CN115038128B

CN115038128B - Cell switching method, device, base station and storage medium

Info

Publication number: CN115038128B
Application number: CN202110244151.1A
Authority: CN
Inventors: 尹志宁
Original assignee: Datang Mobile Communications Equipment Co Ltd
Current assignee: Datang Mobile Communications Equipment Co Ltd
Priority date: 2021-03-05
Filing date: 2021-03-05
Publication date: 2023-11-24
Anticipated expiration: 2041-03-05
Also published as: CN115038128A

Abstract

The embodiment of the invention provides a cell switching method, a cell switching device, a base station and a storage medium, which are applied to the technical field of communication, wherein the method comprises the following steps: and acquiring the network information of the neighbor cells according to the neighbor cell list in the measurement report reported by the terminal. And determining a candidate cell list for the terminal to perform cell switching according to the obtained network information. And instructing the terminal to perform conditional handover CHO based on the determined candidate cell list. The scheme provided by the embodiment of the invention can control the number of the candidate cells in the condition switching process.

Description

Cell switching method, device, base station and storage medium

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a cell handover method, a cell handover device, a base station, and a storage medium.

Background

In a mobile communication network, a terminal is located in a cell of a base station, and network communication is realized based on the located cell. In an actual communication environment, signal strength and the like of a cell in which a terminal is located may change, or the terminal moves to a range covered by other cells, so that the terminal may desire to perform cell handover to continue high-quality network communication. That is, the terminal cuts out from the source cell where it is located and switches to a new target cell, based on which network communication is performed.

In the prior art, a terminal may perform cell handover based on CHO (Conditional HandOver ) mode. In this case, the source base station of the source cell selects a preset number of candidate cells for the terminal, the terminal monitors the conditions of the candidate cells, and when it is monitored that a target cell satisfying a preset handover condition exists in the candidate cells, the terminal cuts out the candidate cells from the source cell and switches to the target cell.

In the process of cell switching based on CHO, a terminal is required to perform condition monitoring on a plurality of candidate cells, a relatively large amount of data processing is required in the process of performing condition monitoring on a plurality of candidate cells, and the data processing capability of the terminal is limited, so that a technology for optimizing and controlling the number of candidate cells in the process of condition switching on a network side is required.

Disclosure of Invention

An object of the embodiments of the present invention is to provide a cell handover method, apparatus, base station, and storage medium, for controlling the number of candidate cells in a conditional handover process. The specific technical scheme is as follows:

in a first aspect, an embodiment of the present invention provides a cell handover method, where the method includes:

acquiring network information of a neighbor cell according to a neighbor cell list in a measurement report reported by a terminal;

According to the obtained network information, determining a candidate cell list for cell switching of the terminal;

and indicating the terminal to perform conditional handover CHO based on the determined candidate cell list.

In a second aspect, an embodiment of the present invention provides a cell handover apparatus, where the apparatus includes:

the information acquisition module is used for acquiring network information of the neighbor cells according to the neighbor cell list in the measurement report reported by the terminal;

the cell determining module is used for determining a candidate cell list for cell switching of the terminal according to the obtained network information;

and the switching indication module is used for indicating the terminal to perform conditional switching CHO based on the determined candidate cell list.

In a third aspect, an embodiment of the present invention provides a base station, including a memory, a transceiver, and a processor:

a memory for storing a computer program; a transceiver for transceiving data under control of the processor; a processor for reading the computer program in the memory and performing the following operations:

In a fourth aspect, embodiments of the present invention provide a processor-readable storage medium storing a computer program for causing the processor to perform the method of any one of the first aspects.

In a fifth aspect, embodiments of the present invention also provide a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of any of the first aspects described above.

The embodiment of the invention has the beneficial effects that:

in the cell switching scheme provided by the embodiment of the invention, the network information of the neighbor cells can be obtained according to the neighbor cell list in the measurement report reported by the terminal. And determining a candidate cell list for the terminal to perform cell switching according to the obtained network information. And instructing the terminal to perform conditional handover CHO based on the determined candidate cell list.

From the above, the source base station does not directly determine the candidate cell list including the preset number of candidate cells, but determines the candidate cell list according to the network information of the neighbor cells. That is, network information of the neighboring cells is obtained based on a measurement report reported by the terminal, candidate cells are dynamically selected, and a candidate cell list is determined, so that the selected candidate cells can be more suitable for the terminal, the number of the selected candidate cells can also change along with the change of the network information of the neighboring cells, and a preset number of candidate cells are not selected uniformly. Therefore, not only can the final selected candidate cell be enabled to contribute to cell handover of the terminal, but also unnecessary cells can be eliminated from the candidate cells, and thus the number of candidate cells in the conditional handover process can be controlled.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are necessary for the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention and that other embodiments may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a flow chart of a first cell handover method according to an embodiment of the present invention;

fig. 2 is a flow chart of a second cell handover method according to an embodiment of the present invention;

fig. 3A is a flow chart of a third cell handover method according to an embodiment of the present invention;

fig. 3B is a schematic diagram of an application scenario of performing cell handover based on CHO mode according to an embodiment of the present invention;

fig. 3C is a schematic flow chart of performing cell handover based on CHO mode according to an embodiment of the present invention;

fig. 4 is a flow chart of a fourth cell handover method according to an embodiment of the present invention;

fig. 5 is a flowchart of a fifth cell handover method according to an embodiment of the present invention;

Fig. 6 is a flowchart of a sixth cell handover method according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a cell switching apparatus according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a base station according to an embodiment of the present invention.

Detailed Description

In the embodiment of the invention, the term "and/or" describes the association relation of the association objects, which means that three relations can exist, for example, a and/or B can be expressed as follows: a exists alone, A and B exist together, and B exists alone. The character "/" generally indicates that the context-dependent object is an "or" relationship.

The term "plurality" in embodiments of the present invention means two or more, and other adjectives are similar.

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention are included in the scope of protection of the present invention.

In the prior art, in the process of performing cell switching, a terminal needs to perform condition monitoring on a plurality of candidate cells, and the process of performing condition monitoring on the plurality of candidate cells needs to perform a large amount of data processing, and the data processing capability of the terminal is limited.

In one embodiment of the present invention, a cell handover method is provided, where the method includes:

and acquiring the network information of the neighbor cells according to the neighbor cell list in the measurement report reported by the terminal.

And determining a candidate cell list for the terminal to perform cell switching according to the obtained network information.

And instructing the terminal to perform conditional handover CHO based on the determined candidate cell list.

The technical scheme provided by the embodiment of the application can be suitable for various systems, in particular to a 5G system. For example, suitable systems may be global system for mobile communications (global system of mobile communication, GSM), code division multiple access (code division multiple access, CDMA), wideband code division multiple access (Wideband Code Division Multiple Access, WCDMA) universal packet Radio service (general packet Radio service, GPRS), long term evolution (long term evolution, LTE), LTE frequency division duplex (frequency division duplex, FDD), LTE time division duplex (time division duplex, TDD), long term evolution-advanced (long term evolution advanced, LTE-a), universal mobile system (universal mobile telecommunication system, UMTS), worldwide interoperability for microwave access (worldwide interoperability for microwave access, wiMAX), 5G New air interface (New Radio, NR), and the like. Terminals and network devices are included in these various systems. Core network parts such as evolved packet system (Evloved Packet System, EPS), 5G system (5 GS) etc. may also be included in the system.

The terminal according to the embodiment of the application can be a device for providing voice and/or data connectivity for a user, a handheld device with a wireless connection function, or other processing devices connected to a wireless modem, etc. The names of terminals may also be different in different systems, for example in a 5G system, a terminal may be referred to as User Equipment (UE). The wireless terminal may communicate with one or more Core Networks (CNs) via a radio access Network (Radio Access Network, RAN), which may be mobile terminals, such as mobile telephones (or "cellular" telephones) and computers with mobile terminals, for example, portable, pocket, hand-held, computer-built-in or vehicle-mounted mobile devices that exchange voice and/or data with the radio access Network. Such as personal communication services (Personal Communication Service, PCS) phones, cordless phones, session initiation protocol (Session Initiated Protocol, SIP) phones, wireless local loop (Wireless Local Loop, WLL) stations, personal digital assistants (Personal Digital Assistant, PDAs), and the like. A wireless terminal may also be referred to as a system, subscriber unit (subscriber unit), subscriber station (subscriber station), mobile station (mobile), remote station (remote station), access point (access point), remote terminal (remote terminal), access terminal (access terminal), user terminal (user terminal), user agent (user agent), user device (user device), and embodiments of the present application are not limited.

In addition, in the embodiment of the present invention, multiple input Multiple output (Multi Input Multi Output, MIMO) transmission may be performed between the base station and the terminal by using one or more antennas, and the MIMO transmission may be Single User MIMO (SU-MIMO) or Multiple User MIMO (MU-MIMO). The MIMO transmission may be 2D-MIMO, 3D-MIMO, FD-MIMO, or massive-MIMO, or may be diversity transmission, precoding transmission, beamforming transmission, or the like, depending on the form and number of the root antenna combinations.

Referring to fig. 1, a flowchart of a first cell handover method according to an embodiment of the present invention is shown, where the method includes the following steps S101 to S103.

The execution body of the embodiment of the present invention may be a base station, and in order to distinguish from other base stations in the following description, the base station as the execution body is referred to as a source base station.

S101: and acquiring the network information of the neighbor cells according to the neighbor cell list in the measurement report reported by the terminal.

Specifically, the terminal monitors the network information of the neighbor cells in the working process, and reports a measurement report containing the neighbor cell list and the network information of the neighbor cells to the source base station, so that the source base station obtains the network information of the neighbor cells. The network information of the neighboring cell may include signal strength, communication quality RxQual, and the like of the neighboring cell. The neighbor cell list may include a cell number, a cell name, etc. of each neighbor cell.

In addition, the terminal is located in a source cell of the source base station, and one or more cells of the source base station may be used, and the terminal may be located in a cell of the source base station and may perform communication based on the source base station.

In addition, the source base station may also communicate with a neighboring base station of the neighboring cell, so as to obtain network information of the neighboring cell.

S102: and determining a candidate cell list for the terminal to perform cell switching according to the obtained network information.

The network information of the adjacent cells can reflect the network conditions of the adjacent cells, and the terminal is switched to the adjacent cells with better network conditions, so that the terminal is facilitated to communicate subsequently, and the candidate cells can be determined based on the network information of the adjacent cells.

Specifically, the candidate cell list for cell handover by the terminal may be determined through at least one of the following steps a to C.

Step A: and selecting the cells with the signal intensity higher than the preset signal intensity in the adjacent cells to obtain a candidate cell list comprising the selected cells.

Specifically, the signal strength may be expressed in the form of RSRP (Reference Signal Receiving Power, reference signal received power), where the unit of RSRP is dB, and the preset signal strength may be-105 dBm, for example.

The higher the signal intensity of the cell in which the terminal is located, the better the communication effect is in the process of communication by the terminal, so that the cell with the signal intensity higher than the preset signal intensity is selected as the candidate cell, the higher the signal intensity of the target cell selected by the terminal from the candidate cells can be, and the better the communication effect is after the terminal is switched to the target cell.

In one embodiment of the present invention, cells with a total number smaller than or equal to a preset number of first cells may be selected as candidate cells from among the neighboring cells with a signal strength higher than a preset signal strength. Specifically, a cell or a neighbor cell with the highest signal strength can be randomly selected from neighbor cells with signal strength higher than preset signal strength, and the selected neighbor cell is used as a candidate cell. For example, the first preset number of cells may be 4, 6, 8, or the like.

And (B) step (B): and selecting a cell with the network load smaller than the preset network load in the adjacent cells to obtain a candidate cell list comprising the selected cell.

The lower the network load of the cell in which the terminal is located, the better the communication effect is in the process of communication by the terminal, so that the cell with the network load smaller than the preset network load is selected as the candidate cell, the network load of the target cell selected by the terminal from the candidate cells is lower, and the communication effect is better after the terminal is switched to the target cell.

The preset network load may be 50%, 60%, etc.

In one embodiment of the present invention, cells with a total number smaller than or equal to a preset number of second cells may be selected as candidate cells from among neighboring cells with a network load smaller than a preset network load. Specifically, a cell can be randomly selected from neighbor cells with a network load smaller than a preset network load or a neighbor cell with the lowest load can be selected as a candidate cell.

The preset number of the second cells may be the same as or different from the preset number of the first cells, for example, the preset number of the second cells may be 4, 6, or 8.

Step C: and acquiring the history cell switching information of the terminal, and acquiring a candidate cell list from candidate cells in the cells which are subjected to history switching of the terminal according to the acquired network information and the history cell switching information.

The terminal is preferably switched to the candidate cell if the terminal is switched to a neighboring cell for a plurality of times, so that the candidate cell can be determined based on the historical cell switching information of the terminal.

In addition, in the process that the terminal communicates based on the source base station, a response message RETRIEVE UE CONTEXT RESPONSE of a HANDOVER REQUEST and terminal context information may be sent to the source base station, where the message may carry the history cell HANDOVER information, and the source base station may store the history cell HANDOVER information carried therein after receiving the message, so that the source base station obtains the history cell HANDOVER information.

Specifically, the history cell handover information may be a set of identifiers of cells to which the terminal is historically handed over, and the identifiers of the cells may be a cell name, a cell number, or the like. The above-described set may be represented in the form of an array, string set, heap, stack, list, or the like.

After the terminal performs cell switching, the terminal can add the identifiers of the switched cells to the historical cell switching information, the historical cell switching information can contain the identifiers of a plurality of cells with preset identifiers at most, and under the condition that the number of the identifiers of the contained cells reaches the preset number of the identifiers, the terminal can delete the identifier of the cell with the earliest switching time and then add the identifier of the cell currently switched to the historical cell switching information. For example, the number of preset identifiers may be 20, 30, etc.

In one embodiment of the present invention, candidate cells for cell switching of the terminal may be directly determined from cells in which the terminal has historically been switched to obtain a candidate cell list, or candidate cells may be determined from cells in which the number of times the terminal has been switched to is greater than a preset number of times to obtain a candidate cell list. For example, the preset number of times may be 2 times, 5 times, or the like.

In addition, a neighbor cell satisfying at least one condition, at least two conditions, or three conditions in the above steps a to C may be determined as the above candidate cell.

S103: the terminal is instructed to CHO based on the determined candidate cell list.

The terminal monitors conditions of candidate cells in the candidate cell list based on CHO, determines the candidate cells meeting preset switching conditions as target cells, and switches the terminal to the target cells to finish CHO switching.

Specifically, the above step S103 may be implemented by steps S103A to S103C, which will not be described in detail herein.

Referring to fig. 2, a flow chart of a second cell handover method according to an embodiment of the present invention, compared with the embodiment shown in fig. 1, the above step S102 may be implemented by the following steps S102A-S102C.

S102A: and obtaining the network information of the source cell where the terminal is located.

In one embodiment of the present invention, since the source cell is a cell of a source base station, the source base station may obtain network information of the source cell from the recorded information of its own cell.

The network information may include signal strength of the source cell, history cut-out information of a terminal located in the source cell from the source cell, and the like.

Specifically, the history handover information may include specific handover situations of each terminal in the source cell, for example, whether each terminal has successfully handover, a cell that has been handed in after handover, and the like. The history handover information may be a handover success rate, a handover failure rate, or the like of each terminal located in the source cell.

S102B: and determining the maximum number of candidate cells according to the network information of the source cell.

Wherein the maximum number is less than or equal to a preset threshold. Specifically, in the case where the cell handover solution provided in the embodiment of the present invention is applied to a 5G communication scenario, the preset threshold may correspond to a 5G standard, for example, in the case where the 5G standard is a Release16 standard, the Release16 standard specifies that the source base station may select at most 8 candidate cells, and then the preset threshold may be 8.

In an embodiment of the present invention, in the case that the network information of the source cell includes the signal strength of the source cell, the maximum number of candidate cells may be determined through the following steps D to E, which will not be described in detail herein.

In another embodiment of the present invention, in the case where the network information of the source cell includes history of handover information of a terminal located in the source cell from the source cell, the maximum number of candidate cells may be determined by the following step F, which is not described in detail herein.

In addition, in the case where the maximum number of candidate cells is determined by both the step D-the step E and the step F, if the maximum numbers determined by both the two methods are different, the maximum value, the minimum value, the average value, or the like of the determined maximum numbers may be selected as the finally determined maximum number of candidate cells.

S102C: and determining candidate cells of which the total number is not more than the maximum number and which are subjected to cell switching by the terminal according to the obtained network information of the adjacent cells, and obtaining a candidate cell list.

Specifically, the candidate cell may be determined by the embodiment shown in the foregoing step S102, which is not described herein. If the number of candidate cells determined by the foregoing embodiment of step S102 is equal to or less than the maximum number, the determined candidate cell may be directly used as the final determined candidate cell.

If the number of candidate cells determined by the foregoing embodiment of step S102 is greater than the above-described maximum number, the finally determined candidate cell may be obtained by at least one of the following means (one) to (three).

The method (one) selects, from among the determined candidate cells, a maximum number of cells having the highest signal strength as the final determined candidate cell.

And (II) selecting the maximum number of cells with the lowest network load from the determined candidate cells as the final determined candidate cells.

And (III) selecting the maximum number of cells with the highest historical switching times from the determined candidate cells as the final determined candidate cells.

From the above, according to the scheme provided by the embodiment of the present invention, the number of candidate cells determined by the source base station is less than or equal to the maximum number, so that the number of candidate cells can be controlled within the maximum number. Therefore, in the process of carrying out cell switching on the determined candidate cells by the terminal, the number of the candidate cells which need to be subjected to condition monitoring by the terminal does not exceed the maximum number, and the control of the number of the candidate cells is realized. And the maximum number is dynamically determined by the source base station according to the network information of the source cell, so that the determined maximum number can be more suitable for the source base station, thereby facilitating the cell switching of the terminal.

In one embodiment of the present invention, in the case that the network information of the source cell includes the signal strength of the source cell, the maximum number of candidate cells may be determined through the following steps D to E.

Step D: and obtaining a speed type representing the moving speed of the terminal according to the signal intensity of the source cell and the reference signal intensity.

Specifically, the speed type may be a preset speed type, and for example, the speed type may include a high speed movement type, a medium speed movement type, a low speed movement type, and the like.

In one embodiment of the present invention, a difference between the reference signal strength and the signal strength of the source cell may be calculated, a preset difference interval to which the calculated difference belongs may be determined, and a speed type characterizing the speed of the terminal is determined according to a correspondence between a preset speed type and the preset difference interval.

For example, if the calculated difference is equal to or smaller than the first difference, the speed type is considered to be a low-speed movement type, if the calculated difference is equal to or larger than the first difference and equal to or smaller than the second difference, the speed type is considered to be a medium-speed movement type, and if the calculated difference is equal to or larger than the second difference, the speed type is considered to be a high-speed movement type. Wherein the first difference is smaller than the second difference.

In another embodiment of the present invention, a ratio between the reference signal strength and the signal strength of the source cell may also be calculated, a preset ratio interval to which the calculated ratio belongs is determined, and a speed type characterizing the speed of the terminal is determined according to a correspondence between a preset speed type and the preset ratio interval.

For example, if the calculated ratio is equal to or smaller than the first ratio, the speed type is considered to be a low-speed movement type, if the calculated difference is equal to or larger than the first ratio and equal to or smaller than the second ratio, the speed type is considered to be a medium-speed movement type, and if the calculated difference is equal to or larger than the second ratio, the speed type is considered to be a high-speed movement type. Wherein the first ratio is less than the second ratio.

In addition, the reference signal strength may be a preset fixed value, for example, -90dBm. The signal strength may be determined based on a historical signal strength of the source cell when the terminal located in the source cell is handed out from the source cell.

Specifically, the reference signal strength may be a historical signal strength of the source cell when the previous device that was cut from the source cell. The reference signal strength may be obtained by selecting a candidate device from among devices cut out from the source cell, and calculating a maximum value, a minimum value, an average value, or the like of the historical signal strength of the source cell when the candidate device is cut out from the source cell.

All the devices cut out from the source cell may be selected as candidate devices, some devices among the devices cut out from the source cell may be randomly selected as candidate devices, devices with a time difference between the cutting-out time and the current time smaller than a preset time difference may be selected as candidate devices, and a preset number of devices with a minimum time difference between the cutting-out time and the current time may be selected as candidate devices.

For example, the preset time difference may be 1h, 5h, etc., and the number of the preset devices may be 3, 4, etc.

Further, since the terminal becomes a device that is cut out from the source cell after the terminal is cut out from the source cell, the reference signal strength can be updated based on the signal strength at the time of the terminal being cut out from the source cell, and can be used in a process in which the device in the source cell performs cell switching thereafter.

Step E: based on a first principle for the above speed type, a maximum number of candidate cells is determined.

Wherein, the first principle is as follows: the higher the speed of the above speed type characterization, the greater the maximum number of candidate cells.

Specifically, the faster the terminal moves, the shorter the time required for the terminal to leave the coverage area of the source cell, so that the terminal can select a larger number of candidate cells, so that the terminal can determine the target cell in a larger number of candidate cells, and the possibility that the terminal determines the target cell from the candidate cells in a short time is improved.

In one embodiment of the present invention, the maximum number of candidate cells may be determined according to a correspondence between a preset speed type and the maximum number of candidate cells.

For example, the maximum number of low speed types is 2, the maximum number of medium speed types is 4, the maximum number of high speed types is 6, and so on.

Specifically, under the condition that the maximum number of candidate cells is determined to be 1, the candidate cells for the terminal to perform cell switching only have 1 candidate cell, that is, the terminal may only switch to the candidate cell, and no other candidate cells are provided for the terminal to perform CHO switching selection, so that the source base station may instruct the terminal to perform cell switching based on the conventional switching manner.

The traditional switching mode is as follows: the source base station determines the target cell and instructs the terminal to directly switch to the target cell, and compared with the CHO switching mode, the terminal does not need to select the target cell from the candidate cells.

In another embodiment of the present invention, in the case that the network information of the source cell includes the history cut information of the terminal in the source cell from the source cell, the determination of the maximum number of candidate cells may be implemented by the following step F.

Step F: the maximum number of candidate cells is determined based on a second principle for history cut-out information.

Wherein, the second principle is as follows: the higher the cut failure rate of the historical cut information characterization, the greater the maximum number of candidate cells.

The cutting failure rate is as follows: the device cuts out the probability of failure from the source cell.

Specifically, the device has a higher cutting failure rate of cutting from the source cell, which means that the terminal has a higher possibility of cutting from the source cell, so that a larger number of candidate cells can be selected, so that the terminal can determine a target cell in the larger number of candidate cells, thereby improving the probability of successful cutting of the terminal.

In one embodiment of the present invention, when the history cutting information includes a specific cutting condition of each device having a history in the source cell, the cutting failure rate may be calculated according to whether each device cuts successfully. When the history cutting information includes the cutting success rate, a difference between 1 and the cutting success rate may be calculated as the cutting failure rate. When the historical cut-out information includes the cut-out failure rate, the cut-out failure rate may be directly determined.

In addition, the maximum number corresponding to the cutting failure rate may be determined according to a preset correspondence between the cutting failure rate and the maximum number. The correspondence relationship may be a linear relationship or a piecewise relationship, where the piecewise relationship indicates that the maximum number of the same cutting failure rate included in the same cutting failure rate interval corresponds to the same cutting failure rate. The handover failure rate interval to which the handover failure rate belongs may be determined, and the maximum number corresponding to the determined handover failure rate interval may be used as the maximum number of candidate cells.

For example, when the cut-out failure rate is equal to or less than the first cut-out failure rate, the maximum number is 2, when the cut-out failure rate is equal to or less than the second cut-out failure rate, the maximum number is 5, and when the cut-out failure rate is equal to or greater than the second cut-out failure rate, the maximum number is 8. The second cut failure rate is greater than the first cut failure rate.

Referring to fig. 3A, a flow chart of a third cell handover method according to an embodiment of the present invention, compared with the embodiment shown in fig. 1, the above step S103 may be implemented by the following steps S103A-S103C.

S103A: a CHO request is sent to candidate base stations of candidate cells in the determined list of candidate cells.

Specifically, the CHO request indicates that the terminal may be handed over to the candidate cell. The candidate base station needs to reserve resources for a terminal that may be handed over to the candidate cell after receiving the CHO request, and send a CHO command to the source base station indicating that the candidate cell can be handed over to by the terminal.

S103B: and receiving the CHO command sent by the candidate base station.

The CHO command may carry cell configuration information of the candidate cell.

S103C: and sending a CHO execution condition for performing CHO switching and a received CHO command to the terminal so that the terminal performs CHO switching when the CHO execution condition is met based on the CHO command aiming at the candidate cell.

Specifically, the source base station may send a RRC configuration (Radio Resource Control configuration ) message carrying CHO execution conditions and CHO commands to the terminal, so as to send the CHO execution conditions and CHO commands to the terminal.

After receiving the RRC configuration message, the terminal may send RRC configuration complete (Radio Resource Control configuration complete, radio resource control configuration completed) to the source base station, which indicates that the terminal has received the CHO execution condition and CHO command, and starts CHO handover when the CHO execution condition is satisfied based on the CHO command for the candidate cell.

Specifically, steps S103A-S103C described above are similar to the CHO switching process described in fig. 3B and 3C, and are not described in detail herein.

As can be seen from the above, after the source base station determines the candidate cell, a CHO request may be sent to the candidate base station of the candidate cell, and only the candidate base station that receives the CHO request will send a CHO command to the source base station. Therefore, the source base station can receive the CHO command of the candidate cell and the CHO execution condition for performing CHO handover after transmitting the CHO execution condition and the received CHO command to the terminal. Therefore, in the process of performing CHO handover based on CHO commands for the candidate cells, the terminal only performs condition monitoring on the candidate cells, but does not perform condition monitoring on other cells. And after determining that the target cell meeting the CHO execution condition exists in the candidate cells, the terminal can switch to the target cell, thereby realizing cell switching.

And because the number of the candidate cells is smaller, the candidate base stations with a smaller number of the candidate cells can reserve resources for the terminal after receiving the CHO request, and other base stations can not reserve resources for the terminal, so that the total resource amount of the resources reserved for the terminal by each base station in the process of carrying out CHO switching on the terminal is smaller, and the influence on the normal operation of other base stations is smaller.

Referring to fig. 3B, an application scenario diagram for performing cell handover based on CHO mode according to an embodiment of the present invention is provided.

The solid oval area represents a source cell, the dotted oval area represents a candidate cell, the terminal is in the source cell, and the terminal realizes network communication based on a source base station of the source cell, and an arrow between the terminal and the source base station indicates that data transmission can be performed between the terminal and the source base station. In addition, there are a plurality of candidate cells of the candidate base station, and an arrow between the source base station and the candidate base station indicates that data transmission is possible between the source base station and the candidate base station.

Referring to fig. 3C, a flowchart of performing cell handover based on CHO mode according to an embodiment of the present invention is shown.

Specifically, before the terminal is handed over to the target cell of the target base station, the target base station serves as one of the candidate base stations, and the operation performed by the candidate base station is the same as that performed by the target base station, so fig. 3C does not show the steps performed by the target base station before the terminal is handed over to the target cell, and the steps performed by the target base station before the terminal is handed over to the target cell can be referred to the steps performed by the candidate base station.

S301: the terminal monitors each adjacent cell and obtains the network information of each adjacent cell.

S302: the terminal transmits a measurement report including network information of each neighbor cell to a source base station.

S303: and the source base station determines to control the terminal to carry out cell switching by adopting a CHO mode according to the network information of each neighbor cell contained in the received measurement report.

S304: the source base station selects a candidate cell from the neighbor cells.

S305: the source base station transmits a CHO request to the candidate base station.

S306: the candidate base station reserves resources required by the terminal to switch to the candidate cell.

S307: the candidate base station transmits a CHO command of the candidate cell to the source base station.

S308: the source base station transmits a CHO command of a candidate cell and CHO execution conditions generated by the source base station to the terminal.

S309: and the terminal sends an information receiving confirmation to the source base station.

S310: and the terminal monitors the conditions of the candidate cells.

S311: the source base station performs Early Status Transfer (early state transmission) to the candidate base station.

S312: and the terminal disconnects the connection with the source base station and switches to the target cell under the condition that the target cell meeting the CHO execution condition exists in the candidate cells.

S313: and the target base station sends information representing successful cell switching of the terminal to the source base station.

S314: the source base station transmits SN (Sequence Number) status information to the target base station.

S315: and the source base station sends information representing cell switching cancellation to the candidate base stations.

S316: and the candidate base station releases the reserved resources required by the terminal to be switched to the candidate cell.

Specifically, the above steps S301 to S316 are basically the same as the procedure of performing cell handover based on CHO mode in the prior art, which is not described in detail in the embodiment of the present invention.

Referring to fig. 4, a flow chart of a fourth cell handover method according to an embodiment of the present invention, compared with the embodiment shown in fig. 3A, the above step S103B may be implemented by the following step S103B 1.

S103B1: and receiving a CHO command sent by the candidate base station within a preset time period from the source base station sending the CHO request.

Specifically, there is a time difference between the time when the source base station receives the CHO command and the time when the source base station transmits the CHO request, due to factors such as network conditions and data processing speeds of candidate base stations. The smaller the time difference is, the better the network condition of the communication between the source base station and the candidate base station is, the higher the data processing speed of the candidate base station is, and the terminal is switched to the candidate cell of the candidate base station with high data processing speed, so that the communication effect of the terminal after the cell is switched is better.

In one embodiment of the present invention, the source base station may set a timer, the timer is started when the source base station sends a CHO request, a time duration of the timer may be set to the preset time duration, and after the time duration of the timer reaches the preset time duration, the source base station does not receive the CHO command sent by the candidate base station any more. If the source base station has received CHO commands sent by all candidate base stations before the timing duration of the timer reaches the preset duration, the timing may be terminated. For example, the preset duration may be 100ms, 300ms, or the like.

In another embodiment of the present invention, after each CHO command sent by the candidate base station is acquired, a time difference between a time when the CHO command is received and a time when the source base station sends the CHO request may be determined, where the time difference is less than or equal to a CHO command with a preset duration.

In addition, after each time of receiving the CHO command sent by the candidate base station, a time difference between the time when the CHO command is received and the time when the CHO request is sent by the source base station may be determined, until the time difference corresponding to the received CHO command is greater than the preset duration, the last time of receiving the CHO command may be cleared, and the CHO command may be stopped being received.

From the above, it can be seen that, since the CHO command received by the source base station is a CHO command sent by the candidate base station within a preset period from when the source base station sends a CHO request. The CHO commands received can therefore be considered CHO commands sent by candidate base stations with higher data processing speeds. Therefore, the terminal performs cell switching based on the CHO command received by the source base station, so that the data processing capability of the candidate base station corresponding to the switched target cell is stronger, and the communication effect of the terminal after cell switching is better. In addition, since part of CHO commands are sent to the source base station after a preset period of time from the sending of CHO requests by the source base station, the source base station does not receive the part of CHO commands any more, so that the terminal does not obtain the part of CHO commands, and the terminal does not perform condition monitoring on candidate cells corresponding to the part of CHO commands, thereby further controlling the number of candidate cells to be monitored in the process of performing cell switching by the terminal.

Referring to fig. 5, a flowchart of a fifth cell handover method according to an embodiment of the present invention is shown, and compared with the embodiment shown in fig. 3A, the above step S103C may be implemented by the following steps S103C1-S103C 2.

S103C1: if the total data volume of the received CHO commands is larger than the preset maximum data volume, selecting the CHO commands with the data volume less than or equal to the maximum data volume according to the data volume of each CHO command and the maximum data volume.

Specifically, the maximum data amount may be a preset fixed data amount, for example, the R15 protocol involved in 5G communication limits the maximum data amount of the CHO command storable by the terminal to 34 kbytes, and the fixed data amount may be 34 kbytes. The maximum data size of the CHO command that can be accommodated by the RRC buffer (Radio Resource Control buffer ) may be limited in the size of the data size that can be accommodated by the RRC buffer for storing the CHO command in the terminal.

The data size of the RRC buffer capable of accommodating data is related to a protocol adopted by the terminal when the terminal communicates, for example, for an R15 protocol in a DC/CA (Dual Connectivity/carrier aggregation) scenario, the data size of the RRC buffer capable of accommodating data is 45 kbytes, and the RRC buffer stores configuration information, measurement configuration information, and CHO execution conditions of the source cell in addition to the CHO command. In most cases, the data amount of the configuration information and the measurement configuration information of the source cell is often 9 kbytes or less, the data amount of CHO execution conditions is often 2 kbytes or less, and the remaining storage space in the RRC buffer may be used for storing the CHO command. In most cases, the RRC buffer may store CHO commands for up to 8 candidate cells.

In one embodiment of the present invention, the total data amount of the CHO commands may be determined, and in the case where the total data amount is greater than a preset maximum data amount, CHO commands may be sequentially removed in order of from large to small or from small to large for each CHO command until the sum of the remaining CHO commands is less than or equal to the maximum data amount. The remaining CHO commands are the CHO commands selected.

In addition, a CHO command may be calculated in which the difference between the total data amount and the maximum data amount of each CHO command is calculated, the sum of the removed data amounts is equal to or greater than the difference, and the sum of the data amounts is closest to the difference.

Specifically, the CHO command may be deleted to remove the CHO command, or the CHO command may be retained but not transmitted to the terminal, which corresponds to the CHO command being removed.

In another embodiment of the present invention, CHO commands may also be selected by the following steps G-H.

Step G: the signal strength of each candidate cell is determined.

The signal strength of the candidate cell may be a signal strength included in a measurement report reported by the terminal to the source base station.

Step H: and selecting the CHO command with the data quantity less than or equal to the maximum data quantity according to the signal strength of the candidate cell corresponding to each CHO command, the data quantity of each CHO command and the maximum data quantity.

In one embodiment of the present invention, CHO commands corresponding to candidate cells may be sequentially removed in order of from small to large signal strengths of the candidate cells until the sum of the remaining CHO commands is equal to or less than the maximum data size. The remaining CHO commands are the CHO commands selected.

In another embodiment of the present invention, a difference between the signal strength of each candidate cell and the data amount of the CHO command corresponding to each candidate cell may be calculated, and the greater the calculated difference is, the higher the priority of the CHO command is. And sequentially removing the CHO commands corresponding to each candidate cell according to the order of the priority from low to high until the sum of the data volumes of the residual CHO commands is less than or equal to the maximum data volume. The remaining CHO commands are the CHO commands selected.

Specifically, since there is a gap between the magnitude of the signal intensity and the magnitude of the data amount, if the signal intensity and the data amount are directly subtracted, the difference between the calculated differences may be small, and it is difficult to prioritize the CHO commands. Therefore, the data amount can be divided by a preset dividend to obtain a calculation result. And calculating a difference between the signal strength and the calculation result as the priority. For example, the predetermined dividend may be 19.

S103C2: and sending the CHO execution condition and the selected CHO command to the terminal so that the terminal performs CHO switching when the CHO execution condition is met based on the selected CHO command.

Specifically, the sum of the data amounts of CHO commands sent by the source base station to the terminal is less than or equal to a preset maximum data amount, that is, when the storage space of the RRC buffer is limited, the RRC buffer can store the CHO commands sent by the source base station to the terminal, so that the terminal can perform cell handover normally.

From the above, since the sum of the data amounts of the selected CHO commands is smaller than or equal to the total data amount, the terminal can store the selected CHO commands, and the terminal can perform cell handover normally according to the CHO commands. In addition, the terminal only receives the selected CHO command and only monitors the condition of the candidate cells corresponding to the received CHO command, so that the number of the candidate cells which need to be monitored by the terminal can be further controlled.

Referring to fig. 6, a flowchart of a sixth cell handover method according to an embodiment of the present invention, compared with the embodiment shown in fig. 1, further includes the following steps S104-S105 after the step S103.

Specifically, in the step of executing step S103, the source base station instructs the terminal to perform cell switching for the determined candidate cell based on CHO, but in the process that the terminal has not completed cell switching yet, the following steps S104 to S105 may be executed.

S104: and determining whether the switching environment of the terminal for CHO switching is changed.

Specifically, the change of the handover environment of the CHO handover performed by the terminal may be caused by the change of the environment of the candidate cell, which is monitored by the terminal in the process of performing condition monitoring on the candidate cell, or may be caused by the change of the environment of the candidate cell, which is monitored by the source base station, or may be caused by the change of the environment of the source base station determining the source cell.

The change of the handover environment may be that the network load of the candidate base station of the candidate cell has reached the maximum network load, and the terminal subsequently handed over to the candidate cell cannot be provided with communication service.

In one embodiment of the present invention, it may be determined whether the handover environment in which the terminal performs CHO handover is changed through the following step I and/or step J.

Step I: and if the terminal sends the cell departure instruction, determining that the switching environment of the terminal for CHO switching is changed.

Wherein the cell departure indication is used for characterization: one or more of the candidate cells do not meet the handover requirements of the terminal.

Specifically, the terminal may be configured to turn on cell departure monitoring, that is, the terminal monitors whether the candidate cell meets the handover requirement of the terminal in the process of performing condition monitoring on the candidate cell. The reportOnLeave attribute value of the terminal may be set to true, which indicates that the terminal starts cell departure monitoring, otherwise, if the reportOnLeave attribute value of the terminal is set to false, the terminal will not perform cell departure monitoring.

Because the probability of the terminal switching to the candidate cell which does not meet the switching requirement is low, the terminal can stop the condition monitoring of the candidate cell which does not meet the switching requirement, and data processing resources are saved. It can be considered that the handover environment in which the terminal performs the cell handover is changed in the case where one or more cells among the candidate cells do not meet the handover requirement.

In one embodiment of the present invention, the terminal may initiate a leave event to report, and in a process of the terminal performing condition monitoring on the candidate cells, the terminal may send information indicating that one or more cells in the candidate cells do not meet the handover requirement to the source base station when it is monitored that one or more cells in the candidate cells do not meet the handover requirement, that is, one or more candidate cells trigger the leave event. The source base station may execute step S105 to update the CHO command of the candidate cell for the terminal, and notify the candidate base station corresponding to the candidate cell that does not meet the handover requirement, so that the candidate base station releases the resource reserved for terminal hand-in.

Specifically, the terminal may determine that one or more cells in the candidate cells do not meet the handover requirement in the case of mn+ofn+ocn+hys < Thresh.

Wherein Mn is a measurement result of the candidate cell, ofn is a specific frequency offset of the frequency of the candidate cell, ocn is a specific cell offset of the candidate cell, hys is a hysteresis of the departure event, and Thresh is a threshold of the departure event.

The value of Ofn may be determined by a parameter QoffsetFreq, which is issued in a measurement object of a measurement control message sent by the source base station to the terminal. The value of the oscn may be determined by a parameter cellindivididualoffset, and the value of the parameter cellindivididualoffset is not issued when the value of the parameter cellindivididualoffset is zero, and the value of the parameter cellindivididualoffset is not issued in the measurement control message when the value of the parameter cellindivididualoffset is zero. The value of the Hys may be issued by a parameter, hystersis, in the measurement configuration information included in the CHO command. The value of Thresh can be issued by the parameter a4-Threshold in the measurement configuration information.

Step J: if other switching modes are triggered, the switching environment of the terminal for CHO switching is determined to be changed.

The switching scheme other than the CHO scheme may be a conventional switching scheme or the like.

Specifically, if the source base station confirms that the terminal performs cell switching in a switching mode other than the CHO mode, the source base station may trigger other switching modes to instruct the terminal to perform cell switching based on the other switching modes, which is more beneficial to improving system performance. The source base station may send a handover command of another handover method to the terminal, so that step S105 may be performed to update the handover command.

After receiving the handover command of the other handover method, the terminal may perform cell handover based on the other handover method and terminate cell handover in CHO.

S105: if the handover environment is changed, updating the CHO command of the candidate cell for the terminal to perform CHO handover, and sending the updated CHO command to the terminal.

In one embodiment of the invention, CHO commands for candidate cells may be updated by the following step K and/or step L.

Step K: and re-determining a candidate cell for the terminal to perform CHO switching according to the network information of the adjacent cell, and obtaining a re-determined CHO command.

Specifically, steps S101-S103 may be executed again to redetermine the candidate cell, redetermine the CHO command of the candidate cell, and redetermine the CHO command of the candidate cell in a manner similar to that of the CHO command, which is not described in detail.

Step L: and deleting part of the CHO command from the CHO command sent to the terminal according to the changed switching environment.

In one embodiment of the present invention, when the terminal receives the cell departure prompt and determines that the switching environment of the terminal for cell switching is changed, the CHO command of the candidate cell that does not meet the switching requirement may be deleted.

In another embodiment of the present invention, when other handover methods are triggered and it is determined that the cell handover condition of the terminal is changed, the source base station needs to send a handover command to the terminal, where the handover command instructs the terminal to perform cell handover according to the other handover methods. Therefore, it is necessary to delete part of CHO commands sent to the terminal, so that the remaining storage space of the terminal can store the handover commands of other handover modes.

Specifically, the original CHO commands may be sequentially determined in order of the data amount from small to large or from large to small until the sum of the determined data amounts of the original CHO commands is equal to or greater than the data amounts of the switching commands of the other switching modes. The determined original CHO command is deleted.

In addition, the original CHO command may be determined such that the sum of the data amounts is equal to or greater than the original CHO command and the data amount closest to the switching command of the other switching system is determined, and the determined original CHO command may be deleted.

As can be seen from the above, in the case that the handover environment in which the terminal performs cell handover changes, the candidate cell to which the terminal is able to handover often changes, so that the handover command of the candidate cell can be updated, and the updated handover command is sent to the terminal, so that the terminal can complete cell handover based on the new handover command. And the process of cell switching by the terminal can be adapted to the change of the switching environment, and the terminal can continuously and smoothly complete the cell switching after the change of the switching environment.

The following describes, by way of specific examples, a cell handover scheme provided by an embodiment of the present invention.

Assuming that there are 8 neighbor cells, the source base station may select a candidate cell from the 8 neighbor cells. The signal intensity of the source cell is-103 dBm, the reference signal intensity is-95 dBm, and under the condition that the difference between the reference signal intensity and the signal intensity of the source cell is larger than 6dB, the speed type of the terminal is considered to be a high-speed moving type, otherwise, the speed type of the terminal is considered to be a low-speed moving type. The terminal starts the leaving event to report, and under the carrier aggregation scene, the terminal is configured with 4 service cells. The information of each neighbor cell is shown in table 1.

TABLE 1 neighbor cell information

Specifically, the source base station may first calculate that the difference between the reference signal strength and the signal strength of the source cell is 8dBm and greater than 6dB, so that the speed type of the terminal is considered to be a high-speed mobile type, and the maximum number of candidate cells selected may be 8.

In addition, the source base station can screen the signal intensity, namely, the RSRP is greater than the neighbor cells of-105 dBm, the selected neighbor cells are neighbor cells 1-8, the neighbor cells with the network load less than 50% are screened, the selected neighbor cells are neighbor cells 1-7, the neighbor cells switched by the terminal are screened, the selected neighbor cells are neighbor cells 1-6, and the neighbor cells 1-6 are determined to be candidate cells.

Further, the source base station sends a CHO request to candidate base stations corresponding to the selected candidate cells, namely neighbor cells 1-6, and receives a CHO command sent by the candidate base stations within 100ms from the CHO request sent by the source base station. Since the receiving delay of the neighboring cell 1-5 is less than 100ms, that is, the time difference between the time when the source base station receives the CHO command sent by the candidate base station of the neighboring cell 1-5 and the time when the source base station sends the CHO request is less than 100ms, the source base station can receive the CHO command sent by the candidate base station of the neighboring cell 1-5.

In addition, the information of CHO commands corresponding to each neighbor cell is shown in table 2.

TABLE 2 information of CHO commands corresponding to neighbor cells

Specifically, referring to table 2, the above terminal sends a measurement report to the source base station, which indicates that the neighbor cell 5 has been determined to be away, so that the above source base station may remove the neighbor cell 5 from the candidate cells, and the remaining candidate cells are neighbor cells 1 to 4.

In addition, the configuration information of the 4 serving cells configured by the terminal is 9 kbytes, the measurement configuration information of the terminal is 8 kbytes, and the storage space of the RRC buffer is 45 kbytes, so the source base station may consider that the size of the storage space of the RRC buffer remaining in the terminal is 45k-9k×4-8k=1 kbytes=8 kbytes, and considering that the size of the storage space required to be reserved in the RRC buffer is 1500bits, the terminal may only store CHO commands of 6500 bits. However, the total data amount of CHO commands corresponding to neighbor cells 1-4 is 6840 bits, so the terminal cannot store all CHO commands corresponding to neighbor cells 1-4. Selection is required among CHO commands corresponding to neighbor cells 1-4. The source cell can sequentially select the CHO commands with the summation of the sub-data amounts smaller than or equal to 6500bits as much as possible according to the priority obtained by calculation and the order from high priority to low, and can sequentially select the CHO commands of the neighbor cell 1, the neighbor cell 4 and the neighbor cell 2, wherein the summation of the sub-data amounts of the CHO commands of the neighbor cells 1, 2 and 4 is 4900 bits, less than 6500bits, and the CHO commands of the neighbor cell 3 are cleared. And the source base station sends CHO commands to the terminal for selected neighbor cells 1, 2 and 4. And in the process of carrying out cell switching, the terminal takes the adjacent cell 1, the adjacent cell 2 and the adjacent cell 4 as candidate cells, and carries out condition monitoring on the 3 cells until the target cell contained in the 3 cells is determined, and the terminal is switched to the target cell.

It can be seen that in the prior art, the source base station directly determines the neighboring cells 1-8 as candidate cells, and the terminal performs condition monitoring on 8 cells in total of the neighboring cells 1-8. However, in the scheme provided by the embodiment of the application, the terminal only monitors the conditions of the adjacent cells 1, 2 and 4. It can be seen that the number of candidate cells is controlled during cell handover compared to the prior art.

Corresponding to the foregoing cell switching method, referring to fig. 7, a schematic structural diagram of a cell switching apparatus according to an embodiment of the present application is provided, where the apparatus includes:

an information obtaining module 701, configured to obtain network information of a neighboring cell according to a neighboring cell list in a measurement report reported by a terminal;

a cell determining module 702, configured to determine a candidate cell list for cell handover by the terminal according to the obtained network information;

and a handover indication module 703, configured to instruct the terminal to perform a conditional handover CHO based on the determined candidate cell list.

It should be noted that, in the embodiment of the present application, the division of the modules is schematic, which is merely a logic function division, and other division manners may be implemented in actual implementation. In addition, each functional module in each embodiment of the present application may be integrated into one processing module, or each module may exist alone physically, or two or more modules may be integrated into one module. The integrated modules may be implemented in hardware or in software functional modules.

The integrated modules, if implemented in the form of software functional modules and sold or used as a stand-alone product, may be stored in a processor-readable storage medium. Based on such understanding, the technical solution of the present application may be embodied in essence or a part contributing to the prior art or all or part of the technical solution in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor (processor) 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 (Random Access Memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

In one embodiment of the present invention, the cell determining module 702 is specifically configured to:

determining a candidate cell list for cell handover by the terminal by at least one of:

selecting a cell with signal intensity higher than preset signal intensity in the adjacent cells to obtain a candidate cell list comprising the selected cell;

selecting a cell with the network load smaller than a preset network load in the adjacent cell to obtain a candidate cell list comprising the selected cell;

and acquiring the historical cell switching information of the terminal, and determining candidate cells from the cells which are subjected to historical switching of the terminal according to the acquired network information and the historical cell switching information to obtain a candidate cell list.

In one embodiment of the present invention, the cell determining module 702 includes:

the information obtaining sub-module is used for obtaining the network information of the source cell where the terminal is located;

a number determination submodule, configured to determine a maximum number of candidate cells according to the network information of the source cell;

and the cell determining submodule is used for determining candidate cells of which the total number is not more than the maximum number and which are subjected to cell switching by the terminal according to the obtained network information of the adjacent cells to obtain a candidate cell list.

In one embodiment of the present invention, the above number determination submodule is specifically configured to:

obtaining a speed type representing the moving speed of the terminal according to the signal intensity of the source cell and the reference signal intensity;

determining a maximum number of candidate cells based on a first principle for the speed type, wherein the first principle is: the higher the speed of the speed type characterization, the greater the maximum number of candidate cells.

In one embodiment of the present invention, the reference signal strength is: and determining the signal strength according to the historical signal strength of the source cell when the terminal in the source cell is cut out from the source cell.

In one embodiment of the present invention, the data determining submodule is specifically configured to:

determining a maximum number of candidate cells based on a second principle for history cut-out information, wherein the second principle is: the higher the cut-out failure rate represented by the historical cut-out information, the larger the maximum number of candidate cells, and the cut-out failure rate is: the device cuts out the probability of failure from the source cell.

In one embodiment of the present invention, the handover indication module 703 includes:

a request sending submodule, configured to send a CHO request to candidate base stations of candidate cells in the determined candidate cell list;

the response receiving submodule is used for receiving the CHO command sent by the candidate base station;

and the information sending submodule is used for sending the CHO execution conditions for carrying out CHO switching and the received CHO commands to the terminal so that the terminal carries out CHO switching when the CHO execution conditions are met based on the CHO commands aiming at the candidate cell.

In one embodiment of the present invention, the response receiving submodule is specifically configured to:

and receiving a CHO command sent by the candidate base station within a preset time period from the source base station sending the CHO request.

In one embodiment of the present invention, the information sending sub-module includes:

the information selection unit is used for selecting the CHO command with the data quantity sum smaller than or equal to the maximum data quantity according to the data quantity of each CHO command and the maximum data quantity if the total data quantity of the received CHO command is larger than the preset maximum data quantity;

and the information sending unit is used for sending the CHO execution conditions and the selected CHO commands to the terminal so that the terminal performs CHO switching when the CHO execution conditions are met based on the selected CHO commands.

In one embodiment of the present invention, the information selecting unit is specifically configured to:

if the total data volume of the received CHO command is larger than the preset maximum data volume, determining the signal intensity of each candidate cell;

And selecting the CHO commands with the data quantity less than or equal to the maximum data quantity according to the signal strength of the candidate cell corresponding to each CHO command, the data quantity of each CHO command and the maximum data quantity.

In one embodiment of the invention, the apparatus further comprises:

the environment change determining module is used for determining whether the switching environment of the terminal for CHO switching is changed or not;

and the information updating module is used for updating the CHO command of the candidate cell for the terminal to carry out CHO switching under the condition that the environment change determining module determines that the switching environment is changed, and sending the updated CHO command to the terminal.

In one embodiment of the present invention, the environment change determining module is specifically configured to:

if a cell departure instruction sent by the terminal is received, determining that the switching environment of the terminal for CHO switching is changed, wherein the cell departure instruction is used for representing: one or more cells in the candidate cells do not meet the handover requirements of the terminal;

and/or

And if other switching modes are triggered, determining that the switching environment of the terminal for CHO switching is changed.

In one embodiment of the present invention, the information updating module is specifically configured to:

under the condition that the environment change determining module determines that the switching environment is changed, a candidate cell for CHO switching of the terminal is redetermined according to the network information of the adjacent cell, and a redetermined CHO command is obtained;

and/or

When the environment change determination module determines that the switching environment is changed, a part of CHO commands are deleted from CHO commands sent to the terminal according to the changed switching environment.

Corresponding to the foregoing cell handover method, referring to fig. 8, there is provided a schematic structure of a base station, which includes, as a source base station, a memory 801, a transceiver 802, and a processor 803:

A memory 801 for storing a computer program; a transceiver 802 for transceiving data under the control of the processor 803; a processor 803 for reading the computer program in the memory 801 and performing the following operations:

according to the obtained information, determining a candidate cell list for cell switching of the terminal;

Where in FIG. 8, a bus architecture may comprise any number of interconnected buses and bridges, with one or more processors, represented in particular by processor 803, and various circuits of memory, represented by memory 801, linked together. The bus architecture may also link together various other circuits such as peripheral devices, voltage regulators, power management circuits, etc., which are well known in the art and, therefore, will not be described further herein. The bus interface provides an interface. The transceiver 802 may be a number of elements, including a transmitter and a receiver, providing a means for communicating with various other apparatus over a transmission medium, including wireless channels, wired channels, optical cables, etc. The processor 803 is responsible for managing the bus architecture and general processing, and the memory 801 may store data used by the processor 803 in performing operations.

The processor 803 may be a Central Processing Unit (CPU), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), a Field programmable gate array (Field-Programmable Gate Array, FPGA) or a complex programmable logic device (Complex Programmable Logic Device, CPLD), or it may employ a multi-core architecture.

In one embodiment of the present invention, the determining, according to the obtained network information, a candidate cell list for cell handover by the terminal specifically includes:

acquiring network information of a source cell where the terminal is located;

determining the maximum number of candidate cells according to the network information of the source cell;

and determining candidate cells of which the total number is not more than the maximum number and which are subjected to cell switching by the terminal according to the obtained network information of the adjacent cells, and obtaining a candidate cell list.

In one embodiment of the present invention, the determining the maximum number of candidate cells according to the network information of the source cell specifically includes:

In one embodiment of the present invention, the instructing the terminal to perform conditional handover CHO based on the determined candidate cell list specifically includes:

transmitting a CHO request to candidate base stations of candidate cells in the determined candidate cell list;

receiving a CHO command sent by a candidate base station;

and sending a CHO execution condition for carrying out CHO switching and a received CHO command to the terminal so that the terminal carries out CHO switching when the CHO execution condition is met based on the CHO command aiming at the candidate cell.

In one embodiment of the present invention, the receiving the CHO command sent by the candidate base station specifically includes:

In one embodiment of the present invention, the sending, to the terminal, CHO execution conditions for performing CHO handover and a received CHO command specifically includes:

If the total data volume of the received CHO commands is larger than the preset maximum data volume, selecting the CHO commands with the data volume sum smaller than or equal to the maximum data volume according to the data volume of each CHO command and the maximum data volume;

and sending the CHO execution condition and the selected CHO command to the terminal.

In one embodiment of the present invention, the CHO command selecting a sum of data amounts equal to or less than the maximum data amount according to the data amount of each CHO command and the maximum data amount specifically includes:

determining the signal strength of each candidate cell;

In one embodiment of the present invention, after the instructing the terminal to perform conditional handover CHO based on the determined candidate cell list, the method further includes:

determining whether the switching environment of the terminal for CHO switching is changed or not;

and if the switching environment is changed, updating the CHO command of the candidate cell for the terminal to perform CHO switching, and sending the updated CHO command to the terminal.

In one embodiment of the present invention, the determining whether the switching environment of CHO switching performed by the terminal is changed specifically includes:

And/or

In one embodiment of the present invention, the updating the CHO command of the candidate cell for CHO handover by the terminal specifically includes:

according to the network information of the adjacent cells, the candidate cell for CHO switching of the terminal is redetermined, and a redetermined CHO command is obtained;

and/or

And deleting part of CHO commands from the CHO commands sent to the terminal according to the changed switching environment.

In yet another embodiment of the present invention, there is also provided a computer readable storage medium having stored therein a computer program which when executed by a processor implements the steps of any of the cell handover methods described above.

The processor-readable storage medium may be any available medium or data storage device that can be accessed by a processor, including, but not limited to, magnetic storage (e.g., floppy disks, hard disks, magnetic tape, magneto-optical disks (MOs), etc.), optical storage (e.g., CD, DVD, BD, HVD, etc.), semiconductor storage (e.g., ROM, EPROM, EEPROM, nonvolatile storage (NAND FLASH), solid State Disk (SSD)), and the like.

Under the condition that the computer program stored in the computer readable storage medium provided by the embodiment of the invention is executed to control the terminal to carry out cell switching, the source base station does not directly determine a candidate cell list containing a preset number of candidate cells, but determines the candidate cell list according to the network information of the neighbor cells. That is, network information of the neighboring cells is obtained based on a measurement report reported by the terminal, candidate cells are dynamically selected, and a candidate cell list is determined, so that the selected candidate cells can be more suitable for the terminal, the number of the selected candidate cells can also change along with the change of the network information of the neighboring cells, and a preset number of candidate cells are not selected uniformly. Therefore, not only can the final selected candidate cell be enabled to contribute to cell handover of the terminal, but also unnecessary cells can be eliminated from the candidate cells, and thus the number of candidate cells in the conditional handover process can be controlled.

In a further embodiment of the present invention, there is also provided a computer program product containing instructions which, when run on a computer, cause the computer to perform the steps of the cell handover method of any of the above embodiments.

Under the condition that the computer program control terminal provided by the embodiment of the invention is executed to carry out cell switching, the source base station does not directly determine a candidate cell list comprising a preset number of candidate cells, but determines the candidate cell list according to the network information of the adjacent cells. That is, network information of the neighboring cells is obtained based on a measurement report reported by the terminal, candidate cells are dynamically selected, and a candidate cell list is determined, so that the selected candidate cells can be more suitable for the terminal, the number of the selected candidate cells can also change along with the change of the network information of the neighboring cells, and a preset number of candidate cells are not selected uniformly. Therefore, not only can the final selected candidate cell be enabled to contribute to cell handover of the terminal, but also unnecessary cells can be eliminated from the candidate cells, and thus the number of candidate cells in the conditional handover process can be controlled.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, produces a flow or function in accordance with embodiments of the present invention, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another, for example, by wired (e.g., coaxial cable, optical fiber, digital Subscriber Line (DSL)), or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains an integration of one or more available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid State Disk (SSD)), etc.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

In this specification, each embodiment is described in a related manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for the apparatus, base station, storage medium, and computer program embodiments, the description is relatively simple, as it is substantially similar to the method embodiments, with reference to the portions of the method embodiments that are relevant.

It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, magnetic disk storage, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer-executable instructions. These computer-executable instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These processor-executable instructions may also be stored in a processor-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the processor-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These processor-executable instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. A method of cell handover, the method comprising:

instructing the terminal to perform conditional handover CHO based on the determined candidate cell list;

if a cell departure instruction sent by the terminal and/or other switching modes are triggered, determining that the switching environment of the terminal for CHO switching is changed, wherein the cell departure instruction is used for representing: one or more cells in the candidate cells do not meet the switching requirement of the terminal, and the terminal determines that one or more cells in the candidate cells do not meet the switching requirement under the condition that Mn+ofn+Ocn+Hys < Thresh, wherein Mn is a measurement result of the candidate cells, ofn is a specific frequency bias of the frequency of the candidate cells, ocn is a specific cell bias of the candidate cells, hys is a leaving event hysteresis quantity, and Thresh is a leaving event threshold value;

2. The method according to claim 1, wherein the determining a candidate cell list for cell handover by the terminal according to the obtained network information comprises:

3. The method according to claim 1, wherein the determining a candidate cell list for cell handover by the terminal according to the obtained network information comprises:

acquiring network information of a source cell where the terminal is located;

4. A method according to claim 3, wherein said determining the maximum number of candidate cells based on the network information of the source cell comprises:

5. The method of claim 4, wherein the reference signal strength is: and determining the signal strength according to the historical signal strength of the source cell when the terminal in the source cell is cut out from the source cell.

6. A method according to claim 3, wherein said determining the maximum number of candidate cells based on the network information of the source cell comprises:

7. The method according to any of claims 1-6, characterized in that the instructing the terminal to perform a conditional handover CHO based on the determined candidate cell list comprises:

receiving a CHO command sent by a candidate base station;

8. The method of claim 7, wherein the receiving CHO commands sent by candidate base stations comprises:

9. The method according to claim 7, wherein the sending CHO execution conditions for CHO handover and the received CHO commands to the terminal comprises:

10. The method according to claim 9, wherein selecting CHO commands having a sum of data amounts equal to or less than the maximum data amount according to the data amount of each CHO command and the maximum data amount comprises:

determining the signal strength of each candidate cell;

11. The method according to claim 1, wherein updating CHO commands for candidate cells for CHO handover of the terminal comprises:

and/or

12. A cell switching apparatus, the apparatus comprising:

the switching indication module is used for indicating the terminal to perform conditional switching CHO based on the determined candidate cell list;

the environment change determining module is configured to determine that a change occurs in a switching environment of CHO switching performed by the terminal if a cell departure indication sent by the terminal is received and/or other switching modes are triggered, where the cell departure indication is used for characterizing: one or more cells in the candidate cells do not meet the switching requirement of the terminal, and the terminal determines that one or more cells in the candidate cells do not meet the switching requirement under the condition that Mn+ofn+Ocn+Hys < Thresh, wherein Mn is a measurement result of the candidate cells, ofn is a specific frequency bias of the frequency of the candidate cells, ocn is a specific cell bias of the candidate cells, hys is a leaving event hysteresis quantity, and Thresh is a leaving event threshold value;

13. A base station comprising a memory, a transceiver, and a processor:

14. The base station according to claim 13, wherein the determining the candidate cell list for cell handover by the terminal according to the obtained network information specifically comprises:

15. The base station according to claim 13, wherein the determining the candidate cell list for cell handover by the terminal according to the obtained network information specifically comprises:

Acquiring network information of a source cell where the terminal is located;

16. The base station according to claim 15, wherein said determining the maximum number of candidate cells based on the network information of the source cell comprises:

17. The base station of claim 16, wherein the reference signal strength is: and determining the signal strength according to the historical signal strength of the source cell when the terminal in the source cell is cut out from the source cell.

18. The base station according to claim 15, wherein said determining the maximum number of candidate cells based on the network information of the source cell comprises:

19. The base station according to any of the claims 13-18, characterized in that said instructing the terminal to perform a conditional handover CHO based on the determined candidate cell list, in particular comprising:

receiving a CHO command sent by a candidate base station;

20. The base station according to claim 19, wherein the receiving the CHO command sent by the candidate base station specifically comprises:

21. The base station according to claim 19, wherein the sending, to the terminal, CHO execution conditions for performing CHO handover and the received CHO commands, specifically comprises:

22. The base station according to claim 21, wherein the CHO commands with a sum of data amounts equal to or less than the maximum data amount are selected according to the data amount of each CHO command and the maximum data amount, specifically comprising:

determining the signal strength of each candidate cell;

23. The base station according to claim 13, wherein the updating CHO commands of candidate cells for CHO handover of the terminal specifically comprises:

and/or

24. A processor-readable storage medium, characterized in that the processor-readable storage medium stores a computer program for causing the processor to perform the method of any one of claims 1 to 11.