CN114466416B

CN114466416B - Cell switching method and device

Info

Publication number: CN114466416B
Application number: CN202011250910.7A
Authority: CN
Inventors: 程运; 李姮; 张一鸣
Original assignee: Datang Mobile Communications Equipment Co Ltd
Current assignee: Datang Mobile Communications Equipment Co Ltd
Priority date: 2020-11-10
Filing date: 2020-11-10
Publication date: 2023-12-01
Anticipated expiration: 2040-11-10
Also published as: CN114466416A

Abstract

The embodiment of the invention provides a cell switching method and a cell switching device, wherein the method comprises the following steps: under the condition that an evolved packet system fallback EPS fallback needs to be initiated for a target terminal to realize voice service, acquiring the switching success rate of each long term evolution LTE neighbor cell corresponding to an NR cell; according to the switching success rate, determining a candidate LTE cell in the LTE neighbor cells, and sending a measurement reconfiguration message to the target terminal, wherein the measurement reconfiguration message carries identification information of the candidate LTE cell; receiving neighbor cell measurement results of candidate LTE cells meeting measurement reporting conditions returned by the target terminal in response to the measurement reconfiguration message; according to the neighbor cell measurement result, determining a target LTE cell in the candidate LTE cells meeting the measurement reporting condition; and sending a switching command to the target terminal so as to enable the target terminal to be switched to the target LTE cell. The embodiment of the invention can reduce the time delay of the voice service and ensure the continuity of the voice service.

Description

Cell switching method and device

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a cell handover method and apparatus.

Background

Two voice access modes are defined in a 5G (5 th generation mobile networks, fifth generation mobile communication technology) NR (New Radio) system: a Voice over NR (new air interface carrying Voice) mode and an EPS fallback (EPS fallback) mode.

The VoNR mode refers to providing voice service based on IMS (IP Multiple Subsystem, IP multimedia subsystem) by the 5G access network and the core network, and the EPS fallback mode refers to the terminal falling back to 4G when initiating an IMS call on the 5G network, and implementing voice service through the 4G network. When the terminal residing in the NR has Voice service and the NR can not provide the VoNR, the network side initiates an EPS fallback flow, falls back to LTE (Long Term Evolution ), and establishes VoLTE (Voice over LTE, LTE bearing Voice) service to provide the Voice service.

Under normal conditions, after triggering an EPS fallback flow, the NR base station selects an LTE cell of the neighbor list to switch or redirect, and successfully falls back to 4G LTE to realize voice service. However, under abnormal conditions, when the NR selects one LTE cell to fail in handover, a blind redirection flow is triggered, wherein the blind redirection flow comprises the issuing of a blind redirection LTE frequency point, the UE performs blind cell searching according to a designated frequency point, measures the cell signal strength and selects the cell with the best signal access, the whole process consumes longer time, increases the time delay of voice service, and influences the continuity and user experience of the voice service.

Disclosure of Invention

The embodiment of the invention provides a cell switching method and a cell switching device, which can reduce the probability of failure of EPS fallback caused by abnormality of a target LTE cell, and further reduce the probability of triggering a blind redirection flow, so that the time delay of voice service can be reduced, the continuity of the voice service is ensured, and the user experience is improved.

The embodiment of the invention provides a cell switching method which is applied to an NR base station and comprises the following steps:

under the condition that an evolved packet system fallback (EPS) fallback is required to be initiated for a target terminal to realize voice service, acquiring the switching success rate of each Long Term Evolution (LTE) neighbor cell corresponding to an NR cell, wherein the NR cell is a service cell of the NR base station;

according to the switching success rate, determining a candidate LTE cell in the LTE neighbor cells, and sending a measurement reconfiguration message to the target terminal, wherein the measurement reconfiguration message carries identification information of the candidate LTE cell;

receiving neighbor cell measurement results of candidate LTE cells meeting measurement reporting conditions returned by the target terminal in response to the measurement reconfiguration message;

according to the neighbor cell measurement result, determining a target LTE cell in the candidate LTE cells meeting the measurement reporting condition;

and sending a switching command to the target terminal so as to enable the target terminal to be switched to the target LTE cell.

The embodiment of the invention provides a cell switching device which is applied to an NR base station, and comprises the following components:

the switching success rate acquisition module is used for acquiring the switching success rate of each Long Term Evolution (LTE) neighbor cell corresponding to an NR cell under the condition that the situation that an evolved packet system fallback (EPS) is required to be initiated for a target terminal to realize voice service is determined, wherein the NR cell is a service cell of the NR base station;

the candidate cell determining module is used for determining candidate LTE cells in the LTE neighbor cells according to the switching success rate, and sending measurement reconfiguration messages to the target terminal, wherein the measurement reconfiguration messages carry identification information of the candidate LTE cells;

the measurement result receiving module is used for receiving neighbor cell measurement results of the candidate LTE cells meeting the measurement reporting condition, which are returned by the target terminal in response to the measurement reconfiguration message;

the target cell determining module is used for determining a target LTE cell in the candidate LTE cells meeting the measurement reporting condition according to the neighbor cell measurement result;

and the switching command sending module is used for sending a switching command to the target terminal so as to enable the target terminal to be switched to the target LTE cell.

The embodiment of the invention has the following advantages:

the embodiment of the invention improves the scheme of selecting the target LTE cell in the EPS fallback flow based on measurement switching. After determining that EPS fallback needs to be initiated for the target terminal to realize voice service, and before triggering the target terminal to execute measurement, acquiring the switching success rate of each LTE neighbor cell corresponding to the NR cell, and screening candidate LTE cells with higher switching success rate to participate in measurement, thereby the finally determined target LTE cell also has higher switching success rate, the probability of failure in switching LTE cells in the EPS fallback process can be reduced, and the probability of triggering the blind redirection process can be further reduced, thereby the continuity of voice service can be ensured, the time delay of voice service is reduced, the conversation quality is improved, and the user experience is improved.

Drawings

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

Fig. 1 shows a schematic EPS fallback flow diagram based on measurement handover;

FIG. 2 shows a blind redirection flow schematic;

fig. 3 shows a flow chart of an embodiment of a cell handover method of the present invention;

fig. 4 shows a schematic flow chart of a NR base station of the present invention for screening candidate LTE cells for measurement in an EPS fallback procedure;

fig. 5 shows a statistical flow diagram of a handover preparation number N1 and a handover success number N2 of an NR cell corresponding to a certain LTE neighboring cell according to the present invention;

fig. 6 shows a block diagram of an embodiment of a cell switching device according to the invention;

fig. 7 shows a schematic structural diagram of an electronic device provided by the invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

For the 5G terminal, the processes of attaching, registering and the like are carried out after the terminal is started, and the terminal enters an idle state after IMS registration is carried out. Thereafter, when the idle state terminal has the calling/called voice service, a session establishment procedure of the IMS domain, the 5G system, such as transmitting Invite signaling to the IMS, etc., is triggered. After Invite signaling to IMS, the IMS instructs the core network (5G), and the core network (5G) initiates PDU SESSION MODIFY REQUEST (Protocol Data Unit, protocol data unit; SESSION, PDU SESSION modification request) to the base station (5G) to establish a bearer (QoS flow) for IMS voice. The base station (5G) decides to use VoNR or trigger EPS fallback to implement voice service according to UE capability, AMF (Access and Mobility ManagementFunction access and mobility management function) indication, network configuration (whether there is a network interface between the 5G network and the 4G network), radio conditions (radio environment information), and the like. If it is decided to initiate EPS fallback, a measurement report is requested to the terminal and PDU SESSION MODIFY REQUEST is rejected informing the core network (5G) that IMS fallback is to be performed.

Referring to fig. 1, a schematic diagram of an EPS fallback flow based on measurement handover is shown. The flow shown in fig. 1 is described as follows:

a1, UE (User Equipment/User/terminal) initiates a Voice Service Request (Service Request).

A2, UE and gndeb (NR base station) complete RRC (Radio Resource Control ) connection setup.

A3, gNodeB transparently passes Service Request to 5GC (5G Core Network) through INITIAL UE MESSAGE. The 5G core network mainly includes AMF (Access and Mobility Management Function, access and mobility management functions), SMF (Session Management Function, session management functions), UPF (User Plane Function, user plane management functions).

A4, the UE and the 5GC finish authentication and NAS (Non-access stratum) encryption negotiation flow.

A5, gNodeB receives INITIAL CONTEXT SETUP REQUEST to establish UE context and IMS signaling bearer.

A6, the gNodeB completes the air interface AS (Access stratum) security algorithm configuration and the UE capability query process.

A7, gNodeB send INITIAL CONTEXT SETUP RESPONSE indicates that initial context setup is complete.

A8, UE initiates SIP (Session Initiation Protocol ) INVITE message to 5GC requesting to establish voice session.

And A9, the gNodeB receives the PDU SESSION RESOURCE MODIFY REQUEST message and instructs the gNodeB to establish the voice special bearer with the value of 5QI=1.

A10, the gNodeB transmits heterogeneous system B1 event measurement and receives neighbor cell measurement results reported by the UE, and the gNodeB determines a target LTE cell according to the neighbor cell measurement results. The B1 event measurement includes the following messages:

gNodeB to UE: RRC Reconfiguration, neighbor measurement configuration.

Ue to gNodeB: RRC Reconfiguration Complete.

Ue to gNodeB: measurementReport, UE reports neighbor cell measurements.

A11, gNodeB replies to 5GC with a rejection PDU session modification and indicates IMS Voice Fallback.

A12, the gNodeB sends a switching request to the 5GC according to the switching parameter configuration and the UE capability judgment.

The a13, 5GC forwards the UE context information to the EPC (Evolved Packet Core,4G core network). The EPC mainly includes network elements such as MME (Mobility Management Entity, mobility management node function), SGW (Serving GateWay), PGW (PDN GateWay), and the like.

A14, EPC initiates a handover request to eNodeB (LTE base station).

A15, EPC receives switching request response of eNodeB.

A16, EPC forwards the handover request success response message of eNodeB to 5 GC.

A17, 5GC initiates a handover command to gNodeB.

A18, gNodeB sends a handover command (mobile FromNRCommand) to the UE.

A19, the UE is switched to the target LTE cell.

A20, eNodeB informs EPC that handover to 4G was successful.

A21, 5GC requires that the enodebs release the UE context.

TAU (Tracking Area Update ) flow is initiated among A22, UE and EPC.

A23, EPC triggers the establishment of a voice specific bearer with qci=1.

The above steps a12 to a21 are a complete and normal signaling procedure for switching the terminal from the NR cell to the LTE cell. When any one of the steps is abnormal, for example, failure of the terminal to access the target LTE cell or transmission failure between the target LTE cell and the MME may cause failure of the EPS fallback procedure, a blind redirection procedure is triggered, and referring to fig. 2, a schematic diagram of the blind redirection procedure is shown. As shown in fig. 2, the blind redirection procedure is illustrated as follows:

b1 and NR base stations send a context release request to 5GC, and carry EPS fallback caused by IMS voice.

The B2, 5GC informs the NR base station to release the UE context.

And B3, the NR base station selects one LTE frequency point for issuing according to the coverage conditions of the LTE cell and the NR cell and the priority of the LTE frequency point.

And B4, the NR base station sends RRC Release redirection information to the UE, carrying the LTE frequency point.

And B5, the UE searches cells on the LTE designated by the LTE frequency point and selects the cell with the strongest signal.

B6, the UE is accessed in the cell with the strongest signal and performs VoLTE flow.

The blind search process in the step B5 takes a long time, and even a few minutes in extreme cases, so that the time delay of the voice service is increased, and the continuity and the user experience of the voice service are affected. Therefore, the method optimizes the scheme of selecting the target LTE cell in the EPS fallback flow based on measurement switching so as to reduce the probability of failure of the EPS fallback caused by the target LTE cell, and further reduce the probability of triggering the blind redirection flow, thereby guaranteeing the continuity of voice service, reducing the time delay of the voice service, improving the conversation quality and improving the user experience.

Referring to fig. 3, a flowchart of an embodiment of a cell handover method according to the present invention is shown, where the method is applied to an NR base station, and may specifically include:

step 101, under the condition that an evolved packet system fallback EPS fallback needs to be initiated for a target terminal to realize voice service, acquiring the switching success rate of each long term evolution LTE neighbor cell corresponding to an NR cell, wherein the NR cell is a service cell of the NR base station;

step 102, determining a candidate LTE cell in the LTE neighbor cells according to the switching success rate, and sending a measurement reconfiguration message to the target terminal, wherein the measurement reconfiguration message carries identification information of the candidate LTE cell;

step 103, receiving neighbor cell measurement results of candidate LTE cells meeting measurement reporting conditions returned by the target terminal in response to the measurement reconfiguration message;

step 104, determining a target LTE cell from the candidate LTE cells meeting the measurement reporting condition according to the neighbor cell measurement result;

step 105, a handover command is sent to the target terminal, so that the target terminal is handed over to the target LTE cell.

The cell switching method provided by the embodiment of the invention improves the scheme of selecting the target LTE cell in the EPS fallback flow based on measurement switching. The method is applicable to NR base stations (i.e. 5G base stations).

The target terminal refers to a terminal currently residing in an NR cell and needing voice service. Wherein, the NR cell is the serving cell of the NR base station. Specifically, when the NR base station receives a PDU SESSION MODIFY REQUEST (PDU session modification request) message sent by the core network AMF, it may determine whether there is a QosFlow with a 5QI equal to 1 in the message, and if there is a QosFlow, it indicates that the terminal needs to perform voice service. Where 5QI is a scalar used to index a 5G QoS characteristic.

When the target terminal residing in the NR cell has voice service and the NR base station can not provide VoNR, the EPS fallback process needs to be initiated for the target terminal, the target terminal falls back to LTE, and VoLTE is established to realize voice service.

Further, the interoperation switch of the NR base station is on and the interoperation type is configured to be a measurement-based handover. That is, if it is determined that the EPS fallback procedure needs to be initiated, a B1 measurement event needs to be triggered at this time, a frequency point and a cell list of an LTE neighboring cell are configured, and a measurement reconfiguration message is sent to the target terminal to notify the target terminal to perform measurement. B1 event, i.e. the inter-system neighbor signal is stronger than the absolute threshold.

The target LTE cell is a target cell in an EPS fallback flow, and the NR cell is a source cell. Namely, the target terminal is switched from the NR cell to the target LTE cell through an EPS fallback procedure. In order to reduce the probability of failure of EPS fallback caused by improper selection of a target LTE cell, the embodiment of the invention acquires the switching success rate of each LTE neighbor cell corresponding to the NR cell under the condition that the EPS fallback is required to be initiated for the target terminal to realize voice service, so as to screen the target LTE cell with higher switching success rate.

In one example, for a certain NR base station, it is assumed that the target terminal UE1 resides in an NR cell covered by the NR base station, denoted as gNB 1. When the target terminal UE1 has a voice service and the NR base station gNB1 cannot provide VoNR, an EPS fallback needs to be initiated for the target terminal UE1 to implement the voice service. The LTE neighbor cells of the NR cell are assumed to include cells 1 to 8, and the corresponding PCIs (Physical Cell Identifier, physical cell identities) are 50, 60, 51, 52, 61, 62, 66, 55, respectively. The handover success rate Psucc of the NR cell corresponding to the LTE neighbor cell is obtained, and the obtained result is shown in table 1. The FREQ is a frequency point of an LTE neighbor cell.

TABLE 1

LTE neighbor cell	PCI	FREQ	Psucc
				cell1	50	23500	0.86
cell2	60	23600	0.75
				cell3	51	23500	0.94
cell4	52	23500	0.88
				cell5	61	23600	0.96
cell6	62	23600	0.72
				cell7	66	23600	0.90
cell8	55	23500	0.83

And then, determining a candidate LTE cell in the LTE neighbor cells according to the acquired switching success rate, and sending a measurement reconfiguration message to the target terminal to inform the target terminal of measurement, wherein the measurement reconfiguration message carries identification information of the candidate LTE cell.

Specifically, the LTE neighbor cells in table 1 may be ranked in order of high-to-low handover success rate, the obtained ranking result is shown in table 2, and the LTE neighbor cells of n before ranking are selected as candidate LTE cells. n is an integer greater than or equal to 1, it being understood that n may be set according to actual needs, for example, n may be 5, 6, 10, etc. Assuming n is 6, in this example, it may be determined that the candidate LTE cell includes: cell5, cell3, cell7, cell4, cell1, cell8, the corresponding PCIs are respectively: 61. 51, 66, 52, 50, 55.

TABLE 2

After determining the candidate LTE cell, the NR base station may assemble a measurement reconfiguration message and send the measurement reconfiguration message to the target terminal to inform the target terminal to make a measurement, which refers to a heterogeneous system B1 event measurement. The embodiment of the invention takes the identification information of the selected candidate LTE cell as an element under measObjectEutra in the measurement reconfiguration message, specifically, the frequency point and PCI corresponding to the candidate LTE cell can be sent to the target terminal through the cell measObjectEUTRA- > cellsToAddModListEUTRAN of the following reconfiguration message. And after receiving the measurement reconfiguration message sent by the NR base station, the target terminal performs B1 measurement and reports neighbor cell measurement results of the candidate LTE cells meeting the B1 measurement reporting condition to the NR base station. Meeting the B1 measurement reporting condition indicates that the quality of the neighboring cells of the different systems is higher than a certain threshold, and the candidate LTE cells meeting the condition are reported. Referring to fig. 4, a flow chart of a NR base station screening candidate LTE cells for measurement in an EPS fallback procedure according to an embodiment of the present invention is shown. Wherein RRCRECONfigure is measurement reconfiguration message, and Measurementreport is neighbor measurement result reported by the terminal.

The neighbor cell measurement result may include a physical cell identifier of a neighbor cell, a cell SSB (Synchronization Signal and PBCH block, synchronization Signal and PBCH (Physical Broadcast Channel, physical broadcast channel) block), or a CSI-RS (Channel State Information-Reference Signal) Signal measurement value. Among the candidate LTE cells satisfying the B1 measurement report condition, the target LTE cell is determined based on the RSRP (Reference Signal Receiving Power, reference signal received power) measurement value of the candidate LTE cell, and for example, the candidate LTE cell with the best reference signal measurement value may be determined as the target LTE cell.

After determining a target LTE cell, the NR base station sends a handover command (mobilityfrommrcommand) to a target terminal to cause the target terminal to handover to the target LTE cell. It should be noted that, for EPS fallback based on measurement handover, the voice traffic and data traffic (if any) of the terminal will be handed over to the LTE side together.

After determining that EPS fallback needs to be initiated for a target terminal to realize voice service and before triggering the target terminal to execute B1 measurement, the embodiment of the invention screens candidate LTE cells with higher switching success rate to participate in B1 measurement, so that the finally determined target LTE cells also have higher switching success rate, the probability of failure in switching LTE cells in the EPS fallback process can be reduced, the probability of triggering a blind redirection process can be further reduced, thereby ensuring the continuity of voice service, reducing the time delay of voice service, improving call quality and improving user experience.

In an optional embodiment of the present invention, before the obtaining the handover success rate of each LTE neighboring cell corresponding to the NR cell in step 101, the method further includes:

step S11, counting the switching preparation times of the LTE neighbor cells at a first moment and counting the switching success times of the LTE neighbor cells at a second moment for each LTE neighbor cell of the NR cells; the first moment is a moment after the NR base station successfully sends a switching request message to a core network, and the second moment is a moment after the NR base station receives a terminal context releasing command sent by the core network;

step S12, calculating the switching success rate of the NR cell corresponding to the LTE neighbor cell according to the counted switching preparation times and switching success times of the LTE neighbor cell in the preset time;

and step S13, recording the switching success rate of the NR base station corresponding to each LTE neighbor cell.

In order to reduce the probability of failure of EPS fallback caused by failure of a terminal to access a target LTE cell or transmission failure between the target LTE cell and an MME, and the like, the embodiment of the invention pre-counts and stores the success rate of switching the terminal from the NR cell to each LTE neighbor cell by the NR base station so as to record the success rate of switching the NR cell station corresponding to each LTE neighbor cell.

Specifically, in the embodiment of the present invention, a statistics time (a first time) of a handover preparation number of each LTE neighboring cell and a statistics time (a second time) of a handover success number of each LTE neighboring cell need to be determined, and according to the handover preparation number of each LTE neighboring cell counted at the first time and the handover success number of each LTE neighboring cell counted at the second time, a handover success rate Psucc of each LTE neighboring cell corresponding to the NR base station may be calculated.

Further, before counting the number of preparation times of handover of the LTE neighboring cell at the first time and counting the number of successful times of handover of the LTE neighboring cell at the second time, the method may further include: initializing the switching preparation times and the switching success times;

the counting of the switching preparation times of the LTE neighbor cell at the first moment and the counting of the switching success times of the LTE neighbor cell at the second moment comprise the following steps:

for the LTE neighbor cell, after the NR base station successfully sends a switching request message to a core network, the switching preparation times of the LTE neighbor cell are accumulated once, and after the NR base station receives a context command of a release terminal sent by the core network, the switching success times of the LTE neighbor cell are accumulated once.

Specifically, before counting the handover success rate of each LTE neighbor cell corresponding to the NR cell, the embodiments of the present invention initialize the handover preparation number and the handover success number of each neighbor cell first, for example, may initialize the handover preparation number and the handover success number of each neighbor cell to a certain initial value, for example, all initialize to 0.

The handover request message is a HANDOVER REQUIRED message, and when the NR base station successfully sends a handover request message to the core network once, which indicates that it is determined that the NR base station is ready to handover a terminal from an NR cell to an LTE neighboring cell, the number of handover preparations of the LTE neighboring cell may be accumulated once at this time. For example, for LTE neighbor cell5, assume that the current handover preparation number is 7, and the number of handover preparations for LTE neighbor cell5 after one accumulation is 8.

The context command of the release terminal is CONTEXT RELEASE COMMAND, and when the NR base station receives the context command of the release terminal sent by the core network, it indicates that it is determined that the NR base station successfully switches a certain terminal from an NR cell to a certain LTE neighboring cell at this time, and then the number of successful switching times of the LTE neighboring cell can be accumulated once at this time. For example, for LTE neighbor cell5, assuming that the current number of successful handover times is 5, when the NR base station receives a context command of a release terminal sent by the core network, which indicates that it is determined that the NR base station has successfully handed over a certain terminal from the NR cell to LTE neighbor cell5, the number of successful handover times of LTE neighbor cell5 is accumulated once, and after accumulation, the number of successful handover times of LTE neighbor cell5 is 6.

Referring to fig. 5, a statistical flow diagram of a handover preparation number N1 and a handover success number N2 of an NR cell corresponding to a certain LTE neighbor cell according to an embodiment of the present invention is shown. As shown in fig. 5, for the LTE neighbor cell, the initial values of N1 and N2 are both 0, when the NR base station successfully transmits a HANDOVER REQUIRED message to the AMF once, N1 is accumulated once, and when the handover is successful, that is, when the NR base station receives a UE CONTEXT RELEASE COMMAND message transmitted by the AMF, N2 is accumulated once. For this LTE neighbor cell, the NR base station has a handover success rate psucc=n2/N1 for this cell (LTE neighbor cell with a number of handover preparations N1 of 0 does not participate in statistics). And similarly, the success rate of switching the NR cell to other LTE neighbor cells can be calculated. For example, the success rate of handover of three LTE neighbor cells corresponding to an NR cell with a PCI of 20 within a preset time is counted, and the data are shown in table 3. The preset time can be selected according to actual needs, such as a week, a month and the like in the past.

TABLE 3 Table 3

In an optional embodiment of the present invention, the acquiring the handover success rate of each LTE neighboring cell corresponding to the NR cell in step 101 includes:

acquiring the switching success rate of each LTE neighbor cell corresponding to the NR cell through inquiring the history record; or,

and acquiring the switching success rate of each LTE neighbor cell corresponding to the NR cell by carrying out real-time calculation on the historical EPS fallback operation data of the NR base station.

It should be noted that, the embodiment of the present invention does not limit a specific manner of acquiring the handover success rate of each LTE neighboring cell corresponding to the NR cell. For example, in the EPS fallback procedure initiated by the NR base station each time, the number of preparation times of switching of a certain LTE neighboring cell is counted at a first time, and the number of successful times of switching of a certain LTE neighboring cell is counted at a second time, and according to the counted number of preparation times of switching of each LTE neighboring cell and the counted number of successful times of switching in a preset time, the success rate of switching of each LTE neighboring cell corresponding to the NR cell is calculated and stored, so that when the EPS fallback is initiated by the NR base station later, the success rate of switching of each LTE neighboring cell corresponding to the NR cell can be obtained by directly querying the stored history record. Or, when the NR base station initiates EPS fallback, the historical EPS fallback operation data of the NR base station can be obtained, and the switching success rate of each LTE neighbor cell corresponding to the NR cell can be calculated in real time according to the historical EPS fallback operation data of the NR base station. The real-time calculation process is the same as the calculation mode in the preliminary statistics process, and will not be described here again.

In order to obtain the switching success rate of each LTE neighbor cell corresponding to the NR cell more quickly. The first mode is preferably adopted in the embodiment of the invention.

In summary, the embodiment of the invention improves the scheme of selecting the target LTE cell in the EPS fallback flow based on measurement switching. After determining that EPS fallback needs to be initiated for the target terminal to realize voice service, and before triggering the target terminal to execute measurement, acquiring the switching success rate of each LTE neighbor cell corresponding to the NR cell, and screening candidate LTE cells with higher switching success rate to participate in measurement, thereby the finally determined target LTE cell also has higher switching success rate, the probability of failure in switching LTE cells in the EPS fallback process can be reduced, and the probability of triggering the blind redirection process can be further reduced, thereby the continuity of voice service can be ensured, the time delay of voice service is reduced, the conversation quality is improved, and the user experience is improved.

It should be noted that, for simplicity of description, the method embodiments are shown as a series of acts, but it should be understood by those skilled in the art that the embodiments are not limited by the order of acts, as some steps may occur in other orders or concurrently in accordance with the embodiments. Further, those skilled in the art will appreciate that the embodiments described in the specification are presently preferred embodiments, and that the acts are not necessarily required by the embodiments of the invention.

Device embodiment

Referring to fig. 6, there is shown a block diagram of an embodiment of a cell switching apparatus of the present invention, applied to an NR base station, which may specifically include:

the handover success rate obtaining module 601 is configured to obtain a handover success rate of each LTE neighbor cell corresponding to an NR cell, where the NR cell is a serving cell of the NR base station, under a condition that it is determined that an evolved packet system fallback EPS fallback needs to be initiated for a target terminal to implement a voice service;

a candidate cell determining module 602, configured to determine a candidate LTE cell in the LTE neighboring cell according to the handover success rate, and send a measurement reconfiguration message to the target terminal, where the measurement reconfiguration message carries identification information of the candidate LTE cell;

a measurement result receiving module 603, configured to receive a neighbor cell measurement result of a candidate LTE cell that satisfies a measurement reporting condition and is returned by the target terminal in response to the measurement reconfiguration message;

the target cell determining module 604 determines a target LTE cell from the candidate LTE cells satisfying the measurement report condition according to the neighbor cell measurement result;

and a handover command sending module 605 configured to send a handover command to the target terminal, so that the target terminal is handed over to the target LTE cell.

Optionally, the apparatus further comprises:

the frequency counting module is used for counting the switching preparation frequency of each LTE neighbor cell of the NR cells at a first moment and counting the switching success frequency of the LTE neighbor cells at a second moment; the first moment is a moment after the NR base station successfully sends a switching request message to a core network, and the second moment is a moment after the NR base station receives a terminal context releasing command sent by the core network;

the success rate calculation module is used for calculating the success rate of switching the NR cell corresponding to the LTE neighbor cell according to the counted switching preparation times and switching success times of the LTE neighbor cell in the preset time;

and the success rate recording module is used for recording the switching success rate of the NR base station corresponding to each LTE neighbor cell.

Optionally, the apparatus further comprises:

the initialization module is used for initializing the switching preparation times and the switching success times;

the frequency counting module is specifically configured to accumulate, for the LTE neighboring cell, the switching preparation frequency of the LTE neighboring cell once after the NR base station successfully sends a switching request message to a core network, and accumulate, for the LTE neighboring cell, the switching success frequency once after the NR base station receives a release terminal context command sent by the core network.

Optionally, the handover success rate acquisition module includes:

the first acquisition submodule is used for acquiring the switching success rate of each LTE neighbor cell corresponding to the NR cell through inquiring the history record; or,

and the second acquisition submodule is used for acquiring the switching success rate of each LTE neighbor cell corresponding to the NR cell by carrying out real-time calculation on the historical EPS fallback operation data of the NR base station.

Optionally, the interoperation switch of the NR base station is on and the interoperation type is configured as a measurement-based handover.

For the device embodiments, since they are substantially similar to the method embodiments, the description is relatively simple, and reference is made to the description of the method embodiments for relevant points.

In this specification, each embodiment is described in a progressive manner, and each embodiment is mainly described by differences from other embodiments, and identical and similar parts between the embodiments are all enough to be referred to each other.

The specific manner in which the various modules perform the operations in the apparatus of the above embodiments have been described in detail in connection with the embodiments of the method, and will not be described in detail herein.

The embodiment of the disclosure further provides an electronic device, referring to fig. 7, including: a processor 701, a memory 702, and a computer program 7021 stored on the memory and executable on the processor, which when executed implements the cell handover method of the foregoing embodiments.

Embodiments of the present disclosure also provide a processor-readable storage medium, which when executed by a processor of an electronic device, enables the electronic device to perform the cell handover method of the foregoing embodiments.

The algorithms and displays presented herein are not inherently related to any particular computer, virtual system, or other apparatus. Various general-purpose systems may also be used with the teachings herein. The required structure for a construction of such a system is apparent from the description above. In addition, embodiments of the present disclosure are not directed to any particular programming language. It will be appreciated that the contents of the embodiments of the present disclosure described herein may be implemented using various programming languages, and the above description of specific languages is provided for disclosure of enablement and best mode of the embodiments of the present disclosure.

In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the disclosure may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the disclosure, various features of embodiments of the disclosure are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, the disclosed method should not be construed as reflecting the intention that: i.e., an embodiment of the disclosure that claims require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this disclosure.

Those skilled in the art will appreciate that the modules in the apparatus of the embodiments may be adaptively changed and disposed in one or more apparatuses different from the embodiments. The modules or units or components of the embodiments may be combined into one module or unit or component and, furthermore, they may be divided into a plurality of sub-modules or sub-units or sub-components. Any combination of all features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or units of any method or apparatus so disclosed, may be used in combination, except insofar as at least some of such features and/or processes or units are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

Various component embodiments of the present disclosure may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art will appreciate that some or all of the functions of some or all of the components in a sorting device according to embodiments of the present disclosure may be implemented in practice using a microprocessor or Digital Signal Processor (DSP). Embodiments of the present disclosure may also be implemented as a device or apparatus program for performing part or all of the methods described herein. Such a program implementing embodiments of the present disclosure may be stored on a computer readable medium or may have the form of one or more signals. Such signals may be downloaded from an internet website, provided on a carrier signal, or provided in any other form.

It should be noted that the above-mentioned embodiments illustrate rather than limit the embodiments of the disclosure, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. Embodiments of the present disclosure may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The use of the words first, second, third, etc. do not denote any order. These words may be interpreted as names.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.

The foregoing description of the preferred embodiments of the present disclosure is not intended to limit the embodiments of the present disclosure, but is intended to cover any modifications, equivalents, and improvements made within the spirit and principles of the embodiments of the present disclosure.

The foregoing is merely a specific implementation of the embodiments of the disclosure, but the protection scope of the embodiments of the disclosure is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the embodiments of the disclosure, and the changes or substitutions are intended to be covered by the protection scope of the embodiments of the disclosure. Therefore, the protection scope of the embodiments of the present disclosure shall be subject to the protection scope of the claims.

Claims

1. A method for cell handover, applied to a new air interface NR base station, the method comprising:

sending a switching command to the target terminal so that the target terminal is switched to the target LTE cell;

before the handover success rate of each long term evolution LTE neighbor cell corresponding to the NR cell is obtained, the method further includes:

for each LTE neighbor cell of the NR cell, counting the switching preparation times of the LTE neighbor cell at a first moment, and counting the switching success times of the LTE neighbor cell at a second moment; the first moment is a moment after the NR base station successfully sends a switching request message to a core network, and the second moment is a moment after the NR base station receives a terminal context releasing command sent by the core network;

calculating the switching success rate of the NR cell corresponding to the LTE neighbor cell according to the switching preparation times and switching success times of the LTE neighbor cell counted in the preset time;

and recording the switching success rate of the NR base station corresponding to each LTE neighbor cell.

2. The method of claim 1, wherein counting the number of handover preparations for the LTE neighbor cell at a first time and counting the number of successful handovers for the LTE neighbor cell at a second time, the method further comprising:

initializing the switching preparation times and the switching success times;

3. The method of claim 1, wherein the obtaining the handover success rate of each LTE neighboring cell for NR cells comprises:

4. A method according to any of claims 1 to 3, characterized in that the interoperable switch of the NR base station is on and the interoperable type is configured as a measurement based handover.

5. A cell switching apparatus for use in an NR base station, the apparatus comprising:

a handover command sending module, configured to send a handover command to the target terminal, so that the target terminal is handed over to the target LTE cell;

the apparatus further comprises:

6. The apparatus of claim 5, wherein the apparatus further comprises:

7. The apparatus of claim 5, wherein the handover success rate acquisition module comprises:

8. The apparatus of any of claims 5 to 7, wherein the NR base station has an interoperable switch on and an interoperable type is configured to be a measurement-based handover.

9. An electronic device, comprising: processor, memory and computer program stored on the memory and executable on the processor, characterized in that the processor implements the cell handover method according to any of claims 1-4 when executing the program.

10. A processor-readable storage medium, wherein instructions in the processor-readable storage medium, when executed by a processor of an electronic device, enable the electronic device to perform the cell handover method of any one of claims 1-4.