reestablishment during HO Prepare).

Step S1112, after the source base station receives the handover command message from the handover target base station, according to the extended cause value carried in the handover command, it does not issue the reconfiguration message of the handover command, and performs operations such as data reverse transmission.

Step S1114, when the target base station has not received the RRC connection reconfiguration completion message after the RRC connection reconfiguration completion wait timer expires, the target base station performs an RRC connection resource release procedure.

Step S1116, the handover source base station waits for the UE context release message (UeContextRelease) timer of the handover target base station to expire, triggering the UE context release process.

Optional Embodiment Five

The fifth optional embodiment of the present invention provides a handover processing method for failing to reconfigure UE successfully after receiving an RRC connection re-establishment request at the S1 handover preparation stage. Fig. 12 is a flow chart of a processing method for re-establishment during inter-base station handover according to optional embodiment 5 of the present invention. As shown in Fig. 12 , the process includes the following steps:

In step S1202, the base station receives the measurement report message sent by the UE, and the base station, as the handover source side, decides to perform S1 handover, and sends an S1 handover request message to the MME.

In step S1204, after receiving the S1 handover request message from the MME, the base station on the handover target side executes a handover preparation process.

In step S1206, due to reasons such as the radio environment, the UE has a radio link failure, starts an RRC connection re-establishment process, and initiates an RRC connection re-establishment request message.

Step S1208, after receiving the RRC connection re-establishment request message, the target base station first suspends the handover being performed, performs re-establishment, and sends an RRC connection re-establishment message to the UE.

Step S1210, after receiving the RRC connection re-establishment completion message, the target base station activates the pending handover process, and sends the RRC connection reconfiguration message to the UE, starts the timer for waiting for the RRC connection re-configuration completion, and at the same time replies to the MME with an extension reason A handover confirmation message with the value (Receive reestablishment during HO Prepare).

Step S1212: After receiving the handover command, the source base station does not send the RRC connection reconfiguration message of the handover command according to the extended cause value carried in the handover command, and performs operations such as data reverse transmission.

Step S1214, when the handover target base station waits for the RRC connection reconfiguration completion timer to expire, perform a UE context release procedure.

Optional embodiment six

The sixth optional embodiment of the present invention provides a method for processing handover cancellation during the re-establishment process after receiving the RRC connection re-establishment request in the X2 handover preparation stage. Fig. 13 is a flow chart of a method for canceling cross-base station handover according to optional embodiment six of the present invention. As shown in Fig. 13 , the process includes the following steps:

In step S1302, the base station receives the measurement report message sent by the UE. The base station, as the handover source side, decides to perform X2 handover, sends an X2 handover request message to the target base station, and starts the X2 handover preparation stage waiting timer (T_X2HoPrep).

Step S1304, after receiving the X2 handover request message from the handover source base station, the handover target base station executes a handover preparation process.

In step S1306, due to reasons such as the radio environment, the UE has a radio link failure, starts an RRC connection re-establishment process, and initiates an RRC connection re-establishment request message.

Step S1308, after receiving the RRC connection re-establishment request message, the target base station first suspends the handover being executed, executes the RRC connection re-establishment, and sends an RRC connection re-establishment message to the UE.

Step S1310, after the T_X2HoPrep waiting timer expires, the handover source base station triggers the handover cancel process, sends a handover cancel message to the handover target side base station, and then performs the UE context release process.

Step S1312, after receiving the handover cancel initiated by the handover source base station, the base station on the handover target side cancels the RRC connection re-establishment process and the pending handover resources, and sends an RRC connection re-establishment rejection message to the UE.

Optional Embodiment Seven

The seventh optional embodiment of the present invention provides a method for processing handover cancellation during the re-establishment process after receiving the RRC connection re-establishment request at the S1 handover preparation stage. FIG. 14 is a flow chart of a method for canceling cross-base station handover according to optional embodiment 7 of the present invention. As shown in FIG. 14 , the process includes the following steps:

In step S1402, the base station receives the measurement report message sent by the UE. The base station, as the handover source side, decides to execute S1 handover, sends an S1 handover request message to the MME, and starts the S1 handover preparation stage waiting timer (T_S1HoPrep).

In step S1404, after receiving the S1 handover request message from the MME, the base station on the handover target side executes a handover preparation process.

Step S1406, due to radio environment and other reasons, the UE has a radio link failure, and then starts an RRC connection re-establishment process, and initiates an RRC connection re-establishment request message.

Step S1408, after receiving the RRC connection re-establishment request message, the target base station first suspends the handover being executed, executes the RRC connection re-establishment, and sends an RRC connection re-establishment message to the UE.

Step S1410, after the T_S1HoPrep waiting timer expires, the handover source base station sends a handover cancel message to the MME.

Step S1412, after the target base station receives the UE context release command from the MME, it instructs to cancel the handover, cancels the RRC connection re-establishment process and the pending handover resources, sends an RRC connection re-establishment rejection message to the UE, and returns the UE context to the MME Release complete message.

In summary, using the method and device for processing re-establishment during inter-base station handover provided by the embodiments and optional embodiments of the present invention, compared with the prior art, it provides an inter-station S1/X2 handover target base station The processing strategy for receiving the RRC connection re-establishment request in the cross-base station handover preparation stage reduces the incidence of UE call drop caused by RRC connection re-establishment failure during the handover preparation process, and improves the stability of handover and user experience.

Obviously, those skilled in the art should understand that each module or each step of the above-mentioned present invention can be realized by a general-purpose computing device, and they can be concentrated on a single computing device, or distributed in a network formed by multiple computing devices Alternatively, they may be implemented in program code executable by a computing device so that they may be stored in a storage device to be executed by a computing device, and in some cases in an order different from that shown here The steps shown or described are carried out, or they are separately fabricated into individual integrated circuit modules, or multiple modules or steps among them are fabricated into a single integrated circuit module for implementation. As such, the present invention is not limited to any specific combination of hardware and software.

The above descriptions are only optional embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (16)

1. A processing method for re-establishing in a cross-base station handover process, characterized in that, comprising: When the target base station receives the RRC connection re-establishment request of the user equipment UE during the handover preparation phase, the target base station suspends the handover preparation process and executes the RRC connection re-establishment process; When the target base station receives the RRC connection re-establishment complete message of the UE, the target base station activates the handover preparation process, sends an RRC connection reconfiguration message to the UE, and sends a handover message carrying an extended cause value Acknowledge the message to the mobility management entity MME or the source base station. 2. The method according to claim 1, wherein the sending of the handover confirmation message carrying the extended cause value by the target base station comprises: When the handover type is S1 handover, the target base station sends the handover acknowledgment message carrying the extended cause value to the MME, where the extended cause value is used to instruct the MME to send sending a handover command with the extended cause value to the source base station, and instructing the source base station not to send an RRC connection reconfiguration message to the UE. 3. The method according to claim 1, wherein the sending of the handover confirmation message carrying the extended cause value by the target base station comprises: When the handover type is X2 handover, the target base station sends the handover confirmation message carrying the extended cause value to the source base station, where the extended cause value is used to indicate that the source base station does not send The UE sends an RRC connection reconfiguration message. 4. The method according to claim 1, wherein after the target base station sends the RRC connection reconfiguration message to the UE, the method further comprises: Start the RRC connection reconfiguration completion timer; When receiving the RRC connection reconfiguration complete message before the RRC connection reconfiguration complete timer expires, the target base station confirms that the UE successfully completes the handover. 5. The method according to claim 4, wherein after the target base station confirms that the UE has successfully completed the handover, the method further comprises: The target base station sends a path switch request message or a handover notification message to the MME, wherein the path switch request message or the handover notification message is used to indicate that the UE has successfully completed the handover. 6. The method according to claim 4, wherein, when the RRC connection reconfiguration completion timer expires and the RRC connection reconfiguration completion message is not received, the method further comprises: The target base station executes an RRC connection resource release procedure of the UE. 7. The method according to any one of claims 1 to 6, wherein after the target base station suspends the handover preparation procedure, the method further comprises: When the handover type is S1 handover, and the target base station has not received the RRC connection re-establishment completion message of the UE, the target base station receives the UE context release command sent by the MME; The target base station sends an RRC connection re-establishment reject message to the UE according to the UE context release command, and sends a UE context release complete message to the MME. 8. The method according to any one of claims 1 to 6, wherein after the target base station suspends the handover preparation procedure, the method further comprises: When the handover type is X2 handover, and the target base station has not received the RRC connection re-establishment completion message of the UE, the target base station receives a handover cancel message sent by the source base station; The target base station sends an RRC connection re-establishment reject message to the UE according to the handover cancel message. 9. A processing device for re-establishment in a cross-base station handover process, applied to a base station, characterized in that it includes: The first processing module is configured to suspend the handover preparation process and execute the RRC connection re-establishment process when the base station as the target base station receives the RRC connection re-establishment request of the user equipment UE during the handover preparation phase; The second processing module is configured to activate the handover preparation process when receiving the RRC connection re-establishment completion message of the UE, send an RRC connection reconfiguration message to the UE, and send a handover confirmation carrying an extended cause value The message is sent to the mobility management entity MME or the source base station. 10. The device according to claim 9, wherein the second processing module is used for: When the handover type is S1 handover, send the handover acknowledgment message carrying the extended cause value to the MME of the mobility management entity, where the extended cause value is used to instruct the MME to send the handover confirmation message carrying the sending a handover command with the extended cause value to the source base station, and instructing the source base station not to send an RRC connection reconfiguration message to the UE. 11. The device according to claim 9, wherein the second processing module is used for: When the handover type is X2 handover, send the handover confirmation message carrying the extended cause value to the source base station, where the extended cause value is used to instruct the source base station not to send RRC connection reconfiguration message. 12. The device according to claim 9, further comprising: A starting module, configured to start the RRC connection reconfiguration completion timer; a confirmation module, configured to confirm that the UE has successfully completed when the RRC connection reconfiguration completion message is received before the RRC connection reconfiguration completion timer expires switch. 13. The device according to claim 12, further comprising: A first sending module, configured to send a path switch request message or a handover notification message to the MME, where the path switch request message or the handover notification message is used to indicate that the UE has successfully completed the handover. 14. The device according to claim 12, further comprising: An executing module, configured to execute the RRC connection resource release procedure of the UE when the RRC connection reconfiguration completion timer expires and the RRC connection reconfiguration completion message is not received. 15. The device according to any one of claims 9 to 14, further comprising: A first receiving module, configured to receive a UE context release command sent by the MME when the handover type is S1 handover and the RRC connection re-establishment completion message of the UE has not been received; The second sending module is configured to send an RRC connection re-establishment rejection message to the UE according to the UE context release command, and send a UE context release complete message to the MME. 16. The device according to any one of claims 9 to 14, further comprising: The second receiving module is configured to receive a handover cancellation message sent by the source base station when the handover type is X2 handover and the RRC connection re-establishment completion message of the UE has not been received; A third sending module, configured to send an RRC connection re-establishment rejection message to the UE according to the handover cancel message.