WO2017101511A1

WO2017101511A1 - Method and device for reestablishment in cross-base station handover process

Info

Publication number: WO2017101511A1
Application number: PCT/CN2016/097238
Authority: WO
Inventors: 邹俊; 赵毅; 杨敏; 陈洪昌
Original assignee: 中兴通讯股份有限公司
Priority date: 2015-12-18
Filing date: 2016-08-29
Publication date: 2017-06-22
Also published as: CN106900015B; CN106900015A

Abstract

Provided in the present invention are a method and device for reestablishment in a cross-base station handover process, the method comprising: when a target base station receives a radio resource control (RRC) connection reestablishment request from a user equipment (UE) at a handover preparation phase, the target base station suspends the handover preparation process and executes an RRC connection reestablishment process; when the target base station receives an RRC connection reestablishment completion message of the UE, the target base station activates the handover preparation process, sends an RRC connection reconfiguration message to the UE, and transmits a handover confirm message carrying an extended reason value to a mobility management entity (MME) or a source base station. The present invention puts forward a processing strategy for when, in related art, a target base station receives an RRC connection reestablishment request at a base station handover preparation phase, which reduces occurrences of a failure of the RRC connection reestablishment in the handover preparation process causing an UE to drop calls, thereby improving handover stability and enhancing user experience.

Description

Processing method and device re-established in cross-base station switching process

Technical field

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

Background technique

In the Long Term Evolution (LTE) system, the state of the 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 handoff is triggered to ensure uninterrupted service. When a UE switches from a cell of an Evolved Node B (eNB, LTE base station) to a cell of another eNB, handover across the base station is triggered. If there is an X2 interface (X2Interface) between the handover source base station and the handover target base station and is connected to the same Mobility Management Entity (MME), according to the prior art (3rd Generation Partnership) Project, abbreviated as 3GPP) protocol, 23.401 protocol), the source eNB will initiate an X2 interface handover (X2Interface Handover), otherwise it will initiate a S1 interface handover (S1Interface Handover). For these two types of handover, according to the different stages of the handover, it is divided into two phases of preparation and execution. The preparation phase consists of the following steps:

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

In the second step, the handover target eNB sends a handover request acknowledgement (Handover Request Ack) message carrying the radio resource control (Radio) for configuring the UE according to the received handover request, after the radio resource admission and the service bearer are established. Resource Control, referred to as RRC) re-allocation message, enters the handover execution phase.

In the third step, after entering the handover execution phase, the handover source side eNB configures the UE according to the RRC connection reconfiguration message generated by the handover target side eNB, and then the UE accesses the target base station to complete the handover.

In the S1/X2 handover preparation phase, the UE that is in the RRC connected state is re-established to the handover target side base station due to air interface quality reasons such as radio link failure (Rain Link Failure, RLF for short). For the handover target base station, the context information of the UE is included and the access stratum (Access Stratum, AS for short) is securely activated. According to the 36.331 protocol, the 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:

Hypothesis 1: The handover target side base station returns the handover preparation failure message to the handover source side base station, which inevitably causes the handover source side base station to re-initiate the next handover or release the UE to other base stations or cells. In fact, the UE has lost the RRC with the handover source base station. Connection; thus, the handover target side base station can only reject the RRC connection re-establishment.

Assume that the handover target eNB sends a handover acknowledgment message to the handover source base station. In fact, the UE has lost the RRC connection with the handover source base station, and the handover source side base station still sends the RRC connection reconfiguration message to the UE. Switching source side base station radio resources waste.

Therefore, regardless of which of the above-mentioned hypothetical processing schemes, the problem that the handover target base station causes the UE to drop the call due to the re-establishment failure in the scenario of receiving the re-establishment request in the handover preparation phase cannot be reasonably and effectively solved.

Summary of the invention

The embodiment of the present invention provides a method and a device for re-establishing a cross-base station handover process, so as to at least solve the problem that the target base station receives the RRC connection re-establishment request in the cross-base station handover preparation phase in the related art, causing the re-establishment failure to cause the UE to drop. The question of words.

According to an aspect of the present invention, a processing method for re-establishment in a handover process between base stations is provided, including: when a target base station receives an RRC connection re-establishment request of a UE in a handover preparation phase, the target base station hangs The handover preparation process is performed to perform an RRC connection re-establishment procedure; when the target base station receives the RRC connection re-establishment completion message of the UE, the target base station activates the handover preparation procedure, and sends an RRC connection reconfiguration message to the The UE sends a handover confirmation message carrying the extension cause value to the MME or the source base station.

Optionally, the sending, by the target base station, the handover confirmation message carrying the extension cause value includes: when the handover type is S1 handover, the target base station sends the handover carrying the extension cause value Acknowledgement message to the MME, where the extension cause value is used to indicate that the MME sends a handover command carrying the extension cause value to the source base station, and indicates that the source base station does not send an RRC connection weight to the UE With a message.

Optionally, the sending, by the target base station, the handover confirmation message carrying the extension cause value includes: when the handover type is X2 handover, the target base station sends a handover confirmation message carrying the extension cause value And the source base station, where the extension cause value is used to indicate that the source base station does not send an RRC connection reconfiguration message to the UE.

Optionally, after the target eNB sends the RRC connection reconfiguration message to the UE, the method further includes: starting an RRC connection reconfiguration complete timer; when the RRC connection reconfiguration complete timer expires Upon 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 successfully completes the handover, the method further includes: the target base station sends a path conversion request message or a handover notification message to the MME, where the path conversion request message Or the handover notification message is used to indicate that the UE has successfully completed the handover.

Optionally, in a case that 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 does not receive the RRC connection re-establishment of the UE. In the case of the 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 the UE context release complete Message to the stated 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 does not receive the RRC connection re-establishment of the UE. In the case of a message, the target base station receives a handover cancellation message sent by the source base station; and the target base station sends an RRC connection re-establishment rejection message to the UE according to the handover cancellation message.

According to another aspect of the present invention, a processing apparatus re-established in a cross-base station handover process is further provided, which is applied to a base station, and includes: a first processing module, configured to be used as a target base station in a handover preparation phase Upon receiving the RRC connection re-establishment request of the UE, the handover preparation procedure is suspended, and the RRC connection re-establishment procedure is performed; the second processing module is configured to activate the handover when the RRC connection re-establishment completion message of the UE is received. The preparation process sends an RRC connection reconfiguration message to the UE, and sends a handover confirmation message carrying the extension 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 extension cause value to the MME, where the extension cause value is used to indicate The MME sends a handover command carrying the extension cause value to the source base station, and indicates that the source base station does not 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 extension cause value to the source base station, where the extension cause value is used for Instructing the source base station not to send an RRC connection reconfiguration message to the UE.

Optionally, the apparatus further includes: a startup module, configured to start an RRC connection reconfiguration complete timer; and an acknowledgment module configured to receive the RRC connection reconfiguration before the RRC connection reconfiguration complete timer expires Upon completion of the message, it is confirmed that the UE successfully completes the handover.

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

Optionally, the apparatus further includes: an execution module, configured to perform an RRC connection resource of the UE if the RRC connection reconfiguration complete timer expires and the RRC connection reconfiguration complete message is not received Release the process.

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

Optionally, the apparatus further includes: a second receiving module, configured to: when the handover type is X2 handover, and the RRC connection re-establishment complete message of the UE is not received, the handover sent by the source base station And canceling the message; the third sending module is configured to send an RRC connection re-establishment reject message to the UE according to the handover cancellation message.

According to still another embodiment of the present invention, a storage medium is also provided. The storage medium is arranged to store program code for performing the following steps:

When the target base station receives the RRC connection re-establishment request of the UE in the handover preparation phase, suspends the handover preparation procedure, and performs an RRC connection re-establishment procedure; when the target base station receives the RRC connection re-establishment completion message of the UE, And the RRC connection reconfiguration message is sent to the UE, and the handover confirmation message carrying the extension cause value is sent to the MME or the source base station.

Optionally, the storage medium is further arranged to store program code for performing the following steps:

If the handover type is the S1 handover, the handover confirmation message carrying the extension cause value is sent to the MME, where the extension cause value is used to indicate that the MME sends the extension cause value The handover command is sent to the source base station, and indicates that the source base station does not send an RRC connection reconfiguration message to the UE.

And sending, in the case that the handover type is the X2 handover, a handover confirmation message carrying the extension cause value to the source base station, where the extension cause value is used to indicate that the source base station does not send the RRC to the UE Connect reconfiguration messages.

According to the embodiment of 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 procedure, and performs an RRC connection re-establishment procedure; when the target base station receives the UE The RRC connection re-establishment completion message, the target base station activates the handover preparation procedure, sends an RRC connection reconfiguration message to the UE, and sends a handover confirmation message carrying the extension cause value, which solves the related art. In the cross-base station handover preparation phase, the target base station receives the RRC connection re-establishment request scenario, and the re-establishment failure causes the UE to drop the call problem, thereby improving the stability of the handover and the user experience.

DRAWINGS

The drawings described herein are intended to provide a further understanding of the invention, and are intended to be a part of the invention. In the drawing:

1 is a flowchart of a processing method for re-establishing in a handover process between base stations according to an embodiment of the present invention;

2 is a structural block diagram of a processing device re-established in a handover process between base stations according to an embodiment of the present invention;

3 is a block diagram 1 of an optional structure of a processing device re-established in a cross-base station handover process according to an embodiment of the present invention;

4 is a block diagram 2 of an optional structure of a processing device re-established in a cross-base station handover process according to an embodiment of the present invention;

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

FIG. 6 is a block diagram showing an optional structure of a processing device re-established in a cross-base station handover process according to an embodiment of the present invention. four;

7 is a block diagram 5 of an optional structure of a processing device re-established in a cross-base station handover process according to an embodiment of the present invention;

FIG. 8 is a flowchart of a method for re-establishing a cross-base station handover process according to an alternative embodiment of the present invention; FIG.

9 is a flowchart of a processing method for re-establishing in a cross-base station handover process according to an alternative embodiment 2 of the present invention;

FIG. 10 is a flowchart of a processing method for re-establishing in a cross-base station handover process according to an alternative embodiment 3 of the present invention; FIG.

11 is a flowchart of a processing method for re-establishing in a cross-base station handover process according to an alternative embodiment 4 of the present invention;

FIG. 12 is a flowchart of a processing method for re-establishing in a cross-base station handover process according to an alternative embodiment 5 of the present invention; FIG.

13 is a flowchart of a method for canceling handover across base stations according to an alternative embodiment 6 of the present invention;

FIG. 14 is a flowchart of a method for canceling handover across base stations according to an alternative embodiment 7 of the present invention.

detailed description

The invention will be described in detail below with reference to the drawings in conjunction with the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict.

It is to be understood that the terms "first", "second" and the like in the specification and claims of the present invention are used to distinguish similar objects, and are not necessarily used to describe a particular order or order.

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

Step S102, 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 procedure, and performs an RRC connection re-establishment procedure;

Step S104: When the target eNB receives the RRC connection re-establishment complete message of the UE, the target base station activates the handover preparation procedure, sends an RRC connection reconfiguration message to the UE, and sends a handover confirmation message carrying the extension cause value to the MME or the source base station. .

Through the above steps, 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 ongoing handover preparation procedure, and first re-establishes the RRC connection with the UE by sending an RRC connection re-establishment message to the UE. When the target eNB receives the RRC connection re-establishment complete message of the UE, it activates the suspended handover preparation procedure, sends an RRC connection reconfiguration message to the UE, and sends a handover confirmation message carrying the extension cause value. It can be seen that the above-mentioned steps solve the problem that the target base station receives the RRC connection re-establishment request and the UE drops the call in the cross-base station handover preparation phase in the related art, and reduces the occurrence of the UE drop-off caused by the RRC connection re-establishment failure during the handover preparation process. Rate, improve the stability of the switch and user experience.

Optionally, after the target base station sends the RRC connection reconfiguration message to the UE, the source base station does not need to send the RRC connection reconfiguration message to the UE according to the indication of the extension cause value after receiving the handover confirmation message carrying the extension cause value. When the handover type is S1 handover, the target base station may send a handover confirmation message carrying an extension cause value indicating that the source base station does not send the RRC connection reconfiguration message to the MME, and then the MME sends the handover command to the source base station. The reason value is carried to indicate that the source base station does not send an RRC connection reconfiguration message to the UE.

For example, in the foregoing step S104, in the case that the handover type is the S1 handover, the target base station may send a handover confirmation message carrying the extension cause value to the MME, where the extension cause value is used to indicate that the MME sends the extension cause value. The 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 notifies the source base station not to send the RRC connection reconfiguration message to the UE through the MME, so that the waste of the RRC connection resource can be avoided, and the UE cannot receive the source when the source base station has disconnected the RRC connection with the UE. The message sent by the base station, which causes the RRC connection reconfiguration failure, the target base station instructs the UE to perform RRC connection reconfiguration, and indicates that the source base station does not send the RRC connection reconfiguration message, which reduces the RRC connection reestablishment failure during the handover preparation process. The occurrence rate of UE dropped calls improves the stability of handover and user experience.

Optionally, after the target base station sends the RRC connection reconfiguration message to the UE, the source base station does not need to send the RRC connection reconfiguration message to the UE according to the indication of the extension cause value after receiving the handover confirmation message carrying the extension cause value. When the handover type is X2 handover, the target base station may send a handover confirmation message carrying an extension cause value indicating that the source base station does not send the RRC connection reconfiguration message to the source base station to indicate that the source base station does not send the RRC connection reconfiguration to the UE. Message.

For example, in the foregoing step S104, in the case that the handover type is X2 handover, the target base station may send a handover confirmation message carrying the extension cause value to the source base station, where the extension cause value is used to indicate that the source base station does not send the RRC to the UE. Connect reconfiguration messages. Through the above steps, the target base station notifies the source base station that the RRC connection reconfiguration message is not sent to the UE, and the waste of the RRC connection resource can be avoided. Meanwhile, when the source base station has disconnected the RRC connection with the UE, the UE cannot receive the source base station to send. The message, causing the RRC connection reconfiguration failure, the target base station instructing the UE to perform RRC connection reconfiguration, and indicating that the source base station does not send the RRC connection reconfiguration message, reducing the RRC connection reestablishment failure during the handover preparation process. The incidence of dropped calls improves the stability of the handover and the user's perception.

Optionally, after the foregoing step S104, the target base station may start an RRC connection reconfiguration complete timer, control the RRC connection reconfiguration process, and receive an RRC connection reconfiguration before the RRC connection reconfiguration complete timer expires. When the message is completed, the target base station can confirm that the UE successfully completes the handover.

Optionally, when the target base station confirms that the UE successfully completes the handover, the target base station may send a path conversion request message or a handover notification message to the MME, to notify the MME that the UE has successfully completed the handover. Thereafter, the MME may notify the source base station to release the context resource of the UE, or the MME may reply the path conversion request acknowledgement message to the target base station, and then notify the source base station to release the context resource of the UE by the target base station.

Optionally, after the target eNB initiates the RRC connection reconfiguration complete timer, the target eNB may further perform the RRC connection resource of the UE if the RRC connection reconfiguration complete timer expires and the RRC connection reconfiguration complete message is not received. Release the process.

Optionally, when the handover type is S1 handover, and the target base station does not receive the RRC connection re-establishment complete message of the UE. In this case, after the foregoing step S102, the target base station may receive the UE context release command sent by the MME. At this time, the target base station may send an RRC connection re-establishment rejection message to the UE according to the UE context release command, and send the UE context release completion. Message to the MME. Alternatively, in the case that the handover type is X2 handover, and the target base station does not receive the RRC connection re-establishment complete message of the UE, after the foregoing step S102, the target base station may receive the handover cancellation message sent by the source base station, and at this time, the target The base station may send an RRC Connection Reestablishment Reject message to the UE according to the handover cancellation message.

Through the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, by hardware, but in many cases, the former is A better implementation. Based on such understanding, the technical solution of the present invention, which is essential or contributes to the prior art, may be embodied in the form of a software product stored in a storage medium (such as ROM/RAM, disk, The optical disc includes a number of instructions for causing a terminal device (which may be a cell phone, a computer, a server, or a network device, etc.) to perform the methods of various embodiments of the present invention.

In this embodiment, a processing device that is re-established in the process of handover between the base stations is also provided, and is applied to the base station, and the device is used to implement the foregoing embodiments and optional implementation manners, and details are not described herein. As used below, the term "module" may implement a combination of software and/or hardware of a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, hardware, or a combination of software and hardware, is also possible and contemplated.

2 is a structural block diagram of a processing device re-established 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 processing module 22 is configured to: when the base station as the target base station receives the RRC connection re-establishment request of the UE in the handover preparation phase, suspend the handover preparation process, and perform an RRC connection re-establishment process; the second processing module 24 is coupled to the first The processing module 22 is configured to: when receiving the RRC connection re-establishment completion message of the UE, activate the handover preparation procedure, send an RRC connection reconfiguration message to the UE, and send a handover confirmation message carrying the extension cause value to the MME or the source base station.

Optionally, the foregoing second processing module 24 is configured to: when the handover type is the S1 handover, send a handover confirmation message carrying the extension cause value to the MME, where the extension cause value is used to indicate that the MME sends the extension cause The value of the handover command to the source base station, and indicates that the source base station does not send an RRC connection reconfiguration message to the UE.

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

FIG. 3 is a block diagram of an optional structure of a processing device re-established in a cross-base station handover process according to an embodiment of the present invention. As shown in FIG. 3, the device further includes: a startup module 32 and a confirmation module 34. The initiating module 32 is coupled to the second processing module 24 and configured to initiate an RRC connection reconfiguration complete timer; the confirmation module 34 is coupled to the initiating module 32 and configured to receive before the RRC connection reconfiguration complete timer expires. When the RRC connection reconfiguration complete message, it is confirmed that the UE successfully completes the handover.

FIG. 4 is a block diagram of an optional structure of a processing device that is re-established in a cross-base station handover process according to an embodiment of the present invention. As shown in FIG. 4, the device further includes: a first sending module 42 coupled. To confirmation module 34, set to The path conversion request message or the handover notification message is sent to the MME, where 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 a block diagram 3 of an optional structure of a processing device re-established in a cross-base station handover process according to an embodiment of the present invention. As shown in FIG. 5, optionally, the device further includes: an execution module 52 coupled to the startup. The module 32 is configured to perform an RRC connection resource release procedure of the UE if the RRC connection reconfiguration complete timer expires and the RRC connection reconfiguration complete message is not received.

FIG. 6 is a block diagram of an optional structure of a processing device re-established in a cross-base station handover process according to an embodiment of the present invention. As shown in FIG. 6 , the device further includes: a first receiving module 62 and a first The second sending module 64, wherein the first receiving module 62 is coupled to the second processing module 24, and is configured to send, when the handover type is the S1 handover type, and the RRC connection re-establishment complete message of the UE is not received, The UE Context Release Command is coupled to the first receiving module 62, configured to send an RRC Connection Reestablishment Reject message to the UE according to the UE context release command, and send a UE Context Release Complete message to the MME.

FIG. 7 is a block diagram 5 of an optional structure of a processing device re-established in a cross-base station handover process according to an embodiment of the present invention. As shown in FIG. 7 , the device further includes: a second receiving module 72 and a a third sending module 74, wherein the second receiving module 72 is coupled to the second processing module 24, and configured to send, when the handover type is X2 handover, and the RRC connection re-establishment complete message of the UE is not received, the receiving source base station sends The switch cancel message is sent; the third sending module 74 is coupled to the second receiving module 72, and is configured to send an RRC connection re-establishment reject message to the UE according to the handover cancel message.

It should be noted that each of the above modules may be implemented by software or hardware. For the latter, the foregoing may be implemented by, but not limited to, the foregoing modules are all located in the same processor; or, the modules are located in multiple In the processor.

Embodiments of the present invention also provide a software for performing the technical solutions described in the foregoing embodiments and optional embodiments.

Embodiments of the present invention also provide a storage medium. In this embodiment, the above storage medium may be configured to store program code for performing the following steps:

Optionally, in the embodiment, the foregoing storage medium may include, but is not limited to, a USB flash drive, a Read-Only Memory (ROM), and a Random Access Memory (RAM). A variety of media that can store program code, such as a hard disk, a disk, or an optical disk.

In order to make the description of the embodiments of the present invention more clear, the following description and description are made in conjunction with the exemplary embodiments.

The re-establishment request scenario is received when the handover target side base station is in the handover preparation phase. According to the prior art, the following two hypothetical processing schemes are available:

Hypothesis 1: The handover target side base station returns the handover preparation failure message to the handover source side base station, which inevitably causes the handover source side base station to re-initiate the next handover or release the UE to other base stations or cells. In fact, the UE has lost the RRC with the handover source base station. The connection is such that the handover target side base station will reject the RRC connection re-establishment of the UE.

Hypothesis 2: The handover target side base station returns a handover confirmation message to the handover source side base station. In fact, the UE has lost the RRC connection with the handover source base station, and the handover source side base station still sends a reconfiguration message of the handover command to the UE, causing the handover. The source side base station wireless resources are wasted.

An alternative embodiment of the present invention relates to an LTE mobile communication system, and proposes a processing method and apparatus for re-establishment in a handover process between base stations. The target base station receives the RRC connection re-establishment request processing policy in the cross-base station handover preparation phase provided by the optional embodiment of the present invention, which can overcome the target-side base station in the handover preparation phase when the inter-station S1/X2 handover exists in the prior art. The RRC connection re-establishment request message causes the re-establishment failure to cause the UE to drop the call. The RRC connection re-establishment failure causes the UE to drop the call rate, which improves the handover stability and user experience. .

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

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

The second step: the handover target base station first suspends the handover preparation process, preferentially performs the RRC connection re-establishment process, and delivers the RRC connection re-establishment message.

Step 3: After receiving the RRC connection re-establishment completion message sent by the UE, the target base station sends an RRC connection reconfiguration message to the UE, and starts to wait for the RRC connection reconfiguration completion timer, and activates the suspended handover, and then activates the suspended handover. Determine the type of pending cross-base station handover (S1 handover or X2 handover).

Step 4: If the previously suspended cross-base station switch type is S1 switch:

<a>Responding to the MME for the handover acknowledgment and carrying the extension cause value. When the S1 handover source side base station receives the handover command carrying the extension cause value sent by the MME, the base station does not deliver the handover command re-allocation to the UE according to the extension reason value indication. Messages, others are processed according to the normal S1 switching 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 returns a 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 complete message after waiting for the RRC connection reconfiguration completion timer to expire, the target base station will directly perform the RRC release procedure.

Step 5: If the previously suspended cross-base station switch type is X2 switch:

<a> Sending a handover confirmation message to the handover source side eNB, and carrying the extension cause value, after switching the source side base station to receive the handover confirmation message, according to the extension cause value indication, the handover command re-distribution message is not sent to the UE, and the other is normal. X2 switching process processing.

<b> If the target base station receives the RRC connection reconfiguration complete message before waiting for the RRC connection reconfiguration complete timer to expire, the target base station returns a path conversion request message to the MME to notify 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 complete timer expires, the target base station will directly execute the UE context release procedure.

The optional embodiments of the present invention are described below with reference to the accompanying drawings.

Alternative embodiment 1

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

Step S802, the handover target side base station receives the RRC connection re-establishment request message of the UE in the preparation phase.

In step S804, the target base station suspends the handover preparation process, performs the RRC connection re-establishment process preferentially, and delivers the RRC connection re-establishment message.

Step S806: After receiving the RRC connection re-establishment, the target base station sends an RRC connection reconfiguration message to the UE, and starts to wait for the RRC connection reconfiguration complete timer, activates the suspended switch, and determines the corresponding handover type. (S1 switch or X2 switch), perform the subsequent process.

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

<a>Responding to the MME for the handover confirmation and carrying the extension cause value: the handover preparation phase receives the RRC connection re-establishment request (Receive reestablishment during the HO Prepare), and when the S1 handover source side base station receives the handover command sent by the MME and carrying the above-mentioned cause value, Then, according to the cause value indication, the handover command re-distribution message is not sent to the UE, and the others are processed according to the normal S1 handover procedure.

<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 returns a handover notification message to the MME to notify that the S1 handover is successful.

<c> When the RRC connection reconfiguration complete message has not been received after waiting for the RRC connection reconfiguration complete timer expires, the target base station directly performs the release procedure of the RRC connection.

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 side base station and carries the extension cause value: Receive reestablishment during the HO Prepare, after the handover source side base station receives the handover confirmation message, according to the cause value indication, the handover command is not sent to the UE. With the message, the other is processed according to the normal X2 switching 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 returns a path conversion request message to the MME to notify that the X2 handover is successful.

<c> When the RRC connection reconfiguration complete message has not been received after waiting for the RRC connection reconfiguration completion timer expires, the target base station directly performs the UE context release procedure.

Alternative embodiment 2:

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

Step S902: The base station receives the measurement report message sent by the UE, and the base station acts as the handover source side, and determines to perform X2 handover, and initiates an X2 handover request message to the target side base station.

Step S904, after the handover target side base station receives the X2 handover request message of the handover source side base station, the handover preparation process is performed.

Step S906: After the radio link fails, the UE starts the RRC connection re-establishment process and initiates an RRC connection re-establishment request message.

Step S908: After receiving the RRC connection re-establishment request message, the target base station suspends the handover that is being executed, performs re-establishment, and sends an RRC connection re-establishment message to the UE.

Step S910: After receiving the RRC connection re-establishment complete message, the target base station activates the suspended handover procedure, and sends an RRC connection reconfiguration message to the UE, starts to wait for the RRC connection reconfiguration complete timer, and simultaneously replies to the handover source side base station. A handover confirmation message carrying a Receive Reestablishment during HO Prepare.

Step S912: After receiving the handover command of the handover target base station, the source base station does not deliver the reconfiguration message of the handover command to the UE according to the extension cause value carried in the handover command, and performs operations such as data back propagation.

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

In step S916, the target base station receives the path conversion request acknowledgement message (PathSwitchRequstAcknowledge) replied by the MME, indicating that the X2 handover succeeds, and sends a UE context release message (UeContextRelease) to the handover source side base station, and releases information such as the radio resource of the source side base station.

Alternative embodiment three

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

Step S1002: The base station receives the measurement report message sent by the UE, and the base station acts as the handover source side, and determines to perform the S1 handover, and initiates an S1 handover request message to the MME.

Step S1004: After receiving the S1 handover request message of the MME, the handover target base station performs a handover preparation process.

Step S1006: The UE fails the radio link due to the wireless environment and the like, starts the 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 suspends the ongoing handover, performs RRC connection re-establishment, and sends an RRC connection re-establishment message to the UE.

Step S1010: After receiving the RRC connection re-establishment complete message, the base station activates the suspended handover procedure, and sends an RRC connection reconfiguration message to the UE, starts to wait for the RRC connection reconfiguration complete timer, and returns a handover confirmation message to the MME. Extended reason value: Receive reestablishment during HO Prepare.

Step S1012: After receiving the handover command message, the source base station does not deliver the RRC connection reconfiguration message of the handover command according to the extension cause value carried in the handover command, and performs operations such as data back propagation.

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

Alternative embodiment four

The optional embodiment 4 of the present invention provides a handover processing method that fails to reconfigure the UE after receiving the RRC connection re-establishment request in the X2 handover preparation phase. FIG. 11 is a flowchart of a method for re-establishing a cross-base station handover process according to an alternative embodiment 4 of the present invention. As shown in FIG. 11, the process includes the following steps:

Step S1102: The base station receives the measurement report message sent by the UE, and the base station acts as the handover source side, and determines to perform the X2 handover, and initiates an X2 handover request message to the target base station.

Step S1104: After receiving the X2 handover request of the handover source side base station, the handover target base station performs a handover preparation process.

Step S1106: The UE fails the radio link due to the wireless environment and the like, starts the 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 suspends the handover being performed, performs RRC connection re-establishment, and sends an RRC connection re-establishment message to the UE.

Step S1110: After receiving the RRC connection re-establishment complete message, the target base station activates the suspended handover procedure, and sends an RRC connection reconfiguration message to the UE, starts to wait for the RRC connection reconfiguration complete timer, and simultaneously replies to the handover source side base station. A handover confirmation message carrying a Receive Reestablishment during HO Prepare.

Step S1112: After receiving the handover command message of the handover target base station, the source base station performs the expansion according to the handover command. The reason value is displayed, the reconfiguration message of the switching command is not issued, and operations such as data back-transmission are performed.

Step S1114: After the RRC connection reconfiguration completion wait timeout expires, and the target base station still does not receive the RRC connection reconfiguration complete message, the target base station performs an RRC connection resource release procedure.

Step S1116: The handover source side base station waits for the UE context release message (UeContextRelease) timer of the handover target side base station to time out, and triggers the UE context release process.

Alternative embodiment five

The optional embodiment 5 of the present invention provides a handover processing method that fails to reconfigure the UE after receiving the RRC connection re-establishment request in the S1 handover preparation phase. FIG. 12 is a flowchart of a method for re-establishing a cross-base station handover process according to an alternative embodiment 5 of the present invention. As shown in FIG. 12, the process includes the following steps:

Step S1202: The base station receives the measurement report message sent by the UE, and the base station acts as the handover source side, and determines to perform the S1 handover, and initiates an S1 handover request message to the MME.

Step S1204: After receiving the S1 handover request message of the MME, the handover target base station performs a handover preparation process.

In step S1206, due to the wireless environment and the like, the UE fails the radio link, starts the 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 suspends the handover that is being executed, performs re-establishment, and sends an RRC connection re-establishment message to the UE.

Step S1210: After receiving the RRC connection re-establishment complete message, the target base station activates the suspended handover procedure, and sends an RRC connection reconfiguration message to the UE, starts to wait for the RRC connection reconfiguration completion timer, and simultaneously returns the MME with the extension reason. A handover confirmation message of the value (Receive reestablishment during HO Prepare).

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

In step S1214, when the handover target side base station waits for the RRC connection reconfiguration completion timer to be exceeded, the UE context release procedure is performed.

Alternative Embodiment 6

The optional embodiment 6 of the present invention provides a processing method for performing handover cancellation in a re-establishment process after receiving an RRC connection re-establishment request in the X2 handover preparation phase. FIG. 13 is a flowchart of a method for canceling cross-base station handover according to an alternative embodiment 6 of the present invention. As shown in FIG. 13, the process includes the following steps:

Step S1302: The base station receives the measurement report message sent by the UE, and the base station acts as the handover source side, decides to perform X2 handover, initiates an X2 handover request message to the target base station, and starts an X2 handover preparation phase waiting timer (T_X2HoPrep).

Step S1304: After receiving the X2 handover request message of the handover source side base station, the handover target base station performs a handover preparation process.

Step S1306: The radio link fails due to the wireless environment, and the UE starts the 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 suspends the handover that is being performed, performs RRC connection re-establishment, and sends an RRC connection re-establishment message to the UE.

Step S1310: After the T_X2HoPrep wait timer expires, the switching source side base station triggers the handover cancel process, sends a handover cancel message to the handover target side base station, and then performs a UE context release procedure.

Step S1312: After receiving the handover cancellation initiated by the handover source side base station, the handover target base station cancels the RRC connection re-establishment procedure and the suspended handover resource, and sends an RRC connection re-establishment rejection message to the UE.

Alternative Embodiment 7

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

Step S1402: The base station receives the measurement report message sent by the UE, and the base station acts as the handover source side, determines to perform the S1 handover, initiates the S1 handover request message to the MME, and starts the S1 handover preparation phase waiting timer (T_S1HoPrep).

Step S1404: After receiving the S1 handover request message of the MME, the handover target base station performs a handover preparation process.

Step S1406: The radio link fails due to the wireless environment and the like, and then the RRC connection re-establishment process is started, and an RRC connection re-establishment request message is initiated.

Step S1408: After receiving the RRC connection re-establishment request message, the target base station suspends the handover that is being performed, performs RRC connection re-establishment, and sends an RRC connection re-establishment message to the UE.

Step S1410: After the T_S1HoPrep wait timer expires, the source side base station is switched to send a handover cancel message to the MME.

Step S1412: After receiving the UE context release command of the MME, the target base station instructs to perform handover cancellation, cancels the RRC connection re-establishment procedure and the suspended handover resource, and sends an RRC connection re-establishment rejection message to the UE, and returns the UE context to the MME. Release the completion message.

In summary, a processing method and apparatus for re-establishing a cross-base station handover process according to an embodiment of the present invention and an optional embodiment are provided. Compared with the prior art, an S1/X2 handover target base station is provided. The processing policy of receiving the RRC connection re-establishment request in the preparation phase of the inter-base station handover reduces the occurrence rate of the dropped call of the UE caused by the failure of the RRC connection re-establishment in the handover preparation process, and improves the stability of the handover and the user experience.

It will be apparent to those skilled in the art that the various modules or steps of the present invention described above can be implemented by a general-purpose computing device that can be centralized on a single computing device or distributed across a network of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device such that they may be stored in the storage device by the computing device and, in some cases, may be different from the order herein. The steps shown or described are performed, or they are separately fabricated into individual integrated circuit modules, or a plurality of modules or steps thereof are fabricated as a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software.

The above description is only an alternative embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Industrial applicability

Claims

A processing method re-established in a process of switching between base stations, including:

When the target base station receives the RRC connection re-establishment request of the user equipment UE in the handover preparation phase, the target base station suspends the handover preparation procedure, and performs an RRC connection re-establishment procedure;

When the target base station receives the RRC connection re-establishment completion message of the UE, the target base station activates the handover preparation procedure, sends an RRC connection reconfiguration message to the UE, and sends a handover carrying the extension cause value. The confirmation message is sent to the mobility management entity MME or the source base station.
The method according to claim 1, wherein the transmitting, by the target base station, the handover confirmation message carrying the extension cause value comprises:

When the handover type is the S1 handover, the target base station sends the handover confirmation message carrying the extension cause value to the MME, where the extension cause value is used to indicate that the MME sends the bearer. Transmitting a handover command of the cause value to the source base station, and instructing the source base station not to send an RRC connection reconfiguration message to the UE.
The method according to claim 1, wherein the transmitting, by the target base station, the handover confirmation message carrying the extension cause value comprises:

In the case that the handover type is the X2 handover, the target base station sends the handover confirmation message carrying the extension cause value to the source base station, where the extension cause value is used to indicate that the source base station does not The UE sends an RRC Connection Reconfiguration message.
The method of claim 1, wherein after the target base station sends the RRC connection reconfiguration message to the UE, the method further includes:

Initiating an 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.
The method of claim 4, wherein after the target base station confirms that the UE successfully completes the handover, the method further includes:

The target base station sends a path conversion request message or a handover notification message to the MME, where the path conversion request message or the handover notification message is used to indicate that the UE has successfully completed the handover.
The method of claim 4, wherein, in a case that 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 performs an RRC connection resource release procedure of the UE.
The method according to any one of claims 1 to 6, wherein after the target base station suspends the handover preparation process, the method further comprises:

And the target base station receives the UE context release command sent by the MME, where the handover type is the S1 handover, and the target base station does not receive the RRC connection re-establishment complete message of the UE;

And 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.
The method according to any one of claims 1 to 6, wherein after the target base station suspends the handover preparation process, the method further comprises:

In a case that the handover type is X2 handover, and the target base station does not receive the RRC connection re-establishment complete message of the UE, the target base station receives a handover cancellation message sent by the source base station;

The target base station sends an RRC Connection Reestablishment Reject message to the UE according to the handover cancellation message.
A processing device re-established in a cross-base station handover process is applied to a base station, including:

The first processing module is configured to suspend the handover preparation process and perform an RRC connection re-establishment process when the base station receives the RRC connection re-establishment request of the user equipment UE as the target base station in the handover preparation phase;

The second processing module is configured to: when receiving the RRC connection re-establishment completion message of the UE, activate the handover preparation procedure, send an RRC connection reconfiguration message to the UE, and send a handover confirmation carrying the extension cause value The message is sent to the mobility management entity MME or the source base station.
The apparatus of claim 9 wherein said second processing module is configured to:

If the handover type is the S1 handover, the handover confirmation message carrying the extension cause value is sent to the MME of the mobility management entity, where the extension cause value is used to indicate that the MME sends the bearer. Transmitting a handover command of the cause value to the source base station, and instructing the source base station not to send an RRC connection reconfiguration message to the UE.
The apparatus of claim 9 wherein said second processing module is configured to:

Transmitting the handover confirmation message carrying the extension cause value to the source base station, where the extension type value is used to indicate that the source base station does not send to the UE, where the handover type is X2 handover. RRC connection reconfiguration message.
The apparatus of claim 9 wherein said apparatus further comprises:

Activating a module, configured to start an RRC connection reconfiguration complete timer; the confirmation module is configured to confirm that the UE successfully completes when receiving the RRC connection reconfiguration complete message before the RRC connection reconfiguration complete timer expires Switch.
The device of claim 12, wherein the device further comprises:

The first sending module is configured to send a path conversion request message or a handover notification message to the MME, where the path conversion request message or the handover notification message is used to indicate that the UE has successfully completed the handover.
The device of claim 12, wherein the device further comprises:

And an execution module, configured to perform an RRC connection resource release procedure of the UE if the RRC connection reconfiguration complete timer expires and the RRC connection reconfiguration complete message is not received.
The device according to any one of claims 9 to 14, wherein the device further comprises:

a first receiving module, configured to receive a UE context release command sent by the MME, if the handover type is S1, and the RRC connection re-establishment complete message of the UE is not received;

The second sending module is configured to send an RRC connection re-establishment reject message to the UE according to the UE context release command, and send a UE context release complete message to the MME.
The device according to any one of claims 9 to 14, wherein the device further comprises:

a second receiving module, configured to: when the handover type is X2 handover, and the RRC connection re-establishment complete message of the UE is not received, receive a handover cancellation message sent by the source base station;

The third sending module is configured to send an RRC connection re-establishment reject message to the UE according to the handover cancellation message.