CN107396387B - MLB and MRO joint optimization method and device in LTE system - Google Patents

Abstract

The invention discloses a combined optimization method and a device of MLB and MRO in an LTE system, wherein after receiving a switching request of a first cell, a target cell judges whether the self load exceeds a threshold value for accepting first UE, and if the self load does not exceed the threshold value for accepting the first UE, the target cell judges whether the switching request is an overload switching request; if the switching request is an overload switching request, configuring preset new switching parameters and common switching parameters to the first UE together, and then receiving the first UE; making switching boundary condition judgment on the first UE through a first inequality, switching out the first UE from the target cell when the signal strength of the first UE meets the first inequality, otherwise, not switching out, wherein the difficulty that the signal strength of the first UE meets the first inequality is greater than the difficulty that the signal strength of the first UE meets an A3 event inequality; the technical problems that in an existing LTE system, first UE cut out from an overload cell is easy to cut back to cause table tennis switching, and further more secondary switching faults and wireless link failures are caused are solved.

Description

MLB and MRO joint optimization method and device in LTE system

Technical Field

The invention relates to the technical field of mobile communication, in particular to a method and a device for joint optimization of MLB (multi level block) and MRO (maximum likelihood error) in an LTE (long term evolution) system.

Background

The rapid development of communication technology enables wireless broadband to become possible, enjoying information life at any time and any place becomes an urgent appeal of human communication, and the market needs a wireless broadband technology with higher bandwidth and better service experience to change human life. In order to meet the market demand of people for higher peak rate, shorter delay, higher flexibility and system compatibility, Long Term Evolution (LTE) technology is in the process of generation. However, the parameters of the LTE system are large and complex, and the manual configuration and management method adopted by the conventional 2G/3G network is obviously not feasible in the presence of the large and complex parameters of the LTE system. In order to improve the operability and easy maintenance of the LTE system, in the network standardization stage of LTE, mobile operators mainly propose the concept of Self-Organized Networks (SON), and the main idea is to implement some autonomous functions of a wireless network, reduce manual participation, and reduce operation cost.

The SON technology mainly includes three functions of Self-configuration (Self-configuration), Self-optimization (Self-optimization), and Self-healing (Self-healing). The self-configuration function means that the equipment installation and power-on are automatically completed to the user equipment to be capable of normally accessing for service operation on the premise of little or no intervention of engineering personnel, and the self-configuration function is applied to the starting stage of the base station. The self-optimization function performs self-adjustment and optimization on network parameters according to network operation conditions such as performance measurement of terminal User Equipment (UE) and an LTE base station (Evolved Node B, eNodeB) so as to improve network performance and quality and reduce network optimization cost, and is applied to a normal operation stage of the base station. The self-healing function is to find out network problems through the detection of system alarm and performance, detect the position by self-checking, partially or totally eliminate the problems, finally realize the minimum influence on the network quality and the user experience, and be applied to the automatic fault detection and recovery stage after the base station has faults.

Mobile Load Balance (MLB) and Mobile Robustness Optimization (MRO) are two of the most important technologies for self-Optimization functions of the self-organizing network SON.

The MLB and MRO techniques affect the handover boundary conditions by adjusting handover parameters such as Hysteresis (hysteris, hyss), Time To Trigger (TTT), Cell specific Offset (CIO), relative trigger Threshold (OFF), and absolute trigger Threshold (Threshold) of an A3 or a5 event, thereby implementing automatic optimization of network parameters. Although the parameters for MLB and MRO optimization are the same, the performance indicators for MLB and MRO optimization are different. The purpose of MLB optimization is to transfer part of User Equipment (UE) traffic of a high-load cell to a lower-load neighbor cell, and to balance the traffic between cells, so that the load between cells is maintained in a relatively balanced state. The purpose of MRO optimization is to avoid or reduce Radio Link Failure (RLF) associated with handover and unnecessary handover failures such as premature handover, late handover, handover to a wrong cell, ping-pong handover, etc. Fig. 1 illustrates the load situation of two adjacent cells before load balancing, and fig. 2 illustrates the load situation of two adjacent cells after load balancing.

In the existing LET system, when the MLB and MRO functions are simultaneously turned on, when a cell is overloaded, the MLB adjusts handover parameters to handover the overloaded UE to a target cell for load balancing, but simultaneously, a large number of RLFs and unnecessary handover failures are caused, for example, the signal strength of the overloaded UE in the target cell may be worse than that in the overloaded cell; in consideration of robustness, the MRO adjusts the handover parameters in the opposite direction in order to reduce RLF and unnecessary handover failures, so as to switch the overloaded UE out of the target cell, and since the target cell is generally the cell with the best signal selected from the neighboring cells of the overloaded cell, the overloaded UE may be switched back to the original overloaded cell in order to enhance the signal strength of the overloaded UE, thereby causing pong handover, and further causing more secondary handover failures and radio link failures.

Disclosure of Invention

The invention provides a combined optimization method and a combined optimization device for MLB (multi level radio block) and MRO (maximum likelihood of being switched) in an LTE (long term evolution) system, and solves the technical problems that in the existing LTE system, first UE (user equipment) switched out from an overload cell is easy to be switched back to cause table tennis switching, and further more secondary switching faults and radio link failures are caused.

The invention relates to a combined optimization method of MLB and MRO in an LTE system, which comprises the following steps:

a target cell receives a switching request of a first UE switched from a first cell;

the target cell judges whether the self load exceeds a threshold value for accepting the first UE, and if the self load does not exceed the threshold value for accepting the first UE, the target cell judges whether the switching request is an overload switching request;

if the switching request is an overload switching request, the target cell configures preset new switching parameters and common switching parameters to the first UE together, and then receives the first UE, wherein the common switching parameters are parameters in an event inequality of switching judgment A;

if the switching request is an overload switching request, the target cell configures preset new switching parameters and common switching parameters to the first UE together, and then receives the first UE, wherein the common switching parameters are parameters in an event inequality of switching judgment A;

the target cell makes a handover boundary condition decision for the first UE through a first inequality, and when the signal strength of the first UE satisfies the first inequality, the first UE is handed out from the target cell, otherwise, the first UE is retained in the target cell, the first inequality is determined according to the new handover parameter and the common handover parameter, and the difficulty that the signal strength of the first UE satisfies the first inequality is greater than the difficulty that the signal strength of the first UE satisfies the handover decision a event inequality.

Preferably, the first and second electrodes are formed of a metal,

when the switching judgment A event is an inequality A3 event inequality, the new switching parameter is a relative threshold value Off triggered by an A3 event_{mlb_mro}Or neighbor specific offset Ocn_{(i,mlb_mro)}；

The first inequality is a second inequality or a third inequality;

the second inequality is based on the relative threshold value Off_{mlb_mro}And the inequality determined by the common switching parameter is used for making switching boundary condition judgment when the first UE is switched out from the target cell to any one adjacent cell;

the third inequality is based on the neighbor specific offset Ocn_{(i,mlb_mro)}And the inequality determined by the common switching parameter is used for making switching boundary condition judgment when the first UE is switched from the target cell to a preset adjacent cell.

Preferably, the first and second electrodes are formed of a metal,

after the target cell receives the handover request of the first UE switched by the first cell, the method further includes:

and carrying out statistical analysis on the switching faults, and then optimizing the new switching parameters according to the statistical analysis result of the switching faults.

Preferably, the first and second electrodes are formed of a metal,

after judging whether the handover request is an overloaded handover request, the method further comprises the following steps:

if the switching request is not an overload switching request, the target cell configures common switching parameters to the first UE and then receives the first UE;

and the target cell makes switching boundary condition judgment on the first UE through the switching judgment A event inequality, and cuts out the first UE from the target cell when the signal of the first UE meets the switching judgment A event inequality, otherwise, the first UE is kept in the target cell.

Preferably, the first and second electrodes are formed of a metal,

the step of judging whether the handover request is an overload handover request by the target cell specifically includes:

and the target cell identifies the filling information of the Cause IE field in the switching request, if the filling information of the Cause IE field is Reduce load in serving cell, the switching request is judged to be an overload switching request, otherwise, the switching request is judged to be a non-overload switching request.

The invention provides a combined optimization device of MLB and MRO in an LTE system, which comprises:

a handover request receiving module, configured to receive a handover request of a first UE switched from a first cell;

the judging module is used for judging whether the self load exceeds a threshold value for accepting the first UE, and if the self load does not exceed the threshold value for accepting the first UE, judging whether the switching request is an overload switching request;

a parameter configuration module, configured to configure a preset new handover parameter and a common handover parameter to the first UE when the handover request is an overload handover request, and then receive the first UE, where the common handover parameter is a parameter in a handover decision event inequality a;

the MRO module is configured to make a handover boundary condition decision for the first UE through a first inequality, and when the signal strength of the first UE satisfies the first inequality, hand off the first UE from the target cell, otherwise, keep the first UE in the target cell, where the first inequality is determined according to the new handover parameter and the common handover parameter, and the difficulty that the signal strength of the first UE satisfies the first inequality is greater than the difficulty that the signal strength of the first UE satisfies the handover decision a event inequality.

Preferably, the first and second electrodes are formed of a metal,

when the switching judgment A event is an inequality A3 event inequality, the new switching parameter is a relative threshold value Off triggered by an A3 event_{mlb_mro}Or neighbor specific offset Ocn_{(i,mlb_mro)}；

The first inequality is a second inequality or a third inequality;

the second inequality is based on the relative threshold value Off_{mlb_mro}And the inequality determined by the common switching parameter is used for making switching boundary condition judgment when the first UE is switched out from the target cell to any one adjacent cell;

the third inequality is based on the neighbor specific offset Ocn_{(i,mlb_mro)}And the inequality determined by the common switching parameter is used for making a switching edge when the first UE is switched from the target cell to a preset adjacent cellAnd (5) boundary condition judgment.

Preferably, the first and second electrodes are formed of a metal,

the combined optimization device for MLB and MRO in the LTE system further includes:

and the fault statistical analysis module is used for performing statistical analysis on the switching faults and then optimizing the new switching parameters according to the statistical analysis result of the switching faults.

Preferably, the first and second electrodes are formed of a metal,

the parameter configuration module is further configured to configure, when the handover request is not an overloaded handover request, the target cell configures a common handover parameter to the first UE, and then receives the first UE;

the MRO module is further configured to make a handover boundary condition decision for the first UE through the handover decision a event inequality, and when a signal of the first UE satisfies the handover decision a event inequality, switch the first UE out of the target cell, otherwise, keep the first UE in the target cell.

Preferably, the first and second electrodes are formed of a metal,

and the judging module is specifically used for judging whether the self load exceeds a threshold value for accepting the first UE, identifying filling information of a Cause IE field in the switching request if the self load does not exceed the threshold value for accepting the first UE, judging the switching request to be an overload switching request if the filling information of the Cause IE field is Reduce load in serving cell, and otherwise, judging the switching request to be a non-overload switching request.

According to the technical scheme, the invention has the following advantages:

1. the invention provides a method and a device for joint optimization of MLB (multi level radio block) and MRO (maximum mobility optimization) in an LTE (long term evolution) system.A target cell receives a switching request of switching first UE (user equipment) from the first cell, judges whether the self load of the target cell exceeds a threshold value for accepting the first UE, and judges whether the switching request is an overload switching request if the self load does not exceed the threshold value for accepting the first UE; if the switching request is an overload switching request, the target cell configures preset new switching parameters and common switching parameters to the first UE together, and then receives the first UE, wherein the common switching parameters are parameters in a switching judgment event inequality A; the target cell judges the switching boundary condition of the first UE through a first inequality, and when the signal intensity of the first UE meets the first inequality, the first UE is switched out of the target cell, otherwise, the first UE is kept in the target cell; because the first inequality is determined according to the new handover parameter and the common handover parameter, the difficulty that the signal strength of the first UE meets the first inequality is greater than the difficulty that the signal strength of the first UE meets the handover decision event inequality A, so the difficulty that the first UE is switched out from the target cell is increased; compared with the existing LTE system, the method has the advantages that the switching boundary condition judgment of the first UE switched out from the target cell is made through the switching judgment event inequality A, the difficulty of switching out the target cell by the first UE is increased, and the technical problems that in the existing LTE system, the first UE switched out from the overload cell is easy to be switched back to cause table tennis switching, and further more secondary switching faults and wireless link failures are caused are solved.

2. The invention provides a combined optimization method and a device of MLB and MRO in an LTE system, wherein a new switching parameter takes effect only when a first cell is overloaded, and the particularity of effective time ensures that the new switching parameter can quickly and reasonably influence a switching boundary condition in a non-step manner under the specific scene that the first cell is overloaded and the combined optimization conflict of the MLB and the MRO is triggered, so that the load of the first cell can be quickly reduced, the repeated ping-pong adjustment of an old switching parameter caused by each overload and overload of the first cell is avoided, and unnecessary first UE ping-pong switching and secondary switching faults and radio link failures in the early stage of load balancing are effectively prevented; and the optimization change of the new parameter value does not influence the prior old switching parameter value only used for MRO optimization adjustment, after the overload is relieved, the new switching parameter value does not take effect any more, the switching boundary judgment condition before the overload can be quickly recovered, and the switching judgment is carried out only by using the old switching parameter, so that the combined optimization of MLB and MRO can effectively balance the load on the basis of not influencing the MRO function.

3. The invention provides a method and a device for joint optimization of MLB (multi level radio base) and MRO (maximum likelihood) in an LTE (long term evolution) system. In the whole process, the Handover Preparation (Handover Preparation) and Handover Resource Allocation (Handover Resource Allocation) flow is utilized to carry out load balancing negotiation with the first cell, so that the function of the existing signaling flow can be fully exerted to quickly negotiate Handover parameters, the receiving capability of the target cell can be comprehensively considered, and the radio link failure caused by the wrong load balancing is prevented.

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 description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

Fig. 1 is a schematic view of load conditions of two adjacent cells before load balancing;

fig. 2 is a schematic view of load conditions of two adjacent cells after load balancing;

fig. 3 is a flowchart illustrating an embodiment of a joint optimization method for MLB and MRO in an LTE system according to an embodiment of the present invention;

fig. 4 is a flowchart illustrating a joint optimization method for MLB and MRO in an LTE system according to another embodiment of the present invention;

fig. 5 is a flowchart illustrating an embodiment of a joint optimization apparatus for MLB and MRO in an LTE system according to an embodiment of the present invention;

fig. 6 is a flowchart illustrating an embodiment of a joint optimization apparatus for MLB and MRO in an LTE system according to an embodiment of the present invention;

fig. 7 is a schematic diagram of signaling interaction flows of MLB and MRO joint optimization load balancing request notification when there is an X2 channel between an overloaded cell and a target cell in the embodiment of the present invention.

Fig. 8 is a schematic diagram illustrating a signaling interaction flow of MLB and MRO joint optimization load balancing request notification when there is no X2 channel between an overloaded cell and a target cell in the embodiment of the present invention;

FIG. 9 illustrates the introduction of an A3 event trigger relative threshold value Off specific to resolving MLB and MRO joint optimization conflicts_{mlb_mro}Joint optimization conflict resolution graph of time.

FIG. 10 illustrates the introduction of a specific offset Ocn specific to resolving MLB and MRO joint optimization conflicts_{(i,mlb_mro)}Joint optimization conflict resolution graph of time.

Detailed Description

The embodiment of the invention provides

A target cell receives a switching request of a first UE switched from a first cell, judges whether the self load of the target cell exceeds a threshold value for accepting the first UE, and judges whether the switching request is an overload switching request if the self load of the target cell does not exceed the threshold value for accepting the first UE; if the switching request is an overload switching request, the target cell configures preset new switching parameters and common switching parameters to the first UE together, and then receives the first UE, wherein the common switching parameters are parameters in a switching judgment event inequality A; the target cell judges the switching boundary condition of the first UE through a first inequality, and when the signal intensity of the first UE meets the first inequality, the first UE is switched out of the target cell, otherwise, the first UE is kept in the target cell; because the first inequality is determined according to the new handover parameter and the common handover parameter, the difficulty that the signal strength of the first UE meets the first inequality is greater than the difficulty that the signal strength of the first UE meets the handover decision event inequality A, so the difficulty that the first UE is switched out from the target cell is increased; compared with the existing LTE system, the method has the advantages that the switching boundary condition judgment of the first UE switched out from the target cell is made through the switching judgment event inequality A, the difficulty of switching out the target cell by the first UE is increased, and the technical problems that in the existing LTE system, the first UE switched out from the overload cell is easy to be switched back to cause table tennis switching, and further more secondary switching faults and wireless link failures are caused are solved.

In order to make the technical scheme of the invention more clear, the following description is made: the handover decision a event is defined by the 3GPP protocol and belongs to the technical term in the field, including but not limited to A3 event, a4 event and a5 event, and the corresponding inequalities are an A3 event inequality, an a4 event inequality and an a5 event inequality, respectively.

Referring to fig. 3, a flowchart of an embodiment of a joint optimization method for MLB and MRO in an LTE system according to the present invention is shown;

the combined optimization method of the MLB and the MRO in the LTE system provided by the embodiment of the invention comprises the following steps:

s101, a target cell receives a switching request of a first cell switching out first UE.

There are various types of handover requests that the target cell receives from the first cell.

As shown in fig. 7, the first cell may transmit a HANDOVER REQ first UEST message to the target cell through an X2 channel established with the target cell, so that the target cell receives a HANDOVER request of the first cell through an X2 channel.

As shown in fig. 8, if no X2 tunnel is established between the first cell and the target cell, the first cell may send a HANDOVER request message to the MME, and then forward the HANDOVER request message to the target cell through the MME, so that the target cell receives the HANDOVER request of the first cell.

It can be understood that, before the target cell receives the handover request of the first cell, the first cell selects, according to the measurement information reported by the second UE, a neighboring cell with the best signal quality as the target cell, where the second UE is different from the first UE mentioned in other parts of this embodiment, and the neighboring cell refers to a neighboring cell of the first cell.

S102, the target cell judges whether the self load exceeds a threshold value for accepting the first UE, and if the self load does not exceed the threshold value for accepting the first UE, the target cell judges whether the switching request is an overload switching request.

And if the load of the target cell exceeds a threshold value for accepting the first UE, refusing to receive the first UE, wherein the first cell needs to reselect the target cell, and the adjacent cell with the second best signal quality is taken as the target cell, and so on until the target cell capable of accepting the first UE is selected.

S103, if the switching request is an overload switching request, the target cell configures preset new switching parameters and common switching parameters to the first UE, and then receives the first UE, wherein the common switching parameters are parameters in the switching judgment event inequality A.

When the target cell configures the preset new handover parameter and the common handover parameter to the first UE, the target cell is in a state of waiting for the first UE to access, and then the first UE attempts to access the target cell, where the first UE may or may not successfully access, and receiving the first UE in step S103 means that the first UE successfully accesses the target cell.

Take the a3 event as an example.

The A3 event inequality is Mn + Ofn + Ocn-Hys > Ms + Ofs + Ocs + Off, wherein Mn and Ms represent measured values of a neighboring area and a service area respectively; ofn and Ofs represent the offsets corresponding to the frequencies of the neighbour and service areas, respectively, i.e. the parameter freqOffset in the cell MeasObjectETURA; ocn and Ocs represent offsets associated with the cell (neighbor and serving), respectively, i.e. cellIndividualOffset parameter in MeasObjectEUTRA; off is a threshold value of an A3 event, which represents the difference between the measurements of the neighboring cell and the service cell (after adding a bias), namely, the parameter a3-Offset of eventA3 in report ConfigEUTRA; hys is the hysteresis of the A3 event.

When the handover decision a event is the inequality A3 event inequality, the common parameters are all parameters in the A3 event inequality.

S104, the target cell judges the switching boundary condition of the first UE through a first inequality, when the signal intensity of the first UE meets the first inequality, the first UE is switched out of the target cell, otherwise, the first UE is kept in the target cell, the first inequality is determined according to the new switching parameter and the common switching parameter, and the difficulty that the signal intensity of the first UE meets the first inequality is larger than the difficulty that the signal intensity of the first UE meets the switching judgment A event inequality.

The first inequality is used for judging the switching boundary condition when the first UE is switched out, so that the switching-out difficulty of the first UE from the target cell is increased, namely the switching-back difficulty of the first UE from the target cell to the first cell is increased, the first UE is reserved in the target cell as much as possible, and the problem of parameter conflict when the MLB and the MRO are simultaneously started is solved.

Referring to fig. 4, a schematic flow chart of another embodiment of a joint optimization method for MLB and MRO in an LTE system according to the present invention is shown;

the combined optimization method of the MLB and the MRO in the LTE system provided by the embodiment of the invention comprises the following steps:

s201, the target cell receives a switching request of a first cell switching out a first UE.

As in S101, the target cell may receive the handover request directly through the X2 tunnel or indirectly through the MME.

S202, judging whether the self load exceeds a threshold value for accepting the first UE, if the self load does not exceed the threshold value for accepting the first UE, identifying filling information of a Cause IE field in the switching request, if the filling information of the Cause IE field is Reduce load in serving cell, judging the switching request to be an overload switching request, otherwise, judging the switching request to be a non-overload switching request.

The Cause IE field is present in the handover request, and after receiving the handover request, the target cell first determines whether the first UE handed out from the first cell can be received, and stores the Cause IE field if the first UE can be received, and then identifies the Cause IE field to determine whether the handover request is an overloaded handover request.

If the first cell is not overloaded, but the signal strength of the first UE in the first cell is too weak, the first UE needs to be handed over to other neighboring cells with better signals, and the handover request in this case is a non-overloaded handover request.

S203, if the handover request is an overload handover request, the target cell configures a preset new handover parameter and a common handover parameter together to the first UE, and then receives the first UE, where the common handover parameter is a parameter in the handover decision event inequality a.

S204, the target cell judges the switching boundary condition of the first UE through a first inequality, when the signal intensity of the first UE meets the first inequality, the first UE is switched out of the target cell, otherwise, the first UE is kept in the target cell, the first inequality is determined according to the new switching parameter and the common switching parameter, and the difficulty that the signal intensity of the first UE meets the first inequality is larger than the difficulty that the signal intensity of the first UE meets the switching judgment event inequality A.

When the handover decision a event is the inequality A3 event inequality, the new handover parameter is the relative threshold value Off triggered by the A3 event_{mlb_mro}Or neighbor specific offset Ocn_{(i,mlb_mro)}The first inequality is a second inequality or a third inequality.

The second inequality is based on the relative threshold value Off_{mlb_mro}The inequality determined by the common switching parameter is used for judging the switching boundary condition when the first UE is switched out from the target cell to any one adjacent cell;

the third inequality is based on the neighbor specific offset Ocn_{(i,mlb_mro)}And an inequality determined by the common handover parameter, for making a handover boundary condition decision when the first UE is handed out from the target cell to a preset one of the neighbor cells.

When the new handover parameter is the relative threshold value Off triggered by the a3 event_{mlb_mro}When the second inequality is Mn + Ofn + Ocn-Hys > Ms + Ofs + Ocs + Off_{mlb_mro}。

When the new handover parameter is the neighbor specific offset Ocn_{(i,mlb_mro)}When the third inequality is Mn + Ofn + Ocn-Ocn_{(i,mlb_mro)}-Hys＞Ms+Ofs+Ocs+Off。

The method for presetting new switching parameters is that event A3 cell of report configEUTRA is configured by expanding EUTRA measurement report in MeasConfig on RRCConnectionReconfiguration message, relative threshold value A3-Offset-MLBANDMRO cell triggered by A3 event or cell specific Offset cellIndidualOffset-MLBANDMRO cell is introduced, and when relative threshold value A3-Offset-MLBANDMRO cell triggered by A3 event is introduced, the structure of the event A3 cell is as follows:

after introducing the cell specific offset cellIndividualOffset-MLBAndMRO cell, the cell structure of the CellsToAddMod cell is as follows:

s205, if the handover request is not an overloaded handover request, the target cell configures the common handover parameters to the first UE, and then receives the first UE.

S206, the target cell makes switching boundary condition judgment on the first UE through the switching judgment A event inequality, when the signal of the first UE meets the switching judgment A event inequality, the first UE is switched out of the target cell, otherwise, the first UE is kept in the target cell.

Comparing S203 and S205, it can be seen that the new handover parameter only takes effect when the first cell is overloaded, and the particularity of the effective time enables the new handover parameter to quickly and non-step reasonably influence the handover boundary condition under the specific scene that the first cell is overloaded and triggers combined optimization conflict of MLB and MRO, so that the load of the first cell can be quickly reduced, repeated ping-pong adjustment of the old handover parameter caused by each overload and overload release of the first cell is avoided, and unnecessary first UE ping-pong handover in the early stage of load balancing, secondary handover failure and radio link failure are effectively prevented; and the optimization change of the new parameter value does not influence the prior old switching parameter value only used for MRO optimization adjustment, after the overload is relieved, the new switching parameter value does not take effect any more, the switching boundary judgment condition before the overload can be quickly recovered, and the switching judgment is carried out only by using the old switching parameter, so that the combined optimization of MLB and MRO can effectively balance the load on the basis of not influencing the MRO function.

And S207, carrying out statistical analysis on the switching faults, and then optimizing new switching parameters according to the statistical analysis result of the switching faults.

The handover failure includes premature handover, late handover, handover to a wrong cell, ping-pong handover, Radio Link Failure (RLF), and the like; these faults are counted and the cause of their occurrence is analyzed.

As shown in fig. 9 and 10, an LTE system is provided for the present inventionJoint optimization method of MLB and MRO in system introduces A3 event trigger relative threshold value Off specific to solving MLB and MRO joint optimization conflict_{mlb_mro}And a specific offset Ocn_{(i,mlb_mro)}Joint optimization conflict resolution graph of time.

S207 is performed after S201, that is, no matter whether the first UE is received or not, as long as the handover request is received, statistical analysis on the handover failure is started; if receiving the first UE, when the first UE is switched, continuing to perform statistical analysis on the switching faults; in summary, all handover failures associated with the handover of the first UE are statistically analyzed to optimize the new handover parameters.

Referring to fig. 5, an embodiment of the present invention provides an apparatus for jointly optimizing MLB and MRO in an LTE system, including:

a handover request receiving module 301, configured to receive a handover request of a first UE handed out from a first cell.

The determining module 302 is configured to determine whether the self load exceeds a threshold for accepting the first UE, and if the self load does not exceed the threshold for accepting the first UE, determine whether the handover request is an overloaded handover request.

A parameter configuration module 303, configured to configure a preset new handover parameter and a common handover parameter to the first UE when the handover request is the overload handover request, and then receive the first UE, where the common handover parameter is a parameter in the handover decision event inequality a.

The MRO module 304 is configured to make a handover boundary condition decision on the first UE through a first inequality, and when the signal strength of the first UE satisfies the first inequality, the MRO module is configured to hand out the first UE from the target cell, otherwise, the MRO module is configured to keep the first UE in the target cell, where the first inequality is determined according to the new handover parameter and the common handover parameter, and the difficulty that the signal strength of the first UE satisfies the first inequality is greater than the difficulty that the signal strength of the first UE satisfies the handover decision event inequality a.

Referring to fig. 6, another embodiment of the present invention provides a joint optimization apparatus for MLB and MRO in an LTE system, including:

a handover request receiving module 401, configured to receive a handover request of a first UE handed out from a first cell.

The determining module 402 is specifically configured to determine whether the self load exceeds a threshold for accepting the first UE, identify, if the self load does not exceed the threshold for accepting the first UE, the filling information of the Cause IE field in the handover request, determine, if the filling information of the Cause IE field is Reduce load in serving cell, that the handover request is an overload handover request, and otherwise, determine, that the handover request is a non-overload handover request.

A parameter configuration module 403, configured to configure a preset new handover parameter and a common handover parameter to the first UE when the handover request is an overload handover request, and then receive the first UE, where the common handover parameter is a parameter in the handover decision event inequality a.

The parameter configuring module 403 is further configured to, when the handover request is not an overloaded handover request, configure the common handover parameter to the first UE by the target cell, and then receive the first UE.

The MRO module 404 is configured to make a handover boundary condition decision on the first UE through a first inequality, and when the signal strength of the first UE satisfies the first inequality, the MRO module is configured to hand out the first UE from the target cell, otherwise, the MRO module is configured to keep the first UE in the target cell, where the first inequality is determined according to the new handover parameter and the common handover parameter, and the difficulty that the signal strength of the first UE satisfies the first inequality is greater than the difficulty that the signal strength of the first UE satisfies the handover decision event inequality a.

The MRO module 404 is further configured to make a handover boundary condition decision for the first UE through a handover decision a event inequality, and if a signal of the first UE satisfies the handover decision a event inequality, the first UE is handed out from the target cell, otherwise, the first UE is retained in the target cell.

And a failure statistical analysis module 405, configured to perform statistical analysis on the switching failure, and then optimize a new switching parameter according to a statistical analysis result of the switching failure.

The above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (8)

1. A joint optimization method for MLB and MRO in an LTE system is characterized by comprising the following steps:

a target cell receives a switching request of a first UE switched from a first cell;

the target cell judges whether the self load exceeds a threshold value for accepting the first UE, and if the self load does not exceed the threshold value for accepting the first UE, the target cell judges whether the switching request is an overload switching request;

if the switching request is an overload switching request, the target cell configures preset new switching parameters and common switching parameters to the first UE and then receives the first UE, wherein the common switching parameters are parameters in a switching judgment A event inequality, and the new switching parameters are relative threshold values Off_{mlb_mro}Or neighbor specific offset Ocn_{(i,mlb_mro)}；

The target cell makes a handover boundary condition decision for the first UE through a first inequality, and when the signal strength of the first UE satisfies the first inequality, the first UE is handed out from the target cell, otherwise, the first UE is retained in the target cell, the first inequality is determined according to the new handover parameter and the common handover parameter, and the difficulty that the signal strength of the first UE satisfies the first inequality is greater than the difficulty that the signal strength of the first UE satisfies the handover decision a event inequality;

wherein, when the event of the switching decision A is an inequality A3 event inequality, the new switching parameter is a relative threshold value Off triggered by an A3 event_{mlb_mro}Or neighbor specific offset Ocn_{(i,mlb_mro)}；

The first inequality is a second inequality or a third inequality;

the second inequality is based on the phaseTo threshold value Off_{mlb_mro}And an inequality determined by the common handover parameter, configured to make a handover boundary condition decision when the first UE is handed out from the target cell to any one of neighboring cells, where the second inequality is: mn + Ofn + Ocn-Hys > Ms + Ofs + Ocs + Off_{mlb_mro}；

The third inequality is based on the neighbor specific offset Ocn_{(i,mlb_mro)}And an inequality determined by the common handover parameter, configured to make a handover boundary condition decision when the first UE is handed out from the target cell to a preset neighbor cell, where a third inequality is: mn + Ofn + Ocn-Ocn_{(i,mlb_mro)}-Hys＞Ms+Ofs+Ocs+Off；

Wherein Mn and Ms respectively represent measured values of a neighboring cell and a service cell; ofn and Ofs represent the offsets corresponding to the frequencies of the neighbour and service areas, respectively, i.e. the parameter freqOffset in the cell MeasObjectETURA; ocn and Ocs represent offsets associated with the cell (neighbor and serving), respectively, i.e. cellIndividualOffset parameter in MeasObjectEUTRA; off is a threshold value of an A3 event, which represents the difference between the measurements of the neighboring cell and the service cell (after adding a bias), namely, the parameter a3-Offset of eventA3 in report ConfigEUTRA; hys is the hysteresis of the A3 event.

2. The method for joint optimization of MLB and MRO in LTE system as claimed in claim 1, wherein after the target cell receives the handover request of the first UE handed out from the first cell, further comprising:

and carrying out statistical analysis on the switching faults, and then optimizing the new switching parameters according to the statistical analysis result of the switching faults.

3. The method for joint optimization of MLB and MRO in an LTE system according to claim 1, further comprising, after determining whether the handover request is an overloaded handover request:

if the switching request is not an overload switching request, the target cell configures common switching parameters to the first UE and then receives the first UE;

and the target cell makes switching boundary condition judgment on the first UE through the switching judgment A event inequality, and cuts out the first UE from the target cell when the signal of the first UE meets the switching judgment A event inequality, otherwise, the first UE is kept in the target cell.

4. The joint optimization method for MLB and MRO in an LTE system according to claim 1, wherein the determining, by the target cell, whether the handover request is an overloaded handover request specifically includes:

and the target cell identifies the filling information of the Cause IE field in the switching request, if the filling information of the Cause IE field is Reduce load in serving cell, the switching request is judged to be an overload switching request, otherwise, the switching request is judged to be a non-overload switching request.

5. A joint optimization device for MLB and MRO in an LTE system is characterized by comprising:

a handover request receiving module, configured to receive a handover request of a first UE switched from a first cell;

the judging module is used for judging whether the self load exceeds a threshold value for accepting the first UE, and if the self load does not exceed the threshold value for accepting the first UE, judging whether the switching request is an overload switching request;

a parameter configuration module, configured to configure a preset new handover parameter and a common handover parameter to the first UE when the handover request is an overload handover request, and then receive the first UE, where the common handover parameter is a parameter in a handover decision a event inequality, and the new handover parameter is a relative threshold value Off_{mlb_mro}Or neighbor specific offset Ocn_{(i,mlb_mro)}；

The MRO module is configured to make handover boundary condition decision on the first UE through a first inequality, and when the signal strength of the first UE satisfies the first inequality, hand out the first UE from a target cell, otherwise, keep the first UE in the target cell, where the first inequality is determined according to the new handover parameter and the common handover parameter, and the difficulty that the signal strength of the first UE satisfies the first inequality is greater than the difficulty that the signal strength of the first UE satisfies the handover decision a event inequality;

wherein, when the event of the switching decision A is an inequality A3 event inequality, the new switching parameter is a relative threshold value Off triggered by an A3 event_{mlb_mro}Or neighbor specific offset Ocn_{(i,mlb_mro)}；

The first inequality is a second inequality or a third inequality;

the second inequality is based on the relative threshold value Off_{mlb_mro}And an inequality determined by the common handover parameter, configured to make a handover boundary condition decision when the first UE is handed out from the target cell to any one of neighboring cells, where the second inequality is: mn + Ofn + Ocn-Hys > Ms + Ofs + Ocs + Off_{mlb_mro}；

The third inequality is based on the neighbor specific offset Ocn_{(i,mlb_mro)}And an inequality determined by the common handover parameter, configured to make a handover boundary condition decision when the first UE is handed out from the target cell to a preset neighbor cell, where a third inequality is: mn + Ofn + Ocn-Ocn_{(i,mlb_mro)}-Hys＞Ms+Ofs+Ocs+Off；

Wherein Mn and Ms respectively represent measured values of a neighboring cell and a service cell; ofn and Ofs represent the offsets corresponding to the frequencies of the neighbour and service areas, respectively, i.e. the parameter freqOffset in the cell MeasObjectETURA; ocn and Ocs represent offsets associated with the cell (neighbor and serving), respectively, i.e. cellIndividualOffset parameter in MeasObjectEUTRA; off is a threshold value of an A3 event, which represents the difference between the measurements of the neighboring cell and the service cell (after adding a bias), namely, the parameter a3-Offset of eventA3 in report ConfigEUTRA; hys is the hysteresis of the A3 event.

6. The joint optimization device for MLB and MRO in LTE system according to claim 5, further comprising:

and the fault statistical analysis module is used for performing statistical analysis on the switching faults and then optimizing the new switching parameters according to the statistical analysis result of the switching faults.

7. The joint optimization device for MLB and MRO in LTE system according to claim 5,

the parameter configuration module is further configured to configure, when the handover request is not an overloaded handover request, the target cell configures a common handover parameter to the first UE, and then receives the first UE;

the MRO module is further configured to make a handover boundary condition decision for the first UE through the handover decision a event inequality, and when a signal of the first UE satisfies the handover decision a event inequality, switch the first UE out of the target cell, otherwise, keep the first UE in the target cell.

8. The joint optimization device for MLB and MRO in LTE system according to claim 5,

and the judging module is specifically used for judging whether the self load exceeds a threshold value for accepting the first UE, identifying filling information of a Cause IE field in the switching request if the self load does not exceed the threshold value for accepting the first UE, judging the switching request to be an overload switching request if the filling information of the Cause IE field is Reduce load in serving cell, and otherwise, judging the switching request to be a non-overload switching request.

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