WO2010105567A1 - Handoff optimization method, equipment and system - Google Patents

Abstract

A handoff optimization method, an equipment and a system are disclosed in the present invention, wherein the method includes: acquiring an event, a working frequency point and a physical layer cell identifier of a cell related to the event and a measurement value recorded during a handoff process of a user equipment (UE); according to the event, the working frequency point and the physical layer cell identifier of the cell related to the event and the measurement value, determining a handoff failure caused by an inappropriate setting of handoff parameters and the handoff parameters needing to be adjusted; and transmitting adjustment information of the handoff parameters to the handoff related cell. With the present invention, the setting of handoff parameters can be optimized, and the probability of handoff failure occurrence can be reduced.

Description

 Switching optimization method, device and system The present application claims priority to Chinese Patent Application No. 200910080286.8, entitled "Switching Optimization Method, Equipment and System", filed on March 17, 2009, the entire contents of which are incorporated herein by reference. This is incorporated herein by reference. Technical field

 The present invention relates to communication technologies, and in particular, to a handover optimization method, device, and system. Background technique

 In mobile networks, handover failure is an easy problem. Since handover failure usually causes dropped calls and seriously deteriorates the user experience, an important goal of network optimization is to reduce the probability of handover failure.

 In the current 3GPP (3rd Generation Partnership Project) Rel-8 version protocol, an RRC (Radio Resource Control) connection re-establishment process is proposed to remediate handover failure and reduce dropped calls. The probability of occurrence. After the UE (User Equipment) cannot access the target cell and the handover fails, if the UE detects that there is a problem with the radio link and cannot recover within the set time, the UE performs an RRC connection reestablishment process.

 When the RRC connection reestablishment is performed, if the context information of the UE is stored in the selected cell (the cell may be the source cell, or the target cell, or the preparation cell, or another cell), the connection reestablishment is successful, which means that although The user's service is affected by some interruptions, such as a brief interruption, but the connection is still maintained and the user does not drop out. Otherwise, the cell will reject the request, the connection reestablishment fails, and the UE enters the RRC idle state from the RRC connection state, meaning that the user drops the call.

With the RRC connection re-establishment process, although the call drop rate of the user can be reduced to some extent, the problem of handover failure cannot be solved. Summary of the invention

 Embodiments of the present invention provide a handover optimization method, device, and system to optimize handover parameter settings and reduce the probability of handover failure occurring.

 To this end, the embodiments of the present invention provide the following technical solutions:

 A handover optimization method, including:

 Acquiring an event recorded by the UE in the UE handover process, a working frequency point and a physical layer d of the cell related to the event, a zone identifier, and a measured value;

 Determining a handover failure due to inappropriate handover parameter setting and a handover parameter that needs to be adjusted according to the event, a working frequency of the event-related cell, and a physical layer cell identifier, and a measured value;

 The adjustment information of the handover parameter is sent to the cell related to the handover.

 A handover optimization device, including:

 An acquiring unit, configured to acquire an event recorded during a UE handover process, a working frequency point of the cell related to the event, a physical layer cell identifier, and a measured value;

 a parameter adjustment determining unit, configured to determine, according to the event, a working frequency point of the event-related cell, a physical layer cell identifier, and a measured value, a handover failure caused by a handover parameter setting and a handover parameter that needs to be adjusted;

 And a sending unit, configured to send the adjustment information of the switching parameter to the small area related to the switching.

 A user equipment, including:

 a recording unit, configured to record an event occurring during the handover, a working frequency point of the cell associated with the event, a physical layer cell identifier, and a measured value;

a sending unit, configured to: after the handover fails or after the radio link fails, send the information recorded by the recording unit in the current handover process to the serving base station by using dedicated RRC signaling; a handover optimization system, including: a user equipment, a serving base station and a handover optimization device; the user equipment, configured to record an event occurring in the handover process, a working frequency point of the cell related to the event, a physical layer cell identifier, and a measured value, and after the handover fails After the radio link fails, the information recorded in the current handover process is sent to the serving base station through dedicated RRC signaling;

 The handover optimization device is configured to acquire information recorded in a user equipment handover process from the serving base station, and determine, according to the information, a handover failure caused by inappropriate handover parameter setting and a handover parameter that needs to be adjusted, and the handover parameter is The adjustment information is sent to the cell associated with the handover.

 The handover optimization method, device and system according to the embodiment of the present invention determine, according to the event recorded by the UE during the handover process, the working frequency of the event-related cell, the physical layer cell identifier, and the measured value, that the handover parameter setting is inappropriate The handover failure and the handover parameter to be adjusted may improve the accuracy of determining the cause of the handover failure, and send the adjustment information of the handover parameter to the cell related to the handover, so that the cell performs corresponding parameter optimization adjustment, thereby reducing handover. The probability of failure increases the user experience. DRAWINGS

 In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description For some embodiments of the present invention, other drawings may be obtained from those skilled in the art without departing from the drawings.

 FIG. 1 is an air interface signaling interaction process in a prior art handover process;

 2 is a flowchart of a handover optimization method according to an embodiment of the present invention;

 3 is a schematic structural diagram of a handover optimization apparatus according to an embodiment of the present invention;

 4 is a schematic structural diagram of a user equipment according to an embodiment of the present invention;

 FIG. 5 is a schematic diagram of networking of a handover optimization system according to an embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the present invention. Embodiments, not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

 In the process of implementing the present invention, the inventor finds that the handover failure is usually caused by related signaling loss or error between the UE and the network side, and the cause of the related signaling loss or error is mostly due to improper parameter setting. , or the network (including the site or antenna) is not planned properly, or the user's fast moving. Therefore, the embodiment of the present invention is directed to the handover failure phenomenon occurring in the LTE (Long Term Evolution) network, and determines the real cause of the failure according to the event and measurement information reported by the UE, and then automatically adjusts the handover parameter to reduce Switching failure probability, reducing call drop rate and improving user experience.

 Figure 1 shows the air interface signaling interaction process during a handover process, including the following steps:

 1. The UE sends an RRC measurement report to the source cell.

 2. The source cell sends a handover preparation message to one or more cells (including the target cell and the preparation cell), and after the cells allocate radio resources to the UE, the cell returns a handover preparation confirmation message;

 3. The source cell determines which one to prepare the cell as the target cell for handover according to the relevant criteria, and then sends an RRC reconfiguration message to the UE, that is, a handover command;

 After the MAC (Media Access Control) layer logical entity of the UE successfully receives the message, it sends a HARQ (Hybrid Auto Repeat Request) confirmation message to the source cell.

 5. The UE performs downlink synchronization with the target cell;

 6. After synchronization, the UE sends an uplink random access preamble (dedicated or random) to the target cell;

 7. After receiving the uplink random access preamble, the target cell sends a downlink random access response message;

8. After receiving the response message of the target side, the UE sends an uplink RRC reconfiguration complete message, that is, the handover is completed; 9. The MAC layer logical entity of the target cell successfully receives the reconfiguration complete message, sends a HARQ acknowledgment message to the UE, and sends a path switch message to the MME (Mobility Management Entity, mobility management entity);

 10. If there is downlink data to be sent, the target cell sends a control message to the UE by using a PDCCH (Packet Dedicated Control Channel) to indicate that the UE is ready to receive downlink data.

 11. The RLC (Radio Link Control) layer logic entity of the target cell sends downlink status information.

 12. The target cell sends a resource release message to the source cell.

 When the UE uses the dedicated preamble on the target side, if the UE receives the A3 message, the UE considers that the handover is successful. For the case where the UE uses the random preamble, only when the UE receives the A6 message, that is, the first When the downlink PDCCH control signaling is used, the handover is considered successful.

 It can be seen from the above process that the RRC layer signaling messages sent on the air interface during the handover process mainly include: a measurement report, a handover command, and a handover confirmation. The measurement report is an uplink message sent by the UE to the network side, and the handover command is a downlink message sent by the source cell to the UE, and the handover confirmation is an uplink message sent by the UE to the target cell of the handover. There are several main reasons for the loss of signaling messages:

 (1) Measurement 4 The report is lost. When the measurement fails to be successfully sent to the network side and the maximum number of retransmissions is reached, the UE initiates an RRC reestablishment. It is also possible that the user's radio channel quality deteriorates to a certain extent before the maximum number of times is reached, the radio link fails, and the UE initiates RRC reestablishment.

 (2) The switching command is lost. The loss of the handover command is most likely caused by the deterioration of the radio link condition. Usually, the radio link fails, and then the UE initiates RRC re-establishment.

 (3) The handover confirmation message is lost. At this time, the UE has successfully accessed on the target side, and the target cell has become the serving cell. When the handover confirmation message cannot be successfully sent to the network side and the maximum number of retransmissions is reached, the UE initiates an RRC reestablishment.

It can be seen that no matter which signaling message is lost or wrong, it will cause the handover to fail or wireless. The link failed.

 The handover optimization method of the embodiment of the present invention acquires event and measurement information recorded during the UE handover process based on the RRC re-establishment process after the handover and the handover failure, and determines, according to the event and the measurement information, the handover failure caused by the handover parameter and needs to be adjusted. The handover parameter is used to send the adjustment information of the handover parameter to the cell related to the handover, thereby implementing self-optimization for handover of the UE.

 In order to implement self-optimization of the LTE network, the UE may start the RRC measurement 4 report to the source cell, until the RRC re-establishment process ends, and record a series of events and measurement information that occurs during the recording, after the handover fails, the UE will record the event and The measurement information is sent to the SON function entity, and the SON (Self-Organizing Networks) functional entity determines the handover failure due to the inappropriate handover parameter setting and the handover parameter that needs to be adjusted according to the event and measurement information, and the parameter is switched. The adjustment information is sent to the cell associated with the handover. The SON function entity is a logical entity, which may be located in the operation management system of the network, or part of the function is located in the operation management system, and another part of the function is located in the base station. The specific application may be determined according to actual needs, which is not limited by the embodiment of the present invention.

 As shown in FIG. 2, it is a flowchart of a UE handover optimization method according to an embodiment of the present invention, which mainly includes the following steps:

 Step 201: Obtain an event and measurement information recorded during a UE handover process.

 In the embodiment of the present invention, a series of events, objects, and measurement information that may occur during the recording, from the start of the measurement report by the UE until the end of the RRC re-establishment process, whether the handover succeeds or fails, mainly includes:

 (1) Messages (including measurement reports, handover commands, handover confirmations, etc.) transmission or reception events, radio link failure events, RRC re-establishment events, random access events on the target side, and time intervals between events;

 (2) The frequency of the cell and the Physical Cell Identifier (PCI) of the cell related to the above events, including the serving cell frequency point and the PCI, the target cell frequency point and the PCI, and the cell frequency point residing at the end of the reconstruction. And PCI;

(3) Signal measurement of the involved cell at the time of the event: RSRP ( Reference Signal Receiving Power (Reference Received Power) and/or RSRQ (Reference Signal Receiving Quality) include RSRP and/or RSRQ of the serving cell and the target cell in the measurement report, and RSRP of the serving cell when the radio link fails. / or RSRQ, RSRP and / or RSRQ of the cell camped after the RRC reestablishment succeeds or fails;

 It may further include:

(4) The mobile speed estimated by the UE itself;

 (5) If the UE has a positioning function, it also records the geographical position coordinates of the UE when the event occurs.

 The UE can set a valid time for each record (this time can be set by the network, or can be set by the UE itself, such as set to half an hour or 1 hour, etc.). If the RRC re-establishment is successful, the UE is still in the connected state, and the record is transmitted to the SON functional entity in the network through the latest serving base station. If the RRC reestablishment fails, the UE loses the connection and enters the idle state, and the UE may re-initiate the connection establishment. Then, when the UE enters the connection state next time, the UE transmits the record to the SON functional entity in the network through the service base station as long as it is still valid. If the valid time expires, the UE still does not transmit the record to the SON function entity in the network, then the timeout record is deleted.

 After the UE fails to switch or the radio link fails, the information recorded in the current handover process is sent to the serving base station through dedicated RRC signaling, and may be further transmitted by the serving base station to other related devices in the network. Preferably, after successfully transmitting the recorded information, the UE deletes the information recorded in the current handover process.

 It should be noted that the information recorded by the foregoing UE is only a preferred embodiment of the present invention, and any information that may cause a handover failure belongs to the protection scope of the present invention.

 Step 202: Determine, according to the event and the measurement information, a handover failure caused by the handover parameter setting being inappropriate and a handover parameter that needs to be adjusted.

The SON function entity determines, according to a large number of UE handover failure records collected from the network, that is, events and measurement information recorded by the UE during the handover process, determining handover failures due to inappropriate handover parameters and handover parameters that need to be adjusted, and determining specifically The process will be described in detail later. If the SON function entity can also obtain the moving speed estimated by the UE itself, it can be set to determine the switching parameter that needs to be adjusted according to the method of the embodiment of the present invention when the moving rate of the UE does not exceed a predetermined value, otherwise other methods may be adopted. to make sure.

 Among them, there may be events with causal associations in multiple events (ie, the previous event leads to the occurrence of the latter event). Therefore, if the interval between any two events mentioned above is less than the predetermined time threshold, the event is determined to be an event with a causal association, otherwise the event is considered not to be associated. For events with causal correlation, two events can be considered together (for example: UE sends measurement report and radio link failure). The predetermined time threshold is specifically: the timeout period of the handover failure configured by the network for the UE; or the duration of the radio link failure detection; or the timeout period of the handover failure configured by the UE for the UE and the duration of the radio link failure detection. Larger time; or greater than the timeout period for the handover failure configured by the network for the UE, and greater than the duration of the radio link failure detection.

 It should be noted that, in the embodiment of the present invention, the events for comprehensively determining the handover failure caused by the inappropriate handover parameter setting and the handover parameters that need to be adjusted are consistent with the requirements of the causal association event.

 The following further describes the handover and RRC re-establishment process of the UE, and details how the SON functional entity determines that the handover parameter is inappropriate due to different handover failures.

 It should be noted that the measurement reports described below do not include the 4 reports for SON ANR (Automatic Neighbour Relation) measurements, and the measures for measuring the gap (measurement interval) switch control.

 1. Failed to send measurement report -> RRC rebuild request -> Rebuild failed, enter IDLE state, reside in another cell

 The scenario is as follows: The UE sends a measurement report, but does not receive the acknowledgement information returned by the network until the maximum number of transmissions is reached, the RLC layer reports an error, or the radio link fails according to the physical layer detection; then the UE initiates an RRC re-establishment process, but reconstructs Failure, the RRC connection of the UE is lost, enters an idle state, and camps on another cell different from the source serving cell, and the cell is a cell.

The SON function entity records events and measurement signals recorded during the UE handover process. Check whether the reconstructed cell A is included in the measurement report.

 If the measurement report includes the reconstructed cell A, compare the RSRP and/or RSRQ values of the cell A in the measurement report and the two times after the reestablishment failure, if the measurement value of the previous time is significantly higher than the corresponding time at the next time The measured value, for example, exceeds 3 dB, and the RSRP and/or RSRQ of the serving cell in the measurement report is also significantly lower than the corresponding measured value of the cell A in the measurement report, then it can be determined that the switching condition is set too strict, and the neighboring area signal is already strong. The UE reports the measurement report. At this time, the quality of the radio link of the serving cell is already poor, and the message cannot be correctly received by the base station. This means that the switching action is too late and misses the better switching moment. In this case, it is necessary to lower the switching threshold, and / or reduce the hysteresis value, and / or reduce the measurement result reporting trigger time, so that the switching action can be advanced.

 2. Send measurement report -> Radio link failed (because the handover command was not received) -> RRC Rebuild Request -> Rebuild successfully, transfer to another cell

 The scenario is as follows: The UE successfully sends a measurement report, the radio link fails soon, and the handover command is not received before the radio link fails. Then the UE initiates RRC reestablishment, the reestablishment is successful, and the UE transfers to another cell. Cell is a cell

 The RRC re-establishment is successful, indicating that the cell B that is finally camping appears in the measurement report message, satisfies the handover requirement, and is selected by the base station as the handover preparation cell. In this case, the RSRP and/or RSRQ values of the serving cell at the two moments when the measurement report is sent and when the radio link fails, and the new cell (ie, the cell B after the reconstruction) are in the measurement report. And RSRP and/or RSRQ values after reconstruction. If the two measured values of the original serving cell at the two moments are not significantly different (for example, less than the first threshold), the difference between the two measured values of the cell B at the two moments is not large (for example, less than the second threshold), and the cell B The average value of the measured values at the above two moments is significantly larger than the average value of the measured values of the original serving cell at the above two moments (for example, greater than the third threshold), then the switching parameters may be inappropriate, resulting in too late switching. When the measurement report is sent, the signal quality of the serving cell has been difficult to ensure the correct reception of the air interface message. In this case, it is necessary to lower the switching threshold, and / or reduce the hysteresis value, and / or reduce the measurement result reporting trigger time, so that the switching action can be advanced.

The first threshold, the second threshold, and the third threshold described above may be based on actual application rings. Set it up.

 3. Send measurement report -> Receive handover command _ > Random access failure on the target side -> RRC reconfiguration request -> Rebuild successful, return the cell before handover

 The scenario is as follows: The UE sends a measurement report, and receives the handover command, but the access fails on the target side, and then the UE initiates RRC reconstruction, the reconstruction is successful, and the UE returns to the source cell before the handover.

 This situation means that for the cell before the handover, the handover is too early, and the signal quality of the target cell is insufficient to ensure the access of the UE. Therefore, the RSRP and/or RSRQ values of the target cells in the measurement report, the random access failure, and the reconstruction are compared.

 If the corresponding measured values at three times are similar (for example, both are smaller than the fourth threshold), the signal of the target cell is relatively stable, and the random access failure means that the signal quality does not reach the level of the serving UE. In this case, the handover requirement can be improved by changing the handover parameters, such as increasing the handover threshold, and/or increasing the hysteresis value, so that the handover is triggered when the target 'J, the zone strength reaches a higher level.

 If the measured value at the first moment is significantly higher than the measured values at the last two moments (for example, both are higher than the fifth threshold), it may be determined that the target cell sends the measurement report to the UE when the UE transmits the measurement report due to the actual propagation environment. The position signal described is relatively strong, but is still weak at other locations. In this case, the triggering time of the measurement result can be increased, and the jitter of the neighboring cell signal at the boundary is filtered to some extent by delaying the measurement reporting.

 The fourth threshold and the fifth threshold described above may be set according to an actual application environment.

4. Send measurement report -> Receive handover command _ > Random access on the target side -> Send handover confirmation message failed -> RRC rebuild request -> Rebuild successful, return to the pre-switched area

 The scenario is as follows: The UE sends a measurement report, and receives the handover command, and then the random access in the target cell is successful, but the uplink handover message fails to be sent. After the maximum number of transmissions is reached, the UE initiates RRC reconstruction, the reconstruction succeeds, and the UE returns to the handover. Source cell.

The scenario is similar to the scenario in the third scenario. In this scenario, the SON function entity determines the event and measurement information recorded during the UE handover process. The process of switching failure caused by the switching parameters and the switching parameters that need to be adjusted is similar to the process in the third case described above, and will not be described in detail herein.

 It should be noted that the previously mentioned switching threshold, hysteresis value, and measurement result reporting trigger time have the same meanings in the prior art. The handover threshold refers to a difference between a signal strength of a neighboring cell and a current serving cell when the handover trigger condition is determined. The hysteresis value refers to that the difference between the signal strength of the neighboring cell and the current serving cell reaches the threshold, and the difference condition is considered to satisfy the trigger condition. The additional difference is the hysteresis value, which is mainly used to prevent Ping Pong switching. The triggering time of the measurement result is that the terminal needs to continue to send the report to the network after the measurement result meets the reporting condition for a period of time, which is mainly used to prevent the measurement result from being shaken.

 Step 203: Send the adjustment information of the handover parameter to the cell related to the handover.

The SON functional entity sends an instruction to the corresponding cell through the base station, indicating that the inappropriate parameter is modified. The adjustment information of the switching parameter may be: directly indicating that a certain switching parameter is adjusted to a certain value, or indicating an adjustment change amount of a certain switching parameter, and preferably, the direction is adjusted by "+" and "-". For example: For the switching threshold, the value is 10 before the adjustment, and the value after the adjustment should be 8, the adjustment information of the switching threshold is "8" or "-2".

 It should be noted that the method for adjusting the direction of the foregoing identifier is only a preferred embodiment of the present invention. Any manner in which the SQN and the network side are well-known to adjust the direction of the identifier belong to the protection scope of the present invention, for example: Raise, use the "b" logo to reduce, such as "b2" to reduce 2 units.

 It can be seen that, in the embodiment of the present invention, the handover optimization method determines, according to an event recorded by the UE in the handover process, a working frequency point of the event-related cell, a physical layer cell identifier, and a measured value, a handover failure caused by an inappropriate handover parameter and The handover parameter that needs to be adjusted can improve the accuracy of determining the cause of the handover failure, and the adjustment information of the handover parameter is sent to the cell related to the handover, so that the cell performs corresponding parameter optimization adjustment, thereby reducing the probability of handover failure. Improve the user experience.

 The embodiment of the present invention further provides a handover optimization device. As shown in FIG. 3, it is a schematic structural diagram of the handover optimization device.

The switching optimization device includes: an obtaining unit 301, a parameter adjustment determining unit 302, and The transmitting unit 303. among them:

 The obtaining unit 301 is configured to acquire an event recorded during a UE handover process, a working frequency point of the cell related to the event, a physical layer cell identifier, and a measured value;

 The parameter adjustment determining unit 302 is configured to determine, according to the event, a working frequency point and a physical layer cell identifier of the event-related cell, and a measured value, a handover failure caused by the handover parameter and a handover parameter that needs to be adjusted;

 The sending unit 303 is configured to send the adjustment information of the handover parameter to the cell related to the handover.

 As described above in the description of the handover optimization method of the present invention, the event includes any one or more of the following events: measurement success or failure of transmission, failure of the radio link, whether the UE receives the network before the radio link fails. The handover command, the success or failure of the transmission handover confirmation message, the success or failure of the random access, the UE transmitting the radio resource control connection reestablishment request, the UE transmitting the radio resource control connection reestablishment completion message, or the UE receiving the radio resource control connection reestablishment rejection message; The measured value includes: a reference symbol received power of the cell related to the event, and/or a reference symbol reception quality of the cell related to the event, when the event occurs, and may further include: a UE estimated moving speed , the geographic location coordinates of the UE. Thereby, the parameter adjustment determining unit 302 can further determine whether the switching parameter needs to be adjusted in conjunction with the moving speed of the UE.

 In the embodiment of the present invention, a preferred structure of the parameter adjustment determining unit 302 is as shown in FIG. 3, including: a handover failure state determining sub-unit 321, a measurement value comparison sub-unit 322, and a handover parameter analysis sub-unit 323. among them:

 a handover failure state determining sub-unit 321 , configured to determine, according to the event, a working frequency point of the event-related cell, and a physical layer cell identifier, a UE handover failure scenario; a measurement value comparison sub-unit 322, configured to compare The measured value associated with the event when different events occur in the scenario;

 The handover parameter analysis sub-unit 323 is configured to determine a handover parameter that needs to be adjusted according to a scenario in which the UE handover fails and a comparison result of the measurement value comparison sub-unit 322. Specifically, there are several situations in which you need to adjust the switching parameters:

(1) if it is determined according to the event and the measurement information that the UE fails to send the measurement report The post-reconstruction fails and resides in a cell included in the measurement report, and the measurement value of the cell in the measurement report is higher than the corresponding measurement value of the cell after the reconstruction failure, and is higher than the corresponding measurement of the serving cell in the measurement report. The value of the switching parameter that needs to be adjusted includes any one or more of the following: lowering the switching threshold, reducing the hysteresis value, and reducing the triggering time of the measurement result reporting;

 (2) if it is determined according to the event and the measurement information that the radio link fails after the UE sends the measurement report, and then the re-establishment succeeds and camps on a handover preparation cell included in the measurement report, and the measurement report is generated and the wireless generation occurs. The measurement values of the original serving cell at the two moments of the link failure are different from the first threshold, and the measured values of the handover preparation cells are different in the measurement report and after the reconstruction is lower than the second threshold, and the handover preparation is performed. If the average value of the measured values of the cell at two times differs from the average value of the corresponding measured values of the original serving cell at two times is higher than the third threshold, determining that the handover parameter to be adjusted includes any one or more of the following: The threshold value, the hysteresis value is reduced, and the triggering time of the measurement result is reduced;

 (3) if, after the UE fails to be handed over according to the event and the measurement information, the reconstruction succeeds and returns to the cell before the handover, and the measurement of the target cell in the measurement report, the random access failure, and the reconstruction time If the value difference is lower than the fourth threshold, determining that the handover parameter that needs to be adjusted includes any one or more of the following: increasing the handover threshold and increasing the hysteresis value;

 (4) If it is determined according to the event and the measurement information that the UE fails to be handed over, the reconstruction succeeds and returns to the cell before the handover, and the measured value of the target cell in the measurement report and the corresponding measurement when the random access fails and the reconstruction If the value difference is higher than the fifth threshold, determining the switching parameters that need to be adjusted includes: increasing the measurement result reporting trigger time.

 It should be noted that, in the switching optimization device of the embodiment of the present invention, each unit may be centrally distributed in a management operating system in the network, or may be distributed in the management operating system and the base station.

In the embodiment of the present invention, the handover optimization device determines, according to the event recorded by the UE during the handover process, the working frequency of the event-related cell, the physical layer cell identifier, and the measured value, the handover failure and the need due to the inappropriate handover parameter setting. Adjusted switch parameters The number can be improved to determine the accuracy of the cause of the handover failure, and the adjustment information of the handover parameter is sent to the cell related to the handover, so that the cell performs corresponding parameter optimization and adjustment, thereby reducing the probability of handover failure and improving the user experience. .

 The embodiment of the invention further provides a user equipment, as shown in FIG. 4, which is a schematic structural diagram of the user equipment.

 In this embodiment, the user equipment includes: a recording unit 401, a transmitting unit 402, and a deleting unit 403. among them:

 The recording unit 401 is configured to record an event occurring during the handover, a working frequency of the cell related to the event, a physical layer cell identifier, and a measured value, and specific events and measured values have been described in detail above. Let me repeat.

 The sending unit 402 is configured to send the information recorded by the recording unit 401 in the current switching process to the serving base station by using dedicated RRC signaling after the handover fails or after the radio link fails.

 The deleting unit 403 is configured to delete the information recorded by the recording unit 401 during the current switching process after the information is successfully sent.

 In order to further ensure that a series of events recorded by the UE is valid, and the event that the different events belong to the same switching process, the event setting unit 404 may be further included in the embodiment of the present invention. Each record of 401 sets a valid time. Thus, the deleting unit 403 is further configured to delete the record after the record exceeds its valid time.

A series of events and measurement values recorded in the recording unit 401 form a handover abnormality or a radio link failure log record. After the handover fails, when the UE has an RRC connection with the base station, the sending unit 402 records the records. It is transmitted to the base station, and then forwarded by the base station to the SON functional entity in the network. For example, after the handover fails, RRC reconstruction is performed. If the RRC re-establishment is successful and the UE is still in the connected state, the new serving base station transmits the records to the SON function entity in the network through the base station; if the RRC reestablishment fails, the UE loses the connection and enters the idle state. When the UE re-initiates the connection establishment process and enters the connection state, if the record is still within the valid time, the transmitting unit 402 transmits the records to the SON function entity in the network through the serving base station. If the records are still not transmitted to the base station after the valid time expires, the deletion unit 403 deletes the records. The setting of the effective time can be flexibly determined, such as 1 minute or 5 minutes.

 The user equipment in the embodiment of the present invention can provide effective reference information for handover optimization, so that the SON functional entity in the network can refer to the information to determine handover abnormalities or radio link failures caused by inappropriate handover parameters.

 The embodiment of the present invention further provides a handover optimization system, as shown in FIG. 5, which is a networking diagram of the system.

 The system includes: a user equipment 501, a serving base station 502, and a handover optimization device 503. among them:

 The user equipment 501 is configured to record an event that occurs during the handover, a working frequency point of the cell related to the event, a physical layer cell identifier, and a measured value, and after the handover fails or the radio link fails, the current handover is performed. The information recorded in the process is sent to the serving base station 502 through dedicated RRC signaling. The specific events and the other measured values are described in detail above, and are not described here.

 The switching optimization device 503 is configured to acquire information recorded during the user equipment handover process from the serving base station 502, and determine, according to the information, a handover failure caused by the handover parameter and a handover parameter that needs to be adjusted, and send the adjustment information of the handover parameter. Give the cell associated with the handover.

 In a specific application, the user equipment 501 may transmit the recorded information by using an existing air interface signaling message, or may transmit by using a new dedicated signaling message, and the serving base station 502 receives the record information sent by the user equipment 501. Thereafter, it is forwarded to the handover optimization device 503. In addition, the user equipment 501 may further carry the recorded information in the uplink data packet, and after receiving the data packet, the serving base station 502 extracts the recorded information from the data packet, and forwards the information to the handover optimization device. 503.

It should be noted that, if the user equipment 501 does not have the positioning function and there is no geographical location information in the record, the serving base station 502 can query the local neighbor relationship table according to the frequency of the cell before forwarding the record to the handover optimization device 503. Point and physical layer cell identifier, obtain the global identifier of each cell in the record, and add to the corresponding record, so that The handover optimization device 503 can correctly identify each cell.

 The specific structure of the user equipment and the handover optimization device in the embodiment of the present invention can be referred to FIG. 4 and FIG. 3 and corresponding text descriptions, respectively, and details are not described herein again.

 In the embodiment of the present invention, the handover optimization system determines, according to the event recorded by the UE during the handover process, the working frequency of the event-related cell, the physical layer cell identifier, and the measured value, the handover failure caused by the inappropriate handover parameter setting and The handover parameter that needs to be adjusted can improve the accuracy of determining the cause of the handover failure, and the adjustment information of the handover parameter is sent to the cell related to the handover, so that the cell performs corresponding parameter optimization adjustment, thereby reducing the probability of handover failure. Improve the user experience.

 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 hardware platform, and of course, can also be through hardware, but in many cases, the former is a better implementation. the way. Based on such understanding, the technical solution of the present invention, which is essential or contributes to the prior art, can be embodied in the form of a software product stored in a storage medium such as: ROM (Read-Only Memory, read-only memory) / RAM (Random Access Memory), disk, CD, etc. The storage medium includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute the program. The methods described in the various embodiments are invented.

 The above disclosure is only a few specific embodiments of the present invention, but the present invention is not limited thereto, and any changes that can be made by those skilled in the art should fall within the protection scope of the present invention.

Claims

Rights request

A handover optimization method, comprising:

 Obtaining an event recorded during a UE handover process, a working frequency of the cell related to the event, a physical layer cell identifier, and a measured value;

 Determining a handover failure due to inappropriate handover parameter setting and a handover parameter that needs to be adjusted according to the event, a working frequency of the event-related cell, and a physical layer cell identifier, and a measured value;

 The adjustment information of the handover parameter is sent to the cell related to the handover.

 2. The method of claim 1 wherein the event comprises any one or more of the following events:

 Measurement report transmission success or failure, radio link failure, whether the UE receives a handover command from the network before the radio link failure occurs, the handover handover acknowledgement message succeeds or fails, the random access succeeds or fails, the UE sends a radio resource control connection The reestablishment request, the UE sends a radio resource control connection reestablishment complete message, or the UE receives a radio resource control connection reestablishment reject message.

 3. The method according to claim 2, wherein a time interval in which any two of the plurality of events have a causal association occurs is less than a predetermined time threshold.

 4. The method according to claim 3, wherein the predetermined time threshold is specifically:

 The timeout period for the handover failure configured by the network for the UE; or

 The duration of the wireless link failure detection; or

 The timeout period between the handover failure time configured by the UE and the duration of the radio link failure detection; or

 It is greater than the timeout period for the handover failure configured by the UE for the UE, and is greater than the duration of the radio link failure detection.

The method according to claim 1, wherein the measured value comprises: when the event occurs, a reference symbol received by the event-related cell, and/or a cell associated with the event Reference symbol reception quality.

The method according to any one of claims 1 to 5, wherein the determining, according to the event, the working frequency of the event-related cell, the physical layer cell identifier, and the measured value, Switching failures caused by improper settings and switching parameters that need to be adjusted include:

 If it is determined according to the event and the measurement information that the UE fails to re-establish the measurement report after failing to transmit and camps on a cell included in the measurement report, and the measurement value of the cell in the measurement report is higher than the corresponding measurement value of the cell after the reestablishment failure And determining that the handover parameter that needs to be adjusted includes any one or more of the following: lowering the handover threshold, reducing the hysteresis value, and reducing the measurement result reporting trigger time;

 If it is determined according to the event and the measurement information that the radio link fails after the UE sends the measurement report, the reconstruction succeeds and camps on a handover preparation cell included in the measurement report, and the measurement report is sent and the radio link fails. The measured values of the original serving cell are different from the first threshold in the two moments, and the measured values of the handover preparation cells are different in the measurement report and after the reconstruction is lower than the second threshold, and the handover preparation cell is in two The average value of the measured values of the time difference is different from the average value of the corresponding measured values of the original serving cell at two times, and the switching parameter that needs to be adjusted includes any one or more of the following: lowering the switching threshold, reducing Small lag value, reduce the triggering time of the measurement result report;

 If the UE fails to be handed over according to the event and the measurement information, the reconstruction succeeds and returns to the cell before the handover, and the measurement values of the target cell in the measurement report, the random access failure, and the reconstruction time are different. Below the fourth threshold, determining that the handover parameter to be adjusted includes any one or more of the following: increasing the handover threshold, increasing the hysteresis value; if it is determined according to the event and the measurement information that the UE handover fails, the reconstruction succeeds and returns to The cell before the handover, and the measured value of the target cell in the measurement report is different from the corresponding measurement value when the random access fails and the reconstruction is higher than the fifth threshold, and determining the handover parameter that needs to be adjusted includes: increasing the measurement result Report the trigger time.

 7. A handover optimization device, comprising:

An acquiring unit, configured to acquire an event recorded during a UE handover process, and the event a working frequency point of the cell and a physical layer cell identifier, and a measured value; a parameter adjustment determining unit, configured to determine, according to the event, a working frequency point of the cell related to the event, a physical layer cell identifier, and a measured value, Switching failure caused by improper parameter setting and switching parameters that need to be adjusted;

 And a sending unit, configured to send the adjustment information of the switching parameter to the small area related to the switching.

 8. The handover optimization device according to claim 7, wherein the event comprises any one or more of the following events:

 Measurement report transmission success or failure, radio link failure, whether the UE receives a handover command from the network before the radio link failure occurs, the handover handover acknowledgement message succeeds or fails, the random access succeeds or fails, the UE sends a radio resource control connection Reestablishing the request, the UE sends a radio resource control connection reestablishment complete message, or the UE receives the radio resource control connection reestablishment reject message;

 The measured value includes: a reference symbol received power of a cell associated with the event, and/or a reference symbol received quality of a cell associated with the event when the event occurs.

 The switching optimization device according to claim 8, wherein the parameter adjustment determining unit comprises:

 a handover failure state determining subunit, configured to determine, according to the event, a working frequency point of the event-related cell, and a physical layer cell identifier, a scenario in which the UE handover fails;

 a measured value comparison subunit, configured to compare measured values associated with the event when different events occur in the scenario;

 And a handover parameter analysis sub-unit, configured to determine, according to a scenario where the UE handover fails, and a comparison result of the measurement value comparison subunit, to determine a handover parameter that needs to be adjusted.

 10. The handover optimization apparatus according to claim 8, wherein the handover parameter analysis subunit determines handover parameters to be adjusted in the following manner:

If it is determined according to the event and the measurement information that the UE fails to re-establish the measurement report after failing to transmit and camps on a cell included in the measurement report, and the measurement value of the cell in the measurement report is higher than the corresponding measurement value of the cell after the reestablishment failure And above the measurement, the corresponding measurement value of the serving cell in the advertisement is determined, and determining the handover parameter that needs to be adjusted includes the following One or more meanings: lowering the switching threshold, reducing the hysteresis value, and reducing the triggering time of the measurement result reporting;

 If it is determined according to the event and the measurement information that the radio link fails after the UE sends the measurement report, the reconstruction succeeds and camps on a handover preparation cell included in the measurement report, and the measurement report is sent and the radio link fails. The measured values of the original serving cell are different from the first threshold in the two moments, and the measured values of the handover preparation cells are different in the measurement report and after the reconstruction is lower than the second threshold, and the handover preparation cell is in two The average value of the measured values of the time difference is different from the average value of the corresponding measured values of the original serving cell at two times, and the switching parameter that needs to be adjusted includes any one or more of the following: lowering the switching threshold, reducing Small lag value, reduce the triggering time of the measurement result report;

 If the UE fails to be handed over according to the event and the measurement information, the reconstruction succeeds and returns to the cell before the handover, and the measurement values of the target cell in the measurement report, the random access failure, and the reconstruction time are different. Below the fourth threshold, determining that the handover parameter to be adjusted includes any one or more of the following: increasing the handover threshold, increasing the hysteresis value; if it is determined according to the event and the measurement information that the UE handover fails, the reconstruction succeeds and returns to The cell before the handover, and the measured value of the target cell in the measurement report is different from the corresponding measurement value when the random access fails and the reconstruction is higher than the fifth threshold, and determining the handover parameter that needs to be adjusted includes: increasing the measurement result Report the trigger time.

 11. A user equipment, comprising:

 a recording unit, configured to record an event occurring during the handover, a working frequency point of the cell associated with the event, a physical layer cell identifier, and a measured value;

 And a sending unit, configured to send the information recorded by the recording unit in the current handover process to the serving base station by using dedicated RRC signaling after the handover fails or after the radio link fails.

 The user equipment according to claim 11, further comprising: a time setting unit, configured to set an effective time for each record of the recording unit;

a deleting unit, configured to delete information recorded by the recording unit in the current switching process after the information is successfully sent; and to delete the record after the record exceeds its effective time Record.

 13. A handover optimization system, comprising: a user equipment, a service base station, and a handover optimization apparatus;

 The user equipment is configured to record an event that occurs during the handover, a working frequency of the cell related to the event, a physical layer cell identifier, and a measured value, and after the handover fails or the radio link fails, the user equipment The information recorded during the handover process is sent to the serving base station through dedicated RRC signaling;

 The handover optimization device is configured to acquire information recorded in a user equipment handover process from the serving base station, and determine, according to the information, a handover failure caused by inappropriate handover parameter setting and a handover parameter that needs to be adjusted, and the handover parameter is The adjustment information is sent to the cell associated with the handover.

 The system according to claim 13, wherein the user equipment is the user equipment according to claim 11 or 12.

 The system according to claim 13, wherein the handover optimization device is the handover optimization device according to any one of claims 7 to 10.