CN101505514A - Processing method for handover failure, method and apparatus for detecting handover success - Google Patents

Abstract

The invention discloses a handover failure processing method, comprising: receiving a message sent by a source base station; the message includes cell reselection information; according to the cell reselection information, cell reselection is performed after the cell handover fails. The invention also discloses a method for detecting handover success, and also discloses user equipment and base station equipment. Through the solution provided by the embodiment of the present invention, the UE can access as soon as possible after the handover fails, ensuring that the communication is not interrupted, and minimizing the service delay caused by the UE after the handover fails, overcoming the current situation. There is a problem in the technology that when the UE fails to switch to the target cell and cannot access the source cell, the service is interrupted. In addition, when the UE performs handover, by confirming that the random access response message sent by the base station does not reject the UE's access, or does not delay the UE's access, the specific method for the successful handover is clarified.

Description

Handover failure processing method, method and device for detecting handover success

technical field

The invention relates to the field of wireless communication, in particular to a method and device for processing handover failure, and a method and device for detecting handover success.

Background technique

In a Long Term Evolution (LTE) system, when it is determined that the radio link fails, the radio link needs to be restored. First, in the first stage, the user equipment (User Equipment, UE) selects the source cell to restore the radio link. If the restoration cannot be completed in the first stage, it enters the second stage. In the second stage, the UE independently selects a The cell sends a radio resource control connection re-establishment request (Radio Resource Control Connection Re-establishment Request) message to the cell. After receiving the message, the cell checks whether it has saved the context of the UE. When the context of the UE exists, Send a message to the UE to notify the UE that the radio link is restored, and the UE sends a radio resource control connection re-establishment complete (RRC Connection Re-establishment Complete) message to the network side; when there is no context for the UE in the cell, send the radio resource to the UE Control the connection re-establishment rejection (RRC Connection Re-establishment Reiect) message, and the UE needs to re-initiate a new RRC connection establishment process. Since the high-level service has not been released at this time, it is only the service terminal of the RRC layer, so the RRC connection needs to be established as soon as possible.

In the LTE system, after the source cell receives a handover (Handover, HO) command message, the UE initiates a handover process to the target cell, but in the handover process, how to determine the success of the UE handover has not yet been clearly defined. The UE is informed in the handover command message to return to the source cell when the handover fails, but when the signal quality of the source cell is not good, there is a danger of call drop or the source cell cannot be accessed at all.

Contents of the invention

The embodiment of the present invention provides a handover failure processing method and device, so that when the UE fails to handover, it selects a suitable cell for access, and reduces the service delay caused by the handover failure of the UE.

The embodiments of the present invention also provide a method and device for detecting handover success, so that the UE can accurately confirm that the UE performs handover successfully during the handover process.

In order to achieve the purpose of the above invention, the embodiment of the present invention provides a handover failure processing method, including: receiving a message sent by the source base station, the message including cell reselection information; according to the cell reselection information, when the cell handover fails Then perform cell reselection.

The embodiment of the present invention also provides a user equipment, including: a first receiving unit, configured to receive a message sent by a source base station, the message including cell reselection information; a cell reselection unit, configured to receive The cell reselection information in the message received by the unit performs cell reselection after the cell handover fails.

The embodiment of the present invention also provides a base station device, including: a second sending unit, configured to send a handover request message to at least two target base stations, and send a handover request message to the UE after the second receiving unit receives the handover request response message. A command message, wherein the handover command message includes cell reselection information; a second receiving unit, configured to receive a handover request response message sent by the target base station.

The embodiment of the present invention also provides a handover failure processing method, including: the UE sends a measurement report to the source cell, and receives a handover command message sent by the source base station where the source cell is located;

When the handover fails, the UE accesses cells in the target base station other than the target cell according to the cell identities of other cells in the target base station where the target cell is located; The cell identifier is used to access the cell in the source base station.

The embodiment of the present invention also provides a user equipment, including: a transceiver unit, configured to send a measurement report to the source cell, and receive a handover command message sent by the source base station where the source cell is located; an access unit, configured to , the UE accesses cells in the target base station other than the target cell according to the cell identifiers of other cells in the target base station where the target cell is located; or, according to the cell identifier of the cell in the source base station where the source cell is located, Access to the cell in the source base station.

The embodiment of the present invention also provides a handover failure processing method, including: the UE sends a measurement report to the source cell; the source cell sends a handover command message to the UE; when the handover fails, the UE selects another cell to access, so The selection of other cells for access includes: the UE searches for cells that meet the access conditions on all frequency bands, and performs access; or according to the measurement report, selects the cell with the best signal quality or strength except the target cell for access. or select the frequency band or system with the highest priority for access reselection.

The embodiment of the present invention also provides a user equipment, including: a transceiver unit, configured to send a measurement report to the source cell; an access unit, configured to search for cells that meet the access conditions on all frequency bands when the handover fails, and Perform access; or select a cell with the best signal quality or strength except the target cell for access according to the measurement report; or select a frequency band or system with the highest priority for access reselection.

The embodiment of the present invention also provides a method for detecting handover success, including: the UE sends a random access preamble message to the base station, and receives a random access response message sent by the base station; when the random access response message does not reject When the UE accesses, or the UE access is not delayed, it is determined that the handover is successful.

The embodiment of the present invention also provides a user equipment, including: a transceiver unit, configured to send a random access preamble message to a base station, and receive a random access response message sent by the base station; a confirmation unit, configured to When the random access response message received by the unit does not reject or delay the handover initiated by the random access preamble message, it confirms that the handover is successful.

Through the scheme provided by the embodiment of the present invention, the source base station sends cell reselection information to the UE. When the UE fails to handover, it can reselect the cell whose signal quality or strength meets the handover conditions as soon as possible according to the cell reselection information sent by the source base station. Cell access ensures uninterrupted communication and minimizes service delay caused by UE handover failure. Or, the UE fails to handover and cannot return to the source cell. When it cannot return to the source cell, it selects other cells for access, which overcomes the problem in the prior art when the UE fails to handover to the target cell and cannot access The problem of service interruption in the case of the source cell. In addition, when the UE performs handover, by confirming that the random access response message sent by the base station does not reject the UE's access, or does not delay the UE's access, the specific method for the successful handover is clarified.

Description of drawings

FIG. 1 is a schematic flowchart of a method for handling handover failure according to the first embodiment of the present invention;

FIG. 2 is a schematic diagram of a handover failure processing method according to the second embodiment of the present invention;

FIG. 3 is a schematic diagram of a handover failure processing method according to the third embodiment of the present invention;

FIG. 4 is a schematic flowchart of a handover failure processing method according to the fifth embodiment of the present invention;

Fig. 5 is a schematic structural diagram of a user equipment according to an eighth embodiment of the present invention.

Detailed ways

In order to make the specific technical solution and the purpose of the invention clearer, further description will be made below in conjunction with specific implementation methods and accompanying drawings.

Referring to FIG. 1 , the first embodiment of the present invention is introduced, which is about a handover failure processing method. In this embodiment, the source base station sends a message including cell reselection information to the UE. When the UE fails to switch from the source cell to the target cell, it can perform cell reselection according to the cell reselection information and access to other target cells. , the method includes:

Step 101: Receive a message sent by a source base station, where the message includes cell reselection information;

Step 102: Perform cell reselection according to the cell reselection information.

In this method, the cell reselection information may include a suitable cell, frequency or system list (suitable cell, frequency or RAT list), and a cell reselection, frequency or system priority list. When preparing for handover, the UE sends the measured cell information that satisfies the measurement event criteria to the source base station in the measurement report, and the source base station selects a target cell that meets the handover conditions according to the measurement report, triggers or prepares for triggering, so that these The target cell that satisfies the handover condition completes the handover preparation. The source base station sends the cell list, frequency list and cell reselection priority list of the target cell meeting the handover condition to the UE, and the source base station may also send the frequency or system list, and the frequency or system priority list to the UE. When the UE fails to hand over, it knows which target base stations have the context of the UE from the list of suitable cells, frequencies or systems, and then selects an appropriate cell to enter according to the cell reselection, frequency or system priority list.

Referring to FIG. 2 , the second embodiment of the present invention will be introduced below, regarding a method for handling handover failure. In this embodiment, after receiving the measurement report sent by the UE and making a handover decision, the source base station sends a handover request message to multiple target base stations regardless of whether the UE's initial handover will fail in the future, triggering multiple target base stations to perform handover. Handover configuration, and send the cell reselection information used by the UE after the handover fails to the UE in the handover command message.

Step 201: The UE sends a measurement report to the source base station, and the measurement report includes the target base stations that meet the measurement event criteria obtained by the UE's measurement.

Step 202: The source base station decides to perform cell handover.

Step 203: the source base station sends a handover request (Handover Request) message to at least two target base stations; thus, when multiple target base stations receive the handover request message sent by the source base station, they obtain the context of the UE.

Step 204: After receiving the handover request message, multiple target base stations complete access control according to the received message and their own resource conditions.

Step 205: after multiple target base stations complete the access control, send a handover request acknowledgment (HandoverRequestACK) message to the source base station; the handover request acknowledgment message contains a transparent container (TransparentContainer), which contains the new cell wireless network temporary Identify C-RNTI, dedicated RACH preamble and parameters for access.

Step 206: After receiving the handover request response messages sent by multiple target base stations, the source base station sends a handover command (Handover Command) message to the UE. In the handover command message, the transparent container contained in the target base station with the best signal quality or strength is included, and the target base station with the best signal quality or strength is selected by the source base station in the handover decision; the handover command message also includes It carries cell reselection information, which may include a list of suitable cells, frequencies or systems, and a list of cell reselection, frequencies or system priorities.

Step 207: According to the handover command message, the UE initiates cell reselection after failing to handover the target base station with the best signal quality or strength. Among the cells recorded in the appropriate cell, frequency or system list, the UE selects an optimal cell as the new handover target cell, except for the cell that currently fails to access, according to the corresponding cell reselection, frequency or system priority list , to perform a cell reselection process.

Step 208: After successfully accessing the newly selected target cell, the UE sends a handover confirmation (HandoverConfirm) message to the target base station, indicating that the handover process is completed.

Step 209: After receiving the handover confirmation message, the target base station sends a Release Resource (ReleaseResource) message to the source base station, indicating that the handover is successfully completed, and at the same time triggers the source base station to release resources.

Referring to FIG. 3 , a third embodiment of the present invention is introduced, which is about a method for handling handover failure. In this embodiment, the source base station sends the cell reselection information used by the UE after the handover fails to the UE in the handover command message, and when the UE fails to perform the handover, the source base station sends handover request messages to multiple target base stations , to trigger multiple target base stations to perform handover configuration. The method includes:

Step 301 and step 302 are the same as steps 201 to 202 in the second embodiment.

Step 303: The source base station sends a handover request message to the target base station with the best signal quality or strength, such as target base station 1, according to the measurement report.

Step 304: The target base station completes access control according to the received message and its own resource conditions.

Step 305: the target base station sends a handover request response message to the source base station.

Step 306: After receiving the handover request response message sent by the target base station, the source base station sends a handover command message to the UE, and carries cell reselection information in the handover command message, including a suitable cell, frequency or system list, and cell reselection, Frequency or system priority list.

Step 307: After the UE fails to handover the target base station according to the handover command, it sends a radio resource control connection re-establishment request (RRC Connection Re-establishment Request) message to the source cell, requesting to re-establish the connection, and triggers the source base station to initiate the configuration of multiple preparations for the target base station. process.

Step 308: the source base station sends a handover request (Handover Request) message to at least two target base stations, such as at least two base stations in the target base station 2 to the target base station N; like this, when multiple target base stations receive the handover request message sent by the source base station After that, the context of the UE is obtained.

Step 309: The source base station sends a radio resource control connection re-establishment rejection (RRC ConnectionRe-establishment Reject) message to the UE, triggering the UE to perform a cell reselection process.

There may not be a necessary sequence relationship between step 308 and step 309 .

Step 310: After receiving the handover request message, multiple target base stations complete access control according to the received message and their own resource conditions.

Step 311: After multiple target base stations complete the access control, send a handover request response (HandoverRequest ACK) message to the source base station, and the handover request response message contains a transparent container (TransparentContainer), which contains a new C-RNTI , a dedicated RACH preamble and parameters for access.

Step 312: After receiving the RRC Connection Re-establishment Reject message, the UE selects a new cell according to the corresponding cell reselection, frequency or system priority list among the cells recorded in the appropriate cell, frequency or system list, and performs cell reselection process.

Step 313 to step 314 are the same as step 208 and step 209 in the second embodiment.

The following introduces the fourth embodiment of the present invention, about a method for handling handover failure. In this embodiment, when the UE fails to perform handover, the source base station sends a handover request message to multiple target base stations to trigger multiple target base stations to perform handover configuration. Select information. The method includes:

Steps 401 to 408 are basically the same as steps 301 to 308 in the third embodiment, the difference is that in step 406, after the source base station receives the request response message sent by the target base station, in the handover command message sent to the UE, It does not contain cell reselection information.

Step 409: The base station sends a RRC Connection Re-establishment Reject message to the UE while sending handover request messages to at least two target base stations, triggering the UE to perform a cell reselection process. The message contains cell reselection information, which may include a suitable cell Among the cells recorded in the , frequency or system list, reselect according to the corresponding cell, frequency or system priority list.

Step 410 to step 414 are the same as step 310 to step 314 in the third embodiment.

In the above embodiments, the source base station sends a handover request message to multiple target base stations before the handover or after the handover fails, triggering multiple target base stations to prepare for handover, so that they have the context of the UE, and send the cell reselection information to to UE. When the handover fails, the UE can re-select the cell whose signal quality or strength meets the handover conditions according to the cell reselection information sent by the source base station as soon as possible, so as to ensure that the communication is not interrupted, and minimize the UE's troubles after the handover fails. Incoming business delay.

Referring to FIG. 4 , the fifth embodiment of the present invention is introduced. Regarding a handover failure processing method, in this embodiment, there are no multiple target base stations prepared, and there is only one prepared target base station. Both the source base station and the target base station can be used. Multiple cells exist. When the handover fails, the UE selects an access source cell or selects another cell for access by means of cell selection, cell reselection, or according to UE measurement report information.

Step 501: UE receives a handover command message, and fails when handing over from a source cell to a target cell. When the UE needs to perform handover, it sends a measurement report to the source cell, and the source cell sends a handover request message to the target cell. After the target cell completes access control, it sends a handover request confirmation message to the source cell. After receiving the handover request confirmation message, the source cell After that, send a handover command message to the UE.

Step 502: When the UE fails in handover, the UE selects another cell to access, and executes Step 505.

In this step, when the handover of the UE fails, before directly selecting other cells for access, it may also try to return to the source cell first, that is, first determine whether the source cell meets the signal quality or strength of the access, if the source cell If the signal quality or strength of the source cell meets the cell selection criterion S, it means that the UE can request access to the source cell; at this time, the signal quality or strength of the source cell may deteriorate further. Intensity, the UE may fail to switch to the target cell and cannot access the source cell, and the service may be interrupted. Therefore, the source cell can reconfigure the threshold S', which is sent by the system broadcast message of the source cell To the UE, or to inform the UE in the handover command message, the standard of the threshold S' is slightly lower than S. Therefore, when the signal quality or strength of the source cell meets the cell selection criterion S or S', perform step 503; if the signal quality or strength of the source cell does not meet the cell selection criterion S or S' for access, then perform step 505.

Step 503: The UE performs a process of accessing the source cell. If the access is successful, execute step 504, and if it fails, execute step 505.

Step 504: After successfully accessing the source cell, the UE reports to the source cell the reason for the failure of handover to the target cell. The UE can carry the reason for the failure to access the target cell in the RRC reconfiguration failure message, and the source cell can refer to it when making subsequent handover decisions, and use the failure reason as the original data for problem location, tracking and optimization of the UE.

Step 505: The UE selects another cell to access. When the UE uses the cell selection method, step 505a is performed; when the UE uses the data in the measurement report, step 505b is performed; when the UE uses the cell reselection method, step 505c is performed.

Step 505a: UE searches in all frequency bands, and selects a suitable cell to access.

Step 505b: The UE adopts the measurement results in the measurement report during the initial handover, that is, directly selects the cell with the best signal quality or strength except the target cell among the cells satisfying the handover condition to access.

In this step, the cells other than the target cell selected in the measurement report can also be sorted according to signal quality or signal strength, and select a cell with the same frequency as the target cell, or a cell with the same frequency as the source cell, or all cells Perform measurement, and select the first cell that meets the cell handover criterion to access according to the measurement result.

Step 505c: the UE selects the frequency band or system with the highest priority to access. The specific access method can refer to the existing parameters used by the UE for cell reselection, which are not necessarily those of the source cell; or through the cell reselection parameters obtained in the system broadcast message of the source cell; or The cell reselection parameters of the UE are informed in the handover command message sent by the source cell. After selecting a suitable frequency band or system, the measurement result of the source cell can be directly used, or the measurement can be performed again, and then the most suitable cell can be selected for access according to the new measurement result.

Step 506: After the UE selects a new cell for access, if the handover is successful, execute step 507, otherwise execute step 508.

Step 507: UE switches to a new cell.

Step 508: UE fails in handover and returns to idle state.

In this embodiment, when the handover fails, the UE first confirms that it can return to the source cell, and if it cannot return to the source cell, it selects another cell through cell selection, cell reselection, and data in the measurement report. The accessing method overcomes the problem of service interruption in the prior art when the UE fails to switch to the target cell and cannot access the source cell.

The sixth embodiment of the present invention is introduced, about a method for handling handover failure. In this embodiment, when the need for handover occurs, the UE performs neighbor cell information measurement and sends a measurement report to the source cell. After the UE receives the handover command message sent by the source cell and fails to handover to the target cell, it needs to The base station with the UE context performs access, and the source base station where the source cell is located and the target base station where the target cell is located have the context of the UE. A base station can have multiple cells. Therefore, the UE can carry the cell identities of other cells in the source base station in the measurement control message, or the system broadcast message of the source cell, or the handover command message sent by the source cell to the UE, and the cell identifiers of other cells in the target base station. When the UE fails to switch to the target cell, it can select a cell in the source base station or a cell other than the target cell in the target base station for access. The cell identities of other cells in the source base station can also be obtained by the UE according to the cell identities of the source cell, and the cell identities of other cells in the target base station can be obtained by the UE according to the cell identities of the target cell. The method specifically includes:

Step 601: UE performs neighbor cell information measurement and sends a measurement report to the source cell. The UE may obtain the cell identities of other cells in the source base station and the cell identities of other cells in the target base station from the measurement control message or the source cell system broadcast message.

Step 602: Receive the handover command message sent by the source cell, the handover command message may also include the cell IDs of other cells in the source base station and the cell IDs of other cells in the target base station; the UE may also obtain the source cell ID according to the cell ID of the source cell. Cell identities of other cells in the base station, and cell identities of other cells in the target base station are obtained according to the cell identities of the target cell.

Step 602: After the UE fails to perform handover, the UE selects other cells in the base station where the target cell is located according to the measurement results of the UE in the measurement report, or the measurement results obtained after the UE performs re-measurement, and selects the cell with the best signal quality or strength access to the community.

If the UE still fails to access other cells in the target base station, then access to the cells in the source base station, including the source cell or other cells except the source cell, and select the cell with the best signal quality or strength as the access condition , for example, the signal strength of the cell is the best, or the signal quality is the best.

In this embodiment, when the UE receives the handover command message sent by the source cell and fails to handover to the target base station, it may also directly choose to access the source cell or other cells in the base station where the source cell is located.

When the handover to the target cell fails, the resources of the UE in the source cell still exist, and it is relatively easy to return to the source cell at this time, so returning to the source cell can be prioritized. If the access to the source cell fails, another cell in the base station where the source cell is located is selected according to the signal quality or signal strength of the cell. Alternatively, instead of giving priority to returning to the access source cell, the optimal cell is directly selected for access according to the signal quality or strength of the source cell and other cells. When the UE fails to access the source cell or other cells in the base station where the UE is located, it then performs an access process to other cells in the base station where the target cell is located.

When the UE preferentially returns to the source cell, further, the source cell can tell the UE a RAT or frequency through redirection information, or the source cell can inform the UE of a RAT or frequency through a message such as a rejection message, a release message, or a configuration message. The UE has a list of cells, etc., to inform the UE of the other cells of the eNB where the source cell and/or the target cell are located. The list of other cells in the cell is sent to the UE, and the UE selects a suitable cell to access after receiving the list.

In this embodiment, according to the fact that there may be multiple cells in the source base station where the source cell is located and the target base station where the target cell is located, by obtaining the cell identities of the cells in the source base station and the target base station, and using the cell identities, the UE sends When the handover of the target cell fails, access to other cells in the target base station or return to the cell in the source base station, which overcomes the problem of service interruption when the UE cannot access the target cell or return to the source cell, and ensures correct selection Subsequent cell access after handover failure.

The seventh embodiment of the present invention is introduced below, which is about a method for detecting handover success. In the LTE system, there are two random access procedures: one is a contention-based random access procedure, and the other is a non-contention-based random access procedure. Usually, when the UE has uplink data, or when the UE initiates random access, it will initiate a contention-based random access procedure; most random access procedures for switching to the target cell, and when the base station has downlink data to send, it will initiate a non-contention-based random access procedure. random access process. The two random access procedures are described below.

1. Contention-based random access process

The random access procedure is completed through several interactions between the UE and the base station, including at least four messages:

Message 1 is sent by the UE to the base station, and the message 1 includes a random access preamble (Preamble);

Message 2, the random access response sent by the base station to the UE, which includes the random access preamble, the random access radio network temporary identifier RA-RNTI, the cell radio network temporary identifier C-RNTI and the uplink information allocated to the UE for message 3 air interface resources;

Message 3 is sent by the UE to the base station. If there are multiple UEs initiating random access, the base station can know exactly which UE is initiating random access through message 3;

Message 4 is a message sent by the base station to the UE after the UE accesses successfully.

2. Non-contention-based random access process

The so-called non-contention means that the base station allocates a dedicated random access preamble to the UE in advance, so that as long as the UE sends the dedicated random access preamble to the base station through message 1, the base station can know which UE the UE is. After the UE receives the message 2 sent by the base station, the UE can know that the connection with the base station has been successfully established, and then through the uplink resources allocated in the message 2, the UE can interact with the base station through the message 3.

It should be noted that for some special cases, such as handover, the target cell defines a validity period for the dedicated random access preamble. During the validity period, the UE accesses the base station based on a non-contention random access process. Once the dedicated random access preamble expires , the UE needs to restart the contention-based random access process. At this time, random access failure may also be determined according to the above method.

In this embodiment, the method for detecting handover success includes:

Step 701: UE sends a random access preamble message to the base station, and receives a random access response message sent by the base station.

Step 702: When the random access response message sent by the base station does not reject the UE's access, or does not delay the UE's access, determine that the handover is successful. For the non-contention-based access process, when the UE receives the random access response message, as long as the random access response message does not reject the UE access, or the base station does not use the Backoff method to delay the UE access, it can confirm that the UE has sent The target base station handover is successful.

For the non-contention-based access process, after receiving the random access response message sent by the base station, the UE sends a handover success message to the base station, even if it does not receive the hybrid automatic repeat request acknowledgment (HARQ ACK) message returned by the base station, Then the base station can also confirm that the handover is successful. Because the HARQ ACK message sent by the base station may be lost after sending, the UE cannot receive the message. When the base station receives the handover success message, it will continue the process and send a resource release message to the source cell. At this time, if the UE encounters It is meaningless to return to the source cell after the failure, so the base station can confirm the success of the handover at this time.

For the contention-based access process, after receiving the Scheduled Transmission (Scheduled Transmission) message sent by the UE, the base station can confirm that the handover is successful after sending a contention resolution (Contention Resolution) message to the UE. Because the base station will continue the process after sending the contention resolution message, and send a resource release message to the source cell, so regardless of whether the UE receives the contention resolution message, it is meaningless for the UE to return to the source cell if it fails. Therefore, this Then the base station can confirm that the handover is successful.

Through the method provided in this embodiment, it is possible to clearly confirm the handover success and handover failure of the UE during the handover process. When the UE handover fails, the method provided by other embodiments of the present invention can be used to recover after the handover failure.

Referring to FIG. 5 , an eighth embodiment of the present invention will be described below, regarding a user equipment, including: a first receiving unit, configured to receive a message sent by a source base station, the message includes cell reselection information, and the cell reselection information can be Including a list of suitable cells, frequencies or systems, and a list of cell reselection, frequency or system priority; a cell reselection unit, configured to, according to the cell reselection information in the message received by the first receiving unit, after cell handover fails Perform cell reselection.

Further, the user equipment may further include a first sending unit, configured to send a measurement report or a radio resource control connection reestablishment request message to the source base station.

When the user equipment needs to perform handover, it performs the measurement of the current cell and the neighboring cell. According to the measurement event criterion, the neighbor cell information is obtained and sent to the source base station in the measurement. After the source base station makes a handover decision, it sends a handover command message to the UE, UE Receive the handover command message and other messages sent by the source base station, and perform handover. The message sent by the source base station includes cell reselection information used by the UE after the handover fails. When the UE fails to handover, it can select a new cell for access according to the received cell reselection information.

The ninth embodiment introduces a base station device, including: a second sending unit, configured to send a handover request message to at least two target base stations, and send a handover command message to the UE after the second receiving unit receives the handover request response message , the handover command message includes cell reselection information; the second receiving unit is configured to receive a handover request response message sent by the target base station.

After receiving the measurement report from the UE, the base station device sends cell reselection information to the UE before the handover starts or after the handover fails, and sends handover request messages to multiple target base stations, triggering it to prepare for handover and making it obtain UE context, so that UE access can be completed when the subsequent UE performs cell reselection.

The following describes the tenth embodiment of the present invention, regarding a user equipment, including: a transceiver unit, configured to send a measurement report to the source cell, and receive a handover command message sent by the source base station where the source cell is located; an access unit, configured to When the handover fails, the UE accesses cells in the target base station other than the target cell according to the cell identities of other cells in the target base station where the target cell is located; or

The UE accesses the cell in the source base station according to the cell identity of the cell in the source base station where the source cell is located.

Further, the user equipment may further include an obtaining unit, configured to obtain the cell identities of other cells in the target base station and the cell identities of other cells in the source base station from the handover command message, the source cell system broadcast message or the measurement control message. A cell identifier; or, obtaining cell identifiers of other cells in the source base station according to the cell identifier of the source cell, and obtaining cell identifiers of other cells in the target base station according to the cell identifier of the target cell.

In this embodiment, according to the fact that there may be multiple cells in the source base station where the source cell is located and the target base station where the target cell is located, the UE obtains the cell identities of the cells in the source base station and the target base station, and uses the cell identities. When the handover of the target cell fails, access to other cells in the target base station or return to the cell in the source base station, which overcomes the problem of service interruption when the UE cannot access the target cell or return to the source cell, and ensures correct selection Subsequent cell access after handover failure.

The following introduces the eleventh embodiment of the present invention, regarding a user equipment, including: a transceiver unit, configured to send a measurement report to the source cell; an access unit, configured to search for all frequency bands that meet the access conditions when the handover fails or select the cell with the best signal quality or strength except the target cell for access according to the measurement report; or select the frequency band or system with the highest priority for access reselection.

In this embodiment, when the handover fails, the UE selects another cell to access through cell selection, cell reselection, and data in the measurement report. When the handover of the UE fails, before directly selecting other cells for access, it can also try to return to the source cell first, that is, first determine whether the source cell meets the signal quality or strength of the access, if the signal quality or strength of the source cell If the cell selection criterion S is met, it means that the UE can request access to the source cell. The solution provided by this embodiment overcomes the problem of service interruption in the prior art when the UE fails to switch to the target cell and fails to access the source cell.

The following introduces the twelfth embodiment of the present invention, regarding a user equipment, including: a transceiver unit, configured to send a random access preamble message to a base station, and receive a random access response message sent by the base station; a confirmation unit, configured to When the random access response message received by the transceiver unit does not reject or delay the handover initiated by the random access preamble message, it is confirmed that the handover is successful.

Through the method provided in this embodiment, the UE can clearly confirm whether the handover is successful or failed during the handover process.

Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention 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 a better implementation Way. Based on this 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 a software product. The computer software product is stored in a storage medium and includes several instructions to make a A computer device (which may be a personal computer, a server, or a network device, etc.) executes the methods described in various embodiments of the present invention.

Although the present invention has been illustrated and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the present invention. The spirit and scope of the invention.

Claims (24)

1. A processing method for handover failure, characterized in that, comprising: receiving a message sent by the source base station, where the message includes cell reselection information; According to the cell reselection information, cell reselection is performed after cell handover fails. 2. The method according to claim 1, wherein the cell reselection information includes a list of suitable cells, frequencies or systems, and a list of cell reselection, frequencies or systems priority. 3. The method according to claim 1 or 2, wherein the message is a handover command message. 4. The method according to claim 3, further comprising: sending a measurement report to the source base station before receiving the message sent by the source base station, and sending the measurement report to the source base station after receiving the measurement report At least two target base stations send handover request messages. 5. The method according to claim 3, further comprising: sending a radio resource control connection reestablishment request message to the source base station after receiving the message sent by the source base station, and the source base station receives After the request message, send a handover request message to at least two target base stations. 6. The method according to claim 1 or 2, wherein the message is a radio resource control connection reestablishment rejection message. 7. The method according to claim 6, further comprising: sending a radio resource control connection reestablishment request message to the source base station before receiving the message sent by the source base station. 8. The method according to claim 6, wherein when the source base station sends the radio resource control connection reestablishment reject message, simultaneously send handover request messages to at least two target base stations. 9. A user equipment, characterized by comprising: a first receiving unit, configured to receive a message sent by a source base station, the message including cell reselection information; A cell reselection unit, configured to perform cell reselection after cell handover fails according to the cell reselection information in the message received by the first receiving unit. 10. The user equipment according to claim 9, wherein the cell reselection information in the message received by the first receiving unit includes a list of suitable cells, frequencies or systems, and cell reselection, frequency or system priority list. 11. The user equipment according to claim 9 or 10, further comprising: a first sending unit, configured to send a measurement report or a radio resource control connection re-establishment request message to the source base station. 12. A base station device, characterized by comprising: a second sending unit, configured to send a handover request message to at least two target base stations, and send a handover command to the UE after the second receiving unit receives the handover request response message message, the handover command message includes cell reselection information; The second receiving unit is configured to receive the handover request response message sent by the target base station. 13. A method for processing handover failure, comprising: the UE sends a measurement report to a source cell, and receives a handover command message sent by a source base station where the source cell is located; When the handover fails, the UE accesses cells in the target base station other than the target cell according to the cell identities of other cells in the target base station where the target cell is located; or The UE accesses the cell in the source base station according to the cell identity of the cell in the source base station where the source cell is located. 14. The method according to claim 13, wherein the cell identities of other cells in the target base station and the cell identities of other cells in the source base station are included in the handover command message, the source cell system broadcast message or sent to the UE in a measurement control message; or The UE obtains cell identities of other cells in the source base station according to the cell identities of the source cell, and obtains cell identities of other cells in the target base station according to the cell identities of the target cell. 15. The method according to claim 13 or 14, wherein when the UE fails to access a cell in the target base station other than the target cell according to the cell identifiers of other cells in the target base station, The UE accesses the cell in the source base station. 16. The method according to claim 13 or 14, wherein when the UE fails to access the cell in the source base station according to the cell ID of the cell in the source base station, the UE sends the target Cells other than the target cell in the base station perform access. 17. A user equipment, characterized by comprising: A transceiver unit, configured to send a measurement report to the source cell, and receive a handover command message sent by the source base station where the source cell is located; An access unit, configured to, when the handover fails, the UE access to a cell in the target base station other than the target cell according to the cell identifiers of other cells in the target base station where the target cell is located; or The UE accesses the cell in the source base station according to the cell identity of the cell in the source base station where the source cell is located. 18. The user equipment according to claim 17, further comprising an obtaining unit, configured to obtain the information of other cells in the target base station from the handover command message, the source cell system broadcast message or the measurement control message a cell identity and cell identities of other cells in said source base station; or Obtaining cell identities of other cells in the source base station according to the cell identities of the source cell, and obtaining cell identities of other cells in the target base station according to the cell identities of the target cell. 19. A method for handling handover failure, comprising: the UE sends a measurement report to a source cell; the source cell sends a handover command message to the UE; When the handover fails, the UE selects other cells for access, and the selection of other cells for access includes: The UE searches for cells that meet the access conditions on all frequency bands and performs access; or According to the measurement report, select a cell with the best signal quality or strength except the target cell for access; or Select the frequency band or system with the highest priority for access reselection. 20. The method according to claim 19, further comprising: before the UE selects another cell to access, if the signal quality or strength of the source cell meets the access requirements, then the UE accesses the source cell. 21. A user equipment, characterized by comprising: a transceiver unit, configured to send a measurement report to the source cell; an access unit, configured to search for cells that meet the access conditions on all frequency bands when the handover fails, and perform access; or According to the measurement report, select a cell with the best signal quality or strength except the target cell for access; or Select the frequency band or system with the highest priority for access reselection. 22. A method for detecting handover success, comprising: The UE sends a random access preamble message to the base station, and receives a random access response message sent by the base station; When the random access response message does not reject the access of the UE, or does not delay the access of the UE, it is determined that the handover is successful. 23. The method according to claim 22, after the UE receives the random access response message, further comprising: sending a handover success message to the base station. 24. A user equipment, characterized by comprising: a transceiver unit, configured to send a random access preamble message to a base station, and receive a random access response message sent by the base station; A confirmation unit, configured to confirm that the handover is successful when the random access response message received by the transceiver unit does not reject or delay the handover initiated by the random access preamble message.

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