CN115297505A

CN115297505A - Communication method, terminal, base station, storage medium, and electronic device

Info

Publication number: CN115297505A
Application number: CN202210929084.1A
Authority: CN
Inventors: 于金杨; 胡春雷; 谢伟良; 许晓航; 林平平
Original assignee: China Telecom Corp Ltd
Current assignee: China Telecom Corp Ltd
Priority date: 2022-08-03
Filing date: 2022-08-03
Publication date: 2022-11-04

Abstract

The disclosure relates to the technical field of communication, and provides a communication method and device, a computer readable storage medium and an electronic device. Wherein, the method comprises the following steps: the terminal receives the information of condition switching; when the terminal determines that the condition of condition switching is met, the terminal sends a first message to a source side base station, so that the source side base station stops scheduling the terminal, and sends communication data related to the terminal to a target base station indicated by the first message. According to the scheme, the source side base station can know the target base station to which the terminal is to be accessed through the first message, so that data can be directly forwarded to the target base station, and the network overhead is reduced while communication data are not lost.

Description

Communication method, terminal, base station, storage medium, and electronic device

Technical Field

The present disclosure relates to the field of communications technologies, and in particular, to a communication method, a terminal, a base station, a computer-readable storage medium, and an electronic device.

Background

In a Conditional Handover (CHO) process, one or more target base stations and Handover conditions corresponding to the target base stations are configured in an RRC (Radio Resource Control) reconfiguration message sent by a source base station to a terminal.

In order to solve the problem that the conditional handover has a packet loss under an UM (Unacknowledged Mode) bearer, in the related art, when an RRC reconfiguration message is sent from a source side base station to a terminal to configure a target base station and handover execution conditions, data forwarding is started to the target base station, and the source side base station does not know to which target base station the terminal is to be finally handed over at this time, so the source side base station can simultaneously forward data to each target base station involved in the conditional handover.

Obviously, when the target base station includes multiple target base stations, the source-side base station needs to forward data to the multiple target base stations at the same time, which increases network overhead. For an NTN (Non-Terrestrial network) network, since a cell covered by a satellite is wider and the number of terminals in the cell is greater, network overhead is greater.

It is to be noted that the information disclosed in the above background section is only for enhancement of understanding of the background of the present disclosure, and thus may include information that does not constitute prior art known to those of ordinary skill in the art.

Disclosure of Invention

An object of the present disclosure is to provide a communication method, a terminal, a base station, a computer-readable storage medium, and an electronic device, thereby improving the problem of high network overhead in conditional access at least to some extent.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows, or in part will be obvious from the description, or may be learned by practice of the disclosure.

According to a first aspect of the present disclosure, there is provided a communication method comprising: the terminal receives the information of condition switching; when the terminal determines that the condition of condition switching is met, the terminal sends a first message to a source side base station, so that the source side base station stops scheduling the terminal, and sends communication data related to the terminal to a target base station indicated by the first message.

In an exemplary embodiment of the present disclosure, based on the foregoing scheme, the first message includes one or more of a measurement report, a target radio resource control protocol message, and a target MAC control element message; the target wireless resource control protocol message carries the target identification of the target base station, and the target MAC layer control unit message carries the target identification of the target base station.

In an exemplary embodiment of the present disclosure, based on the foregoing scheme, when it is determined that the condition for conditional handover is satisfied, the sending, by the terminal, a first message to the source-side base station includes: and when the terminal determines that the condition of condition switching is met, the terminal sends a first message to the source side base station through the uplink scheduling-free resource.

In an exemplary embodiment of the present disclosure, based on the foregoing scheme, the method further includes: under the condition that the remaining uplink scheduling-free resources meet the resources occupied by the timing advance message, the terminal sends the timing advance message to the source side base station; and the remaining uplink scheduling-free resources are determined according to the uplink scheduling-free resources occupied by the first message, and the timing advance message is used for assisting the source side base station in determining the time for the terminal to start to switch to the target base station.

According to a second aspect of the present disclosure, there is provided a communication method comprising: the terminal receives the information of condition switching; when determining that the condition of conditional handover is met, the terminal sends access request information to a target base station indicated by the condition, so that the target base station sends a second message to a source side base station when receiving the access request information, wherein the second message is used for indicating the source side base station to stop scheduling the terminal and sending communication data related to the terminal to the target base station.

According to a third aspect of the present disclosure, there is provided a communication method comprising: the source side base station sends information of condition switching to the terminal; the source side base station stops scheduling the terminal indicated by the target message according to the received target message, and sends communication data related to the terminal to the target base station indicated by the target message; the target message comprises a first message sent to a source base station by a terminal when the condition of conditional handover is determined to be satisfied and/or a second message sent to the source base station by a target base station when the target base station receives an access request message sent by the terminal, wherein the access request message is sent to the target base station by the terminal when the condition of conditional handover is determined to be satisfied.

In an exemplary embodiment of the present disclosure, based on the foregoing scheme, in a case that the communication data includes voice data, the method further includes: and when the source side base station sends the information of condition switching to the terminal, starting to cache all voice data or starting to cache unsuccessfully scheduled voice data.

In an exemplary embodiment of the present disclosure, based on the foregoing scheme, in a case that the source-side base station is capable of determining a target base station to which the terminal is to access according to the information of conditional handover sent to the terminal, the method further includes: when a source base station sends information of condition switching to a terminal, the source base station sends communication data related to the terminal to a target base station.

According to a fourth aspect of the present disclosure, there is provided a terminal comprising: a conditional switch information receiving module configured to receive information of conditional switch by the terminal; the terminal comprises a first message sending module, configured to send a first message to a source side base station when it is determined that a condition for conditional handover is satisfied, so that the source side base station stops scheduling the terminal, and send communication data related to the terminal to a target base station indicated by the first message.

According to a fifth aspect of the present disclosure, there is provided a terminal comprising: a conditional switch information receiving module configured to receive information of conditional switch by the terminal; the second message sending module is configured to send access request information to a target base station indicated by a condition when the terminal determines that the condition for conditional handover is met, so that the target base station sends a second message to a source side base station when receiving the access request information, wherein the second message is used for instructing the source side base station to stop scheduling the terminal and sending communication data related to the terminal to the target base station.

According to a sixth aspect of the present disclosure, there is provided a base station comprising: the source side base station is configured to send information of conditional switching to the terminal; the source base station is configured to stop scheduling the terminal indicated by the target message according to the received target message, and send communication data related to the terminal to the target base station indicated by the target message; the target message comprises a first message sent to a source side base station by the terminal when the condition of conditional handover is determined to be met and/or a second message sent to the source side base station by the target base station when the target base station receives an access request message sent by the terminal, wherein the access request message is sent to the target base station by the terminal when the condition of conditional handover is determined to be met.

According to a seventh aspect of the present disclosure, there is provided a computer-readable storage medium, on which a computer program is stored, which program, when executed by a processor, implements the method according to the above-described embodiments.

According to an eighth aspect of embodiments of the present disclosure, there is provided an electronic apparatus including: a processor; and a storage device for storing one or more programs which, when executed by the one or more processors, cause the one or more processors to implement the method as in the above embodiments.

As can be seen from the foregoing technical solutions, the communication method, the terminal, the base station, and the computer-readable storage medium and the electronic device for implementing the communication method in the exemplary embodiments of the present disclosure have at least the following advantages and positive effects:

in the technical solutions provided by some embodiments of the present disclosure, a terminal receives information of conditional handover, and then when it is determined that a condition of the conditional handover is satisfied, sends a first message to a source-side base station, so that the source-side base station stops scheduling the terminal, and sends communication data related to the terminal to a target base station indicated by the first message. Compared with the related art, on one hand, the communication data related to the terminal is forwarded to the target base station through the source side base station, so that data loss in the condition switching process can be avoided; on the other hand, the method and the device have the advantages that the source side base station can know the target base station to which the terminal is currently accessed by sending the first message to the source side base station through the terminal, so that data can be directionally forwarded only to the target base station, network overhead is reduced, and network resources are saved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the disclosure. It should be apparent that the drawings in the following description are merely examples of the disclosure and that other drawings may be derived by those of ordinary skill in the art without inventive effort.

Fig. 1 illustrates an architectural schematic of a non-terrestrial network in an exemplary embodiment of the present disclosure;

fig. 2 illustrates a flow diagram of a method of communication in an exemplary embodiment of the disclosure;

FIG. 3 is a block diagram illustrating a target MAC control element message in an exemplary embodiment of the disclosure;

FIG. 4 is a flow diagram illustrating a multi-terminal interaction in performing conditional switching in an exemplary embodiment of the present disclosure;

fig. 5 shows a flow diagram of another method of communication in an exemplary embodiment of the present disclosure;

FIG. 6 is a flow chart illustrating a multi-terminal interaction in performing a conditional switch in an exemplary embodiment of the present disclosure;

fig. 7 illustrates a flow diagram of yet another method of communication in an exemplary embodiment of the present disclosure;

FIG. 8 shows a flow diagram of a method of processing speech data in an exemplary embodiment of the disclosure;

fig. 9 shows a schematic structural diagram of a terminal in an exemplary embodiment of the present disclosure;

fig. 10 shows a schematic structural diagram of another terminal in an exemplary embodiment of the present disclosure;

fig. 11 shows a schematic structural diagram of a base station in an exemplary embodiment of the present disclosure;

fig. 12 shows a schematic structural diagram of an electronic device in an exemplary embodiment of the present disclosure.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the disclosure. One skilled in the relevant art will recognize, however, that the subject matter of the present disclosure can be practiced without one or more of the specific details, or with other methods, components, devices, steps, and the like. In other instances, well-known technical solutions have not been shown or described in detail to avoid obscuring aspects of the present disclosure.

The terms "a," "an," "the," and "said" are used in this specification to denote the presence of one or more elements/components/parts/etc.; the terms "comprising" and "having" are intended to be inclusive and mean that there may be additional elements/components/etc. other than the listed elements/components/etc.; the terms "first" and "second," etc. are used merely as labels, and are not limiting on the number of their objects.

Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and a repetitive description thereof will be omitted. Some of the block diagrams shown in the figures are functional entities and do not necessarily correspond to physically or logically separate entities.

3GPP (3 rd Generation Partnership Project) R17 mainly discusses an NTN (Non-Terrestrial network) network of a transparent load architecture, i.e., a base station function is completely located on the ground. The architecture diagram of the NTN network is shown in fig. 1. The types of satellites supported by the NTN network include LEO (Low Earth Orbit) and GEO (geosynchronous Orbit) satellites.

For mobility management in a connected state, the NTN supports a CHO (Conditional Handover) mode, and 3 triggering events are newly added: (1) measuring event A4; (2) time-based trigger event (T1 condition): triggering between a time threshold T1 and a threshold T2; (3) location-based triggering (D1 condition): triggering when the distance to the preferencelocation 1 (reference distance 1) is greater than threshold 1 and the distance to the preferencelocation 2 (reference distance 2) is less than threshold 2.

Because the NTN network has a large propagation delay, the handover generally adopts a Conditional Handover (CHO) mode, and the terminal determines the handover timing and the target base station.

The key difference between the conditional Handover and the normal Handover is that the RRC reconfiguration message sent by the source base station to the terminal during the Handover process is not a Handover Command, but several target cells and corresponding Handover execution conditions are configured, and the RRC reconfiguration complete message fed back by the terminal is not sent to the target base station, but is sent to the source base station. And when the terminal finds that the switching execution condition of a certain target cell is met, the terminal immediately initiates access to the target cell without reporting to the source base station.

In the ordinary Handover process, when an RRC reconfiguration (Handover command) message is sent from the source side to the terminal, the source side stops the scheduling of the terminal, and the service of the terminal starts to be interrupted until the terminal successfully accesses the target cell. And in the process of condition switching, when the source side sends an RRC reconfiguration message to the terminal, the source side does not stop the scheduling of the terminal. Because the source side base station does not know when the terminal initiates the HANDOVER, the source side will always schedule the terminal until the terminal successfully accesses the target cell, and the source side will not stop the scheduling of the terminal and start to forward data to the target side after receiving the HANDOVER SUCCESS message sent by the target side base station. Therefore, all packets (packets) scheduled by the source side cannot be received from the terminal starting to access the target cell until the target side sends a HANDOVER SUCCESS message to the source side.

For the bearers in AM (Acknowledged Mode), the subsequent source side may send these packets to the destination side through data forwarding. However, for the UM (Unacknowledged Mode) Mode bearer, packets already scheduled by the source side will not be forwarded to the target side, i.e. for the UM bearer, the source side will only forward PDCP SDUs (Packet Data Convergence Protocol) SDUs that have not been completely scheduled, and therefore end-to-end Packet loss will occur.

In the related art, a terminal accesses a target base station through a CFRA (Contention Free Random Access), that is, the terminal sends a dedicated preamble to the target base station, and the target base station sends an RAR (Random Access Response) to the terminal. The terminal feeds back a Physical Uplink Shared Channel (PUSCH) to the target base station.

Based on the above process, the time of the terminal service terminal is at least 3 one-way delays, and does not include the interval between messages and the time processed by the target base station. For LEO satellites with an altitude of 150 kilometers, one-way delay is 25.6ms (milliseconds), and then the time for service interruption during CHO handover is at least 77.4ms or more. Taking voice data as an example, at least 4 voice packets will be dropped and voice quality and experience will be affected according to 20ms voice packet calculation.

In the related art, in order to solve the problem of packet loss in the CHO process, a scheme of forwarding at an early stage is adopted, that is, when an RRC reconfiguration message is sent from the source side to the terminal to configure a target cell and handover conditions, data forwarding is started to be initiated to the target side base station. At this time, the source-side base station does not know which target cell the terminal will be finally handed over to, and therefore the source-side base station needs to simultaneously forward data to a plurality of target base stations involved in the CHO, which results in high network overhead.

For the NTN network, the satellite covers a wider range of cells, and the number of terminals in the cell is larger, so the network overhead is larger.

To solve the above problems, the present disclosure proposes a communication method that overcomes, at least to some extent, the above drawbacks of the related art.

Fig. 2 shows a flow diagram of a communication method in an exemplary embodiment of the disclosure, and referring to fig. 2, the method includes:

step S210, the terminal receives the information of condition switching;

step S220, when determining that the condition for conditional handover is satisfied, the terminal sends a first message to the source-side base station, so that the source-side base station stops scheduling the terminal, and sends communication data related to the terminal to the target base station indicated by the first message.

In the technical solution provided in the embodiment shown in fig. 2, the terminal receives information of conditional handover, and then when it is determined that the condition of conditional handover is satisfied, sends a first message to the source-side base station, so that the source-side base station stops scheduling for the terminal, and sends communication data related to the terminal to a target base station indicated by the first message. Compared with the related art, on one hand, the communication data related to the terminal is forwarded to the target base station through the source side base station, so that data loss in the condition switching process can be avoided; on the other hand, the source side base station can know the target base station to which the terminal is currently accessed by sending the first message to the source side base station through the terminal, so that data can be directionally forwarded to the target base station only, network overhead is reduced, and network resources are saved.

The following is a detailed description of the various steps in the example shown in fig. 2:

in step S210, the terminal receives information of condition switching.

For example, after the preparation of the conditional access procedure is completed, the source-side base station may send information of the conditional access to the terminal.

In an exemplary embodiment, the preparation flow of the conditional switch may include: the source base station configures measurement information including a measurement object and a measurement reporting event for the terminal, and the terminal reports the measurement event according to the configured measurement information; according to the measurement event reported by the terminal, the source side base station judges to use the CHO process and sends a Handover Request (Handover Request) to a plurality of candidate target side base stations; after all candidate target base stations judge that the admission control is passed, feeding back a Handover Request acknowledgement (Handover Request confirmation) to the source base station.

As described above, after the preparation procedure for conditional access is completed, the source-side base station may transmit information of the conditional access to the terminal.

The information of the conditional handover may include a RRC reconfiguration message, that is, after the flow preparation of the conditional handover is completed, the source base station may send the RRC reconfiguration message to the terminal. And the RRC reconfiguration message carries the condition of condition switching and the identification of the candidate target base station to be switched.

In an exemplary embodiment, the information of conditional switching may further include uplink scheduling free (CG) resource configuration information. The uplink scheduling-free resource information is used for the terminal to subsequently and timely send a Measurement Report to the source side base station.

In other words, the specific implementation of step S210 may include: and the terminal receives the radio resource control protocol reconfiguration message and the resource configuration information of the uplink scheduling-free resource sent by the source side base station.

In an exemplary embodiment, the terminal may further send a message that the reconfiguration of the radio resource control protocol is completed to the source-side base station, when receiving the reconfiguration message of the radio resource control protocol and the resource configuration information of the uplink non-scheduling resource sent by the source-side base station.

With continued reference to fig. 2, in step S220, when determining that the condition for conditional handover is satisfied, the terminal sends a first message to the source-side base station, so that the source-side base station stops scheduling for the terminal, and sends communication data related to the terminal to the target base station indicated by the first message.

For example, when the terminal determines that the execution condition of the conditional handover is currently satisfied according to the received information of the conditional handover, the terminal may send a first message to the source base station. After receiving the first message, the source-side base station may stop scheduling the terminal, and at the same time, the source-side base station may know, according to the first message, a target base station to which the terminal is currently handed over, and the source-side base station may start to directly send cached communication data, such as voice data and video data, related to the current terminal to the target base station.

In an exemplary embodiment, the first message includes one or more of a measurement report, a target radio resource control protocol message, and a target MAC control element message.

The first message carries a target identifier of a target base station to which the terminal is to be currently switched. That is, under the condition that the first message includes the measurement report, the measurement report carries the target identifier of the target base station to which the terminal is currently switched; under the condition that the first message comprises a target radio resource control protocol message, carrying a target identification of the target base station in the target radio resource control protocol message; and under the condition that the first message comprises a target MAC control unit message, carrying a target identifier of the target base station in the target MAC control unit message.

In an exemplary embodiment, the target RRC message may be understood as a new RRC message, for example, a new Conditional Handover Start message may be added, where the message carries an identifier of a target base station to which the terminal is currently accessing.

In an exemplary embodiment, the target MAC Control Element message may be understood as a new MAC CE (MAC Control Element) message, for example, a new CHOStart MAC CE message, where the message carries PCI (Physical Cell Identifier) information of 10 bits. The schematic diagram of the MAC CE may refer to fig. 3.

In an exemplary embodiment, when it is determined that the condition for conditional handover is satisfied, the terminal sends a first message to the source-side base station, where the first message includes: and when the terminal determines that the condition switching is met, the terminal sends a first message to the source side base station through the uplink scheduling-free resource.

Taking the example that the first message is a measurement report, when determining that the condition for conditional handover is satisfied, the terminal may immediately send the measurement report on the CG resource, and then start accessing the target base station after disconnecting from the source base station. After receiving the measurement report message, the source base station knows the target base station to which the terminal is to be handed over, then sends an SN STATUS TRANSFER (sequence number STATUS TRANSFER) to the target base station, and starts sending communication data related to the terminal to the target base station.

After the terminal successfully accesses the target base station, the target base station may send a HANDOVER SUCCESS message to the source side base station, and certainly, the target base station may not send the HANDOVER SUCCESS message, which is not particularly limited in this exemplary embodiment.

After the terminal successfully accesses the target base station, the target base station may start triggering PATH SWITCH. After the PATH SWITCH is completed, the target base station notifies the source base station to delete the CONTEXT information of the terminal, that is, the target base station notifies the terminal to delete the UE CONTEXT.

For example, when the source-side base station successfully forwards all the communication data related to the terminal, which is cached by the source-side base station, to the target base station, the source-side base station stops forwarding the data to the target base station.

The communication data which is sent by the source side base station to the target base station and is related to the terminal comprises uplink and downlink data which are cached by the source side base station and are related to the terminal before the path switching is completed. In this way, loss of data during conditional switching can be avoided.

In an exemplary embodiment, in a case that the remaining uplink non-scheduling resources satisfy resources occupied by a timing advance message, the terminal may further send the timing advance message to the source-side base station. And the remaining uplink scheduling-free resources are determined according to the uplink scheduling-free resources occupied by the first message, and the timing advance message is used for assisting the source side base station in determining the time for the terminal to start to switch to the target base station.

By way of example, the Timing Advance message may be understood as a Timing Advance Report MAC CE (Timing Advance Report MAC control element) message. If the CG resources are enough, the terminal can simultaneously carry a protocol of a 3GPP R17 version as a Timing Advance Report MAC CE specially introduced by NTN, and the auxiliary source side base station judges the specific time of the terminal switching start.

For example, the terminal may send the Timing Advance Report MAC CE message to the source-side base station if it is determined that the remaining CG resources can satisfy the bit requirement occupied by the Timing Advance Report MAC CE message, except the CG resources occupied by the first message. If the remaining CG resources do not meet the bit requirement occupied by the Timing Advance Report MAC CE message, the Timing Advance Report MAC CE may not be sent to the source side base station.

Next, taking the first message as a measurement report message, and the source base station and the target base station are gnbs (next Generation Node B, i.e. 5G base stations) as an example, a flow diagram of multi-terminal interaction during conditional handover in an exemplary embodiment of the present disclosure is shown in conjunction with fig. 4. Referring to fig. 4, the multi-terminal interaction procedure when the condition switching is performed may include steps S401 to S410. Wherein:

in step S401, a condition switching preparation is performed;

in step S402, the source-side base station 41 sends an RRC reconfiguration message and uplink CG resource information to the terminal 42;

in step S403, the terminal 42 feeds back an RRC reconfiguration complete message to the source base station 41;

in step S404, the terminal 42 evaluates the condition for switching the condition, and after determining that the execution condition for switching the condition is satisfied, proceeds to step S405;

in step S405, the terminal 42 transmits a measurement report to the source-side base station 41;

in step S406, the terminal 42 disconnects from the source-side base station and starts accessing the target base station;

in step S407, the source side base station 41 sends a serial number state transition message to the target side base station 43, and starts sending User data received from a User Plane Function (UPF) to the target base station;

in step S408, the terminal 42 successfully accesses the target base station 43, and the conditional switch is completed;

in step S409, the target base station 43 sends a handover success command to the source base station 41;

in step S410, the target base station 43 triggers path switching to notify the source base station 41 of deleting the terminal context information.

In step S401, the process of preparing for condition switching is the same as the process of preparing for condition switching in the prior art, and is not described here again.

For example, after the conditional handover preparation is completed, the source side base station may send an RRC reconfiguration message and uplink Config Grant resource configuration information (i.e., uplink non-scheduling resource configuration information) to the terminal. And the RRC reconfiguration message is configured with a candidate target record and a switching execution condition of condition switching, and the uplink CG resource is used for the terminal to subsequently and timely send a Measurement Report. After receiving the RRC reconfiguration message and the uplink CG resource configuration message, the terminal may feed back an RRC reconfiguration complete message to the source base station.

And then, the terminal judges whether to execute the condition switching according to the switching execution condition of the condition switching, immediately sends a Measurement Report on an uplink CG resource when the terminal judges that the execution condition of the condition switching is satisfied, and then starts to access the target base station after disconnecting from the source side. And after receiving the Measurement Report message, the source side base station knows the target cell to be switched by the terminal, then sends SN STATUS TRANSFER to the target base station, and starts to forward data.

After the terminal successfully accesses the target base station, the target base station sends a HANDOVER SUCCESS message to the source base station and starts to trigger a PATH SWITCH. After the PATH SWITCH is completed, the target base station notifies the source base station to delete the UE CONTEXT (i.e., the terminal CONTEXT information).

In the embodiment shown in fig. 2, when the terminal starts accessing the target base station, the source side base station is immediately informed of the CHO handover and to which target base station the CHO handover is to be started immediately, and after receiving this message, the source side base station stops scheduling the terminal and starts to forward data to the target base station. Therefore, in the process that the terminal accesses the target base station, the communication data which are cached by the source base station and are related to the terminal are forwarded to the target base station, and the data packet loss in the conditional switching process is reduced. Meanwhile, the terminal informs the source side base station of the target base station to which the source side base station is to be switched, and the source side base station only needs to forward data to the target base station, so that the network overhead is reduced, and the network resources are saved.

Next, fig. 5 shows a flow chart diagram of another communication method in an exemplary embodiment of the present disclosure. Referring to fig. 5, the method may include steps S510 to S520. Wherein:

in step S510, the terminal receives information of condition switching.

For example, the specific implementation of step S510 may refer to the specific implementation of step S210, and details are not described here.

It should be noted that the information of the condition switching received by the terminal in step S510 may not include the uplink scheduling-free resource information, or may include the uplink scheduling-free resource information, which is not particularly limited in this exemplary embodiment.

In other words, in the embodiment shown in fig. 5, after the preparation of conditional handover is completed, the source base station may send an RRC reconfiguration message to the terminal, where the candidate target base station and the execution condition of conditional handover are configured in the reconfiguration message.

In step S520, when it is determined that the condition for conditional handover is satisfied, the terminal sends access request information to the target base station indicated by the condition, so that the target base station sends a second message to a source-side base station when receiving the access request information, where the second message is used to instruct the source-side base station to stop scheduling the terminal, and instruct the source-side base station to send communication data related to the terminal to the target base station.

In an exemplary embodiment, the access request information includes physical random access channel information or physical uplink shared channel information.

For example, when the terminal determines that the condition of condition switching is satisfied, the terminal may access the target base station in a non-contention free access manner, that is, the terminal sends a dedicated preamble to the target-side base station, the target base station sends a random access response RAR to the terminal, and the terminal feeds back a PUSCH to the target base station.

When receiving a first PUSCH message or a first PRACH (Physical Random Access Channel) message transmitted by the terminal, the target base station may transmit a second message, such as a HANDOVER START message, to the source base station, so as to inform the source base station that the terminal has started accessing the target base station. And the source side base station immediately stops scheduling the terminal after receiving the HANDOVER START message and STARTs to send the communication data which is cached in the source side base station and is related to the terminal to the target base station.

Next, taking the source base station and the target base station as a gNB (next Generation Node B, i.e. 5G base station) as an example, a multi-end interaction procedure when performing conditional handover in another embodiment of the present disclosure will be described with reference to an interaction procedure shown in fig. 6. Referring to fig. 6, the multi-terminal interaction process shown in fig. 6 may include steps S601 to S610.

In step S601, a condition switching preparation is performed;

in step S602, the source-side base station 61 sends an RRC reconfiguration message to the terminal 62;

in step S603, the terminal 62 feeds back an RRC reconfiguration complete message to the source-side base station 61;

in step S604, the terminal 62 evaluates the condition for switching the condition, and after determining that the execution condition for switching the condition is satisfied, proceeds to step S605;

in step S605, the terminal 62 disconnects from the source-side base station 61;

in step S606, the terminal 62 sends a PRACH message to the target base station 63, and starts to access the target base station;

in step S607, the target base station 63 transmits a handover start message to the source base station 61 after receiving the PRACH message transmitted by the terminal 62;

in step S608, after receiving the handover start message, the source-side base station 61 sends a serial number state transition message to the target base station, and forwards the user data to the target base station;

in step S609, the terminal 62 successfully accesses the target base station 63, and the conditional switch is completed;

in step S610, the target base station 63 triggers path switching to notify the source base station 61 to delete the terminal context information.

For example, in another exemplary embodiment of the present disclosure, when determining that the CHO execution condition is satisfied, the terminal may disconnect from the source-side base station and then transmit an access request message to the target base station to start accessing the target base station. And after receiving the first PRACH or PUSCH message sent by the terminal, the target base station sends a second message to the source side base station to inform the source side base station that the terminal starts to access the target base station. And after receiving the second message sent by the target base station, the source side base station immediately stops scheduling the terminal, sends SN STATUS TRANSFER (Serial number State TRANSFER information) to the target base station, and starts to send the relevant data of the current terminal cached by the source side base station to the target base station.

After the CHO switching is completed, the target base station starts to trigger PATH SWITCH. And after the PATH SWITCH is completed, the target base station informs the source side base station of deleting the UE CONTEXT.

In an exemplary embodiment, the second message may be generated by: a new message, such as a HANDOVER START message, may be added to the XnAP (XnAP) Protocol and/or the NGAP (Next Generation Application Protocol) Protocol, where the HANDOVER START message includes information such as XnAP ID of the terminal, target base station ID, and the like, and may include a message type, source NG-RAN node UE XnAP (Source access network node terminal Xn ID), target access network NG-RAN node UE XnAP ID (Target access network node terminal XnAP ID), requested Target Cell ID (ID of the Requested Target Cell), and the like.

In the embodiment shown in fig. 5, in the process that the terminal starts to access the target base station, when the target base station receives the first PRACH or the first PUSCH transmitted by the terminal, that is, when the target base station receives the PRACH message or the PUSCH message transmitted by the terminal, the target base station may transmit the second message to the source-side base station, so as to notify the source-side base station that the terminal has started to access the target base station. After receiving the second message, the source base station may immediately stop scheduling the terminal and start to forward the data to the target base station, so that data loss in the CHO process may be avoided. Meanwhile, the source base station can know the target base station to which the terminal is currently accessed through the second message sent by the target base station, so that data can be forwarded to the target base station only, network overhead is reduced, and network resources are saved.

Next, fig. 7 shows a flowchart of a communication method that can be applied to a base station in an exemplary embodiment of the disclosure. Referring to fig. 7, the method may include steps S710 to S720. Wherein:

in step S710, the source-side base station transmits information of the condition switching to the terminal.

For example, after the preparation procedure of the conditional access is completed, the source-side base station may send information of the conditional access to the terminal. The preparation process of conditional switching may refer to the prior art, and is not described herein again.

In an exemplary embodiment, the source side base station sends the information of conditional switch to the terminal, including: and the source side base station sends a radio resource control protocol reconfiguration message to the terminal, wherein the radio resource control protocol reconfiguration message comprises the condition of the condition switching and the identification of the candidate target base station to be switched.

In other words, the information of the conditional handover sent by the source side base station to the terminal may include an RRC reconfiguration message including the candidate target base station and the condition for handover to the candidate target base station.

When the target message includes the first message, the information of conditional handover sent by the source-side base station to the terminal may further include uplink scheduling-free resource configuration information.

In other words, in the case that the target message described below includes the first message, the information of the conditional handover sent by the source-side base station to the terminal may include an RRC reconfiguration message and uplink non-scheduling resource configuration information.

In step S720, the source side base station stops scheduling the terminal indicated by the target message according to the received target message, and sends communication data related to the terminal to the target base station indicated by the target message.

In an exemplary embodiment, the target message includes a first message sent by the terminal to the source-side base station when determining that the condition for conditional handover is satisfied and/or a second message sent by the target base station to the source-side base station when receiving an access request message sent by the terminal, where the access request message is sent by the terminal to the target base station when determining that the condition for conditional handover is satisfied.

In an exemplary embodiment, in the case that the communication data includes voice data, the communication method in the present disclosure may further include: and when the source side base station sends the information of the condition switching to the terminal, the source side base station starts to cache all voice data or starts to cache unsuccessfully scheduled voice data.

The information due to the conditional handover comprises a radio resource control protocol reconfiguration message. Therefore, it can be understood that when the source base station sends the rrc reconfiguration message to the terminal, the source base station starts to buffer all the voice data or starts to buffer the unsuccessfully scheduled voice data.

Wherein, starting to buffer all voice data comprises starting to buffer the voice data which is successfully scheduled and unsuccessfully scheduled. The successfully scheduled voice data includes a voice data packet receiving HARQ ACK (Hybrid-Automatic-Repeat-Request ACK, hybrid Automatic Repeat Request acknowledgement), and the unsuccessfully scheduled voice data includes voice data not receiving HARQ ACK.

Fig. 8 shows a flow diagram of a method of processing speech data in an exemplary embodiment of the disclosure. Referring to fig. 8, the method may include steps S810 to S840. Wherein:

in step S810, the source-side base station sends an RRC reconfiguration message to the terminal, configuring candidate target base stations and conditions for conditional handover;

in step S820, the source-side base station determines whether the terminal has a voice bearer, if so, goes to step S830, and if not, goes to step S850;

in step S830, the source side base station performs special processing on the packet buffer carried by the voice;

in step S840, the source base station sends all buffered packets to the target base station after receiving the handover success command sent by the target base station.

In step S850, no special processing is performed.

Step S830 may include that the source side base station starts to buffer all the voice data or starts to buffer the unsuccessfully scheduled voice data when sending the rrc reconfiguration message to the terminal.

For example, in the present disclosure, in order to reduce the packet loss rate of voice data, the source base station sends an RRC reconfiguration message to the terminal to configure a target cell and CHO handover execution conditions, and the source base station performs special processing on a voice bearer.

In an exemplary embodiment, the special processing of the voice bearer by the source-side base station may include: for the PDCP SDU of the voice, the PDCP SDU is not deleted from the L2 buffer after being completely scheduled, and only after the HARQ ACK of the whole voice packet is received, the PDCP SDU is deleted from the L2 buffer. After receiving a HANDOVER SUCCESS command sent by the target base station, the source side base station sends all voice packets that are not successfully received by the terminal to the target base station, thereby reducing the packet loss rate of voice data.

Since the data volume of the voice bearer is relatively small, in another exemplary embodiment, the special processing of the voice bearer by the source-side base station may include: and the source side base station does not delete all voice PDCP SDUs from the L2 cache from the beginning of sending the RRC reconfiguration message to the terminal. After receiving the HANDOVER SUCCESS sent by the target base station, the source base station sends all voice packets currently cached to the target base station.

By specially processing the voice data, the packet loss of the voice data in the CHO switching process can be further reduced, the voice quality is improved, and the communication experience of a user is further improved.

In some exemplary application scenarios, for certain types of CHO, such as time triggered CHO, the source side base station knows which target base station the terminal is to be eventually handed over to. For example, a LEO satellite only covers a region during a specific time period (10: 00 later the area is covered by another satellite. For this case, as fast as 11: at time 00, the source side satellite is the target cell to which the terminal time-triggered CHO is aware.

Based on this, in the present disclosure, in a case where the source-side base station can determine a target base station to which the terminal is to access, according to a conditional handover message sent to the terminal, the method further includes: when a source side base station sends information of condition switching to a terminal, the source side base station sends communication data related to the terminal to a target base station.

For example, when the source-side base station knows the target base station to which the terminal is to be finally accessed according to the candidate target base station and the handover condition configured in the RRC reconfiguration message sent to the terminal, the source-side base station may start sending uplink and downlink data related to the terminal, which is received by the source-side base station, to the target base station to which the terminal is to be finally accessed when the source-side base station sends the RRC reconfiguration message to the terminal. If the source base station does not know the target base station to which the terminal is to be finally accessed according to the conditional handover information sent to the terminal, the data forwarding in the CHO handover process may be performed according to the embodiments shown in fig. 2 and/or fig. 5.

For example, in time-triggered or geographic location-triggered CHO, when the source-side base station sends the RRC reconfiguration message to the terminal, the source-side base station may start sending, to the target base station to which the terminal is to be finally accessed, uplink and downlink data related to the terminal, which is received by the source-side base station.

In an exemplary embodiment, in case that the target message comprises the first message, the first message comprises one or more of a measurement report, a target radio resource control protocol message, a target MAC control element message; the target radio resource control protocol message carries a target identifier of the target base station, and the target MAC layer control unit message carries the target identifier of the target base station.

In an exemplary embodiment, in a case that the target message includes the first message, the first message is sent by the terminal to the source side base station through the uplink schedule-free resource when it is determined that the condition for conditional handover is satisfied.

In an exemplary embodiment, in a case that the target message includes the first message, the method further includes: the source base station determines the time for the terminal to start switching to the target base station according to the received timing advance message; the timing advance message is sent to the source side base station by the terminal under the condition that the remaining uplink scheduling-free resources meet the resources occupied by the timing advance message; and the remaining uplink scheduling-free resources are determined by the terminal according to the uplink scheduling-free resources occupied by the first message.

In an exemplary embodiment, in a case that the target message includes the second message, the access request message includes physical random access channel information or physical uplink shared channel information.

For the description of the first message, the embodiment shown in fig. 2 may be referred to, and for the specific description of the second message, the embodiment shown in fig. 5 may be referred to, so that details are not described herein again.

In an exemplary application scenario, the terminal may send the first message to the source-side base station only, so that the source-side base station may forward data to the target base station according to the first message.

In another exemplary application scenario, the target base station may also send the second message to the source-side base station only, so that the source-side base station may forward data to the target base station according to the second message.

In another exemplary application scenario, the terminal may send the first message to the source-side base station, the target base station may also send the second message to the source-side base station, and the source-side base station may stop scheduling the terminal and forward data to the target base station when receiving any message, which is not particularly limited in this exemplary embodiment.

In the present disclosure, through the first message and/or the second message, when the terminal starts to access the target base station, the source-side base station may be notified of the target base station to which the terminal is currently accessing, so that the source-side base station only needs to establish a data forwarding channel with one target base station, which ensures that data is not lost during the conditional access process and reduces network overhead.

Meanwhile, through special processing of the voice data, packet loss of the voice data can be avoided, the voice quality is improved, and the user experience is improved.

Those skilled in the art will appreciate that all or part of the steps implementing the above embodiments are implemented as computer programs executed by a CPU. The computer program, when executed by the CPU, performs the functions defined by the method provided by the present invention. The program may be stored in a computer readable storage medium, which may be a read-only memory, a magnetic or optical disk, or the like.

Furthermore, it should be noted that the above-mentioned figures are only schematic illustrations of the processes involved in the method according to exemplary embodiments of the invention, and are not intended to be limiting. It will be readily understood that the processes shown in the above figures are not intended to indicate or limit the chronological order of the processes. In addition, it is also readily understood that these processes may be performed synchronously or asynchronously, e.g., in multiple modules.

Fig. 9 shows a schematic structural diagram of a terminal in an exemplary embodiment of the present disclosure. Referring to fig. 9, the terminal 900 may include a conditional handover information receiving module 910 and a first message transmitting module 920. Wherein:

a conditional switching information receiving module 910 configured to receive information of conditional switching by a terminal;

a first message sending module 920, configured to send a first message to a source-side base station when the terminal determines that a condition for conditional handover is satisfied, so that the source-side base station stops scheduling the terminal, and sends communication data related to the terminal to a target base station indicated by the first message.

In some exemplary embodiments of the present disclosure, based on the foregoing embodiments, the first message includes one or more of a measurement report, a target radio resource control protocol message, a target MAC control element message; the target wireless resource control protocol message carries the target identification of the target base station, and the target MAC layer control unit message carries the target identification of the target base station.

In some exemplary embodiments of the present disclosure, based on the foregoing embodiments, the first message sending module 920 may be further configured to: and when the terminal determines that the condition of condition switching is met, the terminal sends a first message to the source side base station through the uplink scheduling-free resource.

In some exemplary embodiments of the present disclosure, based on the foregoing embodiments, the conditional switching information receiving module 910 may be further configured to: the terminal receives a radio resource control protocol reconfiguration message and resource configuration information of the uplink scheduling-free resource sent by a source side base station; wherein, the radio resource control protocol reconfiguration message includes the condition of the conditional switch and the mark of the candidate target base station to be switched.

In some exemplary embodiments of the present disclosure, based on the foregoing embodiments, the terminal further includes a first feedback module configured to: and the terminal sends a message of completing the reconfiguration of the radio resource control protocol to the source side base station under the condition of receiving the reconfiguration message of the radio resource control protocol and the resource configuration information of the uplink scheduling-free resource sent by the source side base station.

In some exemplary embodiments of the present disclosure, based on the foregoing embodiments, the terminal may further include a timing advance message sending module, where the timing advance message sending module may be configured to send the timing advance message to the source side base station by the terminal when the remaining uplink non-scheduling resources meet the resources occupied by the timing advance message; and the remaining uplink scheduling-free resources are determined according to the uplink scheduling-free resources occupied by the first message, and the timing advance message is used for assisting the source-side base station in determining the time for the terminal to start to switch to the target base station.

Fig. 10 shows a schematic structural diagram of another terminal in an exemplary embodiment of the present disclosure. Referring to fig. 10, the terminal 1000 may include a conditional handover information receiving module 1010 and a second message transmitting module 1020. Wherein:

a conditional switching information receiving module 1010 configured to receive information of conditional switching by the terminal;

a second message sending module 1020, configured to, when it is determined that the condition for conditional handover is satisfied, send access request information to a target base station indicated by the condition, so that the target base station sends, when receiving the access request information, a second message to a source base station, where the second message is used to instruct the source base station to stop scheduling the terminal, and send communication data related to the terminal to the target base station.

In some exemplary embodiments of the present disclosure, based on the foregoing embodiments, the access request information includes physical random access channel information or physical uplink shared channel information.

Fig. 11 shows a schematic structure diagram of a base station in an exemplary embodiment of the present disclosure, and referring to fig. 11, a base station 1100 may include a conditional handover information sending module 1110 and a target information receiving module 1120. Wherein:

a conditional handover information sending module 1110 configured to send information of conditional handover to the terminal by the source-side base station;

a target message receiving module 1120, configured to stop, by the source base station, scheduling the terminal indicated by the target message according to the received target message, and send communication data related to the terminal to the target base station indicated by the target message;

the target message comprises a first message sent to a source base station by a terminal when the condition of conditional handover is determined to be satisfied and/or a second message sent to the source base station by a target base station when the target base station receives an access request message sent by the terminal, wherein the access request message is sent to the target base station by the terminal when the condition of conditional handover is determined to be satisfied.

In some exemplary embodiments of the present disclosure, based on the foregoing embodiments, the source conditional switching information sending module 1110 may be further configured to: and the source side base station sends a radio resource control protocol reconfiguration message to the terminal, wherein the radio resource control protocol reconfiguration message comprises the condition of the condition switching and the identification of the candidate target base station to be switched.

In some exemplary embodiments of the present disclosure, based on the foregoing embodiments, in a case that the communication data includes voice data, the base station further includes a voice data processing module, and the voice data processing module may be configured to: and when the source side base station sends the radio resource control protocol reconfiguration message to the terminal, starting to cache all voice data or starting to cache unsuccessfully scheduled voice data.

In some exemplary embodiments of the present disclosure, based on the foregoing embodiments, in a case that the source-side base station is capable of determining a target base station to which the terminal is to access according to information of conditional handover sent to the terminal, the base station further includes an early forwarding module, and the early forwarding module may be configured to: when a source side base station sends a radio resource control protocol reconfiguration message to a terminal, the source side base station sends communication data related to the terminal to a target base station.

The details of each module in the terminal and the base station have been described in detail in the corresponding communication method, and therefore are not described herein again.

It should be noted that although in the above detailed description several modules or units of the device for action execution are mentioned, such a division is not mandatory. Indeed, the features and functions of two or more modules or units described above may be embodied in one module or unit, according to embodiments of the present disclosure. Conversely, the features and functions of one module or unit described above may be further divided into embodiments by a plurality of modules or units.

Moreover, although the steps of the methods of the present disclosure are depicted in the drawings in a particular order, this does not require or imply that these steps must be performed in this particular order, or that all of the depicted steps must be performed, to achieve desirable results. Additionally or alternatively, certain steps may be omitted, multiple steps combined into one step execution, and/or one step broken down into multiple step executions, etc.

Through the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein may be implemented by software, or by software in combination with necessary hardware. Therefore, the technical solution according to the embodiments of the present disclosure may be embodied in the form of a software product, which may be stored in a non-volatile storage medium (which may be a CD-ROM, a usb disk, a removable hard disk, etc.) or on a network, and includes several instructions to enable a computing device (which may be a personal computer, a server, a mobile terminal, or a network device, etc.) to execute the method according to the embodiments of the present disclosure.

In an exemplary embodiment of the present disclosure, there is also provided a computer storage medium capable of implementing the above method. On which a program product capable of implementing the method described above in this specification is stored. In some possible embodiments, various aspects of the disclosure may also be implemented in the form of a program product comprising program code for causing a terminal device to perform the steps according to various exemplary embodiments of the disclosure described in the "exemplary methods" section above of this specification, when the program product is run on the terminal device.

Embodiments of the present disclosure may also include a program product for implementing the above method, which may employ a portable compact disc read only memory (CD-ROM) and include program code, and may be run on a terminal device, such as a personal computer. However, the program product of the present disclosure is not limited thereto, and in this document, a readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

The program product may employ any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the foregoing. More specific examples (a non-exhaustive list) of the readable storage medium include: an electrical connection having one or more wires, a portable disk, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

A computer readable signal medium may include a propagated data signal with readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated data signal may take many forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A readable signal medium may be any readable medium that is not a readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

Program code embodied on a readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

Program code for carrying out operations for the present disclosure may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, C + + or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computing device, partly on the user's device, as a stand-alone software package, partly on the user's computing device and partly on a remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any kind of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computing device (e.g., through the internet using an internet service provider).

In addition, in an exemplary embodiment of the present disclosure, an electronic device capable of implementing the above method is also provided.

As will be appreciated by one skilled in the art, aspects of the present disclosure may be embodied as a system, method or program product. Accordingly, various aspects of the present disclosure may be embodied in the form of: an entirely hardware embodiment, an entirely software embodiment (including firmware, microcode, etc.) or an embodiment combining hardware and software aspects that may all generally be referred to herein as a "circuit," module "or" system.

An electronic device 1200 according to this embodiment of the disclosure is described below with reference to fig. 12. The electronic device 1200 shown in fig. 12 is only an example and should not bring any limitation to the functions and the scope of use of the embodiments of the present disclosure.

As shown in fig. 12, the electronic device 1200 is embodied in the form of a general purpose computing device. Components of the electronic device 1200 may include, but are not limited to: the at least one processing unit 1210, the at least one memory unit 1220, a bus 1230 connecting various system components (including the memory unit 1220 and the processing unit 1210), and a display unit 1240.

Wherein the storage unit stores program code that is executable by the processing unit 1210 to cause the processing unit 1210 to perform steps according to various exemplary embodiments of the present disclosure described in the above section "exemplary methods" of this specification. For example, the processing unit 1210 may perform the steps as described above in fig. 2.

The storage unit 1220 may include a readable medium in the form of a volatile memory unit, such as a random access memory unit (RAM) 12201 and/or a cache memory unit 12202, and may further include a read only memory unit (ROM) 12203.

Storage unit 1220 may also include a program/utility 12204 having a set (at least one) of program modules 8205, such program modules 12205 including, but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which, or some combination thereof, may comprise an implementation of a network environment.

Bus 1230 may be one or more of several types of bus structures, including a memory unit bus or memory unit controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

The electronic device 1200 can also communicate with one or more external devices 1300 (e.g., keyboard, pointing device, bluetooth device, etc.), one or more devices that enable a user to interact with the electronic device 1200, and/or any device (e.g., router, modem, etc.) that enables the electronic device 1200 to communicate with one or more other computing devices. Such communication may occur via input/output (I/O) interfaces 1250. Also, the electronic device 1200 may communicate with one or more networks (e.g., a Local Area Network (LAN), a Wide Area Network (WAN), and/or a public network such as the Internet) via the network adapter 1260. As shown, the network adapter 1260 communicates with the other modules of the electronic device 1200 via the bus 1230. It should be appreciated that although not shown, other hardware and/or software modules may be used in conjunction with the electronic device 1200, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems, among others.

Through the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein may be implemented by software, or by software in combination with necessary hardware. Therefore, the technical solution according to the embodiments of the present disclosure may be embodied in the form of a software product, which may be stored in a non-volatile storage medium (which may be a CD-ROM, a usb disk, a removable hard disk, etc.) or on a network, and includes several instructions to enable a computing device (which may be a personal computer, a server, a terminal device, or a network device, etc.) to execute the method according to the embodiments of the present disclosure.

Furthermore, the above-described figures are merely schematic illustrations of processes included in methods according to exemplary embodiments of the present disclosure, and are not intended to be limiting. It will be readily understood that the processes shown in the above figures are not intended to indicate or limit the chronological order of the processes. In addition, it is also readily understood that these processes may be performed synchronously or asynchronously, e.g., in multiple modules.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

Claims

1. A method of communication, comprising:

the terminal receives the information of condition switching;

when the terminal determines that the condition of condition switching is met, the terminal sends a first message to a source side base station, so that the source side base station stops scheduling the terminal, and sends communication data related to the terminal to a target base station indicated by the first message.

2. The communication method according to claim 1, wherein the first message comprises one or more of a measurement report, a target radio resource control protocol message, a target MAC control element message;

the target wireless resource control protocol message carries the target identification of the target base station, and the target MAC layer control unit message carries the target identification of the target base station.

3. The communication method according to claim 1 or 2, wherein the terminal sends a first message to a source-side base station when determining that the condition for conditional handover is satisfied, the method comprising:

and when the terminal determines that the condition of condition switching is met, the terminal sends a first message to the source side base station through the uplink scheduling-free resource.

4. The communication method of claim 3, wherein the method further comprises:

under the condition that the remaining uplink scheduling-free resources meet the resources occupied by the timing advance message, the terminal sends the timing advance message to the source side base station;

and the remaining uplink scheduling-free resources are determined according to the uplink scheduling-free resources occupied by the first message, and the timing advance message is used for assisting the source-side base station in determining the time for the terminal to start to switch to the target base station.

5. A method of communication, comprising:

the terminal receives the information of condition switching;

when determining that the condition of conditional handover is met, the terminal sends access request information to a target base station indicated by the condition, so that the target base station sends a second message to a source side base station when receiving the access request information, wherein the second message is used for indicating the source side base station to stop scheduling the terminal and sending communication data related to the terminal to the target base station.

6. A method of communication, comprising:

the source side base station sends information of condition switching to the terminal;

the source side base station stops scheduling the terminal indicated by the target message according to the received target message, and sends communication data related to the terminal to the target base station indicated by the target message;

the target message comprises a first message sent to a source side base station by the terminal when the condition of conditional handover is determined to be met and/or a second message sent to the source side base station by the target base station when the target base station receives an access request message sent by the terminal, wherein the access request message is sent to the target base station by the terminal when the condition of conditional handover is determined to be met.

7. The communication method according to claim 6, wherein in the case where the communication data includes voice data, the method further comprises:

when the source side base station sends the information of condition switching to the terminal, all voice data starts to be cached or unsuccessfully scheduled voice data starts to be cached.

8. The communication method according to claim 6, wherein in a case where the source-side base station is able to determine a target base station to which the terminal is to access, based on the information of the conditional handover sent to the terminal, the method further comprises:

when a source base station sends information of condition switching to a terminal, the source base station sends communication data related to the terminal to a target base station.

9. A terminal, comprising:

a condition switching information receiving module configured to receive information of condition switching by a terminal;

the terminal comprises a first message sending module, configured to send a first message to a source side base station when it is determined that a condition for conditional handover is satisfied, so that the source side base station stops scheduling the terminal, and send communication data related to the terminal to a target base station indicated by the first message.

10. A terminal, comprising:

a conditional switch information receiving module configured to receive information of conditional switch by the terminal;

the second message sending module is configured to send access request information to a target base station indicated by a condition when the terminal determines that the condition for conditional handover is met, so that the target base station sends a second message to a source-side base station when receiving the access request information, where the second message is used to instruct the source-side base station to stop scheduling the terminal, and send communication data related to the terminal to the target base station.

11. A base station, comprising:

the conditional switching information sending module is configured to send conditional switching information to the terminal by the source side base station;

the source base station is configured to stop scheduling the terminal indicated by the target message according to the received target message, and send communication data related to the terminal to the target base station indicated by the target message;

12. A computer-readable storage medium, on which a computer program is stored, which program, when being executed by a processor, carries out the method according to any one of claims 1 to 8.

13. An electronic device, comprising:

one or more processors;

storage means for storing one or more programs which, when executed by the one or more processors, cause the one or more processors to carry out the method of any one of claims 1 to 8.