WO2012003717A1 - Methods and devices for determining radio link failure reason and adjusting handover parameter threshold - Google Patents

Abstract

Methods and devices for determining Radio Link Failure (RLF) reason and adjusting handover parameter threshold are provided in the present invention. Through the statistical analysis on the handover data of the User Equipment (UE) in the cell handover procedure, the RLF reason is determined. For example, through obtaining the identifier information of a first cell in which the UE is located when the RLF occurs, the identifier information of a second cell and the identifier information of a third cell with which the UE re-establishes the connection after the RLF occurs and then according to the signal strength information, when it is judged that the variety trend of the reference signal strength in a preset period is weakening gradually, the identifier information of the second cell and the third cell are consistent by comparison and the identifier information of the first cell and the third cell are inconsistent by comparison, the RLF reason can be determined as a too early handover occurring when the UE is handed over from said second cell to said first cell, therefore enabling RLF reason determination.

Description

 Determination of cause of wireless link failure, handover parameter threshold adjustment method and device

 The present invention relates to the field of communications technologies, and in particular, to a method and apparatus for determining a cause of failure of a radio link, and a method and apparatus for adjusting a threshold value of a handover parameter. Background technique

 The Long Term Evolution (LTE) mobile communication system consists of a core network and an access network. The core network includes a mobility management entity/serving gateway (MME/S-GW) device, and the access network includes a network evolution node eNodeB (also Referred to as eNB) device. The network topology of the LTE mobile communication system is shown in Figure 1. The eNodeBs communicate with each other through the X2 interface. The eNodeB is connected to the core network through the S1 interface. The eNodeB passes the XI interface (ie, air interface) and the user terminal (UE, User Equipment). Communication.

 In practice, the UE in the connected state can move freely between adjacent cells. When the UE leaves one cell and enters another cell, the weakening of one cell signal and the enhancement of another cell signal are weakened. The eNodeB corresponding to the cell signal triggers a handover procedure, so that the UE switches to a cell with strong signal.

 After the UE performs cell handover, there may be a radio link failure (RLF, Radio Link Failure). The analysis and determination of the cause of the failure of the radio link will help to adjust the cell handover parameter threshold to avoid premature handover, late handover, and false handover. However, the prior art does not provide a A solution to determine the cause of a wireless link failure. Summary of the invention

 The embodiments of the present invention provide a method and a device for determining a cause of a failure of a radio link, which are used to implement analysis and determination of a cause of failure of a radio link.

The embodiment of the invention further provides a switching parameter threshold adjustment method and device. The following technical solutions are used in the embodiments of the present invention:

 A method for determining a cause of a failure of a radio link, comprising: acquiring identity information of a first cell where a radio link failure occurs when a user terminal occurs; and determining, before the user terminal fails, that the radio terminal fails Obtaining the signal strength information of the reference signal received in a cell within a specified length of time; and determining that the user terminal is handed over to the first cell by the second cell before the failure of the radio link occurs, Identification information of the second cell; acquiring identification information of the third cell that is connected and reconstructed with the user terminal after the failure of the radio link; and determining, according to the signal strength information, that the length is within the specified time length Determining the wireless link when the change trend of the signal strength of the reference signal is gradually weakened, and the identification information of the second and third cells are consistently matched, and the identification information of the first and third cells are inconsistent. The reason for the failure is that a premature handover occurs when the user terminal switches from the second cell to the first cell.

 A method for determining a cause of a failure of a radio link, comprising: acquiring identity information of a first cell where a radio link failure occurs when a user terminal occurs; and determining, before the user terminal fails, that the radio terminal fails Obtaining the signal strength information of the reference signal received in a cell within a specified length of time; and determining that the user terminal is handed over to the first cell by the second cell before the failure of the radio link occurs, Identification information of the second cell; acquiring identification information of the third cell that is connected and reconstructed with the user terminal after the failure of the radio link; and determining, according to the signal strength information, that the length is within the specified time length The trend of the signal strength of the reference signal is gradually weakened, and when the identification information of the first, second, and third cells are inconsistent with each other, the reason for determining that the radio link fails is that the user terminal is from the An error handover occurs when the two cells switch to the first cell.

A method for determining a cause of a failure of a wireless link, comprising: acquiring identification information of a first cell where a user terminal fails to generate a wireless link; and determining, before determining that the user terminal fails the wireless link, by other When the cell switches to the first cell, determining that the reference signal received by the user terminal in the first cell is specified before the radio link fails. Signal strength information within a length of time; acquiring identification information of a second cell that is connected and reconstructed with a user terminal after the failure of the radio link; and determining, within the specified length of time, based on the signal strength information The change trend of the signal strength of the reference signal is a stepwise enhancement, and when the identification information of the first and second cells is inconsistent, the reason for determining that the radio link fails is that the user terminal switches to the first cell. A too late switch occurred.

 A method for determining a cause of a failure of a radio link, comprising: acquiring identity information of a first cell where a user terminal fails to generate a radio link; and determining, before determining that the user terminal fails the radio link, by other When the cell is handed over to the first cell, the identifier information of the second cell that is connected and reestablished with the user terminal after the failure of the radio link is obtained; when the matching of the identifier information of the first cell and the second cell is inconsistent, The reason for determining that the radio link fails is that a late handover occurs when the user terminal switches from the first cell to the third cell.

 A switching parameter threshold adjustment method includes: determining, according to the determined cause of the failure of the radio link, a handover parameter threshold to be adjusted; and adjusting the determined handover parameter threshold.

A device for determining a cause of a failure of a radio link, comprising: a first cell identifier information acquiring unit, configured to acquire identifier information of a first cell where a user terminal fails to generate a radio link; and a signal strength information determining unit, configured to determine The signal strength information of the reference signal received by the user terminal in the first cell within a specified length of time before the radio link fails; the second cell identifier information acquiring unit is configured to determine the user terminal And acquiring, by the second cell, the identifier information of the second cell, when the second cell is switched to the first cell, where the second cell identifier information acquiring unit is configured to acquire and generate the wireless chain The identification information of the third cell that is connected and reconstructed by the user terminal after the failure of the path; the failure cause determining unit is configured to determine, according to the signal strength information, the signal strength information determined by the unit, and determine that the reference signal is within the specified time length The trend of the signal strength is gradually weakened, and the second cell identification information acquisition list is compared. Obtaining that the acquired identifier information of the second cell is consistent with the identifier information of the third cell acquired by the third cell identifier information acquiring unit, and the first identifier information acquired by the first cell identifier information acquiring unit matches the identifier information of the third cell. When inconsistent, determine The reason for the failure of the radio link is that a premature handover occurs when the user terminal switches from the second cell to the first cell.

 A device for determining a cause of a failure of a radio link, comprising: a first cell identifier information acquiring unit, configured to acquire identifier information of a first cell where a user terminal fails to generate a radio link; and a signal strength information determining unit, configured to determine The signal strength information of the reference signal received by the user terminal in the first cell within a specified length of time before the radio link fails; the second cell identifier information acquiring unit is configured to determine the user terminal And acquiring, by the second cell, the identifier information of the second cell, when the second cell is switched to the first cell, where the second cell identifier information acquiring unit is configured to acquire and generate the wireless chain The identification information of the third cell that is connected and reconstructed by the user terminal after the failure of the path; the failure cause determining unit is configured to determine, according to the signal strength information, the signal strength information determined by the unit, and determine that the reference signal is within the specified time length The trend of the signal strength is gradually weakened, and the first cell identification information is compared. Determining, when the identifier information of the first cell acquired by the unit, the identifier information of the second cell acquired by the second cell identifier information acquiring unit, and the identifier information of the third cell acquired by the third cell identifier information acquiring unit are inconsistent with each other The reason for the failure of the radio link is that an erroneous handover occurs when the user terminal switches from the second cell to the first cell.

A device for determining a cause of a failure of a radio link, comprising: a first cell identifier information acquiring unit, configured to acquire identifier information of a first cell where a user terminal fails to generate a radio link; and a signal strength information determining unit, configured to Determining, when the user terminal switches to the first cell by another cell before the radio link fails, determining that the user terminal receives in the first cell before the radio link fails The signal strength information of the reference signal in the specified time length; the second cell identifier information acquiring unit, configured to acquire the identifier information of the second cell that is connected and reconstructed with the user terminal after the radio link failure occurs; And determining, according to the signal strength information, the signal strength information determined by the unit, determining that the change trend of the signal strength of the reference signal is gradually enhanced during the specified length of time, and comparing the first cell identifier information acquiring unit to obtain Identification information of the first cell and the second cell identifier When the identification information of the second cell acquired by the information acquiring unit is inconsistent, the reason for determining that the radio link fails is that the user terminal switches too late when switching to the first cell.

 A device for determining a cause of a failure of a radio link, comprising: a first cell identifier information acquiring unit, configured to acquire identifier information of a first cell where a user terminal fails to generate a radio link; and a second cell identifier information acquiring unit, Obtaining, after determining that the user terminal does not switch to the first cell by another cell before the radio link fails, acquiring an identifier of the second cell that is connected and reestablished with the user terminal after the radio link failure occurs. And the failure cause determining unit is configured to determine, when the identifier information of the first cell acquired by the first cell identifier information acquiring unit is inconsistent with the identifier information of the second cell of the second cell identifier information acquiring unit, The reason for the link failure is that the user terminal switches too late when switching from the first cell to the third cell.

 A switching parameter threshold adjusting device, comprising: a switching parameter threshold determining unit, configured to determine, according to a reason for failure of a radio link determined by a failure reason determining unit, a switching parameter threshold to be adjusted; and an adjusting unit, configured to switch the parameter The switching parameter threshold determined by the value determining unit is adjusted.

 The beneficial effects of the embodiments of the present invention are as follows:

The solution provided by the embodiment of the present invention performs statistics and analysis on the handover data of the UE in the cell handover process, for example, by acquiring the identifier information of the first cell where the user terminal fails to generate a radio link, in the first cell. The signal strength information of the reference signal received within the specified time length, and when the user terminal is determined to be handed over to the first cell by the second cell before the radio link failure occurs, acquiring the Identification information of the second cell, and acquiring identification information of the third cell that is connected and reconstructed with the user terminal after the failure of the radio link; thereby determining, according to the signal strength information, the reference within the specified length of time The change trend of the signal strength of the signal is gradually weakened, and when the identification information of the second and third cells are matched and the identification information of the first and third cells are inconsistent, the wireless chain can be determined. The reason for the road failure is that the user terminal switches from the second cell to the first A premature handover occurs in a cell, thereby realizing the determination of the cause of the failure of the radio link. DRAWINGS

 1 is a network topology diagram of an LTE mobile communication system in the prior art;

 2 is a schematic flowchart of a method for determining an RLF cause according to an embodiment of the present invention;

 FIG. 3 is a schematic flowchart of another method for determining an RLF cause according to an embodiment of the present disclosure;

 FIG. 4 is a schematic flowchart of still another method for determining an RLF cause according to an embodiment of the present invention;

 FIG. 5 is a schematic flowchart of a method for determining a cause of an RLF according to an embodiment of the present disclosure;

 FIG. 6 is a schematic flowchart of a method for adjusting a threshold value of a switching parameter according to an embodiment of the present invention;

 Figure 8a is a schematic diagram of a scenario in which a late switch occurs;

 FIG. 8b is a schematic flowchart of determining the cause of the RLF in the scenario shown in FIG. 8a; FIG. 9a is a schematic diagram of a scenario in which the premature handover occurs;

 FIG. 9b is a schematic flowchart of determining the cause of the RLF in the scenario shown in FIG. 9a; FIG. 10a is a schematic diagram of another scenario in which the premature handover occurs;

 FIG. 10b is a schematic flowchart of determining the cause of the RLF in the scenario shown in FIG. 10a; FIG. 11a is another schematic diagram of the scenario where the error switching occurs;

Figure lib is a schematic flowchart of determining the cause of the RLF in the scenario shown in Figure 11a. Figure 12 is a schematic structural diagram of a device for determining a cause of failure of a radio link according to an embodiment of the present invention; FIG. 13 is a schematic structural diagram of a switching parameter threshold adjustment apparatus according to an embodiment of the present invention. detailed description

 During the research process, the inventor performs statistics and analysis on the handover data of the UE during the cell handover process, and finds that the common causes of the failure of the radio link of the user terminal mainly include premature handover, late handover, and handover to the wrong neighbor. (ie wrong switching).

 The too late handover means that when the UE moves from the cell A to the cell B, the handover of the UE to the cell B is triggered when the cell A signal is already very poor, and even worse, the handover to the cell B is not yet available, and the UE is in the UE. The cell A has an RLF, and the subsequent UE performs an RRC connection re-process in the cell B and the cell B. In general, a scene in which a late switch occurs includes a scenario in which the UE moves from one cell to another at a faster speed on a highway or a high speed railway.

 The premature handover refers to a small area in the cell A that contains a strong cell B signal. When the UE moves through the small area, the UE triggers the handover of the UE to the cell B, but After the cell B, the cell B signal is rapidly weakened, so that the UE generates RLF in the cell B, and the subsequent UE and the cell A perform an RRC connection reestablishment process. In general, a scene in which a premature handover occurs includes a scenario in which the UE moves in a dense urban area where cell signals are likely to overlap.

 The erroneous handover means that the correct handover mode of the UE should be switched from the cell A to the cell C. However, because the setting of the handover parameter threshold is unreasonable, the UE erroneously switches from the cell A to the cell B, so that the UE is in the cell B. The RLF occurs rapidly, and the UE performs an RRC connection reestablishment process with the cell C after the RLF occurs.

 Based on the above qualitative analysis of the cause of the RLF, the embodiment of the present invention provides a method for determining the cause of the RLF, which is used to determine the cause of the RLF.

First, the embodiment of the present invention provides a method for determining the cause of the RLF. The specific process diagram of the method is shown in FIG. 2, and includes the following steps: Step 21: Obtain identification information of the first cell where the RLF is generated by the UE, where the identifier information of the first cell may be, but is not limited to, a number, an ID number, and the like allocated in advance for the first cell. Step 22: determining that the UE is occurring Before the RLF, the signal strength information of the reference signal received in the first cell is within a specified length of time. In the embodiment of the present invention, the signal strength information herein may be, but is not limited to, a reference that can reflect the signal strength information from the side. Signal Received Power (RSRP) or Reference Signal Received Quality (RSR) information;

 Step 23: Determine whether the UE is handed over to the first cell by another cell, and determine that the UE obtains the identity information of the second cell when the second cell switches to the first cell before the RLF occurs. Step 24: Acquire and generate the RLF The identification information of the third cell that the UE performs connection reconstruction;

 Step 25: Determine, according to the determined signal strength information, that the change trend of the signal strength of the reference signal is gradually weakened during the specified length of time, and compare that the identifier information of the second and third cells are consistent, first, When the identification information of the third cell is inconsistent, the reason for determining the RLF is that the UE has switched too early when switching from the second cell to the first cell.

 In the embodiment shown in FIG. 2 of the present invention, the order of execution of the above steps is not limited, and those skilled in the art according to the above schemes are all in the protection scope of the present invention by simply changing the order of execution of the steps. Inside.

 The embodiment of the present invention further provides another method for determining the cause of the RLF. The specific process diagram of the method is shown in FIG. 3, and includes the following steps:

 Step 31: Obtain identification information of the first cell where the UE has no RLF. Step 32: Determine signal strength information of the reference signal received by the UE in the first cell within a specified time length before the RLF occurs.

 Step 33: When it is determined that the UE is handed over to the first cell by the second cell before the RLF occurs, obtain the identifier information of the second cell.

Step 34: Acquire an identifier of a third cell that is connected and reestablished with the UE after the RLF is generated. Information

 Step 35: Determine, according to the determined signal strength information, that the change trend of the signal strength of the reference signal is gradually weakened during the specified length of time, and compare that the identification information of the first, second, and third cells are inconsistent with each other. The reason for determining the RLF is that an erroneous handover occurs when the UE switches from the second cell to the first cell.

 Another specific schematic diagram of a method for determining the cause of the RLF provided by the embodiment of the present invention is as shown in FIG. 4, and includes the following steps:

 Step 41: Obtain identification information of the first cell where the UE generates the RLF.

 Step 42: Determine, when the UE is handed over to the first cell by the other cell before the RLF occurs, determine signal strength information of the reference signal received by the UE in the first cell within a specified time length before the RLF occurs;

 Step 43: Obtain identification information of a second cell that is connected and reestablished with the UE after the RLF is generated.

 Step 44: According to the signal strength information, when it is determined that the change trend of the signal strength of the reference signal is gradually enhanced within a specified length of time, and the matching information of the first and second cells is inconsistent, the reason for determining the RLF is the UE. A late switch occurred when switching to the first cell.

 A specific flow chart of a method for determining the cause of the RLF provided by the embodiment of the present invention is as shown in FIG. 5, and includes the following steps:

 Step 51: Obtain identification information of the first cell where the UE generates the RLF.

 Step 52: When it is determined that the UE does not switch to the first cell by another cell before the RLF occurs, obtain the identifier information of the second cell that is connected and reestablished with the UE after the RLF occurs.

 Step 53: When the matching of the identification information of the first and second cells is inconsistent, the reason for determining the RLF is that the UE has switched too late when switching from the first cell to the third cell.

In order to implement the foregoing method provided by the embodiment of the present invention, in an actual application, since the RLF is not known in the cell in which the UE is to be used, in the embodiment of the present invention, the identifier information of the cell where the UE is located may be recorded in real time. Way to the UE during the move The identification information of the cell at the location is saved, and at the same time, the signal strength information of the reference signal received by the UE within a specified time period after the handover occurs may be recorded. Since the RLF may occur soon after the handover occurs, the specified length of time may be set to be shorter. For example, the specified length of time may be set to be within a first few seconds after the UE successfully switches to the cell.

 According to the solution provided by the embodiment of the present invention, the reason for the RLF can be quantitatively determined according to the information in the series of processes in which the UE performs handover (or may not have handover), then RLF, and finally performs RRC connection re-establishment. After determining the cause of the RLF, according to the reason, the switching parameter threshold can be adjusted in the embodiment of the present invention to prevent the same cause of the RLF from appearing again. The foregoing solution provided by the embodiment of the present invention has a very important significance in practical applications, because the determined RLF causes a basis for the subsequent processing such as the switching parameter threshold.

 In the actual communication network, the eNodeB triggering the handover process of the UE involves many handover parameter threshold settings, and triggers the handover process of the UE when the measurement value satisfies the handover parameter threshold. In the prior art, due to characteristics such as network topology and geographic location, the switching parameter threshold settings between each pair of neighboring cells are often different from each other. A reasonable switching parameter threshold setting can ensure the stability of the UE handover and reduce unnecessary handover. In order to make a reasonable adjustment of the handover parameter threshold, to avoid unnecessary handover of the UE, and to prevent the UE from generating an RLF after the unnecessary handover occurs, the embodiment of the present invention further provides a method for determining the RLF cause. As shown in FIG. 6, the switching parameter threshold adjustment method mainly includes the following steps:

 Step 61: Determine a switching parameter threshold to be adjusted according to the determined reason of the RLF. Step 62: Adjust the determined switching parameter threshold. The application is taken as an example to describe in detail the specific application process of the solution. Specifically, the specific application process of the solution may include the following steps as shown in FIG. 7:

Step 71: The UE needs to record information 1~3 during the mobile process, and the content of the information 1~3 is as follows: The content of the information 1 is: If the UE successfully cuts in from the other cell before the RLF occurs The cell where the RLF is generated records the source identification information of the current handover, and records a set of RSRP/RSRQ information that the UE switches to the start of the cell where the RLF occurs. The source identification information and the RSRP/RSRQ information are Constructing information 1; if the UE does not switch from another cell to the cell where the RLF occurred before the RLF occurs, the information 1 is not recorded;

 The content of the information 2 is: the identification information of the cell where the UE occurs when the RLF occurs;

 The content of the information 3 is: the identity information of the cell that is RRC connection reestablished with the UE after the RLF occurs.

 Step 72, the UE completes the record of the information 1, the information 2, the information 3, and after re-establishing the RRC connection with the eNodeB, the information is reported to the eNodeB through the XI interface;

 Step 73: The eNodeB forwards the information reported by the UE to the device in the relevant cell (for example, the device in the cell where the current UE is located), and the device in the cell determines the cause of the RLF according to the information 1, 2, and 3. Or, the eNodeB may determine, according to the information reported by the UE, 1, 2, and 3, the reason for the RLF to be generated, and then forward the information for indicating the determined cause to the device of the relevant cell.

 In practical applications, the method of judging the late switch is as follows:

 When the information reported by the UE is not empty, that is, when the UE reports the source identification information and the RSRP/RSRQ information, if the following two conditions are met, the UE is switched from the cell where the RLF occurs to the cell where the RRC reestablishment is established. A late switch occurred:

 Condition 1: The RSRP/RSRQ information in the information reported by the UE indicates that the signal strength of the reference signal exhibits an increasing trend at the beginning of the foregoing period.

 Condition 2: In the information 2, the identity information of the cell in which the UE is in the RLF is consistent with the identity information of the cell in the information 3 that is RRC connection reestablishment.

When the information reported by the UE is empty, that is, when the UE reports the identity information of the source cell and the RSRP/RSRQ information (the UE should be considered to have no switching behavior before the RLF occurs), if the condition is met: In the case where the identification information of the cell in which the RLF occurs in the UE occurs in the 2, and the identification information of the cell in the information 3 that is RRC-reestablished with the UE is inconsistent, the UE is described. The reason for the occurrence of the RLF is that an excessive handover occurs when the cell in which the RLF occurs is switched to the cell in which the RRC connection reestablishment is established with the UE.

 The method of judging the premature switching is as follows:

 When the following three conditions are met, it is determined that the reason for the UE to generate the RLF is that the handover occurs from the cell in which the RLF occurs to the cell in which the RRC connection is established with the UE.

 Condition 1: The identity information of the source cell in the information 1 is consistent with the identity information of the cell in the information 3 that is RRC-connected and reconstructed by the UE.

 Condition 2: The RSRP/RSRQ information in the information reported by the UE indicates that the signal strength of the reference signal exhibits a decreasing trend at the beginning of the foregoing period.

 Condition 3: In the information 2, the identity information of the cell in which the UE generates the RLF is inconsistent with the identity information of the cell in which the UE performs the RRC link reestablishment.

 The method of judging the error switching is as follows:

 When the following three conditions are met, it is determined that the reason for the UE to generate the RLF is that an error occurs when switching from the cell in which the RLF occurs to the cell in which the RRC connection is established with the UE:

 Condition 1: The identification information of the source cell in the information 1 is inconsistent with the identification information of the information about the RRC connection reestablishment cell in the information 3.

 Condition 2: The RSRP/RSRQ information in the information reported by the UE indicates that the signal strength of the reference signal exhibits a decreasing trend at the beginning of the foregoing period.

 Condition 3: In the information 2, the identity information of the cell in which the UE is in the RLF is inconsistent with the identity information of the cell in which the UE performs RRC reestablishment.

 The following describes the application scenarios of late switchover, premature switchover, and error switchover. The details of how to determine the cause of RLF are used to determine the specific RLF cause.

 First embodiment:

The first embodiment is mainly directed to an application scenario in which a late handover occurs. The application scenario is as shown in FIG. 8a. The cell A is adjacent to the cell B, the cell B is adjacent to the cell C, and the UE in the RRC-CONNECTED state is configured. Cell A gradually moves to cell B, and the successful cell A is switched to the cell B, the arrow in the figure is used to indicate the moving direction of the UE, and the location of the UE indicated by the solid line block diagram is used to indicate the location where the UE occurs when the RLF occurs.

 In this scenario, the process for determining the cause of the RLF is as shown in FIG. 8b, and includes the following steps: Step 81: The UE records the identification information of the cell A during the mobile process, and records the first 2 seconds after the UE records the handover to the cell B. Within the clock, measure and record a set of RSRP/RSRQ information;

 Step 82: The UE continues to move from the cell B to the cell C. Because the handover parameter threshold is unreasonable, the UE still does not receive the handover command sent by the cell B when the cell B edge is located. Therefore, the UE generates the RLF at the edge of the cell B. The UE records the identification information of the cell B;

 Step 83: The UE initiates an RRC connection reestablishment in the cell C, and records the identifier information of the cell C. Step 84: After the UE re-establishes an RRC connection with the eNodeB in the cell C or other cell, the UE passes the air interface to the 61^0 (16:8).艮 Recorded information, the information of these records includes information 1: identification information of source cell A and a set of RSRP/RSRQ information measured and recorded within the first 2 seconds after switching to cell B; information 2: where the UE occurs when RLF occurs Identification information of the cell B. Information 3: The identity information of the cell C that is RRC connection reestablishment with the UE. It should be noted that the subsequent UE may not successfully implement the RRC connection reestablishment with the cell C, but this does not affect the UE to the cell C. a record of identification information;

 Step 85: After receiving the information reported by the UE, the eNodeB forwards the information reported by the UE to the device of the cell B. If the cell B belongs to another eNodeB, the information is forwarded through the X2 port or the S1 port.

Step 86: After receiving the information reported by the UE, the device of the cell B determines, according to the information, that the condition 1 is: the RSRP/RSRQ value measured and recorded in the first 2 seconds after the UE switches to the cell B is incremented. The information is also inconsistent with the condition 2: the identity information of the cell B where the UE is located is inconsistent with the identity information of the RRC connection reestablishment cell C when the RLF occurs, so that the device of the cell B determines that the UE switches from the cell B to the cell C. An excessive switch occurs, and the count value of the counter for counting the number of times the UE switches from cell B to cell C is too late is incremented by one; Step 87: When the count value of the counter is accumulated in the first predetermined time period to be consistent with the predetermined first count threshold, it may be determined that the threshold value of the handover parameter when the preset UE switches from the cell B to the cell C is unreasonable. Therefore, the handover parameter threshold of the UE switching from the cell B to the cell C can be adjusted. For example, the value of the celllndividualOffset parameter can be increased. It should be noted that, if it is only necessary to determine the cause of the RLF, and the switching parameter threshold is not adjusted according to the reason, the step 47 may not be performed.

 Second embodiment:

 The second embodiment is mainly directed to an application scenario in which a premature handover occurs. The application scenario is as shown in FIG. 9a. The cell B is adjacent to the cell C, and the RRC-CONNECTED UE moves from the cell B to the cell C. At the B edge, the UE still does not receive the handover command sent by the cell B, and then the RLF occurs at the edge of the cell B. The arrow in the figure is used to indicate the moving direction of the UE, and the location of the UE indicated by the solid line diagram is used to indicate The location where the UE is located when the RLF occurs.

 In this scenario, the process for determining the cause of the RLF is as shown in FIG. 9b, and includes the following steps: Step 91: The UE records the identifier information of the cell B.

 Step 92: The UE initiates an RRC connection reestablishment process in the cell C, and records the identity information of the cell C.

 Step 93: After the UE re-establishes an RRC connection with the eNodeB, the UE records the information recorded to the eNodeB through the air interface. Since the UE does not switch from the other cell to the cell B, the information 1 is empty and can be invalid. The value NULL indicates the message 1. The information reported by the UE includes the information 1: NULL; the information 2: the identity information of the cell B where the UE is in the RLF; the information 3: the identity information of the cell C in which the RRC connection is reestablished with the UE;

 Step 94: After receiving the information reported by the UE, the eNodeB forwards the information reported by the UE to the device of the cell B. If the cell B belongs to another eNodeB, the information is forwarded through the X2 port or the S1 port.

Step 95: After receiving the information reported by the UE, the device of the cell B is The information of the cell 1 is empty. Therefore, the device of the cell B can satisfy the condition that the identifier information of the cell B where the RLF occurs when the UE generates the RLF according to the currently received information is inconsistent with the identifier information of the cell C where the UE performs the RRC connection reestablishment. When the UE switches from cell B to cell C, a late switch occurs, so the count value of the counter for counting the number of times that the UE has switched too late when cell B is switched to cell C is increased by one;

 Step 96: When the cell B to cell C occurrence of the late switch counter value is accumulated in the second predetermined time period to be consistent with the predetermined second count threshold, the preset UE may be determined to switch from the cell B to the cell C. If the value is unreasonable, you can adjust the switch parameter threshold, such as increasing the value of the celllndividualOffset parameter.

 Third embodiment:

 The third embodiment is mainly applied to a scenario in which the cell A includes a small cell region with a strong cell B signal, so that the UE is switched from the cell A to the cell B, and the application scenario is as shown in FIG. 10a. The UE in the connected state moves from the cell A to the cell B, and successfully switches from the cell A to the cell B. The arrow in the figure is used to indicate the moving direction of the UE, and the location of the UE indicated by the solid line diagram is used to indicate The location where the UE is located when the RLF occurs.

 In this scenario, the process for determining the cause of the RLF is as shown in FIG. 10b, and includes the following steps: Step 101: The UE records the identifier information of the cell A.

 Step 102: The UE records the RSRP/RSRQ information of the cell B measured in the first 2 seconds after switching to the cell B.

 Step 103: The UE continues to move from the cell B to the cell A. The cell B does not receive the handover command sent by the cell B, and the RLF is quickly generated in the cell B, and the UE records the identity information of the cell B. Step 104, the UE is in the cell A. Initiating an RRC connection reestablishment, and recording the identification information of the cell A;

Step 105: After the UE establishes an RRC connection with the eNodeB, the UE records the information recorded by the air interface to the eNodeB, including the information 1: the identification information of the cell A, and switches to the first 2 seconds after the cell B. Measured RSRP/RSRQ information of cell B; information 2: The identity information of the cell B where the UE is in the RLF; the information 3: the RRC connection with the UE reestablishes the identity information of the cell A;

 Step 106: After receiving the information reported by the UE, the eNodeB forwards the information reported by the UE to the device of the cell A. If the cell A belongs to another eNodeB, the information is forwarded through the X2 port or the S1 port.

 Step 107: After receiving the reported message from the UE, the device of the cell A determines that the condition 1 is satisfied according to the information 1, 2, and 3: the identity information of the source cell A in the information 1 and the RRC with the UE in the information 3. The identity information of the cell A of the connection reestablishment is consistent; condition 2: the RSRP/RSRQ information of the cell B measured in the first 2 seconds after the UE switches to the cell B is in a decreasing trend; Condition 3: the cell B where the UE occurs when the RLF occurs The identifier information is inconsistent with the identifier information of the cell A that is RRC connection reestablishment with the UE. Therefore, the device of the cell A determines that the UE has switched from the cell A to the cell B, and the control is used to the UE from the cell A. The count value of the counter that counts the number of premature handovers when switching to cell B is increased by 1;

 Step 108: When the count value of the counter in step 107 is accumulated in the third predetermined timing time to be consistent with the predetermined third count threshold, the handover parameter when the preset UE switches from the cell A to the cell B may be determined. The threshold setting is unreasonable, so that the handover parameter threshold from the UE to the cell B can be adjusted, for example, the value of the celllndividualOffset parameter can be reduced.

 Fourth embodiment:

 The fourth embodiment is mainly directed to an application scenario in which an erroneous handover occurs. The application scenario is as shown in FIG. 11a. The cell A is adjacent to the cell B, the cell A and the cell C are also adjacent, and the UE in the RRC-CONNECTED state is configured. Cell A gradually moves to cell B, successfully switches from cell A to cell B, and then moves from cell B to cell C. The arrows in the figure are used to indicate the direction of movement of the UE, and the location of the UE indicated by the solid line diagram is used to indicate where the UE is located when the RLF occurs.

In this scenario, the process for determining the cause of the RLF is shown in Figure lib, which includes the following steps: Step 111: The UE in the connected state moves from the cell A to the cell B, and successfully switches from the cell A to the cell B, and the UE records the identification information of the cell A.

 Step 112: The UE records the RSRP/RSRQ information of the cell B measured in the first 2 seconds after switching to the cell B.

 Step 113: The UE continues to move from the cell B to the cell C. The UE has not received the handover command sent by the cell B, and the RLF is quickly generated in the cell B, and the UE records the identity information of the cell B. Step 114, the UE initiates in the cell C. RRC connection re-establishment process, and record the identification information of the cell C;

 Step 115: After the cell C or another cell re-establishes an RRC connection with the eNodeB, the UE records the information recorded to the eNodeB through the air interface, including the information 1: the identity information of the source cell A, and switches to the cell 2 for the first 2 seconds. The measured RSRP/RSRQ information of the cell B; the information 2: the identity information of the cell B where the UE is in the RLF; the information 3: the identity information of the cell C in which the RRC connection reestablishment with the UE is performed;

 Step 116: After receiving the information reported by the UE, the eNodeB forwards the information of the UE to the device of the cell A (if the cell A belongs to another eNodeB, and performs information forwarding through the X2 port or the S1 port);

 Step 117: The device of the cell A receives the forwarded information of the UE, and determines that the condition 1 is met: the identifier information of the source cell A in the information 1 is inconsistent with the identifier information of the cell in the information 3 that is RRC connection reestablishment with the UE. Condition 2: The RSRP/RSRQ information of the cell B measured in the first 2 seconds after the UE switches to the cell B is in a decreasing trend; Condition 3: The identity information of the cell B where the UE is RLF occurs and the RRC connection of the UE reestablishes the cell C. The identification information is inconsistent. According to the conditions, the device of the cell A determines that the UE has erroneously switched from the cell A to the cell B, and controls a counter for counting the number of times the erroneous handover occurs when the cell A switches to the cell B. The count value is increased by 1;

Step 118: When the count value of the counter described in step 117 is accumulated in the fourth predetermined timing time to coincide with the predetermined fourth count threshold, it may be determined that the monthly UE is switched from the cell A to the small The setting of the handover parameter threshold value in the area B is unreasonable, so that the handover parameter threshold value from the UE to the cell B can be adjusted, for example, the value of the celllndividualOffset parameter related to the cell B can be reduced, or the value of the celllndividualOffset parameter can be increased. The value of the celllndividualOffset parameter related to the large cell C. It is carried out by the cooperation of the UE, the eNodeB and the cell device, or by a determining device of an independent RLF cause. Corresponding to the method for determining the cause of the RLF provided by the embodiment of the present invention, a specific structural diagram of the apparatus for determining the cause of the RLF provided by the embodiment of the present invention is as shown in FIG. 12, and includes the following functional units:

 The first cell identifier information acquiring unit 121 is configured to acquire identifier information of a first region in which the UE generates the RLF;

 The signal strength information determining unit 122 is configured to determine signal strength information of the reference signal received by the UE in the first cell within a specified time length before the RLF occurs;

 The second cell identifier information acquiring unit 123 is configured to acquire the identifier information of the second cell when the UE is determined to be handed over to the first cell by the second cell before the RLF occurs.

 The third cell identifier information acquiring unit 124 is configured to acquire identifier information of the third cell that is connected and reestablished with the UE after the RLF occurs;

 The failure cause determining unit 125 is configured to determine, according to the signal strength information determined by the signal strength information, the signal strength information of the reference signal in the specified length of time is gradually weakened, and compare the second cell identification information. The identifier information of the second cell acquired by the obtaining unit 123 is consistent with the identifier information of the third cell acquired by the third cell identifier information acquiring unit 124, and the first identifier information acquired by the first cell identifier information acquiring unit 121 and the third cell When the identifier information is inconsistent, the reason for determining the RLF is that the UE has switched too early when switching from the second cell to the first cell.

Another determining device for the RLF cause provided by the embodiment of the present invention includes the following functional units: a first cell identifier information acquiring unit, configured to acquire identifier information of a first cell where the UE generates an RLF, and a signal strength information determining unit, configured to determine a reference signal received by the UE in the first cell before the RLF occurs a signal strength information in a specified length of time; a second cell identifier information acquiring unit, configured to acquire, when the UE is handed over to the first cell by the second cell before the RLF occurs, acquiring the identifier information of the second cell; a cell identifier information acquiring unit, configured to acquire identifier information of a third cell that is connected and reestablished with the UE after the RLF is generated, and a failure cause determining unit, configured to determine, according to the signal strength information, the signal strength information determined by the unit, The change trend of the signal strength of the reference signal in the time length is gradually weakened, and the identifier information of the first cell acquired by the first cell identifier information acquiring unit and the identifier information of the second cell acquired by the second cell identifier information acquiring unit are compared. The identification information of the third cell acquired by the third cell identity information acquiring unit does not match each other. When activated, determine the cause of the RLF occurred during handover error UE from a first cell to a second cell.

 The apparatus for determining the cause of the RLF provided by the embodiment of the present invention includes the following functional unit: a first cell identifier information acquiring unit, configured to acquire identifier information of a first cell where the RLF occurs when the UE occurs; and a signal strength information determining unit, After determining that the UE is handed over to the first cell by the other cell before the RLF occurs, determining signal strength information of the reference signal received by the UE in the first cell within a specified time length before the RLF occurs; a cell identifier information acquiring unit, configured to acquire identifier information of a second cell that is connected and reestablished with the UE after the RLF is generated; a failure cause determining unit, configured to determine, according to the signal strength information, the signal strength information determined by the unit, The change trend of the signal strength of the reference signal is gradually enhanced, and the identifier information of the first cell acquired by the first cell identifier information acquiring unit is matched with the identifier information of the second cell acquired by the second cell identifier information acquiring unit. In case of inconsistency, the reason for determining the RLF is when the UE switches to the first cell. A late switch has occurred.

The apparatus for determining the cause of the RLF provided by the embodiment of the present invention includes the following functional unit: a first cell identifier information acquiring unit, configured to acquire identifier information of a first cell where the UE is RLF, and a second cell identifier information acquiring unit , used to determine that the UE is before the RLF occurs. When the other cell is not switched to the first cell, the identifier information of the second cell that is connected to the UE after the RLF is reestablished is obtained; the failure cause determining unit is configured to compare the first acquired by the first cell identifier information acquiring unit. When the identification information of the cell is inconsistent with the identification information of the second cell of the second cell identity information acquiring unit, the reason for determining the RLF is that the UE has switched too late when switching from the first cell to the third cell.

 The apparatus for determining the cause of any of the above-mentioned RLFs is provided by the embodiment of the present invention. The embodiment of the present invention further provides a switching parameter threshold adjustment apparatus. The specific structure of the apparatus is shown in FIG. 13 and mainly includes the following functional units:

 The switching parameter threshold determining unit 131 is configured to determine a switching parameter threshold to be adjusted according to the reason of the RLF determined by the failure reason determining unit;

 The adjusting unit 132 is configured to adjust the switching parameter threshold determined by the switching parameter threshold determining unit 131. The spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and modifications of the invention

Claims

Claim  A method for determining a cause of a failure of a wireless link, comprising:  Obtaining identification information of the first cell where the user terminal fails when the radio link fails; and determining, by the user terminal, the reference signal received in the first cell for a specified length of time before the radio link fails Signal strength information within;  Obtaining, when the user terminal is handed over to the first cell by the second cell before the radio link fails, acquiring the identifier information of the second cell;  Obtaining identification information of a third cell that is connected and reestablished with the user terminal after the failure of the radio link occurs;  Determining, according to the signal strength information, that the change trend of the signal strength of the reference signal is gradually weakened during the specified length of time, and comparing that the identifier information of the second and third cells are consistently consistent, When the identification information of the first and third cells are inconsistent, the reason for determining that the radio link fails is that a premature handover occurs when the user terminal switches from the second cell to the first cell.  2. A method for determining a cause of a failure of a wireless link, comprising:  Obtaining identification information of the first cell where the user terminal fails when the radio link fails; and determining, by the user terminal, the reference signal received in the first cell for a specified length of time before the radio link fails Signal strength information within;  Obtaining, when the user terminal is handed over to the first cell by the second cell before the radio link fails, acquiring the identifier information of the second cell;  Obtaining identification information of a third cell that is connected and reestablished with the user terminal after the failure of the radio link occurs; Determining, according to the signal strength information, that the change trend of the signal strength of the reference signal is gradually weakened during the specified length of time, and comparing that the identification information of the first, second, and third cells match each other In case of inconsistency, the reason for determining that the wireless link fails is the end of the user. An erroneous handover occurs when the terminal switches from the second cell to the first cell.  A method for determining a cause of a failure of a wireless link, comprising:  Obtaining identification information of the first cell where the user terminal fails when the radio link fails; and determining, when it is determined that the user terminal switches to the first cell before the radio link fails, determining the user terminal Signal strength information of a reference signal received in the first cell within a specified length of time before the radio link fails;  Acquiring identification information of the second cell that is connected and reconstructed by the user terminal after the failure of the radio link occurs;  Determining, according to the signal strength information, that the change trend of the signal strength of the reference signal is gradually enhanced during the specified time length, and comparing that the identification information of the first and second cells is inconsistent, determining The reason for the failure of the radio link is that a late handover occurs when the user terminal switches to the first cell.  A method for determining a cause of a failure of a wireless link, comprising:  Acquiring the identification information of the first cell where the radio link fails when the user terminal fails; and acquiring and generating when the user terminal is not switched to the first cell by other cells before the radio link failure occurs. The identification information of the second cell that is connected and reconstructed by the user terminal after the radio link fails;  When the matching of the identification information of the first and second cells is inconsistent, the reason for determining that the wireless link fails is that a handover occurs when the user terminal switches from the first cell to the third cell.  A method for determining a reason for failure of a wireless link according to claim 1, 2, 3 or 4, characterized in that it comprises:  Determining, according to the determined cause of the failure of the radio link, a handover parameter threshold to be adjusted; and adjusting the determined handover parameter threshold.  A device for determining a cause of a failure of a wireless link, comprising: a first cell identifier information acquiring unit, configured to acquire, when the user terminal fails to generate a wireless link Identification information of the first cell where it is located;  a signal strength information determining unit, configured to determine signal strength information of a reference signal received by the user terminal in the first cell within a specified length of time before the radio link fails;  a second cell identifier information acquiring unit, configured to acquire, after the second cell is handed over to the first cell, the identifier information of the second cell, when the user terminal determines that the wireless link fails;  a third cell identifier information acquiring unit, configured to acquire identifier information of a third cell that is connected and reconstructed by the user terminal after the radio link failure occurs;  a failure cause determining unit, configured to determine, according to the signal strength information, the signal strength information determined by the unit, and determine that the change trend of the signal strength of the reference signal is gradually weakened during the specified time length, and compare the second cell identifier The identifier information of the second cell acquired by the information acquiring unit is consistent with the identifier information of the third cell acquired by the third cell identifier information acquiring unit, and the first identifier information acquired by the first cell identifier information acquiring unit and the third cell When the identifier information is inconsistent, the reason for determining that the radio link fails is that a premature handover occurs when the user terminal switches from the second cell to the first cell.  A device for determining a cause of a failure of a radio link, comprising: a first cell identifier information acquiring unit, configured to acquire identifier information of a first cell where a user terminal fails to generate a radio link;  a signal strength information determining unit, configured to determine signal strength information of a reference signal received by the user terminal in the first cell within a specified length of time before the radio link fails;  a second cell identifier information acquiring unit, configured to acquire, after the second cell is handed over to the first cell, the identifier information of the second cell, when the user terminal determines that the wireless link fails; a third cell identifier information acquiring unit, configured to acquire and after the failure of the wireless link occurs The identification information of the third cell that the user terminal performs connection reestablishment;  a failure cause determining unit, configured to determine, according to the signal strength information, the signal strength information determined by the unit, and determine that the change trend of the signal strength of the reference signal is gradually weakened during the specified time length, and compare the first cell identifier When the identifier information of the first cell acquired by the information acquiring unit, the identifier information of the second cell acquired by the second cell identifier information acquiring unit, and the identifier information of the third cell acquired by the third cell identifier information acquiring unit are inconsistent with each other, The reason for the failure of the radio link is that an error handover occurs when the user terminal switches from the second cell to the first cell.  A device for determining a cause of a failure of a radio link, comprising: a first cell identifier information acquiring unit, configured to acquire identifier information of a first cell where a user terminal fails to generate a radio link;  a signal strength information determining unit, configured to determine, before the user terminal switches to the first cell by another cell before the radio link fails, determining that the user terminal fails before the radio link fails Generating signal strength information of the reference signal received in the first cell within a specified length of time;  a second cell identifier information acquiring unit, configured to acquire identifier information of a second cell that is connected and reconstructed by the user terminal after the radio link failure occurs;  a failure cause determining unit, configured to determine, according to the signal strength information, the signal strength information determined by the unit, and determine that the change trend of the signal strength of the reference signal is gradually enhanced within the specified time length, and compare the first cell identifier When the identifier information of the first cell acquired by the information acquiring unit is inconsistent with the identifier information of the second cell acquired by the second cell identifier information acquiring unit, the reason for determining that the radio link fails is that the user terminal switches to the first cell. A too late switch occurred. A device for determining a cause of a failure of a radio link, comprising: a first cell identifier information acquiring unit, configured to acquire identifier information of a first cell where a user terminal fails to generate a radio link; a second cell identifier information acquiring unit, configured to: when it is determined that the user terminal is not switched to the first cell by another cell before the radio link fails, acquiring, and acquiring, the user terminal after the radio link failure occurs Identifying information of the second cell that is connected and reconstructed;  a failure cause determining unit, configured to determine, when the identity information of the first cell acquired by the first cell identity information acquiring unit is inconsistent with the identity information of the second cell of the second cell identity information acquiring unit, determining the wireless link The reason for the failure is that a late handover occurs when the user terminal switches from the first cell to the third cell.  A device for determining a cause of failure of a radio link according to claim 6, 7, 8 or 9, characterized in that it comprises:  a switching parameter threshold determining unit, configured to determine, according to the reason for the failure of the wireless link determined by the failure reason determining unit, the switching parameter threshold to be adjusted;  And an adjusting unit, configured to adjust the switching parameter threshold determined by the handover parameter threshold determining unit.