CN112702770B

CN112702770B - Switching control method and related equipment

Info

Publication number: CN112702770B
Application number: CN201911013923.XA
Authority: CN
Inventors: 葛晨晖; 李文; 古江春
Original assignee: Shanghai Huawei Technologies Co Ltd
Current assignee: Shanghai Huawei Technologies Co Ltd
Priority date: 2019-10-23
Filing date: 2019-10-23
Publication date: 2022-05-13
Anticipated expiration: 2039-10-23
Also published as: WO2021077866A1; CN112702770A

Abstract

The embodiment of the application discloses a switching control method, which can be applied to Long Term Evolution (LTE), enhanced machine type communication (eMTC), 5G NR and the like, wherein a base station acquires a first network signal quality parameter corresponding to a first terminal, acquires an A2 measurement threshold according to the first network signal quality parameter and configures an A2 measurement threshold for a second terminal, and if the base station receives an A2 measurement report reported by the second terminal, the base station configures a measurement GAP and switching measurement for the second terminal, can automatically determine an A2 measurement threshold to trigger the measurement GAP and the switching measurement, and is suitable for specific conditions under different environments.

Description

Switching control method and related equipment

Technical Field

The embodiment of the application relates to the technical field of communication, in particular to a switching control method and related equipment.

Background

In order to meet the requirement of the internet of everything, the third generation partnership project (3 GPP) proposes a new internet of things technology called enhanced machine-type communication (eMTC) in the Long Term Evolution (LTE) standard protocol evolution. In order to ensure that no service interruption or even call drop occurs during the process of moving the terminal from the serving cell to another serving cell, the eMTC terminal needs to support a handover function between different cells. According to the 3GPP TS 36.300V13.4.0 specification, eMTC terminals typically need to start GAP when measuring on the same frequency A3, mainly because: in order to reduce the cost, the eMTC terminal of release13 version only supports a single Narrowband (NB), that is, the receiver only supports 6 continuous RBs at most, so that the receiver cannot tune to the center 6RB to measure the neighboring cell, if the co-frequency A3 measurement needs to be performed, a GAP measurement mechanism needs to be relied on to enable the receiver to measure the signal quality of the neighboring cell during a GAP, generally, the eMTC terminal only has one receiver, if the eMTC terminal needs to switch cells, both the A3 measurement needs to be performed and the GAP also needs to be measured, and since the GAP measurement affects the throughput of the eMTC terminal, unnecessary GAP measurement needs to be reduced as much as possible.

After an eMTC terminal enters a network, firstly, a network maintainer sets a fixed threshold value according to an empirical value and configures a2 measurement, the eMTC terminal performs a2 measurement, if the eMTC terminal reports a2 measurement to a base station, it indicates that the signal quality of a current serving cell measured by the eMTC terminal is lower than the fixed threshold value, the base station can determine that the eMTC terminal has moved to the edge of the serving cell, at this time, the eMTC terminal needs to perform measurement GAP and A3 measurement, and if the eMTC terminal does not report a2 measurement, the eMTC terminal does not need to perform measurement GAP and A3 measurement.

However, in the prior art, the a2 measurement threshold of each terminal is a fixed value set by a network maintainer according to the environment of each cell, the fixed value is generally an experience value of the network maintainer, if the fixed value is set too high, the eMTC terminal may frequently perform measurement GAP and A3 measurement, which affects throughput, and if the fixed value is set too low, the timeliness of cell switching is affected, so the manner of setting the a2 measurement threshold in the prior art cannot flexibly adapt to various network environments.

Disclosure of Invention

The embodiment of the application provides a switching control method and related equipment, which are used for a base station to automatically determine a threshold and trigger measurement GAP and switching measurement through the threshold.

A first aspect of the embodiments of the present application provides a handover control method, including:

when the first terminal accesses the network, if the first terminal moves to the edge of the service cell and needs to switch the cell, the base station can receive the switching measurement report sent by the first terminal and obtain the first network signal quality parameter in the switching measurement report, the first network signal quality parameter is related to the signal quality of the serving cell where the first terminal is located, the base station may perform handover operations for the first terminal, the base station may obtain an a2 measurement threshold, the A2 measurement threshold is obtained by processing the first network signal quality parameter, when the second terminal accesses the network, the base station configures the A2 measurement threshold for the second terminal, the second terminal is a terminal needing to measure GAP for switching cells and the second terminal and the first terminal belong to the service cell, if the base station receives the A2 measurement report reported by the second terminal, the base station configures measurement GAP and switching measurement for the second terminal, the a2 measurement report is used to indicate that the second network signal quality parameter corresponding to the second terminal reaches the a2 measurement threshold.

According to the embodiment of the application, the base station acquires the first network signal quality parameter corresponding to the first terminal, the A2 measurement threshold is obtained by processing the first network signal quality parameter, the base station configures the A2 measurement threshold for the second terminal, and as the A2 measurement threshold is obtained by processing the first network signal quality parameter sent by the first terminal, the A2 measurement threshold can be automatically determined to trigger measurement GAP and switching measurement according to the characteristics of different cells, so that the method and the device are suitable for specific situations under different environments.

Based on the first aspect of the embodiment of the present application, in the first implementation manner of the first aspect of the embodiment of the present application, there are various manners for the base station to obtain the a2 measurement threshold, for example: the base station processes the following steps: after obtaining a first network signal quality parameter corresponding to a first base station, the base station records the first network signal quality parameter to obtain a sample set, the base station processes the sample set to obtain a target parameter, and the base station adds a first redundancy quantity on the basis of the target parameter to obtain an a2 measurement threshold, where the first redundancy quantity may be related to a moving speed or a channel fading of a second terminal.

In the embodiment of the application, the base station can obtain the A2 measurement threshold by processing the first network signal quality parameter by the base station, reduce the steps that the third device receives the first network signal quality parameter, process the first network signal quality parameter to obtain the A2 measurement threshold, and send the measurement threshold to the base station A2, so that the integrated processing capability of the base station is improved.

Based on the first implementation manner of the first aspect of the embodiment of the present application, in the second implementation manner of the first aspect of the embodiment of the present application, the base station may further obtain an a1 measurement threshold, where the a1 measurement threshold is used to determine the quality of the signal of the second terminal in the serving cell, for example: after processing the sample set, the base station may add a second redundancy amount to the target parameter to obtain an a1 measurement threshold, where the second redundancy amount may be related to a moving speed or a channel fading of the second terminal, and the second redundancy amount is greater than the first redundancy amount, and after the base station obtains the a1 measurement threshold, the base station may configure an a1 measurement threshold for the second terminal, if the second terminal reports an a1 measurement report, it indicates that the signal quality of the second terminal in the serving cell is higher than an a1 measurement threshold, and if the second terminal does not report an a1 measurement report, it indicates that the signal quality of the second terminal in the serving cell is not higher than the a1 measurement threshold.

In the embodiment of the application, the base station may obtain the a1 measurement threshold through the target parameter, and determine the quality of the signal quality of the second terminal in the serving cell through the a1 measurement threshold.

Based on the second implementation manner of the first aspect of the present application, in the third implementation manner of the first aspect of the present application, if the base station configures a measurement GAP and performs handover measurement for the second terminal, the base station does not receive a handover measurement report reported by the second terminal and receives an a1 measurement report reported by the second terminal, which indicates that the signal quality of the second terminal in the serving cell is higher than an a1 measurement threshold, in other words, the second terminal moves to the center of the serving cell, and the base station may configure a measurement GAP and perform handover measurement for the second terminal.

In the embodiment of the application, the base station may configure measurement GAP and handover measurement for the second terminal by receiving the a1 measurement threshold sent by the second terminal, which reduces unnecessary configuration and measurement and improves the throughput of the second terminal.

Based on the first implementation manner of the first aspect of the embodiment of the present application, in the fourth implementation manner of the first aspect of the embodiment of the present application, the base station may process the sample set to obtain the target parameter in a variety of manners, for example: the base station may input the first network signal quality parameter in the sample set into the cumulative distribution function to obtain a cumulative distribution function of the first network signal quality parameter, and then select a value corresponding to the first network signal quality parameter in the cumulative distribution function as a target parameter according to a target probability, where the target probability is set as needed, and if the target probability is 0.8, it indicates that the values of the first network signal quality parameter corresponding to the serving cell are all less than or equal to the target parameter when 80% of the first terminals in the sample set switch services.

In the embodiment of the application, the base station can control the switching condition of the terminal through the accumulative distribution function, and network maintenance personnel can obtain the target parameter according to the required probability.

Based on the first implementation manner of the first aspect of the embodiment of the present application, in the fifth implementation manner of the first aspect of the embodiment of the present application, there may be multiple manners for the base station to process the sample set to obtain the target parameter, for example: the base station may calculate an average value of all first network signal quality parameters in the sample set to obtain a target parameter.

In the embodiment of the application, the base station uses the average value of all the first network signal quality parameters in the sample set as the target parameter, so that the realizability of the scheme is improved.

Based on the first aspect of the embodiment of the present application, in a sixth implementation manner of the first aspect of the embodiment of the present application, there are multiple manners for the base station to obtain the a2 measurement threshold, for example: the following are obtained through the processing of the network management server: the base station sends a first network signal quality parameter to the network management server, and receives an A2 measurement threshold sent by the network management server, wherein the A2 measurement threshold is obtained by processing the first network signal quality parameter by the network management server.

In the embodiment of the application, the base station can send the first network signal quality parameter to the network management server, the network management server processes the first network signal quality parameter to obtain the a2 measurement threshold, and then the a2 measurement threshold is sent to the base station, so that the calculation load of the base station is reduced.

Based on the first aspect of the present application, in a seventh implementation manner of the first aspect of the present application, the first terminal may specifically be a long term evolution LTE terminal or a new air interface NR terminal, and the second terminal is an enhanced machine type communication eMTC terminal.

In the embodiment of the application, specific implementation forms of the first terminal and the second terminal are limited, and the realizability of the scheme is improved.

Based on the first implementation manner of the first aspect of the embodiment of the present application, in an eighth implementation manner of the first aspect of the embodiment of the present application, the first network signal quality parameter may specifically be a reference signal received power RSRP when the first terminal is handed over from a serving cell to a target cell, the second network signal quality parameter may specifically be an RSRP, and the target parameter may specifically be a target RSRP.

In the embodiment of the application, specific implementation forms of the first network signal quality parameter, the second network signal quality parameter and the target parameter are defined, and the realizability of the scheme is improved.

Based on the first implementation manner of the first aspect of the embodiment of the present application, in a ninth implementation manner of the first aspect of the embodiment of the present application, the first network signal quality parameter may specifically be a reference signal received power RSRQ when the first terminal is handed over from a serving cell to a target cell, the second network signal quality parameter may specifically be an RSRQ, and the target parameter may specifically be a target RSRQ.

Based on the first implementation manner of the first aspect of the embodiment of the present application, in a tenth implementation manner of the first aspect of the embodiment of the present application, the first network signal quality parameter may specifically be a reference signal received power SINR when the first terminal is handed over from the serving cell to the target cell, the second network signal quality parameter may specifically be an SINR, and the target parameter may specifically be a target SINR.

Based on the first aspect of the embodiment of the present application, in an eleventh implementation manner of the first aspect of the embodiment of the present application, the switching measurement may specifically be an A3 measurement, an a4 measurement, or an a5 measurement.

In the embodiment of the application, the specific implementation form of switching measurement is limited, and the realizability of the scheme is improved.

A second aspect of the present application provides a handover control method, including:

the network management server receives a first network signal quality parameter sent by a base station, the first network signal quality parameter is related to the signal quality of a service cell where a first terminal is located, the network management server analyzes the first network signal quality parameter to obtain a target parameter, the network management server processes the target parameter to obtain an A2 measurement threshold, and sends the A2 measurement threshold to the base station, so that the base station configures the A2 measurement threshold for a second terminal, the second terminal needs to measure a GAP for a handover cell, and the second terminal and the first terminal belong to the service cell.

In the embodiment of the application, a network management server receives a first network signal quality parameter corresponding to a first terminal, the first network signal quality parameter is analyzed and processed to obtain an a2 measurement threshold, and the a2 measurement threshold is sent to a base station, so that the base station configures the a2 measurement threshold for a second terminal, and the a2 measurement threshold can be automatically determined to trigger measurement GAP and switching measurement according to the characteristics of different cells, thereby adapting to specific situations in different environments.

Based on the second aspect of the embodiment of the present application, in the first implementation manner of the second aspect of the embodiment of the present application, the network management server may analyze the first network signal quality parameter in various ways, for example: the network management server may input the first network signal quality parameter in the sample set into the cumulative distribution function to obtain a cumulative distribution function of the first network signal quality parameter, and then select a value corresponding to the first network signal quality parameter in the cumulative distribution function as a target parameter according to a target probability, where the target probability is set as needed, and if the target probability is 0.8, it indicates that the values of the first network signal quality parameter corresponding to the serving cell of 80% of the first terminals in the sample set are less than or equal to the target parameter when switching services.

In the embodiment of the application, the network management server can control the switching condition of the terminal through the accumulative distribution function, and network maintenance personnel can obtain the target parameter according to the required probability.

Based on the second aspect of the embodiment of the present application, in the second implementation manner of the second aspect of the embodiment of the present application, the manner in which the network management server processes the sample set to obtain the target parameter may be various, for example: the network management server can calculate the average value of all the first network signal quality parameters in the sample set to obtain the target parameters.

In the embodiment of the application, the network management server uses the average value of all the first network signal quality parameters in the sample set as the target parameter, so that the realizability of the scheme is improved.

Based on the second aspect of the embodiment of the present application, in a third implementation manner of the second aspect of the embodiment of the present application, the network management server processes the target parameter, and specifically, a first redundancy may be added on the basis of the target parameter to obtain an a2 measurement threshold, where the first redundancy may be related to a moving speed or a channel fading of the second terminal.

In the embodiment of the application, the specific implementation form of the processing target parameter is limited, and the realizability of the scheme is improved.

Based on the third implementation manner of the second aspect of the embodiment of the present application, in the fourth implementation manner of the second aspect of the embodiment of the present application, the network management server may further obtain an a1 measurement threshold, where the a1 measurement threshold is used to determine the quality of the signal of the second terminal in the serving cell, for example: the network management server may add a second redundancy to obtain an a1 measurement threshold based on the target parameter, where the second redundancy may be related to the moving speed or channel fading of the second terminal, and the second redundancy is greater than the first redundancy, and after the network management server obtains the a1 measurement threshold, the network management server may send the a1 measurement threshold to the base station.

In this embodiment, the network management server may obtain the a1 measurement threshold through the target parameter, and send the a1 measurement threshold to the base station, so that the base station determines the quality of the signal of the second terminal in the serving cell through the a1 measurement threshold.

Based on the second aspect of the embodiment of the present application, in a fifth implementation manner of the second aspect of the embodiment of the present application, the first network signal quality parameter may specifically be a reference signal received power RSRP when the first terminal is handed over from the serving cell to the target cell, and the target parameter may specifically be a target RSRP.

In the embodiment of the application, the specific implementation forms of the first network signal quality parameter and the target parameter are defined, and the realizability of the scheme is improved.

Based on the second aspect of the embodiment of the present application, in a sixth implementation manner of the second aspect of the embodiment of the present application, the first network signal quality parameter may specifically be a reference signal received power RSRQ when the first terminal is handed over from the serving cell to the target cell, and the target parameter may specifically be a target RSRQ.

Based on the second aspect of the embodiment of the present application, in a seventh implementation manner of the second aspect of the embodiment of the present application, the first network signal quality parameter may specifically be a reference signal received power SINR when the first terminal is handed over from the serving cell to the target cell, and the target parameter may specifically be a target SINR.

Based on the second aspect of the present application, in an eighth implementation manner of the second aspect of the present application, the first terminal may specifically be a long term evolution LTE terminal or a new air interface NR terminal, and the second terminal is an enhanced machine type communication eMTC terminal.

A third aspect of the embodiments of the present application provides a handover control method, including:

after the target terminal accesses the network, the base station may configure a measurement threshold for the target terminal, where the target terminal is a terminal that needs to measure a GAP in a handover cell, and if the base station receives a preset event, the base station configures a measurement GAP and a handover measurement for the target terminal, where the preset event is used to indicate that the quality of a downlink channel corresponding to the target terminal reaches the measurement threshold.

In the embodiment of the application, the base station configures the measurement threshold for the target terminal, and if the base station receives the preset event, the base station configures the measurement GAP and the switching measurement for the target terminal, and because the preset event is used for indicating that the downlink channel quality corresponding to the target terminal reaches the measurement threshold, the measurement threshold can be automatically determined by monitoring the downlink channel quality of the target terminal to trigger the measurement GAP and the switching measurement, so that the method and the device adapt to specific conditions under different environments.

Based on the third aspect of the present application, in the first implementation manner of the third aspect of the present application, there are various manners for triggering the base station to configure the measurement GAP and the handover measurement for the target terminal, for example: the base station may obtain a channel quality indicator CQI reported by the target terminal, where the measurement threshold may be a low threshold of a value of the CQI, a value lower than the low threshold indicates that a downlink channel quality of the target terminal is low, and when the value of the CQI is lower than the low threshold, the base station may be triggered to configure a measurement GAP and a handover measurement for the target terminal.

According to the embodiment of the application, the base station can judge whether to trigger the base station to configure the measurement GAP and switch the measurement for the target terminal or not according to the CQI value reported by the target terminal, so that the sending and receiving times of the base station and the target terminal are saved.

Based on the first implementation manner of the third aspect of the present application, in the second implementation manner of the third aspect of the present application, the value of the CQI may specifically be an instantaneous value of the CQI reported by the target terminal.

In the embodiment of the application, the specific implementation form of the CQI value is limited, and the realizability of the scheme is improved.

Based on the first implementation manner of the third aspect of the present application, in the third implementation manner of the third aspect of the present application, the value of the CQI may specifically be a filtered CQI value.

Based on the first implementation manner of the third aspect of the present application, in a fourth implementation manner of the third aspect of the present application, the value of the CQI may specifically be an average value of CQIs within a period of time.

Based on the third aspect of the present application, in a fifth implementation manner of the third aspect of the present application, there are multiple manners for triggering the base station to configure a measurement GAP and handover measurement for the target terminal, for example: the base station may determine a modulation and coding strategy MCS selected when the target terminal schedules the downlink transport block, where the measurement threshold is a low threshold of the MCS, a value lower than the low threshold indicates that the downlink channel quality of the target terminal is low, and when the value of the MCS is lower than the low threshold, the base station may be triggered to configure a measurement GAP and perform handover measurement for the target terminal.

According to the embodiment of the application, the base station can judge whether to trigger the base station to configure measurement GAP and switch measurement for the target terminal or not by determining the modulation and coding strategy MCS selected when the target terminal of the target terminal schedules the downlink transmission block, so that the sending and receiving times of the base station and the target terminal are saved.

Based on the third aspect of the present embodiment, in a sixth implementation manner of the third aspect of the present embodiment, there are multiple manners for triggering the base station to configure a measurement GAP and handover measurement for the target terminal, for example: the base station can monitor the target terminal downlink residual block error rate RBLER, the measurement threshold is a high threshold of the RBLER, the high threshold is higher than the high threshold, which indicates that the downlink channel quality of the target terminal is low, and when the RBLER is higher than the high threshold, the base station can be triggered to configure measurement GAP and switch measurement for the target terminal.

According to the embodiment of the application, the base station can judge whether to trigger the base station to configure measurement GAP and switch measurement for the target terminal or not by monitoring the target terminal downlink residual block error rate RBLER, so that the sending and receiving times of the base station and the target terminal are saved.

Based on the third aspect of the present embodiment, in a seventh implementation manner of the third aspect of the present embodiment, there are multiple manners for triggering the base station to configure a measurement GAP and handover measurement for the target terminal, for example: the base station can monitor the missing detection of the machine type communication physical downlink control channel (MPDCCH) of the target terminal to obtain the Discontinuous Transmission (DTX) proportion, the measurement threshold is the high threshold of the DTX proportion, the quality of the downlink channel of the target terminal is low when the DTX proportion is higher than the high threshold, and the base station can be triggered to configure measurement GAP and switch measurement for the target terminal when the DTX proportion is higher than the high threshold.

According to the embodiment of the application, the base station can judge whether to trigger the base station to configure the measurement GAP and switch the measurement for the target terminal or not by monitoring the missing detection of the MPDCCH (physical downlink control channel) of the machine type communication of the target terminal, so that the sending and receiving times of the base station and the target terminal are saved.

Based on the third aspect of the present embodiment, in an eighth implementation manner of the third aspect of the present embodiment, the target terminal may specifically be an enhanced machine type communication eMTC terminal.

In the embodiment of the application, the specific implementation form of the target terminal is limited, and the realizability of the scheme is improved.

Based on the third aspect of the embodiment of the present application, in a ninth implementation manner of the third aspect of the embodiment of the present application, the switching measurement may specifically be an A3 measurement, an a4 measurement, or an a5 measurement.

A fourth aspect of the embodiments of the present application provides a base station, where the base station performs the method of the foregoing first aspect or third aspect.

A fifth aspect of embodiments of the present application provides a base station, where the base station performs the method of the foregoing first aspect or third aspect.

A sixth aspect of the embodiments of the present application provides a network management server, where the network management server executes the method of the foregoing second aspect.

A seventh aspect of the embodiments of the present application provides a network management server, where the network management server executes the method of the foregoing second aspect.

An eighth aspect of embodiments of the present application provides a computer storage medium having instructions stored therein, where the instructions, when executed on a computer, cause the computer to perform the method of the foregoing first aspect, second aspect, or third aspect.

A ninth aspect of embodiments of the present application provides a computer software product, which when executed on a computer causes the computer to perform the method of the first, second or third aspect.

Drawings

FIG. 1 is a diagram of a network architecture in an embodiment of the present application;

fig. 2 is a schematic flow chart illustrating a handover control method according to an embodiment of the present application;

FIG. 3 is another schematic flow chart illustrating a handover control method according to an embodiment of the present application;

FIG. 4 is a diagram illustrating a cumulative distribution function according to an embodiment of the present application;

FIG. 5 is a schematic flow chart illustrating a handover control method according to an embodiment of the present application;

fig. 6 is another schematic flow chart illustrating a handover control method according to an embodiment of the present application;

fig. 7 is another schematic flow chart illustrating a handover control method according to an embodiment of the present application;

fig. 8 is another schematic flow chart illustrating a handover control method according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of a base station in the embodiment of the present application;

fig. 10 is a schematic structural diagram of a base station in the embodiment of the present application;

fig. 11 is a schematic structural diagram of a base station in the embodiment of the present application;

fig. 12 is a schematic structural diagram of a base station in the embodiment of the present application;

fig. 13 is a schematic structural diagram of a base station in the embodiment of the present application;

fig. 14 is a schematic structural diagram of a base station in the embodiment of the present application;

fig. 15 is a schematic structural diagram of a base station in the embodiment of the present application;

fig. 16 is a schematic structural diagram of a base station in the embodiment of the present application;

fig. 17 is a schematic structural diagram of a base station in the embodiment of the present application;

fig. 18 is a schematic structural diagram of a network management server in the embodiment of the present application;

fig. 19 is another schematic structural diagram of the network management server in the embodiment of the present application.

Detailed Description

Referring to fig. 1, a network architecture in an embodiment of the present application includes:

a network management server 101, a serving CELL base station 102, a neighbor CELL base station 103, a Long Term Evolution (LTE) terminal 104, an enhanced machine-type communication (eMTC) terminal 105, a serving CELL1, and a neighbor CELL 2.

In this embodiment, 102 and 103 may be serving CELL base stations or neighboring CELL base stations, and similarly, CELL1 and CELL2 may be serving CELLs or neighboring CELLs, where only 102 is a serving CELL base station, 103 is a neighboring CELL base station, CELL1 is a serving CELL, and CELL2 is a neighboring CELL, which are taken as examples for schematic description, and are not limited herein.

The network management server 101 is configured to manage a serving cell base station 102 and a neighbor cell base station 103.

In this embodiment, the serving cell base station 102 and the neighboring cell base station 103 may be managed by the same network management server 101, or managed by different network management servers, which is not limited herein.

The serving CELL1 managed by the serving CELL base station 102, the serving CELL2 managed by the neighboring CELL base station 103, the serving CELL1, and the neighboring CELL2 may be intra-frequency CELLs or inter-frequency CELLs, and are not limited herein.

The LTE terminal 104 and the eMTC terminal 105 may switch from the serving CELL1 to the neighbor CELL2 under the control of the serving CELL base station 102.

In the embodiment of the present application, 104 may be an LTE terminal. The terminal may also be an eMTC terminal, and 105 may also be an eMTC terminal, and may also be a massive machine type of communication (mtc) terminal, which is not limited herein.

The embodiments of the present application can be applied to the handover of the same-frequency cell and the handover of the different-frequency cell, and the following processes are only schematically described with the same-frequency cell, and are not limited herein.

The general flow of cell handover is as follows:

when an eMTC terminal accesses the network, a base station configures A2 measurement for the terminal, after the terminal reports an A2 measurement report, the base station determines that the terminal moves to the edge of a cell, and configures measurement GAP, switching measurement and A1 measurement for the terminal so as to measure a proper adjacent cell, and if the terminal reports the switching measurement, a switching command is issued to switch the terminal to the adjacent cell; if the terminal does not report the handover measurement, but reports the a1 measurement, the base station determines that the terminal moves to the cell center, and the base station configures a measurement GAP and a handover measurement for the terminal to eliminate the negative impact introduced by the measurement GAP.

In the embodiment of the present application, the handover measurement may be an A3 measurement or an a4 measurement, and it is understood that in practical application, the handover measurement may also be an a5 measurement, which is not limited herein.

With reference to fig. 1, the embodiments of the present application provide various methods for handover control, which are described below:

firstly, setting a measurement threshold of a second terminal by taking a network signal quality parameter when a first terminal is switched as a basis:

in this embodiment, the first terminal may be a terminal under an LTE network architecture, or may be a terminal under an eMTC network architecture or a new air interface NR terminal, and the second terminal may be a terminal under an eMTC network architecture, or may be a terminal under an mtc network architecture, in the following process, only the first terminal is used as the LTE terminal, and the second terminal is used as the eMTC terminal to perform schematic description.

In this embodiment, the base station may obtain a target parameter according to a network signal quality parameter when the first terminal performs handover, and set a measurement threshold of the second terminal according to the target parameter, in practical application, the measurement threshold of the second terminal may be calculated by the base station, or may be calculated by the base station and handed to the network management server, which is described below:

1. the base station calculates a measurement threshold of the second terminal:

referring to fig. 2, a handover control method in the embodiment of the present application includes:

201. the base station configures switching measurement for the first terminal;

the base station configures the measurement type of the LTE terminal through a measurement configuration cell (means config) carried in an RRC reconfiguration message, where the means config may include the following: at least one of a measurement object, a report configuration report config, a reporting standard (which triggers the LTE terminal to send a measurement report, and may be a periodic or single description), a reporting format (for example, the number of reporting cells), a measurement identifier, a number configuration, and a measurement interval, which is not limited herein.

The handover measurement in the embodiment of the present application may be an A3 measurement in intra-frequency handover, or an a4 or a5 measurement in inter-frequency handover, and in the following process, only the handover measurement is an A3 measurement in intra-frequency handover, which is schematically described, and is not limited herein.

The base station in this embodiment may be an eNodeB of LTE, or may be a gsnodeb of 5G NR, which is not specifically limited herein.

202. A first terminal reports a first network signal quality parameter to a base station;

the LTE terminal performs measurement configuration at an RRC protocol end of the LTE terminal according to measurement control issued by the base station, and sends an RRC connection configuration complete message to the base station to indicate that the measurement configuration is completed.

The LTE terminal performs measurement according to the content of the handover measurement control, and reports a handover measurement report to the base station when a handover measurement report condition is satisfied, where the handover measurement report may include: the measurement identifier, the measurement result of the serving cell or the measurement result of the neighboring cell, and the first network signal quality parameter of the serving cell may be understood that the LTE terminal may also report a handover measurement report to the base station, where the handover measurement report includes the first network signal quality parameter.

In the embodiment of the present application, only the first network signal quality parameter and the second network signal quality parameter are taken as Reference Signal Receiving Power (RSRP) for schematic explanation, and it can be understood that the first network signal quality parameter or the second network signal quality parameter may be RSRP or Reference Signal Receiving Quality (RSRQ), and in practical applications, the first network signal quality parameter or the second network signal quality parameter may also be other parameters, for example: the first network signal quality parameter or the second network signal quality parameter may be a signal to interference plus noise ratio (SINR), which is not limited herein.

203. The base station records a first network signal quality parameter to obtain a sample set;

after receiving the RSRP reported by the LTE terminal, the base station records the RSRP value, and the base station can locally record the RSRP every time the LTE terminal reports the RSRP value, so as to obtain a sample set.

204. The base station processes the first network signal quality parameter in the sample set to obtain a target parameter;

after the base station records the RSRP, the base station may process the sample set at intervals, or may process the sample set when the RSRP accumulates to a certain amount.

The period of time may be one day or one week, and is not limited herein. The number of the pieces may be 10 ten thousand, or 100 ten thousand, and is not limited herein.

There are two main ways for the base station to process the sample set, which are described below:

1.1, a base station processes a sample set by utilizing a CDF (cumulative distribution function) method;

after the base station obtains the sample set, the base station inputs the RSRP of all LTE terminal switching moments in the sample set into a Cumulative Distribution Function (CDF), and then selects a numerical value corresponding to the RSRP from the CDF as a target parameter according to the target probability.

In the embodiment of the present application, only the target parameter is schematically described as the target RSRP, it may be understood that the target parameter may be the target RSRP or the target RSRQ, and in practical application, the target parameter may also be the target SINR, which is not limited herein specifically.

For convenience of description, reference is made to fig. 4, where the abscissa is the RSRP value at the LTE terminal handover time, and the unit is dBm, and the ordinate is the probability of RSRP occurring in the sample set, and the curve in fig. 4 is the probability of RSRP occurring in the sample set at the handover time in the sample set, and assuming that the target probability is 0.8, the corresponding target RSRP value is-95 dBm, as shown by the points pointed by two arrows in fig. 4, which means that 80% of the LTE terminals in the sample set have RSRP values less than or equal to-95 dBm in the handover serving cell.

1.2, the base station processes a sample set by using a statistical average method;

after the base station obtains the sample set, the base station may count the values of all RSRPs in the sample set, then calculate an average value, and use the average value as a target parameter.

In the embodiment of the present application, the base station may obtain the target parameter by using a CDF method, or may obtain the target parameter by using a statistical average method, and it can be understood that, in practical application, the base station may also obtain the target parameter by using other methods, for example: the base station may select a maximum value in the sample set as a target parameter, which is not limited herein.

205. The base station processes the target parameters to obtain an A2 measurement threshold and an A1 measurement threshold;

after the base station obtains the target parameters, the base station increases the first redundancy quantity on the basis of the target parameters to obtain an A2 measurement threshold of the eMTC terminal, and increases the second redundancy quantity to obtain an A1 measurement threshold of the eMTC terminal.

The first and second amounts of redundancy may be related to a rate of movement of the eMTC terminal, the faster the movement, the greater the first and second amounts of redundancy, and may also be related to channel fading, the faster the channel fading, the greater the first and second amounts of redundancy. The first and second amounts of redundancy may be a fixed parameter at a cell level, where the a1 measurement threshold is greater than the a2 measurement threshold, so the second amount of redundancy is greater than the first amount of redundancy.

The first redundancy amount and the second redundancy amount in this embodiment are set by a network maintenance worker according to experience or needs, and specific numerical values are not limited here, for example: the A2 measurement threshold is the target RSRP +2dB, and the A1 measurement threshold is the target RSRP +6 dB.

206. The base station configures A2 measurement events for the second terminal;

because the eMTC terminal generally employs in-band inband deployment, i.e., co-cell deployment with LTE, the eMTC and LTE are the same networking method, and therefore have the same handover point.

According to the 3GPP TS 36.300V13.4.0 specification, eMTC terminals typically need to start GAPs when measuring on the same frequency A3, mainly because: in order to reduce the cost, the eMTC terminal of release13 version only supports a single Narrowband (NB), that is, the receiver only supports 6 continuous RBs at most, so that the receiver cannot tune to the center 6RB to measure the neighboring cell, and if the same-frequency A3 measurement needs to be performed, the receiver needs to rely on a measurement GAP mechanism to measure the signal quality of the neighboring cell during GAP.

In the embodiment of the present application, the GAP pattern may be GAP0, the GAP period is 40ms, or may be GAP1, and the GAP period is 80ms, which is not limited herein.

In addition, the A3 measurement of the LTE terminal does not need to measure the GAP, so the LTE terminal can always configure A3 measurement, and can measure the neighboring cell in time and perform handover, so the handover point of the LTE user in the cell can be obtained by counting the first network signal quality parameter in the A3 measurement report reported by the co-frequency handover of the LTE terminal in the same cell, and the a2 measurement threshold of the eMTC terminal in the cell is set in a targeted manner, and the eMTC terminal can also set the a2 measurement threshold by taking the handover record of other eMTC terminals in the same cell as a reference.

When the eMTC terminal accesses the network, the base station sends a measurement notification A2 carried in the measurement control message to the eMTC terminal, that is, an A2 measurement event is issued. The a2 measurement event indicates that the serving cell signal quality becomes lower than the corresponding threshold, and the threshold for the a2 measurement event is the a2 measurement threshold obtained in step 205.

207. The second terminal reports an A2 measurement report to the base station;

after the base station configures an a2 measurement event for the eMTC terminal, the eMTC terminal performs measurement according to the content of the measurement control message, and when a reporting condition of the a2 measurement event is satisfied, the eMTC terminal reports an a2 measurement report to the base station, where the a2 measurement report may include a measurement ID and a measurement quantity (RSRP, RSRQ, or SINR) of the serving cell, and the measurement quantity may be a second network signal quality parameter.

208. The base station configures the second terminal with measurement GAP, handover measurement and a1 measurement events.

When a base station receives an a2 measurement report reported by an eMTC terminal, that is, the signal strength of a serving cell is lower than a corresponding threshold, the base station determines that the eMTC terminal moves to the edge of the serving cell, the eMTC terminal needs to switch the cell to improve the signal strength, measurement of an intra-frequency neighboring cell is generally measured by using A3, measurement of A3 shows that the signal quality of the neighboring cell of the serving cell is higher than that of the serving cell by a certain threshold, the base station notifies the eMTC terminal of an A3 measurement configuration message through a measurement configuration cell (means config) carried in an RRC reconfiguration message, that is, issues A3 measurement control, and as A3 measurement of the eMTC terminal needs to be measured, as described in the network framework, it is further required to determine whether the eMTC terminal moves to the center of the serving cell through a1 measurement, so that after the eMTC terminal reports an a1 measurement report, measurement GAP and A3 are configured.

The base station configures an a1 measurement event for the second terminal, and the threshold of the a1 measurement event is the a1 measurement threshold obtained in step 205.

2. The network management server calculates the measurement threshold of the second terminal:

referring to fig. 3, a handover control method in the embodiment of the present application includes:

301. the base station configures switching measurement for the first terminal;

302. a first terminal reports a first network signal quality parameter to a base station;

step 301 and step 302 in this embodiment are similar to step 201 and step 202 in the embodiment shown in fig. 2, and are not described herein again.

303. The base station sends a first network signal quality parameter to a network management server;

and after receiving the first network signal quality parameter reported by the first terminal, the base station sends the first network signal quality parameter to the network management server.

304. The network management server records a first network signal quality parameter to obtain a sample set;

the network management server records the value of the first network signal quality parameter after receiving the first network signal quality parameter of the LTE terminal sent by the base station, and the network management server can record the first network signal quality parameters every time the base station sends the first network signal quality parameter, so that a sample set is obtained.

305. The network management server processes the first network signal quality parameter in the sample set to obtain a target parameter;

after the network management server records the first network signal quality parameter, the network management server can process the sample set at intervals, and can also process the sample set when the first network signal quality parameter is accumulated to a certain quantity.

The network management server mainly has the following two modes for processing the sample set, which are respectively described as follows:

2.1, the network management server processes the sample set by using a Cumulative Distribution Function (CDF) method;

after the network management server obtains the sample set, the network management server inputs the first network signal quality parameters of all LTE terminal switching moments in the sample set into the cumulative distribution function CDF, and then selects the numerical values corresponding to the first network signal quality parameters in the CDF as target parameters according to the target probability.

For convenience of description, reference is made to fig. 4, where the abscissa is the RSRP value at the handover time, unit dBm, and the ordinate is the CDF of RSRP, the curve in fig. 4 is the probability that the RSRP value at the handover time appears in the sample set, and assuming that the target probability is 0.8, the corresponding target RSRP value is-95 dBm, as shown by the points pointed by two arrows in fig. 4, which means that 80% of LTE terminals in the sample set have RSRP values smaller than or equal to-95 dBm in the handover serving cell.

2.2, the network management server processes the sample set by using a statistical average method;

after the network management server obtains the sample set, the network management server can count the numerical values of all the first network signal quality parameters in the sample set, then calculate the average value, and take the average value as the target parameter.

In the embodiment of the present application, the network management server may obtain the target parameter by using a CDF method, or may obtain the target parameter by using a statistical average method, and it can be understood that, in practical applications, the network management server may also obtain the target parameter by using other methods, for example: the network management server may select a maximum value in the sample set as a target parameter, which is not limited herein.

306. The network management server processes the target parameters to obtain an A2 measurement threshold and an A1 measurement threshold;

after the network management server obtains the target parameters, the network management server increases the first redundancy quantity on the basis of the target parameters to obtain an A2 measurement threshold of the eMTC terminal, and increases the second redundancy quantity to obtain an A1 measurement threshold of the eMTC terminal.

The first and second amounts of redundancy may be related to a moving rate of the eMTC terminal, and the faster the movement, the larger the first and second amounts of redundancy, and may also be related to channel fading, which the faster the channel fading, the larger the first and second amounts of redundancy. The network management server stores a first redundancy amount and a second redundancy amount, wherein the A1 measurement threshold is greater than the A2 measurement threshold, so the second redundancy amount is greater than the first redundancy amount.

307. The network management server sends an A2 measurement threshold and an A1 measurement threshold to the base station;

the network management server processes the target parameters to obtain an A2 measurement threshold and an A1 measurement threshold, and sends the A2 measurement threshold and the A1 measurement threshold to the base station;

308. the base station configures A2 measurement events for the second terminal;

the threshold for the a2 measurement event is the a2 measurement threshold obtained in step 306.

309. The second terminal reports an A2 measurement report to the base station;

310. the base station configures the second terminal with measurement GAP, handover measurement and a1 measurement events.

The threshold for the a1 measurement event is the a1 measurement threshold obtained in step 306.

Steps 308 to 310 in this embodiment are similar to steps 206 to 208 in the embodiment shown in fig. 2, and are not described again here.

Secondly, setting a measurement threshold of the second terminal according to the downlink channel quality:

in this embodiment, a base station may evaluate a quality of a downlink channel according to a Channel Quality Indication (CQI) reported by an eMTC terminal, and set a measurement threshold of the eMTC terminal according to the CQI, the base station may also evaluate a modulation and coding strategy MCS selected when the eMTC terminal schedules a downlink transport block according to the eMTC terminal, evaluate a quality of the downlink channel, and set the measurement threshold of the eMTC terminal according to the MCS, in practical applications, the base station may evaluate a quality of the downlink channel according to a residual block error rate (RBLER), set a measurement threshold of the eMTC terminal according to the RBLER, the base station may also evaluate a quality of the downlink channel according to a Discontinuous Transmission (DTX) ratio, set a measurement threshold of the eMTC terminal according to the DTX ratio, and respectively explain the following four cases:

in the embodiment of the present application, only the target terminal is used as the eMTC terminal for schematic illustration, it may be understood that the target terminal may be an eMTC terminal or an LTE terminal, and in practical applications, the target terminal may also be another terminal, and the target terminal is a terminal that needs to measure a GAP when a cell is switched, and specific details are not limited herein.

1. Setting a measurement threshold of the second terminal based on a value of a Channel Quality Indication (CQI):

referring to fig. 5, a handover control method in the embodiment of the present application includes:

501. the base station configures a measurement threshold;

the CQI is an important index for the eMTC terminal to feed back the quality of the downlink channel to the base station. The CQI can be used to trigger handover measurements.

The measurement threshold may be a low threshold of the CQI value, which is set by the network operation and maintenance personnel according to experience or needs, and ranges from 0 to 15, for example: the low threshold may be set to 2, and the specific value is not limited herein.

It can be understood that, because the downlink channel quality fluctuates, the base station generally sets a high threshold in addition to a low threshold, and when the CQI value is lower than the low threshold, the downlink channel quality of the eMTC terminal is considered to be low, and when the CQI value is higher than the low threshold, the downlink channel quality of the eMTC terminal is considered to be high. In this embodiment of the present application, the base station may set one threshold (a low threshold), or may set two thresholds (a low threshold and a high threshold), which is not limited herein.

The base station may configure a periodic CQI or an aperiodic CQI, which is not limited herein.

502. A target terminal reports a Channel Quality Indicator (CQI) to a base station;

since the base station needs to determine the coding mode (for example, the LTE terminal has three coding modes, i.e., OPSK, 16QAM, and 64QAM), the eMTC terminal needs to feed back CQI, and the protocol quantizes the channel quality to a sequence of 0 to 15.

The periodic CQI is generally reported through a Physical Uplink Control Channel (PUCCH), and the aperiodic CQI is generally reported through a Physical Uplink Shared Channel (PUSCH).

The CQI value of the embodiment of the present application can be obtained in various ways, and only three ways are schematically described below:

1.1, the CQI value is the CQI instantaneous value reported by the eMTC terminal;

1.2, the CQI value is the filtered CQI value;

1.3, the value of CQI is the average of the CQI values over a period of time.

The period of time may be one second or two seconds, and is not limited herein.

503. The base station configures measurement GAP and switching measurement for the target terminal.

When the value of the CQI reported by the target terminal is lower than the low threshold, the quality of the downlink channel of the eMTC terminal is low, the quality of the downlink channel of the eMTC terminal can be improved by switching cells, and the base station configures measurement GAP and switching measurement for the eMTC terminal.

2. Setting a measurement threshold of the second terminal according to a Modulation and Coding Scheme (MCS) selected finally:

referring to fig. 6, a handover control method in the embodiment of the present application includes:

601. configuring a measurement threshold by a base station;

the MCS table is a representation of the communication rate, and each MCS index corresponds to a physical transmission rate under a set of parameters. The MCS may be used to trigger handover measurements.

The measurement threshold may be a low threshold of the value of MCS, which is set by the network operation and maintenance personnel according to experience or need, and ranges from 0 to 28, for example: the low threshold may be set to 1, and the specific value is not limited herein.

It can be understood that, because the quality of the downlink channel fluctuates, the base station generally sets a high threshold in addition to a low threshold, and when the value of the MCS is lower than the low threshold, the downlink channel quality of the eMTC terminal is considered to be low, and when the value of the MCS is higher than the low threshold, the downlink channel quality of the eMTC terminal is considered to be high. In this embodiment, the base station may set one threshold (a low threshold), or may set two thresholds (a low threshold and a high threshold), which is not limited herein.

602. A base station determines a modulation and coding strategy MCS selected when a target terminal schedules a downlink transmission block;

the base station can perform link adaptive selection of the MCS according to the CQI reported by the eMTC terminal and acknowledgement/non-acknowledgement (ACK/NACK) information of the transport block fed back by the eMTC terminal, and the base station can monitor the MCS (value range 0 to 28) finally selected by the downlink transport block scheduled by the eMTC terminal.

603. The base station configures measurement GAP and switching measurement for the target terminal.

When the value of the MCS is lower than the low threshold of the MCS, it indicates that the quality of the downlink channel of the eMTC terminal is low, the quality of the downlink channel of the eMTC terminal can be improved by switching cells, and the base station configures a measurement GAP and a switching measurement for the eMTC terminal.

3. Setting a measurement threshold of the second terminal by taking residual block error rate (RBLER) as a basis:

referring to fig. 7, a handover control method in the embodiment of the present application includes:

701. configuring a measurement threshold by a base station;

in a wireless network, a base station transmits data to an eMTC terminal in blocks.

The residual block error rate RBLER is the ratio of the number of erroneous blocks to the number of effectively transmitted blocks multiplied by one hundred percent after the maximum number of transmissions has been reached. Since RBLER is an important index reflecting network performance service quality, and the quality of RBLER directly affects the quality of voice service and the throughput rate of data transmission service, the RBLER can be used for triggering handover measurement.

The measurement threshold may be a high threshold of RBLER, which is set by network operation and maintenance personnel according to experience or need, and ranges from 0% to 100%, for example: the high threshold may be set at 5%.

It can be understood that, because the quality of the downlink channel fluctuates, a general base station may set a low threshold in addition to a high threshold, and when the RBLER value is higher than the high threshold, the downlink channel quality of the eMTC terminal is considered to be low, and when the RBLER value is lower than the low threshold, the downlink channel quality of the eMTC terminal is considered to be high. In the embodiment of the present application, the base station may set one threshold (high threshold), or may set two thresholds (low threshold and high threshold), which is not limited herein.

702. A base station monitors a target terminal downlink residual block error rate RBLER;

after the base station schedules the downlink transmission block each time, the eMTC terminal feeds back ACK/NACK information through PUCCH/PUSCH, namely feeds back whether the downlink transmission block is correctly received.

703. The base station configures measurement GAP and switching measurement for the target terminal.

When the value of the RBLER is higher than the high threshold, the downlink channel quality of the eMTC terminal is considered to be low, the downlink channel quality of the eMTC terminal can be improved by switching cells, and the base station configures measurement GAP and switching measurement for the eMTC terminal.

4. Setting a measurement threshold of the second terminal according to a Discontinuous Transmission (DTX) ratio:

referring to fig. 8, a handover control method in the embodiment of the present application includes:

801. configuring a measurement threshold by a base station;

the eMTC terminal has machine type communication physical downlink control channel (MPDCCH) missed detection, which is recorded as DTX, and the DTX ratio is defined as the ratio of the number of missed detections of the MPDCCH to the total number of transmission of the MPDCCH multiplied by one hundred percent.

The measurement threshold may be a DTX high threshold, which is set by the network operation and maintenance personnel according to experience or needs, and ranges from 0% to 100%, for example: the high threshold may be set at 10%.

It can be understood that, because the quality of the downlink channel fluctuates, the base station may set a low threshold in addition to the high threshold, and when the DTX ratio is higher than the high threshold, the quality of the downlink channel of the eMTC terminal is considered to be low, and when the DTX ratio is lower than the low threshold, the quality of the downlink channel of the eMTC terminal is considered to be high. In the embodiment of the present application, the base station may set one threshold (high threshold), or may set two thresholds (low threshold and high threshold), which is not limited herein.

802. A base station monitors the omission of the MPDCCH of a target terminal;

after the base station sends the scheduling authorization of the downlink transmission block through the MPDCC, the eMTC terminal feeds back ACK/NACK information through the PUCCH/PUSCH, and if the eMTC terminal does not feed back the corresponding ACK/NACK information, the eMTC terminal is considered to have MPDCCH missing detection and is marked as DTX.

803. The base station configures measurement GAP and switching measurement for the target terminal.

When the DTX ratio is higher than the high threshold, the downlink channel quality of the eMTC terminal is considered to be low, the downlink channel quality of the eMTC terminal can be improved by switching cells, and the base station configures a measurement GAP and switches measurement for the eMTC terminal.

The above describes the handover control method in the embodiment of the present application, and the following describes related devices corresponding to a handover control method in the embodiment of the present application, in which a base station and a network management server are provided in the embodiment of the present application, and the following description is respectively given:

firstly, a base station:

1. the base station sets the measurement threshold of the second terminal according to the network signal quality parameter when the first terminal switches:

referring to fig. 9, an embodiment of a base station in the embodiment of the present application includes:

an obtaining unit 901, configured to obtain a first network signal quality parameter corresponding to a first terminal, where the first network signal quality parameter is related to signal quality of a serving cell where the first terminal is located;

the obtaining unit 901 is further configured to obtain an a2 measurement threshold, where the a2 measurement threshold is obtained by processing a first network signal quality parameter;

a configuring unit 902, configured to configure an a2 measurement threshold for a second terminal, where the second terminal is a terminal that needs to measure a GAP for switching cells, and the second terminal and the first terminal belong to a serving cell;

a receiving unit 903, configured to receive an a2 measurement report reported by the second terminal;

the configuring unit 902 is further configured to configure a measurement GAP and a handover measurement for the second terminal if the receiving unit 903 receives an a2 measurement report reported by the second terminal, where the a2 measurement report is used to indicate that a second network signal quality parameter corresponding to the second terminal reaches an a2 measurement threshold.

In this embodiment, operations performed by each unit of the base station are similar to those described in the embodiments shown in fig. 2 and fig. 3, and are not described again here.

In this embodiment, the obtaining unit 901 obtains a first network signal quality parameter corresponding to the first terminal, the first network signal quality parameter is processed to obtain an a2 measurement threshold, and the configuration unit 902 configures the a2 measurement threshold for the second terminal, because the a2 measurement threshold is processed based on the first network signal quality parameter sent by the first terminal, the a2 measurement threshold may be automatically determined to trigger GAP measurement and handover measurement according to the characteristics of different cells, so as to adapt to specific situations in different environments.

The base station may obtain a target parameter according to a network signal quality parameter when the first terminal performs handover, and set a measurement threshold of the second terminal according to the target parameter, as shown in fig. 10 specifically, in practical application, the measurement threshold of the second terminal may be calculated by the base station, or may be calculated by the base station handing over to a network management server, as shown in fig. 11 or fig. 12 specifically, the following description is respectively made:

referring to fig. 10, another embodiment of the base station in the embodiment of the present application includes:

an obtaining unit 1001, configured to obtain a first network signal quality parameter corresponding to a first terminal, where the first network signal quality parameter is related to signal quality of a serving cell where the first terminal is located;

the obtaining unit 1001 is further configured to obtain an a2 measurement threshold, where the a2 measurement threshold is obtained by processing a first network signal quality parameter;

a configuration unit 1002, configured to configure an a2 measurement threshold for a second terminal, where the second terminal is a terminal that needs to measure a GAP for cell switching, and the second terminal and the first terminal belong to a serving cell;

a receiving unit 1003, configured to receive an a2 measurement report reported by the second terminal;

the configuring unit 1002 is further configured to configure a measurement GAP and a handover measurement for the second terminal if the receiving unit 1003 receives an a2 measurement report reported by the second terminal, where the a2 measurement report is used to indicate that a second network signal quality parameter corresponding to the second terminal reaches an a2 measurement threshold;

a deconfiguration unit 1004, configured to deconfigure the measurement GAP and the handover measurement for the second terminal when the receiving unit does not receive the handover measurement report sent by the second terminal and the receiving unit receives an a1 measurement report sent by the second terminal;

a recording unit 1005, configured to record a first network signal quality parameter, so as to obtain a sample set;

a processing unit 1006, configured to process the sample set to obtain a target parameter;

an adding unit 1007, configured to add a first redundancy amount on the basis of the target parameter, to obtain an a2 measurement threshold, where the first redundancy amount is related to the moving speed or channel fading of the second terminal.

Referring to fig. 11, another embodiment of a base station in the embodiment of the present application includes:

an obtaining unit 1101, configured to obtain a first network signal quality parameter corresponding to a first terminal, where the first network signal quality parameter is related to signal quality of a serving cell where the first terminal is located;

the obtaining unit 1101 is further configured to obtain an a2 measurement threshold, where the a2 measurement threshold is obtained by processing a first network signal quality parameter;

a configuration unit 1102, configured to configure an a2 measurement threshold for a second terminal, where the second terminal is a terminal that needs to measure a GAP for cell switching and the second terminal and the first terminal belong to a serving cell;

a receiving unit 1103, configured to receive an a2 measurement report reported by the second terminal;

the configuration unit 1102 is further configured to configure a measurement GAP and a handover measurement for the second terminal if the receiving unit 1103 receives an a2 measurement report reported by the second terminal, where the a2 measurement report is used to indicate that a second network signal quality parameter corresponding to the second terminal reaches an a2 measurement threshold;

a deconfiguration unit 1104, configured to deconfigure the measurement GAP and the handover measurement for the second terminal by the deconfiguration unit 1104 when the receiving unit does not receive the handover measurement report sent by the second terminal and the receiving unit receives an a1 measurement report sent by the second terminal;

a sending unit 1105, configured to send a first network signal quality parameter to a network management server;

the receiving unit 1103 is further configured to receive an a2 measurement threshold sent by the webmaster server, where the a2 measurement threshold is obtained by processing the first network signal quality parameter by the webmaster server.

2. And the base station sets the measurement threshold of the second terminal according to the downlink channel quality:

referring to fig. 12, another embodiment of a base station in the embodiment of the present application includes:

a configuration unit 1201, configured to configure a measurement threshold for a target terminal, where the target terminal is a terminal that needs to measure a GAP for switching a cell;

a receiving unit 1202, configured to receive a preset event;

the configuration unit 1201 is further configured to configure a measurement GAP and a handover measurement for the target terminal if the receiving unit 1202 receives a preset event, where the preset event is used to indicate that the quality of the downlink channel corresponding to the target terminal reaches a measurement threshold.

Referring to fig. 13, another embodiment of a base station in the embodiment of the present application includes:

a configuration unit 1301, configured to configure a measurement threshold for a target terminal, where the target terminal is a terminal that needs to measure a GAP for cell switching;

a receiving unit 1302, configured to receive a preset event;

the configuration unit 1301 is further configured to configure a measurement GAP and a handover measurement for the target terminal if the receiving unit 1302 receives a preset event, where the preset event is used to indicate that the quality of the downlink channel corresponding to the target terminal reaches a measurement threshold;

an obtaining unit 1303, configured to obtain a channel quality indicator CQI reported by a target terminal;

the measurement threshold is a low threshold of the CQI value, and the quality of a downlink channel of the target terminal is low when the measurement threshold is lower than the low threshold;

a first triggering unit 1304, configured to trigger the configuration unit 1301 to configure the measurement GAP and the step of switching the measurement for the target terminal when the value of the CQI is lower than the lower threshold of the CQI.

Referring to fig. 14, another embodiment of a base station in the embodiment of the present application includes:

a configuration unit 1401, configured to configure a measurement threshold for a target terminal, where the target terminal is a terminal that needs to measure a GAP for switching a cell;

a receiving unit 1402, configured to receive a preset event;

the configuration unit 1401 is further configured to configure a measurement GAP and a handover measurement for the target terminal if the receiving unit 1402 receives a preset event, where the preset event is used to indicate that the quality of the downlink channel corresponding to the target terminal reaches a measurement threshold;

a determining unit 1403, configured to determine a modulation and coding strategy MCS selected by the target terminal when scheduling the downlink transport block;

the measurement threshold is a low threshold of the MCS, and the quality of a downlink channel of the target terminal is low when the measurement threshold is lower than the low threshold;

and a second triggering unit 1404, configured to, when the value of the MCS is lower than the lower threshold of the MCS, trigger the configuration unit 1401 to configure the measurement GAP and the handover measurement for the target terminal.

Referring to fig. 15, another embodiment of a base station in the embodiment of the present application includes:

a configuration unit 1501, configured to configure a measurement threshold for a target terminal, where the target terminal is a terminal that needs to measure a GAP for switching a cell;

a receiving unit 1502 for receiving a preset event;

the configuration unit 1501 is further configured to configure a measurement GAP and a handover measurement for the target terminal if the receiving unit 1502 receives a preset event, where the preset event is used to indicate that the quality of a downlink channel corresponding to the target terminal reaches a measurement threshold;

a first monitoring unit 1503, configured to monitor a target terminal downlink residual block error rate RBLER;

the measurement threshold is a high threshold of RBLER, and the quality of a downlink channel of the target terminal is low when the measurement threshold is higher than the high threshold;

a third triggering unit 1504, configured to trigger the configuration unit 1501 to configure measurement GAP and handover measurement for the target terminal when RBLER is higher than the upper threshold of RBLER.

Referring to fig. 16, another embodiment of a base station in the embodiment of the present application includes:

a configuration unit 1601, configured to configure a measurement threshold for a target terminal, where the target terminal is a terminal that needs to measure a GAP for switching a cell;

a receiving unit 1602, configured to receive a preset event;

the configuration unit 1601 is further configured to configure a measurement GAP and a handover measurement for the target terminal if the receiving unit 1602 receives a preset event, where the preset event is used to indicate that the quality of a downlink channel corresponding to the target terminal reaches a measurement threshold;

a second monitoring unit 1603, configured to monitor missing detection of an MPDCCH (physical downlink control channel) of the target terminal machine type communication to obtain a ratio of discontinuous transmission DTX;

the measurement threshold is a high threshold of a DTX ratio, and the quality of a downlink channel of the target terminal is low when the measurement threshold is higher than the high threshold;

a fourth triggering unit 1604, configured to, when the DTX proportion is higher than the high threshold of the DTX proportion, configure the measurement GAP and the handover measurement for the target terminal by the trigger configuration unit 1601.

Fig. 17 is another structural diagram of a base station in the embodiment of the present application, where the base station 1700 may include one or more Central Processing Units (CPUs) 1701 and a memory 1705, and one or more applications or data are stored in the memory 1705.

The memory 1705 may be volatile memory or persistent memory, among others. The program stored in the memory 1705 may include one or more modules, each of which may include a series of instruction operations on a server. Further, the central processor 1701 may be configured to communicate with the memory 1705 to execute a series of instruction operations in the memory 1705 on the base station 1700.

The base station 1700 may also include one or more power supplies 1702, one or more wired or wireless network interfaces 1703, one or more input-output interfaces 1704, and/or one or more operating systems, such as Windows Server, Mac OS XTM, UnixTM, LinuxTM, FreeBSDTM, etc.

The central processor 1701 may perform the operations performed by the base station in the embodiments shown in fig. 2 and fig. 3, which are not described herein again.

Secondly, the network management server:

referring to fig. 18, an embodiment of a network management server in the embodiment of the present application includes:

a receiving unit 1801, configured to receive a first network signal quality parameter sent by a base station, where the first network signal quality parameter is related to signal quality of a serving cell where a first terminal is located;

an analyzing unit 1802, configured to analyze a first network signal quality parameter to obtain a target parameter;

a processing unit 1803, configured to process the target parameter to obtain an a2 measurement threshold;

a sending unit 1804, configured to send an a2 measurement threshold to the base station, so that the base station configures an a2 measurement threshold for the second terminal, where the second terminal is a terminal that needs to measure a GAP for cell handover, and the second terminal and the first terminal belong to a serving cell.

In this embodiment, operations executed by each unit of the network management server are similar to those described in the embodiment shown in fig. 3, and are not described herein again.

Fig. 19 is another schematic structural diagram of the network management server in the embodiment of the present application, where the network management server 1900 may include one or more Central Processing Units (CPUs) 1901 and a memory 1905, and the memory 1905 stores one or more application programs or data.

The memory 1905 may be volatile storage or persistent storage, among others. The program stored in the memory 1905 may include one or more modules, each of which may include a series of instructions operating on a server. Further, the central processor 1901 may be configured to communicate with the memory 1905, and execute a series of instruction operations in the memory 1905 on the webmaster server 1900.

The webmaster server 1900 may also include one or more power supplies 1902, one or more wired or wireless network interfaces 1903, one or more input-output interfaces 1904, and/or one or more operating systems, such as Windows Server, Mac OS XTM, UnixTM, LinuxTM, FreeBSDTM, etc.

The central processor 1901 may execute the operations executed by the network management server in the embodiment shown in fig. 3, and details thereof are not described herein.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, a division of a unit is merely a logical division, and an actual implementation may have another division, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

Units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be substantially implemented or contributed to by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and the like.

Claims

1. A handover control method, comprising:

a base station acquires a first network signal quality parameter corresponding to a first terminal, wherein the first network signal quality parameter is related to the signal quality of a service cell where the first terminal is located;

the base station acquires an A2 measurement threshold, and the A2 measurement threshold is obtained by processing the first network signal quality parameter;

the base station configures the A2 measurement threshold for a second terminal, the second terminal is a terminal needing to measure GAP for switching cells, and the second terminal and the first terminal belong to the serving cell;

and if the base station receives an a2 measurement report reported by the second terminal, the base station configures a measurement GAP and a handover measurement for the second terminal, and the a2 measurement report is used for indicating that a second network signal quality parameter corresponding to the second terminal reaches the a2 measurement threshold.

2. The handover control method according to claim 1, wherein after the base station obtains the first network signal quality parameter corresponding to the first terminal, and before the base station obtains an a2 measurement threshold, the method further comprises:

the base station records the first network signal quality parameter to obtain a sample set;

the base station processes the sample set to obtain target parameters;

and the base station adds a first redundancy quantity on the basis of the target parameter to obtain the A2 measurement threshold, wherein the first redundancy quantity is related to the moving speed or channel fading of the second terminal.

3. The handover control method of claim 2, wherein after the base station processes the sample set, the method further comprises:

the base station adds a second redundancy quantity on the basis of the target parameter to obtain an A1 measurement threshold, wherein the second redundancy quantity is related to the moving speed or channel fading of the second terminal, and the second redundancy quantity is greater than the first redundancy quantity;

after the base station configures the a2 measurement threshold for the second terminal, the method further includes:

and the base station configures the A1 measurement threshold for the second terminal.

4. The handover control method according to claim 3, wherein after the base station configures a measurement GAP for the second terminal and performs handover measurement, the method further comprises:

and when the base station does not receive the switching measurement report sent by the second terminal and the base station receives the A1 measurement report sent by the second terminal, the base station configures a measurement GAP and switching measurement for the second terminal.

5. The handover control method of claim 2, wherein the processing of the sample set by the base station comprises:

the base station inputs the first network signal quality parameter in the sample set into a Cumulative Distribution Function (CDF) to obtain the CDF of the first network signal quality parameter;

and the base station selects a numerical value corresponding to the first network signal quality parameter in the CDF as the target parameter according to a target probability, wherein the target probability is set according to needs.

6. The handover control method of claim 2, wherein the processing of the sample set by the base station comprises:

and the base station calculates the average value of all the first network signal quality parameters in the sample set to obtain a target parameter.

7. The handover control method according to claim 1, wherein before the base station obtains the a2 measurement threshold, the method further comprises:

the base station sends the first network signal quality parameter to a network management server;

and the base station receives the A2 measurement threshold sent by the network management server, wherein the A2 measurement threshold is obtained by processing the first network signal quality parameter by the network management server.

8. The handover control method according to claim 1, wherein the first terminal is a Long Term Evolution (LTE) terminal or a new air interface (NR) terminal, and the second terminal is an enhanced machine type communication (eMTC) terminal.

9. The handover control method of claim 2, wherein the first network signal quality parameter is a reference signal received power, RSRP, when the first terminal is handed over from the serving cell to a target cell, the second network signal quality parameter is RSRP, and the target parameter is a target RSRP.

10. The handover control method of claim 2, wherein the first network signal quality parameter is a reference signal received quality, RSRQ, when the first terminal is handed over from the serving cell to a target cell, the second network signal quality parameter is RSRQ, and the target parameter is a target RSRQ.

11. The handover control method of claim 2, wherein the first network signal quality parameter is a signal-to-interference-plus-noise ratio (SINR) when the first terminal is handed over from the serving cell to a target cell, wherein the second network signal quality parameter is an SINR, and wherein the target parameter is a target SINR.

12. The handover control method according to claim 1, wherein the handover measurement is an A3 measurement, an a4 measurement, or an a5 measurement.

13. A handover control method, comprising:

a network management server receives a first network signal quality parameter sent by a base station, wherein the first network signal quality parameter is related to the signal quality of a service cell where a first terminal is located;

the network management server analyzes the first network signal quality parameter to obtain a target parameter;

the network management server processes the target parameters to obtain an A2 measurement threshold;

the network management server sends the A2 measurement threshold to the base station, so that the base station configures the A2 measurement threshold for the second terminal, the second terminal is a terminal needing to measure GAP for switching cells, and the second terminal and the first terminal belong to the service cell.

14. The handover control method according to claim 13, wherein the analyzing the first network signal quality parameter by the webmaster server comprises:

the network management server inputs the first network signal quality parameter in the sample set into a Cumulative Distribution Function (CDF) to obtain the CDF of the first network signal quality parameter;

and the network management server selects a numerical value corresponding to the first network signal quality parameter in the CDF as the target parameter according to a target probability, wherein the target probability is set according to needs.

15. The handover control method according to claim 13, wherein the analyzing of the first network signal quality parameter by the network management server comprises:

and the network management server calculates the average value of all the first network signal quality parameters in the sample set to obtain a target parameter.

16. The handover control method according to claim 13, wherein the processing of the target parameter by the network management server comprises:

and the network management server adds a first redundancy quantity on the basis of the target parameter to obtain the A2 measurement threshold, wherein the first redundancy quantity is related to the moving speed or channel fading of the second terminal.

17. The handover control method according to claim 16, wherein after the webmaster server analyzes the first network signal quality parameter, the method further comprises:

the network management server adds a second redundancy quantity on the basis of the target parameter to obtain an A1 measurement threshold, wherein the second redundancy quantity is related to the moving speed or channel fading of the second terminal, and the second redundancy quantity is greater than the first redundancy quantity;

and the network management server sends the A1 measurement threshold to the base station.

18. The handover control method of claim 13, wherein the first network signal quality parameter is a reference signal received power, RSRP, when the first terminal is handed over from the serving cell to a target cell, and wherein the target parameter is a target RSRP.

19. The handover control method of claim 13, wherein the first network signal quality parameter is a reference signal received quality, RSRQ, when the first terminal is handed over from the serving cell to a target cell, and wherein the target parameter is a target RSRQ.

20. The handover control method of claim 13, wherein the first network signal quality parameter is a signal-to-interference-plus-noise ratio (SINR) when the first terminal is handed over from the serving cell to a target cell, and wherein the target parameter is a target SINR.

21. The handover control method according to claim 13, wherein the first terminal is a Long Term Evolution (LTE) terminal or a new air interface (NR) terminal, and the second terminal is an enhanced machine type communication (eMTC) terminal.

22. A base station, comprising:

an obtaining unit, configured to obtain a first network signal quality parameter corresponding to a first terminal, where the first network signal quality parameter is related to signal quality of a serving cell where the first terminal is located;

the obtaining unit is further configured to obtain an a2 measurement threshold, where the a2 measurement threshold is obtained by processing the first network signal quality parameter;

a configuration unit, configured to configure the a2 measurement threshold for a second terminal, where the second terminal is a terminal that needs to measure a GAP for switching cells, and the second terminal and the first terminal belong to the serving cell;

a receiving unit, configured to receive an a2 measurement report reported by the second terminal;

the configuration unit is further configured to configure a measurement GAP and a handover measurement for the second terminal if the receiving unit receives an a2 measurement report reported by the second terminal, where the a2 measurement report is used to indicate that a second network signal quality parameter corresponding to the second terminal reaches the a2 measurement threshold.

23. The base station of claim 22, wherein the base station further comprises:

the recording unit is used for recording the first network signal quality parameter to obtain a sample set;

the processing unit is used for processing the sample set to obtain a target parameter;

and the increasing unit is used for increasing a first redundancy quantity on the basis of the target parameter to obtain the A2 measurement threshold, wherein the first redundancy quantity is related to the moving speed or the channel fading of the second terminal.

24. The base station according to claim 23, wherein said adding unit is further configured to add a second redundancy amount based on said target parameter, resulting in an a1 measurement threshold, said second redundancy amount being related to the moving speed or channel fading of said second terminal, said second redundancy amount being greater than said first redundancy amount;

the configuration unit is further configured to configure the a1 measurement threshold for the second terminal.

25. The base station of claim 24, wherein the base station further comprises:

a deconfiguration unit, configured to, when the receiving unit does not receive the handover measurement report sent by the second terminal, and the receiving unit receives an a1 measurement report sent by the second terminal, deconfiguration unit deconfigures a measurement GAP and a handover measurement for the second terminal.

26. The base station according to claim 23, wherein the processing unit is specifically configured to input the first network signal quality parameter in the sample set into a Cumulative Distribution Function (CDF) to obtain a CDF of the first network signal quality parameter;

the processing unit is specifically configured to select, in the CDF, a value corresponding to the first network signal quality parameter as the target parameter according to a target probability, where the target probability is set as needed.

27. The base station of claim 23, wherein the processing unit is specifically configured to calculate an average value of all first network signal quality parameters in the sample set to obtain a target parameter.

28. The base station of claim 22, wherein the base station further comprises:

a sending unit, configured to send the first network signal quality parameter to a network management server;

the receiving unit is further configured to receive the a2 measurement threshold sent by the network management server, where the a2 measurement threshold is obtained by the network management server processing the first network signal quality parameter.

29. The base station of claim 22, wherein the first terminal is a Long Term Evolution (LTE) terminal or a new air interface (NR) terminal, and wherein the second terminal is an enhanced machine type communication (eMTC) terminal.

30. The base station of claim 23, wherein the first network signal quality parameter is a reference signal received power, RSRP, when the first terminal is handed over from the serving cell to a target cell, the second network signal quality parameter is RSRP, and the target parameter is a target RSRP.

31. The base station of claim 23, wherein the first network signal quality parameter is a reference signal received quality, RSRQ, when the first terminal is handed over from the serving cell to a target cell, wherein the second network signal quality parameter is RSRQ, and wherein the target parameter is a target RSRQ.

32. The base station of claim 23, wherein the first network signal quality parameter is a signal to interference plus noise ratio (SINR) when the first terminal is handed over from the serving cell to a target cell, wherein the second network signal quality parameter is a SINR, and wherein the target parameter is a target SINR.

33. The base station of claim 22, wherein the handover measurement is an A3 measurement, an a4 measurement, or an a5 measurement.

34. A network management server, comprising:

the receiving unit is used for receiving a first network signal quality parameter sent by a base station, wherein the first network signal quality parameter is related to the signal quality of a service cell where a first terminal is located;

the analysis unit is used for analyzing the first network signal quality parameter to obtain a target parameter;

the processing unit is used for processing the target parameters to obtain an A2 measurement threshold;

a sending unit, configured to send the a2 measurement threshold to the base station, so that the base station configures the a2 measurement threshold for the second terminal, where the second terminal is a terminal that needs to measure a GAP for cell handover, and the second terminal and the first terminal belong to the serving cell.

35. The webmaster server of claim 34, wherein the analyzing unit is specifically configured to input the first network signal quality parameter in the sample set into a Cumulative Distribution Function (CDF) to obtain a CDF of the first network signal quality parameter;

the analysis unit is specifically configured to select, in the CDF, a value corresponding to the first network signal quality parameter as the target parameter according to a target probability, where the target probability is set as needed.

36. The webmaster server of claim 34, wherein the analysis unit is specifically configured to calculate an average value of all first network signal quality parameters in the sample set to obtain a target parameter.

37. The webmaster server of claim 34, wherein the processing unit is specifically configured to add a first redundancy amount on the basis of the target parameter, to obtain the a2 measurement threshold, where the first redundancy amount is related to a moving speed or a channel fading of the second terminal.

38. The webmaster server of claim 37, wherein the processing unit is further configured to add a second redundancy amount based on the target parameter to obtain an a1 measurement threshold, where the second redundancy amount is related to a moving speed or a channel fading of the second terminal, and the second redundancy amount is greater than the first redundancy amount;

the sending unit is further configured to send the a1 measurement threshold to the base station.

39. The network management server of claim 34, wherein the first network signal quality parameter is a reference signal received power, RSRP, when the first terminal is handed over from the serving cell to a target cell, and wherein the target parameter is a target RSRP.

40. The network management server of claim 34, wherein the first network signal quality parameter is a reference signal received quality, RSRQ, when the first terminal is handed over from the serving cell to a target cell, and wherein the target parameter is a target RSRQ.

41. The network management server of claim 34, wherein the first network signal quality parameter is a signal to interference plus noise ratio (SINR) when the first terminal is handed over from the serving cell to a target cell, and wherein the target parameter is a target SINR.

42. The network management server of claim 34, wherein the first terminal is a Long Term Evolution (LTE) terminal or a new air interface (NR) terminal, and the second terminal is an enhanced machine type communication (eMTC) terminal.

43. A base station, comprising:

the system comprises a processor, a memory, a bus and input and output equipment;

the processor is connected with the memory and the input and output equipment;

the bus is respectively connected with the processor, the memory and the input and output equipment;

the processor performs the method of any one of claims 1 to 12.

44. A network management server, comprising:

the processor is connected with the memory and the input and output equipment;

the processor performs the method of any one of claims 13 to 21.

45. A computer storage medium having stored therein instructions that, when executed on a computer, cause the computer to perform the method of any one of claims 1 to 21.

46. A computer program product, which, when executed on a computer, causes the computer to perform the method of any one of claims 1 to 21.