Serving cell handover method, electronic device and computer program product

Abstract

Provided in an embodiment of the present application are a serving cell handover method, an electronic device and a computer program product, the serving cell handover method comprising: after a terminal in an idle state or an inactive state moves to a target serving cell, the terminal sends a first cell handover request to a source serving cell, the first cell switching request carries a target service cell identifier; and the terminal receives a first cell switching instruction from the source service cell, and switches to the target service cell based on the first cell switching instruction. Through the embodiment of the invention, the problem that the terminal mobility cannot be supported in the idle state or inactive state data sending process in the related technology is at least solved, and the effect of supporting the terminal mobility in the idle state or inactive state data sending process is achieved.

Description

Technical Field

[0001] This application relates to the field of communications, and more specifically, to a serving cell handover method, electronic device, and computer program product. Background Technology

[0002] 6G networks will be integrated networks of communication, sensing, computing, and intelligence, requiring a large number of devices to connect to the network. These IoT devices are characterized by low cost and low power consumption. Although Small Data Transmission (SDT) technology was introduced in Release 17, enabling User Equipment (UE) to transmit data in an inactive state, if the UE performs cell reselection during the inactive data transmission phase, the UE will enter an idle state. Therefore, the UE cannot continue to use the target cell's SDT resources for transmission after cell reselection.

[0003] The current protocol only supports mobility during data transmission in the connected state, and does not support mobility during data transmission in the inactive state. In the Random Access-Small Data Transmission (RA-SDT) scenario, the UE is in an inactive state, and mobility is not supported during data transmission. The UE's Radio Resource Control (RRC) state will transition to the idle state.

[0004] In summary, the relevant technologies cannot support terminal mobility during data transmission in idle or inactive states. Summary of the Invention

[0005] This application provides a serving cell handover method, electronic device, and computer program product to at least solve the problem in the related art that terminal mobility cannot be supported during data transmission in the idle or inactive state.

[0006] According to one embodiment of this application, a serving cell handover method is provided, comprising: after a terminal in an idle or inactive state moves to a target serving cell, the terminal sends a first cell handover request to a source serving cell, the first cell handover request carrying a target serving cell identifier; the terminal receives a first cell handover instruction from the source serving cell, and handes over to the target serving cell based on the first cell handover instruction.

[0007] According to another embodiment of this application, a serving cell handover method is provided, comprising: after a terminal in an idle state or an inactive state moves to a target serving cell, the terminal sends a second cell handover request to the target serving cell, the second cell handover request carrying an active serving cell identifier; the terminal receives a second cell handover instruction from the target serving cell, and handes over to the target serving cell based on the second cell handover instruction.

[0008] According to another embodiment of this application, a serving cell handover method is provided, comprising: after a terminal in an idle or inactive state moves to a target serving cell, a source serving cell receives a first cell handover request from the terminal, the first cell handover request carrying a target serving cell identifier; the source serving cell sends a first cell handover instruction to the terminal, so that the terminal handovers to the target serving cell based on the first cell handover instruction.

[0009] According to another embodiment of this application, a serving cell handover method is provided, comprising: after a terminal in an idle or inactive state moves to a target serving cell, the target serving cell receives a second cell handover request from the terminal, the second cell handover request carrying an active serving cell identifier; the target serving cell sends a second cell handover instruction to the terminal, so that the terminal hands over from the active serving cell to the target serving cell.

[0010] According to yet another embodiment of this application, a computer-readable storage medium is also provided, wherein a computer program is stored therein, and the computer program is configured to perform the steps in any of the above method embodiments when it is run.

[0011] According to yet another embodiment of this application, an electronic device is also provided, including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the steps in any of the above method embodiments.

[0012] According to yet another embodiment of this application, a computer program product is also provided, including a computer program that, when executed by a processor, implements the steps in any of the above method embodiments.

[0013] The above embodiments of this application provide a serving cell handover method. After a terminal in an idle or inactive state moves to a target serving cell, the terminal sends a first cell handover request to the source serving cell, the first cell handover request carrying the target serving cell identifier; the terminal receives a first cell handover instruction from the source serving cell and handes over to the target serving cell based on the first cell handover instruction. This at least solves the problem in related technologies that cannot support terminal mobility during data transmission in an idle or inactive state, achieving the effect of supporting terminal mobility during data transmission in an idle or inactive state. Attached Figure Description

[0014] Figure 1 This is a hardware structure block diagram of the mobile terminal for the serving cell handover method implemented in the method embodiments of this application;

[0015] Figure 2 This is a flowchart of the serving cell handover method according to an embodiment of this application;

[0016] Figure 3 This is another flowchart of the serving cell handover method according to an embodiment of this application;

[0017] Figure 4 This is yet another flowchart of the serving cell handover method according to an embodiment of this application;

[0018] Figure 5 This is another flowchart of the serving cell handover method according to an embodiment of this application;

[0019] Figure 6 This is a schematic diagram illustrating the principle of the serving cell handover process in an embodiment of this application;

[0020] Figure 7 This is a structural example diagram of the DL MAC CE according to an embodiment of this application;

[0021] Figure 8 This is another schematic diagram illustrating the serving cell handover process in an embodiment of this application. Detailed Implementation

[0022] The embodiments of this application will be described in detail below with reference to the accompanying drawings and examples.

[0023] It should be noted that the terms "first," "second," etc., in the specification, claims, and drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0024] The methods and embodiments provided in this application can be executed in a mobile terminal, base station, or similar computing device. Taking running on a mobile terminal as an example, Figure 1This is a hardware structure block diagram of the mobile terminal implementing the serving cell handover method in the embodiments of this application. For example... Figure 1 As shown, a mobile terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0025] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the serving cell handover method in this embodiment. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thus implementing the above-described method. The memory 104 may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0026] The transmission device 106 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 106 may be a Radio Frequency (RF) module, used for wireless communication with the Internet.

[0027] This application provides a method for serving cell handover. Figure 2 This is a flowchart of the serving cell handover method according to an embodiment of this application, such as... Figure 2 As shown, the process includes the following steps:

[0028] In step S202, after the terminal in the idle or inactive state moves to the target serving cell, the terminal sends a first cell handover request to the source serving cell. The first cell handover request carries the identifier of the target serving cell.

[0029] In this embodiment of the application, the first cell handover request is a cell handover request sent by the terminal to the source serving cell, and the second cell handover request is a cell handover request sent by the terminal to the target serving cell.

[0030] In one exemplary embodiment, the first cell handover request is a first uplink medium access control element (UL MAC CE).

[0031] In an exemplary embodiment, the terminal sends the first UL MAC CE to the source serving cell in the following ways: the terminal reuses the dynamic scheduling resources of uplink transmission data to send the first UL MAC CE to the source serving cell; or, the terminal receives periodic uplink authorization information from the network side and uses the resources indicated by the uplink authorization information to send the first UL MAC CE to the source serving cell; or, the terminal initiates random access to the source serving cell to send the first UL MAC CE to the source serving cell.

[0032] In step S204, the terminal receives a first cell handover instruction from the source serving cell and switches to the target serving cell based on the first cell handover instruction.

[0033] In one exemplary embodiment, the first cell handover instruction is a first downlink medium access control element (DL MAC CE).

[0034] In an exemplary embodiment, the first DL MAC CE includes at least one of the following: Cell Radio Network Temporary Identifier (C-RNTI) scrambling of the terminal in the target serving cell; parameter effective area of ​​the target serving cell; target serving cell identifier; Timing Advance (TA); Random Access Channel (RACH) dedicated resources; target serving cell broadcast; packet data aggregation protocol configuration; and service data adaptation protocol configuration.

[0035] In one exemplary embodiment, in response to the target serving cell and the source serving cell not belonging to the same parameter effective area, the first DL MAC CE carries the terminal's C-RNTI in the target serving cell; or, in response to the terminal performing a non-contention handover, the first DL MAC CE carries RACH dedicated resources; or, in response to the target serving cell and the source serving cell not belonging to the same parameter effective area, the first DL MAC CE carries the packet data aggregation protocol configuration or service data adaptation protocol configuration of the target serving cell; or, in response to the target serving cell and the source serving cell having different System Information Blocks (SIB1), the first DL MAC CE carries the SIB1 configuration of the target serving cell.

[0036] In one exemplary embodiment, the first cell handover instruction is downlink control information.

[0037] In one exemplary embodiment, after the terminal switches to the target serving cell based on the first cell handover instruction, the method further includes: the terminal sending a second UL MAC CE to the target serving cell to notify the target serving cell that the handover is complete, and simultaneously transmitting uplink data.

[0038] In one exemplary embodiment, the second UL MAC CE is identified as a cell handover completion MAC CE by a Logical Channel Identifier (LCID).

[0039] The above steps provide a serving cell handover method. After a terminal in an idle or inactive state moves to a target serving cell, the terminal sends a first cell handover request to the source serving cell, the first cell handover request carrying the target serving cell identifier. The terminal receives a first cell handover instruction from the source serving cell and hands over to the target serving cell based on the first cell handover instruction. This at least solves the problem in related technologies that cannot support terminal mobility during data transmission in an idle or inactive state, achieving the effect of supporting terminal mobility during data transmission in an idle or inactive state.

[0040] This application provides a method for serving cell handover. Figure 3 This is another flowchart of the serving cell handover method according to an embodiment of this application, such as... Figure 3 As shown, the process includes the following steps:

[0041] In step S302, after the terminal in an idle or inactive state moves to the target serving cell, the terminal sends a second cell handover request to the target serving cell. The second cell handover request carries the active serving cell identifier.

[0042] In the embodiments of this application, after a cell reselection occurs, the UE can send a handover request to the source serving cell or a cell handover request to the target serving cell.

[0043] In this embodiment of the application, the first cell handover request is a cell handover request sent by the terminal to the source serving cell, and the second cell handover request is a cell handover request sent by the terminal to the target serving cell.

[0044] In one exemplary embodiment, the terminal sends uplink data to the target serving cell simultaneously with sending a second cell handover request to the target serving cell.

[0045] In one exemplary embodiment, the second cell handover request is a radio resource control signaling message, which also carries a scrambled C-RNTI of the terminal's Radio Network Temporary Identifier.

[0046] In one exemplary embodiment, the second cell handover request is a third uplink media access control element UL MAC CE, which carries the terminal's radio network temporary identifier scrambled with C-RNTI and the source serving cell identifier.

[0047] In one exemplary embodiment, the resource block configuration of the third UL MAC CE or the C-RNTI of the terminal is effective within a specific parameter effective area, and the target serving cell is within the specific parameter effective area.

[0048] In this embodiment of the application, the effective area of ​​the above parameters is a geographical area.

[0049] In this embodiment of the application, the resource block configuration used by the UE to send the third UL MAC CE or the C-RNTI of the terminal UE needs to be effective within a certain parameter effective area, namely the aforementioned specific parameter effective area, and the target serving cell is within the parameter effective area to ensure that the target serving cell can identify the C-RNTI of the terminal UE.

[0050] In an exemplary embodiment, the terminal sends a third UL MAC CE to the target serving cell in the following ways: the terminal sends the third UL MAC CE using pre-configured resources of the target serving cell; or, the terminal sends the third UL MAC CE to the target serving cell using resources indicated by the uplink authorization information received periodically from the network side; or, the terminal sends the third UL MAC CE to the target serving cell by initiating random access to the target serving cell.

[0051] In step S304, the terminal receives a second cell handover instruction from the target serving cell and switches to the target serving cell based on the second cell handover instruction.

[0052] In one exemplary embodiment, the second cell handover instruction is a second downlink media access control element (DL MAC CE).

[0053] In one exemplary embodiment, the second DL MAC CE includes at least one of the following: scrambling the Radio Network Temporary Identifier (C-RNTI) of the terminal in the target serving cell; the parameter effective area of ​​the target serving cell; the target serving cell identifier; the timing advance TA; the random access channel dedicated resource; the target serving cell broadcast; the packet data aggregation protocol configuration; and the service data adaptation protocol configuration.

[0054] This application provides a method for serving cell handover. Figure 4 This is another flowchart of the serving cell handover method according to an embodiment of this application, such as... Figure 4 As shown, the process includes the following steps:

[0055] In step S402, after the terminal in an idle or inactive state moves to the target serving cell, the source serving cell receives a first cell handover request from the terminal, and the first cell handover request carries the target serving cell identifier.

[0056] In step S404, the source serving cell sends a first cell handover instruction to the terminal, so that the terminal can hand over to the target serving cell based on the first cell handover instruction.

[0057] In an exemplary embodiment, before the source serving cell sends a first cell handover instruction to the terminal, the method further includes: in response to the source serving cell and the target serving cell not belonging to the same parameter effective area, the source serving cell requests the target serving cell to configure the radio resource control parameters, so that the target serving cell controls the terminal to handover to the target serving cell according to the radio resource control parameter configuration.

[0058] In this embodiment, since the target serving cell and the source serving cell are in the same parameter domain, and the target serving cell ID, security parameters, UE C-RNTI and SIB1 configuration in the target serving cell are valid in the region and do not need to support non-contention random access, these parameters can be used directly in the target serving cell. Therefore, the source serving cell and the target serving cell do not need to exchange handover preparation information.

[0059] Otherwise, the source serving cell and the target serving cell need to negotiate new Radio Resource Control (RRC) parameter configurations. The source serving cell needs to send the target cell ID, security parameters, UE's C-RNTI, TA, SIB1 configuration in the target serving cell, and RACH dedicated resources (including preamble and beam information) to the target serving cell.

[0060] In one exemplary embodiment, the radio resource control parameter configuration includes at least one of the following: target serving cell identifier; security parameters; scrambling of the UE's Radio Network Identifier (C-RNTI) in the target cell; timing advance (TA); system information block (SIB1) configuration; and dedicated resources for the random access channel (RACH).

[0061] This application provides a method for serving cell handover. Figure 5 This is another flowchart of the serving cell handover method according to an embodiment of this application, as follows: Figure 5 As shown, the process includes the following steps:

[0062] In step S502, after the terminal in an idle or inactive state moves to the target serving cell, the target serving cell receives a second cell handover request from the terminal, and the second cell handover request carries the active serving cell identifier.

[0063] In step S504, the target serving cell sends a second cell handover instruction to the terminal so that the terminal can hand over from the source serving cell to the target serving cell.

[0064] In an exemplary embodiment, before the target serving cell sends a second cell handover instruction to the terminal, the method further includes: in response to the source serving cell and the target serving cell not belonging to the same parameter effective area, the target serving cell requests the source serving cell to configure the radio resource control parameters of the target serving cell, so that the target serving cell controls the terminal to handover to the target serving cell according to the radio resource control parameter configuration.

[0065] In this embodiment, since the target serving cell and the source serving cell are in the same parameter domain, and the target serving cell ID, security parameters, UE C-RNTI and SIB1 configuration in the target serving cell are valid in the region and do not need to support non-contention random access, these parameters can be used directly in the target serving cell. Therefore, the source serving cell and the target serving cell do not need to exchange handover preparation information.

[0066] Otherwise, the source serving cell and the target serving cell need to negotiate new RRC parameter configurations. The source serving cell needs to send the target cell ID, security parameters, UE's C-RNTI, TA, SIB1 configuration in the target serving cell, and RACH dedicated resources (including preamble and beam information) to the target serving cell.

[0067] In one exemplary embodiment, the radio resource control parameter configuration includes at least one of the following: target serving cell identifier; security parameters; scrambling of the UE's Radio Network Identifier (C-RNTI) in the target cell; timing advance (TA); system information block (SIB1) configuration; and dedicated resources for the random access channel (RACH).

[0068] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0069] This application also provides a terminal for implementing the serving cell handover method steps described in the above embodiments.

[0070] This application also provides a base station for implementing the serving cell handover method steps described in the above embodiments.

[0071] This embodiment also provides a serving cell handover apparatus, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0072] This application embodiment also provides a serving cell handover device, which can be installed in a terminal, including a first sending module and a first receiving module. The first sending module is configured to send a first cell handover request to the source serving cell after the terminal, which is in an idle or inactive state, moves to the target serving cell. The first cell handover request carries an identifier of the target serving cell. The first receiving module is configured to receive a first cell handover instruction from the source serving cell and handover to the target serving cell based on the first cell handover instruction.

[0073] This application embodiment also provides a serving cell handover device, which can be disposed in a terminal, including a second sending module and a second receiving module. The second sending module is configured to send a second cell handover request to the target serving cell after the terminal, which is in an idle or inactive state, moves to the target serving cell. The second cell handover request carries an active serving cell identifier. The second receiving module is configured to receive a second cell handover instruction from the target serving cell and handover to the target serving cell based on the second cell handover instruction.

[0074] This application embodiment also provides a serving cell handover apparatus, which can be located in the source serving cell and includes a third receiving module and a third sending module. The third receiving module is configured to receive a first cell handover request from the terminal after the terminal, which is in an idle or inactive state, moves to the target serving cell. The first cell handover request carries a target serving cell identifier. The third sending module is configured to send a first cell handover instruction to the terminal, so that the terminal hands over to the target serving cell based on the first cell handover instruction.

[0075] This application embodiment also provides a serving cell handover apparatus, which can be located in a target serving cell. It includes a fourth receiving module and a fourth sending module. The fourth receiving module is configured to receive a second cell handover request from a terminal that is in an idle or inactive state after the terminal moves to the target serving cell. The second cell handover request carries an active serving cell identifier. The fourth sending module is configured to send a second cell handover instruction to the terminal, causing the terminal to handover from the source serving cell to the target serving cell.

[0076] In this embodiment, the serving cell handover device may further include different modules, and the naming and functional division of these modules may be selected in different ways according to the actual situation, without specific restrictions.

[0077] It should be noted that the above modules can be implemented by software or hardware. For the latter, they can be implemented in the following ways, but are not limited to: all the above modules are located in the same processor; or, the above modules are located in different processors in any combination.

[0078] Embodiments of this application also provide a computer-readable storage medium storing a computer program, wherein the computer program is configured to execute the steps in any of the above method embodiments when run.

[0079] In one exemplary embodiment, the aforementioned computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard disk, magnetic disk, or optical disk.

[0080] Embodiments of this application also provide an electronic device including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the steps in any of the above method embodiments.

[0081] In one exemplary embodiment, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor and the input / output device is connected to the processor.

[0082] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps in any of the above method embodiments.

[0083] In one exemplary embodiment, the computer program product described above includes a non-volatile computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the methods described in various embodiments of this application.

[0084] Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.

[0085] Obviously, those skilled in the art should understand that the modules or steps of this application described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented here, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, this application is not limited to any particular combination of hardware and software.

[0086] To enable those skilled in the art to better understand the technical solutions of this application, the following description is provided in conjunction with different embodiments.

[0087] Example 1

[0088] The amount of data sent by IoT terminals is relatively small, but the duration of data transmission for some UEs may be relatively long, or the IoT terminals may move at a relatively high speed. Therefore, there is a need for IoT terminals to transmit data during mobility.

[0089] This application provides a mobility method for a UE transmitting small data while in an idle / inactive state. When the UE is in an idle or inactive state and there are still uplink and downlink service interactions between the UE and the network, if the UE moves to a new cell, the UE's state will not transition to an idle state as in the current protocol, but will continue to maintain the current RRC state and reselect to the new cell. To achieve this, the UE needs to actively inform the current serving cell (i.e., the source serving cell) that it has moved to another cell. The source serving cell sends a cell handover command to the UE and forwards downlink data to the target serving cell to avoid downlink packet loss. Furthermore, since the relevant parameters of the UE in an inactive or idle state can be effective within a certain area, if the source serving cell and the target serving cell are in the same area, the size of the cell handover command can be further simplified.

[0090] Figure 6 This is a schematic diagram illustrating the serving cell handover process according to an embodiment of this application. In this embodiment, after a cell reselection occurs, the UE sends a cell handover request to the source serving cell, such as... Figure 6 As shown, it includes the following steps:

[0091] S1~S2: When the UE moves to a new cell, i.e. the target serving cell, and meets the cell reselection criteria, the UE sends a Cell Switch Request (which can be a MAC CE, i.e. a new UL MAC CE) to notify the source serving cell, and carries the target serving cell ID.

[0092] In this embodiment, the Cell Switch Request is the first Cell Switch Request in the above embodiment. In this embodiment, the UL MAC CE is the first UL MAC CE in the above embodiment.

[0093] In this embodiment of the application, the transmission method of the first UL MAC CE includes: the terminal reusing the dynamic scheduling resources of uplink transmission data to send the first UL MAC CE to the source serving cell; or, the terminal receiving periodic uplink authorization information from the network side and using the resources indicated by the uplink authorization information to send the first UL MAC CE to the source serving cell; or, the terminal initiating random access to the source serving cell to send the first UL MAC CE to the source serving cell.

[0094] S3a~S3b: S3a is when the source serving cell sends a handover request to the target serving cell and sends an RRC container, which carries the necessary information required for the target serving cell to prepare for handover. S3b is when the target serving cell, after receiving the handover request, sends a handover request confirmation message to the source serving cell, which carries the information required for the UE handover.

[0095] In this embodiment of the application, steps S3a to S3b are optional, and their optionality is determined based on the following steps:

[0096] If the target serving cell and the source serving cell are within the same parameter area, and the target serving cell ID, security parameters, UE's C-RNTI, and SIB1 configurations in the target serving cell are valid within this parameter area, and non-contention-based random access is not required, then these parameters can be directly used in the target serving cell. Therefore, the source and target serving cells do not need to exchange handover preparation information, and steps S3a to S3b can be omitted. In this case, it is assumed that the target base station can accept the UE's access.

[0097] Otherwise, the source serving cell and the target serving cell need to negotiate new RRC parameter configurations, so steps S3a to S3b cannot be omitted. The source serving cell needs to send the target cell ID, security parameters, UE's C-RNTI, TA, SIB1 configuration in the target serving cell, and RACH dedicated resources to the target serving cell. The RACH dedicated resources may include preamble and beam information.

[0098] Unlike existing protocols that require steps S3a to S3b, the S3a to S3b interaction process can be omitted in this embodiment because some configuration parameters can take effect within a certain range.

[0099] S4: The source serving cell sends a cell handover instruction to the UE, which is the first cell handover instruction in the above embodiment. The first cell handover instruction can be defined as a new DL MAC CE.

[0100] Figure 7 This is a structural example diagram of the DL MAC CE according to an embodiment of this application, as shown below. Figure 7As shown, the DL MAC CE content, depending on the specific circumstances, includes the UE's Radio Network Identifier (C-RNTI) scrambling in the target serving cell, the Parameter Notification Area, the target cell ID, TA, RACH dedicated resources (including preamble and beam information), target cell broadcast, and configuration of Packet Data Convergence Protocol (PDCP) or Service Data Adaptation Protocol (SDAP). Figure 7 The DL MAC CE shown is for example only; the final number of field bits in the DL MAC CE is yet to be determined.

[0101] In this embodiment of the application, in response to the UE's C-RNTI being effective within a certain range, the first DL MAC CE does not need to carry the UE's C-RNTI in the target cell.

[0102] In this embodiment of the application, in response to the UE performing a non-contention handover, the first DL MAC CE carries RACH dedicated resources.

[0103] In this embodiment of the application, in response to the fact that the source serving cell and the target serving cell of the UE are within the same parameter effective area, the first DL MAC CE does not need to carry PDCP / SDAP configuration, etc.

[0104] In this embodiment of the application, in response to the fact that the SIB1 content of the source serving cell and the target serving cell are the same, the DLMAC CE does not need to carry the configuration of the source cell's SIB1.

[0105] In this embodiment of the application, the cell handover command can also be issued via DCI.

[0106] In this embodiment, the use of DL MAC CE to send cell handover commands differs from existing protocols. Since UE parameters are effective within a certain range, handover commands can be sent through lightweight MAC CE or DCI. For example, in this embodiment, a Target Configuration ID (candidate cell ID) is not required. Only when the UE's movement range exceeds the effective range of the parameters is a new parameter effective range configuration sent, or a new C-RNTI is configured for the UE.

[0107] S5: The source serving cell forwards data to the target serving cell. The specific process may include serial number (SN) status transmission, etc., which are standard techniques in this field and will not be described in detail here.

[0108] S6a~S6b: The UE sends a Random Access (RA) preamble to the target serving cell and receives the RA response from the target serving cell.

[0109] In this embodiment, the UE performs uplink synchronization and receives uplink grant. This process is optional. Specifically, the processes S6a to S6b are conventional techniques in the art and will not be described in detail here.

[0110] S7: The UE sends a handover completion MAC CE to the target serving cell, defines a new cell handover completion UL MAC CE, which is the second UL MAC CE in the above embodiment, and can send uplink data.

[0111] In this embodiment of the application, the design of the second UL MAC CE is identified by the Logical Channel Identifier (LCID), and the Service Data Unit (SDU) of the UL MAC CE can be fixed at 0 bits.

[0112] S8~S11: These are standard steps involved in conventional techniques in this field. If the xNB is replaced, a path switching process is required, which will not be described in detail here.

[0113] In this application embodiment, a method is provided for a terminal to perform cell reselection when transmitting small data in an idle or inactive state. When the UE is in an RRC idle or inactive state and transmitting data, if the UE initiates cell reselection at this time, the source serving cell and the target serving cell exchange the UE's context information to ensure the continuity of the UE's services during the cell reselection process.

[0114] The mobility method for a UE transmitting small data while in an idle / inactive state, provided in this application embodiment, possesses some characteristics of idle / inactive / connected states. UE mobility is also based on cell reselection in the idle / inactive state; however, because the UE transmits data while in an idle / inactive state, the processing differs somewhat from traditional cell reselection in the idle / inactive state and cell handover in the connected state.

[0115] The difference between the serving cell handover method in this application embodiment and the idle / inactive state is as follows: After the UE performs cell reselection, it needs to notify the base station to perform cell reselection itself. In this way, for DL ​​Data, the source cell can forward the DL Data to the target cell. Otherwise, if the source cell does not know that the UE has moved to a new cell and continues to send DL Data to the UE, it will lead to downlink packet loss.

[0116] The difference between the serving cell handover method in this application embodiment and the connected state is as follows: the parameters required for UE data transmission in the idle or inactive state can be effective within a certain area, so some parameters adopt the default configuration, and the signaling size for cell reselection sent by the network side to the UE can be smaller.

[0117] Example 2

[0118] In this embodiment, after a cell reselection occurs, the UE sends a cell handover request to the target serving cell.

[0119] Figure 8 This is another schematic diagram illustrating the serving cell handover process according to an embodiment of this application, such as... Figure 8 As shown, it includes the following steps:

[0120] S1: The UE discovers a cell that meets the cell reselection conditions in the idle or inactive state.

[0121] S2: The UE uses a Cell Switch Request to notify the target serving cell.

[0122] The Cell Switch Request sent by the UE to the target serving cell is the second cell switch request in the above embodiment.

[0123] In the embodiments of this application, the Cell Switch Request can be either RRC signaling or MACCE.

[0124] In this embodiment of the application, the Cell Switch Request carries the UE's C-RNTI and the source serving cell ID.

[0125] In this embodiment, the second cell handover request can also be made by the UE sending a new UL MAC CE to the target serving cell, namely the third UL MAC CE in the above embodiment. The third UL MAC CE carries the UE's C-RNTI and the source serving cell ID, and is scrambled using the UE's C-RNTI.

[0126] In this embodiment of the application, the RB configuration used by the UE to send the third UL MAC CE or the UE's C-RNTI needs to be effective within a certain range, and the target serving cell needs to be within the effective range of this parameter to ensure that the DU of the target serving cell can recognize the UE's C-RNTI.

[0127] In this application embodiment, the authorization method of the UE's Cell Switch Request may include the following: sending through pre-configured resources of the target serving cell, or sending through a random access request to the target serving cell, or requesting uplink authorization by sending an SR request to the target serving cell. Among these, SR resources also need to be reserved.

[0128] In this embodiment, the cell reselection threshold configured by the network side for the UE is more lenient because the measurement period is longer when the UE is in idle or inactive state. If the UE has moved to the target serving cell, the source serving cell side may not receive the UE's Cell Switch Request. Therefore, the UE can send a Cell Switch Request to the target serving cell.

[0129] S3a~S3b: After the target serving cell receives the admission control, it sends a handover request to the source serving cell through step 3a. Step 3b is when the source serving cell receives the handover request and sends an RRC container (carrying the necessary information required for the target serving cell to prepare for handover) to the target serving cell. In actual implementation, steps 3a~3b are optional. Whether they are optional is determined according to the following steps.

[0130] In this embodiment, in response to the fact that the target serving cell and the source serving cell are in the same parameter area, and the target serving cell ID, security parameters, UE's C-RNTI and SIB1 configuration in the target serving cell are valid in the area and do not need to support non-contention random access, these parameters can be used directly in the target serving cell. Therefore, the source serving cell and the target serving cell do not need to exchange handover preparation information, so steps S3a to S3b can be omitted. It is assumed that the target base station can accept the UE's access.

[0131] Otherwise, the source serving cell and the target serving cell need to negotiate new RRC parameter configurations, so steps S3a to S3b cannot be omitted. The source serving cell needs to send the target cell ID, security parameters, UE's C-RNTI, TA, SIB1 configuration in the target serving cell, and RACH dedicated resources (including preamble and beam information) to the target serving cell.

[0132] Unlike existing protocols that require steps S3a to S3b, the S3a to S3b interaction process can be omitted in this embodiment because some configuration parameters can take effect within a certain range.

[0133] S4: The target serving cell sends a cell handover instruction to the UE, which is the second cell handover instruction in the above embodiment. The second cell handover instruction can be defined as a new DL MAC CE, that is, the second DL MAC CE in the above embodiment. An example of the structure of the second DL MAC CE is shown below. Figure 7 As shown, Figure 7 The second DL MAC CE shown is only an example; the final number of field bits in the second DL MAC CE is yet to be determined. Depending on the specific circumstances, the content of this second DL MAC CE may include the UE's Radio Network Identifier (C-RNTI) scrambled in the target serving cell, the Parameter Notification Area, the target cell ID, TA, RACH-specific resources (including preamble and beam information), target cell broadcast, PDCP / SDAP configuration, etc.

[0134] In this embodiment of the application, in response to the UE's C-RNTI being effective within a certain range, the second DL MAC CE does not need to carry the UE's C-RNTI in the target cell.

[0135] In this embodiment of the application, in response to the UE not needing to support non-contention handover, the second DL MAC CE does not need to carry RACH dedicated resources.

[0136] In this embodiment of the application, in response to the fact that the source serving cell and the target serving cell of the UE are in the same parameter effective area, the second DL MAC CE does not need to carry the Packet Data Convergence Protocol (PDCP) or Service Data Adaptation Protocol (SDAP) configuration, etc.

[0137] In this embodiment of the application, in response to the fact that the SIB1 content of the source serving cell and the target serving cell are the same, the second DL MAC CE does not need to carry the configuration of the source cell's SIB1.

[0138] In this embodiment of the application, the cell handover command can also be issued through downlink control information (DCI).

[0139] In this embodiment, the use of the second DL MAC CE to send cell handover commands differs from existing protocols. Since UE parameters are effective within a certain range, handover commands can also be sent through a lightweight MAC CE or DCI. For example, in this embodiment, a Target Configuration ID (candidate cell ID) is not required. Only when the UE's movement range exceeds the effective range of the parameters is a new parameter effective range configuration sent, or a new C-RNTI is configured for the UE.

[0140] S5: The source serving cell forwards data to the target serving cell. The specific process may include SN state transmission, etc., which are standard techniques in this field and will not be described in detail here.

[0141] S6a~S6b: The UE sends a Random Access (RA) preamble to the target serving cell and receives the RA response from the target serving cell.

[0142] In this embodiment, the UE performs uplink synchronization and receives uplink grant. This process is optional. Specifically, the processes S6a to S6b are conventional techniques in the art and will not be described in detail here.

[0143] S7: The UE sends a handover completion MAC CE to the target serving cell, defines a new cell handover completion UL MAC CE, and can send uplink data.

[0144] In this embodiment of the application, the design of the UL MAC CE is identified by LCID, and the SDU of the UL MAC CE can be fixed at 0 bits.

[0145] S8~S11: These are standard steps involved in conventional techniques in this field. If the xNB is replaced, a path switching process is required.

[0146] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.

Claims

1. A method for handover to a serving cell, characterized in that, include: After a terminal in an idle or inactive state moves to the target serving cell, the terminal sends a first cell handover request to the source serving cell, the first cell handover request carrying the target serving cell identifier; The terminal receives a first cell handover instruction from the source serving cell and switches to the target serving cell based on the first cell handover instruction.

2. The method according to claim 1, characterized in that, in, The first cell handover request is the first uplink media access control element UL MAC CE.

3. The method according to claim 2, characterized in that, The terminal sends the first UL MAC CE to the source serving cell in the following ways: The terminal reuses the dynamic scheduling resources of uplink transmission data to send the first UL MAC CE to the source serving cell; Alternatively, the terminal may receive periodic uplink authorization information from the network side and use the resources indicated by the uplink authorization information to send the first UL MAC CE to the source serving cell; Alternatively, the terminal may send the first UL MAC CE to the source serving cell by initiating random access to the source serving cell.

4. The method according to claim 1, characterized in that, in, The first cell handover instruction is the first downlink media access control element DL MAC CE.

5. The method according to claim 4, characterized in that, The first DL MAC CE includes at least one of the following: The terminal scrambles the Radio Network Identifier (C-RNTI) of the target serving cell; the parameter effective area of ​​the target serving cell; the target serving cell identifier; the timing advance TA; and the dedicated resource for the Random Access Channel (RACH). Target service cell broadcast; packet data aggregation protocol configuration; business data adaptation protocol configuration.

6. The method according to claim 5, characterized in that, in, In response to the fact that the target serving cell and the source serving cell do not belong to the same parameter effective area, the first DLMAC CE carries the C-RNTI of the terminal in the target serving cell; Alternatively, in response to the terminal performing a non-contention handover, the first DL MAC CE carries RACH dedicated resources; Alternatively, in response to the fact that the target serving cell and the source serving cell do not belong to the same parameter effective area, the first DL MAC CE carries the packet data aggregation protocol configuration or service data adaptation protocol configuration of the target serving cell. Alternatively, in response to the fact that the System Information Block (SIB1) of the target serving cell and the source serving cell are different, the first DL MAC CE carries the SIB1 configuration of the target serving cell.

7. The method according to claim 1, characterized in that, in, The first cell handover command is downlink control information.

8. The method according to claim 1, characterized in that, After the terminal switches to the target serving cell based on the first cell handover instruction, the method further includes: The terminal sends a second UL MAC CE to the target serving cell to notify the target serving cell that the handover is complete, and simultaneously transmits uplink data.

9. The method according to claim 8, characterized in that, in, The second UL MAC CE is identified as the cell handover completion media access control element MAC CE by the logical channel identifier LCID.

10. A method for handover of a serving cell, characterized in that, include: After a terminal in an idle or inactive state moves to a target serving cell, the terminal sends a second cell handover request to the target serving cell, the second cell handover request carrying an active serving cell identifier; The terminal receives a second cell handover instruction from the target serving cell and switches to the target serving cell based on the second cell handover instruction.

11. The method according to claim 10, characterized in that, in, While the terminal sends the second cell handover request to the target serving cell, the terminal also sends uplink data to the target serving cell.

12. The method according to claim 10, characterized in that, in, The second cell handover request is a radio resource control signaling message, which also carries the terminal's radio network identifier scrambled C-RNTI.

13. The method according to claim 10, characterized in that, in, The second cell handover request is a third uplink media access control element UL MAC CE, which also carries the terminal's radio network identifier scrambled C-RNTI.

14. The method according to claim 13, characterized in that, in, The resource block configuration of the third UL MAC CE or the C-RNTI of the terminal is effective within a specific parameter effective area, and the target serving cell is within the specific parameter effective area.

15. The method according to claim 13, characterized in that, The terminal sends the third UL MAC CE to the target serving cell in the following ways: The terminal uses the pre-configured resources of the target serving cell to send the third UL MAC CE; Alternatively, the terminal may receive periodic uplink authorization information from the network side and use the resources indicated by the uplink authorization information to send the third UL MAC CE to the target serving cell; Alternatively, the terminal may send the third UL MAC CE to the target serving cell by initiating random access to the target serving cell.

16. The method according to claim 10, characterized in that, in, The second cell handover instruction is the second downlink media access control element DL MAC CE.

17. The method according to claim 16, characterized in that, The second DL MAC CE includes at least one of the following: The terminal scrambles the C-RNTI of the radio network identifier of the target serving cell; the parameter effective area of ​​the target serving cell; Target serving cell identifier; timed advance TA; dedicated resources for random access channels; Target service cell broadcast; packet data aggregation protocol configuration; business data adaptation protocol configuration.

18. A method for handover of a serving cell, characterized in that, include: After a terminal in an idle or inactive state moves to the target serving cell, the source serving cell receives a first cell handover request from the terminal, the first cell handover request carrying the target serving cell identifier; The source serving cell sends a first cell handover instruction to the terminal, so that the terminal can hand over to the target serving cell based on the first cell handover instruction.

19. The method according to claim 18, characterized in that, Before the source serving cell sends a first cell handover instruction to the terminal, the method further includes: In response to the fact that the source serving cell and the target serving cell do not belong to the same parameter effective area, the source serving cell requests the target serving cell's radio resource control parameter configuration, so that the target serving cell controls the terminal to switch to the target serving cell according to the radio resource control parameter configuration.

20. The method according to claim 19, characterized in that, in, The wireless resource control parameter configuration includes at least one of the following: Target serving cell identifier; security parameters; UE radio network identifier scrambling C-RNTI in the target cell; timing advance TA; system information block SIB1 configuration; dedicated resources for random access channel RACH.

21. A method for handover to a serving cell, characterized in that, include: After a terminal in an idle or inactive state moves to a target serving cell, the target serving cell receives a second cell handover request from the terminal, the second cell handover request carrying an active serving cell identifier; The target serving cell sends a second cell handover instruction to the terminal, so that the terminal can hand over from the source serving cell to the target serving cell.

22. The method according to claim 21, characterized in that, Before the target serving cell sends a second cell handover instruction to the terminal, the method further includes: In response to the fact that the source serving cell and the target serving cell do not belong to the same parameter effective area, the target serving cell requests the radio resource control parameter configuration of the target serving cell from the source serving cell, so that the target serving cell controls the terminal to switch to the target serving cell according to the radio resource control parameter configuration.

23. The method according to claim 22, characterized in that, in, The wireless resource control parameter configuration includes at least one of the following: Target serving cell identifier; security parameters; UE radio network identifier scrambling C-RNTI in the target serving cell; timing advance TA; system information block SIB1 configuration; dedicated resources for random access channel RACH.

24. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein the computer program, when executed by a processor, implements the steps of the method described in any one of claims 1 to 23.

25. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method described in any one of claims 1 to 23.

26. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method described in any one of claims 1 to 23.

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