Cell handover controlling method and device

[0026] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In the following detailed description, many specific details are proposed in order to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by showing examples of the present invention. The present invention is by no means limited to any specific configurations and algorithms proposed below, but covers any modification, replacement and improvement of elements, components and algorithms without departing from the spirit of the present invention. In the drawings and the following description, well-known structures and technologies are not shown in order to avoid unnecessary obscurity of the present invention.

[0027] It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other if there is no conflict. Hereinafter, the present application will be described in detail with reference to the drawings and in conjunction with embodiments.

[0028] The embodiment of the present invention provides a cell handover control method and device for the handover technology in the prior art that is mainly based on signal strength, and the communication quality may not be high.

[0029] The main idea of ​​the embodiment of the present invention is to filter out target cells with poor wireless quality by analyzing the data of the measurement report record (MRR) of the user equipment (UE). Then the selected target cell is controlled by handover control based on the reference signal received quality (RSRQ), so as to ensure that the UE can smoothly and successfully handover to the target cell, improve the handover success rate, and also ensure that the handover to the target cell The signal strength and communication quality of the UE.

[0030] It should be understood that the technical solutions of the embodiments of the present invention can be applied to various communication systems, such as: Global System of Mobile communication (GSM) system, Code Division Multiple Access (Code Division Multiple Access, abbreviated as " CDMA") system, Wideband Code Division Multiple Access (WCDMA") system, General Packet Radio Service (General Packet Radio Service, "GPRS"), Long Term Evolution (Long Term Evolution, abbreviated as " LTE") system, LTE Frequency Division Duplex ("FDD") system, LTE Time Division Duplex ("TDD"), Universal Mobile Telecommunication System (Universal Mobile Telecommunication System, "FDD") UMTS”), Worldwide Interoperability for Microwave Access (WiMAX) communication system, etc.

[0031] It should also be understood that in the embodiments of the present invention, user equipment (User Equipment, referred to as "UE") may be called a terminal (Terminal), a mobile station (Mobile Station, referred to as "MS"), and a mobile terminal (Mobile Terminal). ) Etc., the UE can communicate with one or more core networks via a radio access network (Radio Access Network, referred to as "RAN"). For example, the UE can be a mobile phone (or called a "cellular" phone) with The computer of the mobile terminal, for example, the UE may also be a portable, pocket-sized, handheld, built-in computer or vehicle-mounted mobile device, which exchanges voice and/or data with the wireless access network.

[0032] In the embodiment of the present invention, the base station can be a base station in GSM or CDMA (Base TransceiverStation, referred to as "BTS"), a base station in WCDMA (NodeB, referred to as "NB"), or a base station in LTE Evolutional Node B (referred to as "ENB or e-NodeB" for short), which is not limited in the embodiment of the present invention. In general, the range covered by a base station's signal can be defined as a cell or a wireless cell.

[0033] Reference reception quality (RSRQ) is a measurement value for judging signal quality. The RSRQ value changes with network compliance and interference. The greater the network compliance, the greater the interference and the smaller the RSRQ value. RSRQ is calculated as follows:

[0034] RSRQ=RSRP*NPRB/RSSI (1)

[0035] Among them, RSRQ is the reference signal received quality; RSRP is the reference signal received power; NPRB is the total number of physical resource blocks (PRB) required in downlink transmission; RSSI is the carrier received signal strength indicator.

[0036] Among them, RSSI is calculated as follows:

[0037] RSSI=PPRB*NPRB*PathLoss/NSymbol (2)

[0038] Among them, RSSI is the carrier received signal strength indicator; PPRB is the average transmit power of PRBs in two time slots within the system receiving bandwidth; NPRB is the total number of PRBs required in downlink transmission; PathLoss is the path loss between eNodeB and UE ; NSymbol is the number of OFDM symbols on each PRB, determined by the CP configuration.

[0039] Through the definition of RSRQ and RSSI and the interpretation of the above two formulas, it can be seen that RSRQ can more accurately reflect the LTE signal quality, and it is more suitable to use the RSRQ-based handover control method in a poor wireless environment.

[0040] Such as figure 1 As shown, figure 1 A flowchart of a cell handover control method 100 according to an embodiment of the present invention is shown. The embodiment of the present invention provides a cell handover control method, which includes:

[0041] Step 110: Obtain the MRR of the UE;

[0042] Step 120: Screen out target cells according to MRR and screening conditions;

[0043] Step 130: Configure handover control parameters for the target cell to implement handover control based on RSRQ;

[0044] Step 140: Obtain drive test indicators of the target cell;

[0045] Step 150: When the drive test index gain increases, the target cell retains the handover control parameters;

[0046] Step 160: The RSRQ of the serving cell measured by the UE and the RSRQ of the target cell measured by the UE satisfy the handover control condition, and the UE is handed over from the serving cell to the target cell.

[0047] The MRR of the UE in the embodiment of the present invention includes data information such as the cell handover success rate, the number of handover attempts, the number of handover successes, the cell RSRQ, the cell RSRP, the average channel quality index (CQI), and interference. The MRR data in the embodiment of the present invention may be reported by one UE, or may be reported by multiple UEs. The cell in the embodiment of the present invention refers to an area covered by a base station or a base station subsystem. The cell in the location area is identified by the cell global identification code (CGI), which is a basic wireless coverage area in the network. In the embodiment of the present invention, the UE's MRR data itself has very detailed network information. The configuration information of the base station in the embodiment of the present invention includes the latitude and longitude of the base station, the direction angle of the cell antenna, and the cell frequency point number (EARFCN). The configuration information of the cell includes the cell location area code (TAC), 4G cell identity (ECI) and physical cell identity (PCI).

[0048] The implementation process of obtaining the MRR of the UE in the embodiment of the present invention specifically includes:

[0049] Collect the sampling time period and sampling range of the UE's MRR;

[0050] During the call, the UE will automatically report the MRR and reach the network management system (OMC) through the base transceiver station (ENOBEB).

[0051] In the cell handover control method 100 of the embodiment of the present invention, after completing the MRR acquisition work, the target cell is screened from the existing cells according to the obtained MRR and screening conditions, and the screened target cell is configured to implement handover control based on RSRQ Switch control parameters. The target cell that has completed the handover control parameter configuration will perform handover control on the UE based on the handover control conditions of the RSRQ. For the target cell that adopts RSRQ-based handover control, the CQI value will increase, which improves the channel quality and the downlink rate. After the UE switches from the serving cell to the target cell, the target cell can ensure the UE's signal quality and communication quality high.

[0052] Optionally, the screening conditions of the embodiment of the present invention may be that the handover success rate of the target cell is less than 90%, the RSRP of the target cell is greater than -90 dBm, and the ratio of the number of sampling points of the first type to the number of all sampling points is greater than 20%. The RSRQ of the target cell of the first type of sampling point is less than -14.5dB. The target cell selected by the screening condition is a cell with high RSRP and poor RSRQ. The MRR includes the number of sampling points of all RSRQ of the target cell and the number of sampling points where the RSRQ is less than -14.5dB. The switching success rate is the percentage of the number of successful switching to the number of switching attempts.

[0053] Specifically, for a target cell with a handover success rate lower than 90%, the ratio of the sampling points with RSRP greater than -90dBm, RSRQ less than -14.5dB, and RSRQ less than -14.5dB to all RSRQ sampling points greater than 20%, when the UE When a handover attempt occurs, the probability of a UE handover failure is high, which affects the call quality and usage experience of the UE. At the same time, when the UE successfully switches to the target cell, due to poor RSRQ, it will also affect the call quality and usage experience of the UE. After the target cell selected by the above screening conditions is configured with appropriate handover control parameters based on RSRQ to achieve handover control, the handover success rate of the UE can be improved, while ensuring the call quality of the UE after the handover is successful, and improving the user experience satisfaction.

[0054] Optionally, the screening conditions in the embodiment of the present invention may also be that the handover success rate of the target cell is less than 90%, the RSRP of the target cell is greater than -90 dBm, and the CQI is less than 7. The target cell selected by the screening condition is a cell with high RSRP and poor CQI.

[0055] Specifically, for a target cell with a handover success rate lower than 90%, and a target cell with an RSRP greater than -90dBm and a CQI less than 7, when the UE attempts to handover, the probability of the UE handover failure is higher, which affects the call quality and usage of the UE Feel that when the UE successfully switches to the target cell, the CQI is small and the channel quality is poor, which will affect the stability of the UE's use process. After the target cell selected by the above screening conditions is configured with appropriate handover control parameters based on RSRQ to achieve handover control, the handover success rate of the UE can be improved, and the channel quality can be maintained in a good state to ensure the success of the handover of the UE. The stability of the use process improves use satisfaction.

[0056] Optionally, the screening conditions in the embodiment of the present invention may also be that the handover success rate of the target cell is less than 90%, the RSRP of the target cell is greater than -90 dBm, and the average interference is greater than -100 dB. The target cell selected by the screening condition is a high RSRP interference high cell.

[0057] Specifically, for a target cell with a handover success rate lower than 90%, and a target cell with RSRP greater than -90dBm and average interference greater than -100dB, when the UE attempts to handover, the probability of the UE handover failure is higher, which affects the UE's call quality And use experience, and at the same time, when the UE is successfully handed over to the target cell, the interference will be large, which will affect the smoothness of the UE's use process. After the target cell selected by the above screening conditions is configured with appropriate handover control parameters based on RSRQ to achieve handover control, the handover success rate of the UE can be improved, while the influence of interference is also reduced, and the use process of the UE after the handover is successful The smoothness of the system improves user satisfaction.

[0058] In the embodiment of the present invention, after the target cell is filtered out using the screening condition, the handover control parameter is configured for the target cell. The handover control condition after the target cell is reconfigured is to implement handover control based on RSRQ. For the target cell that completes the handover control parameter configuration, the handover control conditions include that the RSRQ of the target cell measured by the UE is greater than the RSRQ of the serving cell measured by the UE, and the RSRQ of the target cell measured by the UE is greater than the RSRQ of the serving cell measured by the UE The duration of is greater than or equal to the trigger time.

[0059] The handover control parameters in the embodiment of the present invention include an intra-frequency handover offset value (A3offset value) and a trigger time, where the RSRQ of the target cell measured by the UE is greater than the RSRQ value of the serving cell where the UE measures the A3offset value.

[0060] In a preferred embodiment, the RSRQ of the target cell measured by the UE is greater than the RSRQ of the serving cell measured by the UE by at least 2dB, that is, the A3offset value is greater than or equal to 2dB, and the trigger time is 640ms. When the RSRQ of the target cell measured by the UE is greater than the RSRQ of the serving cell by at least 2 dB, and the duration is greater than or equal to 640 ms, the UE switches from the serving cell where it is currently located to the target cell.

[0061] In addition to the above-mentioned A3offset value and trigger time, the handover control parameters of the embodiment of the present invention also include different frequency measurement methods, different frequency measurement thresholds, same frequency switching methods, A3 trigger measurement methods (RSRQ), and handover hysteresis (hysteresisA3). , RSRQ filter coefficient (filterCoefficientEUtraRsrq) and inter-frequency switching mode.

[0062] In a preferred embodiment, the inter-frequency measurement mode of the switching control parameters is A2, the inter-frequency measurement threshold is -80dB, the same-frequency switching mode is A3, the trigger time is 640ms, the same-frequency switching offset value is 2dB, and A3 switching Hysteresis (hysteresisA3) is 1dB, RSRQ filter coefficient (filterCoefficientEUtraRsrq) is 4, and inter-frequency switching mode is A3.

[0063] After completing the configuration of the handover control parameters of the target cell, the handover control parameters of the target cell need to be evaluated. Namely: Obtain the drive test index of the target cell, and measure the gain of the drive test index. When the gain of the drive test index increases, the target cell passes the evaluation and retains the configured handover control parameters. The drive test indicators in the embodiment of the present invention include cell RSRQ, signal to dry ratio (SINR), quadrature amplitude modulation (64QAM) and CQI.

[0064] The cell handover control method 100 of the embodiment of the present invention obtains the MRR, and then analyzes the MRR data using the set screening conditions to accurately screen out target cells that are suitable to be configured to perform handover control based on RSRQ. Configure the appropriate handover control parameters based on RSRQ handover control for the target cell. After the handover control parameter configuration is completed, the CQI value of the target cell will increase, which improves the channel quality and the downlink rate, which can ensure that the signal strength of the UE handed over to the target cell is high and the communication quality is good.

[0065] Such as figure 2 As shown, an embodiment of the present invention also provides a cell handover control device 200, including:

[0066] The first obtaining module 210 is configured to obtain the MRR of the UE;

[0067] The screening module 220 screens out the target cell according to the MRR and screening conditions;

[0068] The configuration module 230 is configured to configure handover control parameters for the target cell to implement handover control based on RSRQ;

[0069] The second obtaining module 240 is configured to obtain the drive test index of the target cell;

[0070] The judging module 250 is used for judging the drive test index gain. When the drive test index gain increases, the target cell retains the handover control parameters;

[0071] The handover control module 260 is configured to perform handover control for the UE. The RSRQ of the serving cell where the UE measures and the RSRQ of the target cell measured by the UE meet the handover control conditions, and the UE switches from the serving cell to the target cell.

[0072] The cell handover control apparatus 200 of the embodiment of the present invention can filter out the target cell from the acquired MRR data, and configure the handover control condition based on RSRQ for the target cell. Evaluate the target cell after configuration. The evaluated target cell retains the current handover control parameters. When the RSRQ of the serving cell measured by the UE and the RSRQ of the target cell measured by the UE satisfy the handover control condition, the UE switches from the serving cell to the target cell. Using the target cell based on RSRQ handover control, the CQI value will increase, channel quality is improved, and the downlink rate is also improved, which can make the signal quality and communication quality of the UE after switching to the target cell good.

[0073] Optionally, the screening conditions in the embodiment of the present invention may be that the handover success rate of the target cell is less than 90%, the reference received power RSRP of the target cell is greater than -90dBm, and the ratio of the number of sampling points of the first type to the number of all sampling points is greater than 20 %. The RSRQ of the target cell of the first type of sampling point is less than -14.5dB. The target cell selected by the screening condition is a cell with high RSRP and poor RSRQ. The MRR includes the number of sampling points of all RSRQ of the target cell and the number of sampling points where the RSRQ is less than -14.5dB.

[0074] Specifically, for a target cell with a handover success rate lower than 90%, the ratio of the sampling points with RSRP greater than -90dBm, RSRQ less than -14.5dB, and RSRQ less than -14.5dB to all RSRQ sampling points greater than 20%, when the UE When a handover attempt occurs, the probability of a UE handover failure is high, which affects the call quality and usage experience of the UE. At the same time, when the UE successfully switches to the target cell, due to poor RSRQ, it will also affect the call quality and usage experience of the UE. After the target cell selected by the above screening conditions is configured with appropriate handover control parameters based on RSRQ to achieve handover control, the handover success rate of the UE can be improved, while ensuring the call quality of the UE after the handover is successful, and improving the user experience satisfaction.

[0075] Optionally, the screening conditions in the embodiment of the present invention may also be that the handover success rate of the target cell is less than 90%, the reference received power RSRP of the target cell is greater than -90 dBm, and the average channel quality index CQI is less than 7.

[0076] Specifically, for a target cell with a handover success rate lower than 90%, and a target cell with an RSRP greater than -90dBm and a CQI less than 7, when the UE attempts to handover, the probability of the UE handover failure is higher, which affects the call quality and usage of the UE Feel that when the UE successfully switches to the target cell, the CQI is small and the channel quality is poor, which will affect the stability of the UE's use process. After the target cell selected by the above screening conditions is configured with appropriate handover control parameters based on RSRQ to achieve handover control, the handover success rate of the UE can be improved, and the channel quality can be in a better condition to ensure the success of the UE after the handover. The stability of the use process improves use satisfaction.

[0077] Optionally, the screening conditions in the embodiment of the present invention may also be that the handover success rate of the target cell is less than 90%, the reference received power RSRP of the target cell is greater than -90dBm, and the average interference is greater than -100dB.

[0078] Specifically, for a target cell with a handover success rate lower than 90%, and a target cell with RSRP greater than -90dBm and average interference greater than -100dB, when the UE attempts to handover, the probability of the UE handover failure is higher, which affects the UE's call quality And use experience, and at the same time, when the UE is successfully handed over to the target cell, the interference will be large, which will affect the smoothness of the UE's use process. After the target cell selected by the above screening conditions is configured with appropriate handover control parameters based on RSRQ to achieve handover control, the handover success rate of the UE can be improved, while the influence of interference is also reduced, and the use process of the UE after the handover is successful The smoothness of the system improves user satisfaction.

[0079] In the embodiment of the present invention, after the target cell is filtered out using the screening condition, the handover control parameter is configured for the target cell. The handover control condition after the target cell is reconfigured is to implement handover control based on RSRQ. For the target cell that completes the handover control parameter configuration, the handover control conditions include that the RSRQ of the target cell measured by the UE is greater than the RSRQ of the serving cell measured by the UE, and the RSRQ of the target cell measured by the UE is greater than the RSRQ of the serving cell measured by the UE The duration of is greater than or equal to the trigger time.

[0080] The handover control parameters in the embodiment of the present invention include the A3offset value and the trigger time, where the RSRQ of the target cell measured by the UE is greater than the RSRQ of the serving cell measured by the UE. The value is the A3offset value. In a preferred embodiment, the RSRQ of the target cell measured by the UE is greater than the RSRQ of the serving cell measured by the UE by at least 2dB, that is, the A3offset value is greater than or equal to 2dB, and the trigger time is 640ms. When the RSRQ of the target cell measured by the UE is greater than the RSRQ of the serving cell by at least 2 dB, and the duration is greater than or equal to 640 ms, the UE switches from the serving cell where it is currently located to the target cell.

[0081] In addition to the above-mentioned A3offset value and trigger time, the handover control parameters of the embodiment of the present invention also include different frequency measurement methods, different frequency measurement thresholds, same frequency switching methods, A3 trigger measurement methods (RSRQ), and handover hysteresis (hysteresisA3). , RSRQ filter coefficient (filterCoefficientEUtraRsrq) and inter-frequency switching mode. In a preferred embodiment, the inter-frequency measurement mode of the switching control parameters is A2, the inter-frequency measurement threshold is -80dB, the same-frequency switching mode is A3, the trigger time is 640ms, the same-frequency switching offset value is 2dB, and A3 switching Hysteresis (hysteresisA3) is 1dB, RSRQ filter coefficient (filterCoefficientEUtraRsrq) is 4, and inter-frequency switching mode is A3.

[0082] After configuring the handover control parameters of the target cell, the handover control parameters of the target cell need to be evaluated. Obtain the drive test index of the target cell, and measure and judge the gain of the drive test index. When the gain of the drive test index is judged to increase, the target cell passes the evaluation and retains the configured handover control parameters. The drive test indicators in the embodiment of the present invention include cell RSRQ, signal-to-dry ratio (SINR), quadrature amplitude modulation (64QAM), and CQI.

[0083] Such as image 3 As shown, the figure schematically shows the comparison of the RSRQ segment before the target cell is configured with the handover control parameters and after the target cell is configured with the handover control parameters. The abscissa in the figure represents the sampling value of RSRQ, image 3 The ordinate on the left in the middle represents the segment comparison of the SINR before modification. The ordinate on the right represents the segment comparison of the modified SINR. Detect the RSRQ of the target cell before and after the target cell is configured with the handover control parameters, and the RSRQ of the target cell that has completed the handover control parameter configuration has been significantly improved, and the RSRQ value is mostly between -9.5dB and -3.5dB .

[0084] Such as Figure 4 As shown, the figure schematically shows the comparison of the CQI segment before the target cell is configured with the handover control parameters and after the target cell is configured with the handover control parameters. Detecting the RSRQ before the target cell is configured with the handover control parameters and after the target cell is configured with the handover control parameters, the CQI of the target cell after the handover control parameter configuration is completed has changed significantly, and the channel quality is significantly improved.

[0085] Such as Figure 5 As shown, the figure schematically shows the comparison of the downlink rate before the target cell is configured with the handover control parameters and after the target cell is configured with the handover control parameters. The downlink rate of the target cell before the handover control parameter is configured and the target cell after the handover control parameter is configured is detected, and the downlink rate of the target cell that has completed the handover control parameter configuration is significantly improved. In the figure, before the modification, the downstream rate was 13 Mbps, and after the modification, the downstream rate was 26 Mbps.

[0086] The cell handover control method 100 and the cell handover control device 200 of the embodiment of the present invention obtain the MRR of the UE, and then analyze the MRR data using the set filtering conditions to accurately screen out the ones that are suitable to be configured for handover control based on RSRQ Target cell. Configure the appropriate handover control parameters based on RSRQ handover control for the target cell. After the configuration is completed, the RSRQ of the target cell has been significantly improved, the CQI value is increased, the channel quality is correspondingly improved, and the downlink rate is correspondingly improved, which can ensure that the signal strength of the UE handed over to the target cell is high and the communication quality is good.

[0087] Although the present invention has been described with reference to the preferred embodiments, without departing from the scope of the present invention, various modifications can be made thereto and the components therein can be replaced with equivalents. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any manner. The present invention is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.