Method and system for acquiring cell timing advance information, and terminal and base station

Abstract

The present disclosure relates to the field of wireless communication and provides a method and system for acquiring cell timing advance information, and a terminal and a base station. The method comprises: a terminal receiving an RRC reconfiguration message from a source cell, wherein the RRC reconfiguration message carries configuration information related to random access of a candidate cell; receiving a PDCCH command from the source cell, wherein the PDCCH command carries a candidate cell identifier or index; sending a random access preamble to the candidate cell on the basis of the candidate cell identifier or index; and acquiring target cell timing advance information from a cell handover command sent by the source cell, or acquiring candidate cell timing advance information from a random access response. A terminal acquires, in advance, timing advance information of a candidate / target cell on the basis of a network signaling configuration, thereby reducing a cell handover delay, and shortening data interruption time of the terminal during the handover process.

Description

Method and system for obtaining cell timing advance information, terminal and base station

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the application with CN application number 202311014371.0 and application date August 11, 2023, and claims its priority. The disclosed content of the CN application is hereby introduced as a whole into this application. Technical Field

[0003] The present disclosure relates to the field of wireless communications, and in particular to a method and system for acquiring cell timing advance information, a terminal, and a base station. Background Art

[0004] In some related technologies, serving cell switching is based on L3 measurements and triggered by RRC (Radio Resource Control) signaling. The terminal needs to perform a complete cell reconfiguration and L1 / L2 reestablishment process, resulting in significant handover latency and signaling overhead. L1 refers to Layer 1, the physical layer; L2 refers to Layer 2, the MAC (Media Access Control) layer; and L3 refers to Layer 3, the RRC layer.

[0005] In other related technologies, the LTM (L1 / L2 Triggered Mobility) mechanism triggers the handover of a serving cell through L1 / L2 signaling to achieve the goals of low latency, low overhead, and low data interruption time.

[0006] During the cell handover process, the terminal needs to obtain the TA (Timing Advance, or timing advance value) of the target cell so as to establish uplink synchronization with the target cell.

[0007] As shown in FIG1 , a method for obtaining cell timing advance information in some related technologies includes: in a candidate cell configuration preparation phase, in step 101, a terminal sends a measurement report to a base station of a source cell; in step 102, the base station of the source cell sends a handover request to the base station of the candidate cell; in step 103, the base station of the candidate cell performs access control and sends a handover request response to the base station of the source cell; in step 104, the base station of the source cell sends an RRC reconfiguration to the terminal, completing the candidate cell configuration preparation phase; in step 105, the terminal sends a measurement report to the base station of the source cell; in step 106, the base station of the source cell selects a target cell based on the measurement result and sends a cell handover command to the terminal; in step 107, the terminal performs downlink synchronization with the target cell; in step 108, the terminal sends a random access preamble (RACH Msg1) to the target cell to initiate random access; in step 109, the target cell sends a random access response (RAR) to the terminal, carrying the timing advance information of the target cell; and in step 110, the terminal determines a timing advance value based on the timing advance information.

[0008] After receiving a cell handover command, the terminal usually initiates a random access process to the target cell based on the target cell identifier or index in the cell handover command to obtain the TA of the target cell.

[0009] Summary of the Invention

[0010] Some embodiments of the present disclosure provide a method for obtaining cell timing advance information, which is applied to a terminal and includes:

[0011] receiving a radio resource control (RRC) reconfiguration message from a source cell, which carries configuration information related to random access of a candidate cell;

[0012] receiving a physical downlink control channel (PDCCH) command from a source cell, which carries a candidate cell identifier or index;

[0013] Sending a random access preamble to the candidate cell according to the candidate cell identifier or index;

[0014] The target cell timing advance information is obtained from the cell handover command sent by the source cell, or the candidate cell timing advance information is obtained from the random access response RAR.

[0015] In some embodiments, acquiring the target cell timing advance information from a cell handover command sent by a source cell, or acquiring the candidate cell timing advance information from a random access response RAR includes:

[0016] If the configuration information indicates that the terminal has a RAR message, the terminal obtains the candidate cell timing advance information from the RAR; or,

[0017] If the configuration information indicates that the terminal has no RAR message, the terminal obtains the candidate cell timing advance information from the cell handover command sent by the source cell;

[0018] The terminal determines a timing advance value based on the timing advance information.

[0019] In some embodiments, obtaining the candidate cell timing advance information from the RAR further includes: when the configuration information indicates that the terminal has a RAR, if the RAR is not received, resending the random access preamble code to the candidate cell according to the retransmission configuration information of the preamble code in the configuration information.

[0020] In some embodiments, obtaining the candidate cell timing advance information from the RAR includes:

[0021] receiving, according to the RAR source indication information in the configuration information, a RAR from a source cell or a candidate cell indicated by the RAR source indication information;

[0022] The RAR received from the source cell is sent by the candidate cell to the source cell.

[0023] In some embodiments, obtaining the candidate cell timing advance information from the RAR includes: the RAR includes a candidate cell identifier or index and timing advance information, and obtaining the candidate cell timing advance information from the RAR.

[0024] In some embodiments, the cell handover command includes target cell timing advance information, and the target cell timing advance information is obtained by the source cell by receiving timing advance information sent by the candidate cell and determining the candidate cell as the target cell.

[0025] In some embodiments, the candidate cell identifier or index is indicated by downlink control information DCI format Format 1-0 in a PDCCH command.

[0026] In some embodiments, the cell handover command is sent via a layer 2 signaling medium access control element MAC CE.

[0027] In some embodiments, the RRC reconfiguration message includes:

[0028] Candidate cell identifier or index;

[0029] Configuration information related to random access of the candidate cell includes configuration information related to the preamble code of the candidate cell and / or configuration information related to RAR.

[0030] In some embodiments, the preamble-related configuration information includes one or more of the following information:

[0031] Generate the root sequence index required for the preamble;

[0032] Time-frequency resource location information for sending preamble codes;

[0033] Time information of sending preamble;

[0034] Preamble retransmission configuration information.

[0035] In some embodiments, the retransmission configuration information of the preamble includes one or more of the following information:

[0036] Whether to retransmit;

[0037] Maximum number of retransmissions;

[0038] Initial transmission power;

[0039] Power ramp-up strategy.

[0040] In some embodiments, the RAR-related configuration information includes one or more of the following information:

[0041] Whether there is RAR message indication information;

[0042] RAR source indication information is used to indicate whether the terminal receives the RAR from the source cell or the candidate cell;

[0043] The length of the RAR detection window.

[0044] In some embodiments, the candidate cells include one or more cells.

[0045] Some embodiments of the present disclosure provide a method for obtaining cell timing advance information, which is applied to a base station and includes:

[0046] The base station of the source cell sends a radio resource control (RRC) reconfiguration message to the terminal, which carries configuration information related to random access of the candidate cell;

[0047] The base station of the source cell sends a physical downlink control channel PDCCH command to the terminal, which carries a candidate cell identifier or index, and is used to instruct the terminal to send a random access preamble code to the candidate cell to obtain timing advance information.

[0048] In some embodiments, it also includes: if the configuration information indicates that the terminal has a RAR message, and the RAR source indication information in the configuration information indicates that the RAR is received from the source cell, the base station of the source cell receives the RAR sent by the base station of the candidate cell and forwards it to the terminal, and the RAR includes the candidate cell identifier or index and timing advance information.

[0049] In some embodiments, it also includes: if the configuration information indicates that the terminal has a RAR message, and the RAR source indication information in the configuration information indicates that the RAR is received from the candidate cell, the base station of the candidate cell sends the RAR to the terminal, and the RAR includes the candidate cell identifier or index and timing advance information.

[0050] In some embodiments, it also includes: if the configuration information indicates that the terminal has no RAR message, the base station of the source cell receives the candidate cell timing advance information sent by the base station of the candidate cell, and after determining the target cell, sends a cell switching command to the terminal, which includes the target cell timing advance information.

[0051] In some embodiments, the cell switching command is sent via layer 2 signaling MAC CE.

[0052] In some embodiments, the downlink control information DCI format Format 1-0 in the PDCCH command indicates the candidate cell identifier or index.

[0053] In some embodiments, the RRC reconfiguration message includes:

[0054] Candidate cell identifier or index;

[0055] Configuration information related to random access of the candidate cell includes configuration information related to the preamble code of the candidate cell and / or configuration information related to RAR.

[0056] In some embodiments, the preamble-related configuration information includes one or more of the following information:

[0057] Generate the root sequence index required for the preamble;

[0058] Time-frequency resource location information for sending preamble codes;

[0059] Time information of sending preamble;

[0060] Preamble retransmission configuration information.

[0061] In some embodiments, the retransmission configuration information of the preamble includes one or more of the following information:

[0062] Whether to retransmit;

[0063] Maximum number of retransmissions;

[0064] Initial transmission power;

[0065] Power ramp-up strategy.

[0066] In some embodiments, the RAR-related configuration information includes one or more of the following information:

[0067] Whether there is RAR message indication information;

[0068] RAR source indication information is used to indicate whether the terminal receives the RAR from the source cell or the candidate cell;

[0069] The length of the RAR detection window.

[0070] In some embodiments, the candidate cells include one or more cells.

[0071] Some embodiments of the present disclosure provide a terminal, including: a memory; and a processor coupled to the memory, wherein the processor is configured to execute a method for acquiring cell timing advance information based on instructions stored in the memory.

[0072] Some embodiments of the present disclosure provide a terminal, including: a module for executing a method for acquiring cell timing advance information.

[0073] Some embodiments of the present disclosure provide a base station, including: a memory; and a processor coupled to the memory, wherein the processor is configured to execute a method for acquiring cell timing advance information based on instructions stored in the memory.

[0074] Some embodiments of the present disclosure provide a base station, including: a module for executing a method for acquiring cell timing advance information.

[0075] Some embodiments of the present disclosure provide a system for obtaining cell timing advance information, including:

[0076] A terminal configured to execute a method for obtaining cell timing advance information on a terminal side; and

[0077] The base station is configured to execute a method for obtaining cell timing advance information on the base station side.

[0078] Some embodiments of the present disclosure provide a non-transitory computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the steps of the method for obtaining cell timing advance information are implemented.

[0079] Some embodiments of the present disclosure provide a computer program, comprising: instructions, which, when executed by a processor, cause the processor to execute a method for acquiring cell timing advance information. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] The following briefly introduces the drawings required for describing the embodiments or related technologies. The present disclosure can be more clearly understood based on the following detailed description with reference to the drawings.

[0081] Obviously, the drawings described below are only some embodiments of the present disclosure. A person skilled in the art can derive other drawings based on these drawings without inventive effort.

[0082] FIG1 is a schematic diagram showing a method for obtaining cell timing advance information in some related technologies.

[0083] FIG2 shows a schematic diagram of a method for acquiring cell timing advance information according to some embodiments of the present disclosure.

[0084] FIG3 shows a schematic diagram of a method for acquiring cell timing advance information according to some embodiments of the present disclosure.

[0085] FIG4 is a schematic diagram showing the composition and comparison of cell switching delays in related technologies and the solution disclosed herein.

[0086] FIG5 shows a schematic diagram of a system for acquiring cell timing advance information according to some embodiments of the present disclosure.

[0087] FIG6 shows a schematic structural diagram of a terminal according to some embodiments of the present disclosure.

[0088] FIG7 shows a schematic structural diagram of a base station according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0089] The technical solutions in the embodiments of the present disclosure will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present disclosure.

[0090] During a cell handover, terminal data interruption time is the time between receiving the cell handover command and completing the connection with the target cell. Uplink synchronization delay is a major component of this delay. In related technologies, during a cell handover, the terminal performs uplink and downlink synchronization with the target cell after receiving the cell handover command, which increases the data interruption time caused by the cell handover.

[0091] In the embodiment of the present disclosure, after the terminal receives the candidate cell configuration, the timing advance information of the candidate / target cell is acquired in advance based on the network signaling configuration, thereby reducing the cell switching delay and shortening the data interruption time during the terminal switching process.

[0092] The disclosed embodiments provide a method for a terminal to obtain cell timing advance information in advance under the LTM mechanism, thereby advancing uplink and downlink synchronization to before a cell handover command arrives. The terminal can establish uplink and downlink synchronization with the target cell before receiving the cell handover command, thereby reducing handover latency and the data transmission interruption time experienced by the terminal during the handover process, ensuring user service continuity, and improving the user service experience.

[0093] FIG2 shows a schematic diagram of a method for acquiring cell timing advance information according to some embodiments of the present disclosure.

[0094] As shown in FIG2 , the method for acquiring cell timing advance information in this embodiment includes the following steps.

[0095] In step 201, the terminal receives a radio resource control (RRC) reconfiguration message from a source cell, which carries configuration information related to random access of candidate cells.

[0096] The terminal is, for example, a user equipment (UE).

[0097] In some embodiments, the RRC reconfiguration message includes, for example, but is not limited to: a candidate cell identifier or index; configuration information related to random access of the candidate cell, including candidate cell preamble code related configuration information, and / or RAR related configuration information; and other candidate cell random access related configuration information.

[0098] In some embodiments, the preamble-related configuration information includes one or more of the following information: a root sequence index required to generate the preamble; time-frequency resource location information for sending the preamble; time information for sending the preamble; and retransmission configuration information for the preamble. The retransmission configuration information for the preamble includes one or more of the following information: whether to retransmit; a maximum number of retransmissions; an initial transmission power; and a power ramping strategy.

[0099] In some embodiments, the RAR-related configuration information includes one or more of the following information: whether there is a RAR message indication information; RAR source indication information, used to indicate whether the terminal receives the RAR from the source cell or the candidate cell; RAR detection window time length.

[0100] In step 202, the terminal receives a physical downlink control channel (PDCCH) command from a source cell, which carries a candidate cell identifier or index. The PDCCH command is used to instruct the terminal to send a random access preamble to the candidate cell to obtain timing advance information.

[0101] In some embodiments, the candidate cells include one or more cells.

[0102] In some embodiments, the candidate cell identifier or index is indicated by a DCI (Downlink Control Information) format Format 1-0 in a PDCCH (Physical Downlink Control Channel) command.

[0103] Table 1: DCI format 1-0 fields of PDCCH command

[0104] The size of the candidate cell identifier or index is related to the maximum number of candidate cells supported by the terminal.

[0105] In some embodiments, if the terminal supports configuring up to 4 candidate cells each time, the length of the corresponding candidate cell identifier or index field under the DCI format 1-0 field is 2 bits, the reserved bit is 8 bits, and so on.

[0106] In some embodiments, the candidate cell identifier or index is filled with a logical cell identifier or a physical cell identifier of the candidate cell.

[0107] The reserved bits of the existing PDCCH command DCI format1-0 field are used to select X bits to indicate the candidate cell identifier or index, so as to instruct the terminal to send a random access preamble to the candidate cell to obtain timing advance information.

[0108] In step 203, the terminal sends a random access preamble (Random Access Preamble) to the candidate cell according to the candidate cell identifier or index.

[0109] That is, the terminal sends a random access Msg1 message to the candidate cell according to the candidate cell identifier or index, so as to send a random access preamble to the candidate cell.

[0110] In some embodiments, the terminal generates a random access preamble according to a root sequence index in the candidate cell preamble-related configuration information in the configuration information, and sends it to the candidate cell via a PRACH (Physical Random Access Channel).

[0111] In step 204, the terminal indicates whether the terminal has a RAR message according to the configuration information. If the configuration information indicates that the terminal has a RAR message, the terminal obtains the candidate cell timing advance information from the RAR (204a); if the configuration information indicates that the terminal does not have a RAR message, the terminal obtains the candidate cell timing advance information from the cell handover command sent by the source cell (204b); and the terminal determines a timing advance value based on the timing advance information (204c).

[0112] The RAR message is, for example, a random access Msg2 message.

[0113] In some embodiments, if the configuration information indicates that the terminal has a RAR, if the terminal does not receive the RAR, the terminal resends the random access preamble to the candidate cell according to the preamble retransmission configuration information in the configuration information. The terminal determines whether the maximum number of retransmissions in the preamble retransmission configuration information has been reached. If the maximum number of retransmissions has not been reached, the terminal resends the random access preamble to the candidate cell. If the maximum number of retransmissions has been reached, the terminal fails to obtain the cell timing advance information in advance and waits for further instructions from the network.

[0114] In some embodiments, if the configuration information indicates that the terminal has a RAR message, and the RAR source indication information in the configuration information indicates receiving the RAR from the source cell, the base station of the source cell receives the RAR sent by the base station of the candidate cell and forwards it to the terminal, wherein the RAR includes the candidate cell identifier or index and timing advance information. If the configuration information indicates that the terminal has a RAR message, and the RAR source indication information in the configuration information indicates receiving the RAR from the candidate cell, the base station of the candidate cell sends the RAR to the terminal, wherein the RAR includes the candidate cell identifier or index and timing advance information. Based on the RAR source indication information in the configuration information, the terminal receives the RAR from the source cell or the indicated candidate cell indicated by the RAR source indication information within the RAR detection window; wherein the RAR received from the source cell is sent by the candidate cell to the source cell. The RAR includes the candidate cell identifier or index and timing advance information, and the terminal obtains the candidate cell timing advance information from the RAR.

[0115] In some embodiments, if the configuration information indicates that the terminal has no RAR message, the base station of the source cell receives the candidate cell timing advance information sent by the base station of the candidate cell, and after determining the target cell, sends a cell switching command to the terminal, which includes the target cell timing advance information. The target cell timing advance information is obtained by the source cell by receiving the timing advance information sent by the candidate cell and determining the candidate cell as the target cell.

[0116] In some embodiments, the cell switching command is sent via a layer 2 signaling Media Access Control Element (MAC CE).

[0117] In some embodiments, the terminal determines the timing advance value based on the timing advance information, including: the timing advance information includes a timing advance command (TA command) field, and the terminal decodes the field to obtain the timing advance value.

[0118] Through the above embodiment, the terminal can obtain the timing advance information of the candidate / target cell before or when receiving the cell switching command, thereby effectively reducing the switching delay, reducing the data transmission interruption time experienced by the terminal during the switching process, ensuring user service continuity, and improving user service experience.

[0119] FIG3 shows a schematic diagram of a method for acquiring cell timing advance information according to some embodiments of the present disclosure.

[0120] As shown in FIG3 , the method for acquiring cell timing advance information in this embodiment includes the following steps.

[0121] Step 301: During the candidate cell configuration preparation phase, the terminal sends an L3 measurement report to the source cell (ie, the current serving cell).

[0122] The L3 measurement report includes, for example, signal quality information of surrounding cells measured by the terminal.

[0123] Step 302: The source cell selects one or more suitable candidate cells for the terminal according to the L3 measurement results reported by the terminal, and initiates an LTM handover request to the candidate cells.

[0124] Step 303: The candidate cell determines whether it can accept the current LTM handover request based on its own resource conditions. If it can accept the current LTM handover request, it feeds back an LTM handover request response to the source cell.

[0125] Step 304: The terminal receives the RRC reconfiguration message sent by the source cell.

[0126] In some embodiments, the RRC reconfiguration message includes, for example, but is not limited to: a candidate cell identifier or index; configuration information related to random access of the candidate cell, including candidate cell preamble code related configuration information, and / or RAR related configuration information; and other candidate cell random access related configuration information.

[0127] In some embodiments, the preamble-related configuration information includes one or more of the following information: a root sequence index required to generate the preamble; time-frequency resource location information for sending the preamble; time information for sending the preamble; and retransmission configuration information for the preamble. The retransmission configuration information for the preamble includes one or more of the following information: whether to retransmit; a maximum number of retransmissions; an initial transmission power; and a power ramping strategy.

[0128] In some embodiments, the RAR-related configuration information includes one or more of the following information: whether there is a RAR message indication information; RAR source indication information, used to indicate whether the terminal receives the RAR from the source cell or the candidate cell; RAR detection window time length.

[0129] If the RRC reconfiguration message does not carry RAR related configuration information, it indicates that the terminal does not need to detect the RAR after initiating random access to the candidate cell through the PRACH.

[0130] Step 305: The terminal performs a downlink synchronization process toward the candidate cell, and completes downlink synchronization with the candidate cell based on the SSB signal of the candidate cell.

[0131] Among them, SSB stands for Synchronization Signal and PBCH block (SSB for short), which consists of three parts: Primary Synchronization Signals (PSS for short), Secondary Synchronization Signals (SSS for short), and PBCH (physical broadcast channel).

[0132] Step 306: The terminal performs candidate cell uplink synchronization. During the candidate cell timing advance information acquisition phase, the terminal receives a PDCCH command from the source cell, which carries a candidate cell identifier or index, instructing the terminal to send a random access preamble to the candidate cell to acquire timing advance information.

[0133] Step 307: The terminal generates a random access preamble (RACH Msg1) for the corresponding candidate cell based on the candidate cell identifier or index in the PDCCH command and the candidate cell preamble configuration information in the RRC reconfiguration, and sends it to the candidate cell via PRACH. The candidate cell determines the timing advance information.

[0134] Step 308: The terminal feeds back the L1 measurement result of each candidate cell to the source cell.

[0135] Step 309: If there is RAR configuration information, the terminal waits and detects the random access response of the candidate cell within the RAR detection window time, thereby obtaining the timing advance information of the candidate cell. The random access response mode is determined by the RAR configuration information.

[0136] If the configuration information indicates that the terminal has a RAR message, and the RAR source indication information in the configuration information indicates that the RAR is received from the source cell, the terminal executes step 309-1-A / B; if the configuration information indicates that the terminal has a RAR message, and the RAR source indication information in the configuration information indicates that the RAR is received from the candidate cell, the terminal executes step 309-2.

[0137] Step 309-1-A: The candidate cell sends a RAR to the source cell through inter-interface signaling. The RAR includes the candidate cell identifier or index and timing advance information. The RAR is scrambled using the RA-RNTI.

[0138] RA-RNTI stands for Random Access Radio Network Temporary Identifier, which is used to describe the location where the terminal sends a random preamble.

[0139] Step 309-1-B: The source cell sends a RAR to the terminal. The RAR includes the candidate cell identifier or index and timing advance information. The RAR is scrambled using the RA-RNTI. The terminal receives the RAR within the RAR detection window, obtains the candidate cell timing advance information from the RAR, and determines the timing advance value based on the timing advance information.

[0140] Step 309-2: When the terminal is downlink synchronized with the candidate cell, if the source cell and the candidate cell are in downlink synchronization, for example, the source cell and the candidate cell are in the same distributed unit (DU), the candidate cell can directly send a RAR to the terminal. The RAR includes the candidate cell identifier or index and timing advance information, and the RAR is scrambled using the RA-RNTI. The terminal receives the RAR fed back by the target cell within the RAR detection window, obtains the candidate cell timing advance information from the RAR, and determines the timing advance value based on the timing advance information.

[0141] When the terminal receives the RAR within the detection window, it parses the RAR, confirms that it is a random access response sent by itself to a candidate cell, and obtains the timing advance information and timing advance value of the candidate cell from the RAR.

[0142] When the terminal does not receive the RAR within the detection window, it determines whether the random access to the candidate cell has reached the maximum number of retransmissions. If not, it returns to step 307. If it has reached the maximum number of retransmissions, the current acquisition of the cell timing advance information has failed, and the terminal waits for further instructions from the network.

[0143] Step 310: If there is no RAR-related configuration information, the terminal waits for and receives an LTM cell handover command from the source cell, which includes the target cell identifier or index and timing advance information. The terminal obtains the target cell timing advance information from the LTM cell handover command and determines the timing advance value based on the timing advance information.

[0144] If the LTM cell handover command does not carry the target cell timing advance information, random access is performed with the target cell according to the target cell identifier or index in the LTM cell handover instruction.

[0145] Through the above embodiment, the timing advance information of the candidate / target cell is obtained in advance, and the uplink / downlink synchronization is advanced to before the cell switching command arrives, so that the terminal can obtain the timing advance information of the candidate / target cell before or when receiving the cell switching command, thereby effectively reducing the switching delay and the data transmission interruption time experienced by the terminal during the switching process, ensuring user service continuity and improving user service experience.

[0146] The frequency range supported by the NR system ranges from medium and low frequencies to ultra-high frequencies. As the frequency increases, the cell coverage decreases, and users will experience more frequent cell switching in the network. In the cell switching process of the related technology, the terminal performs uplink and downlink synchronization with the target cell after receiving the cell switching command, which increases the data interruption time caused by the cell switching. The embodiment of the present disclosure obtains the candidate / target cell timing advance information in advance, and advances the uplink and downlink synchronization to before the cell switching command arrives, which significantly reduces the data interruption time, ensures user service continuity, and improves the user service experience. Figure 4 shows a schematic diagram of the composition and comparison of the cell switching delay of the related technology and the disclosed solution. The meaning of each symbol is shown in Table 2.

[0147] Table 2

[0148] Figure 5 is a schematic diagram of a system for obtaining cell timing advance information according to some embodiments of the present disclosure. As shown in Figure 5, the system 500 for obtaining cell timing advance information according to this embodiment includes: a terminal 510 configured to execute a terminal-side method for obtaining cell timing advance information; and a base station 520 configured to execute a base station-side method for obtaining cell timing advance information.

[0149] FIG6 shows a schematic structural diagram of a terminal according to some embodiments of the present disclosure.

[0150] As shown in FIG6 , the terminal 600 of this embodiment includes: a memory 610 and a processor 620 coupled to the memory 610 , and the processor 620 is configured to execute the method for obtaining cell timing advance information in any of the aforementioned embodiments based on instructions stored in the memory 610 .

[0151] The terminal 600 may further include an input / output interface 630 , a network interface 640 , a storage interface 650 , etc. These interfaces 630 , 640 , 650 , the memory 610 , and the processor 620 may be connected via a bus 660 , for example.

[0152] The memory 610 may include, for example, a system memory, a fixed non-volatile storage medium, etc. The system memory may store, for example, an operating system, application programs, a boot loader, and other programs.

[0153] The processor 620 may be implemented using a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, or discrete hardware components such as discrete gates or transistors.

[0154] Among them, the input and output interface 630 provides a connection interface for input and output devices such as a display, mouse, keyboard, and touch screen. The network interface 640 provides a connection interface for various networked devices. The storage interface 650 provides a connection interface for external storage devices such as SD cards and USB flash drives. The bus 660 can use any of a variety of bus structures. For example, bus structures include but are not limited to the Industry Standard Architecture (ISA) bus, the Micro Channel Architecture (MCA) bus, and the Peripheral Component Interconnect (PCI) bus.

[0155] FIG7 shows a schematic structural diagram of a base station according to some embodiments of the present disclosure.

[0156] As shown in FIG7 , the base station 700 of this embodiment includes: a memory 710 and a processor 720 coupled to the memory 710 , and the processor 720 is configured to execute the method for obtaining cell timing advance information in any of the aforementioned embodiments based on instructions stored in the memory 710 .

[0157] The base station 700 may further include an input / output interface 730 , a network interface 740 , a storage interface 750 , etc. These interfaces 730 , 740 , 750 , the memory 710 , and the processor 720 may be connected via a bus 760 , for example.

[0158] The memory 710 may include, for example, a system memory, a fixed non-volatile storage medium, etc. The system memory may store, for example, an operating system, application programs, a boot loader, and other programs.

[0159] The processor 720 may be implemented using a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, or discrete hardware components such as discrete gates or transistors.

[0160] Among them, the input and output interface 730 provides a connection interface for input and output devices such as a display, mouse, keyboard, and touch screen. The network interface 740 provides a connection interface for various networked devices. The storage interface 750 provides a connection interface for external storage devices such as SD cards and USB flash drives. The bus 760 can use any of a variety of bus structures. For example, bus structures include but are not limited to the Industry Standard Architecture (ISA) bus, the Micro Channel Architecture (MCA) bus, and the Peripheral Component Interconnect (PCI) bus.

[0161] A terminal includes: a module for executing a method for obtaining cell timing advance information. Each module is described in detail below.

[0162] The receiving module is configured to receive a radio resource control (RRC) reconfiguration message from a source cell, which carries configuration information related to random access of a candidate cell; receive a physical downlink control channel (PDCCH) command from the source cell, which carries an identifier or index of the candidate cell;

[0163] an access module configured to send a random access preamble to a candidate cell according to the candidate cell identifier or index;

[0164] The acquisition module is configured to acquire the target cell timing advance information from the cell handover command sent by the source cell, or acquire the candidate cell timing advance information from the random access response RAR.

[0165] An acquisition module is configured to, if the configuration information indicates that the terminal has a RAR message, obtain the candidate cell timing advance information from the RAR; or, if the configuration information indicates that the terminal has no RAR message, obtain the candidate cell timing advance information from the cell handover command sent by the source cell; and the terminal determines a timing advance value based on the timing advance information.

[0166] The access module is configured to resend the random access preamble to the candidate cell according to the retransmission configuration information of the preamble in the configuration information if the RAR is not received when the configuration information indicates that the terminal has the RAR.

[0167] The acquisition module is configured to receive the RAR from the source cell or the candidate cell indicated by the RAR source indication information according to the RAR source indication information in the configuration information; wherein the RAR received from the source cell is sent by the candidate cell to the source cell.

[0168] The acquisition module is configured to obtain the candidate cell timing advance information from the RAR, including the candidate cell identifier or index and the timing advance information.

[0169] The cell handover command includes the target cell timing advance information, which is obtained by the source cell by receiving the timing advance information sent by the candidate cell and determining the candidate cell as the target cell.

[0170] The candidate cell identifier or index is indicated by the downlink control information DCI format Format 1-0 in the PDCCH command.

[0171] The cell switching command is sent via layer 2 signaling MAC CE.

[0172] A base station includes: a module for executing a method for obtaining cell timing advance information. Each module is described in detail below.

[0173] The indication module, when used for the base station of the source cell, is configured to send a radio resource control RRC reconfiguration message to the terminal, which carries configuration information related to random access of the candidate cell; and send a physical downlink control channel PDCCH command to the terminal, which carries the candidate cell identifier or index, used to instruct the terminal to send a random access preamble code to the candidate cell to obtain timing advance information.

[0174] The indication module, when used for the base station of the source cell, is configured to receive the RAR sent by the base station of the candidate cell and forward it to the terminal if the configuration information indicates that the terminal has a RAR message and the RAR source indication information in the configuration information indicates that the RAR is received from the source cell, wherein the RAR includes a candidate cell identifier or index and timing advance information.

[0175] The indication module, when used for the base station of the candidate cell, is configured to send the RAR to the terminal if the configuration information indicates that the terminal has a RAR message and the RAR source indication information in the configuration information indicates that the RAR is received from the candidate cell, wherein the RAR includes the candidate cell identifier or index and timing advance information.

[0176] The indication module, when used for the base station of the source cell, is configured to receive the candidate cell timing advance information sent by the base station of the candidate cell if the configuration information indicates that the terminal has no RAR message, and after determining the target cell, send a cell switching command to the terminal, which includes the target cell timing advance information.

[0177] The cell switching command is sent via layer 2 signaling MAC CE.

[0178] The downlink control information DCI format Format 1-0 in the PDCCH command indicates the candidate cell identifier or index.

[0179] A non-transitory computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of a method for obtaining cell timing advance information.

[0180] Those skilled in the art will appreciate that embodiments of the present disclosure may be provided as methods, systems, or computer program products. Therefore, the present disclosure may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present disclosure may take the form of a computer program product implemented on one or more non-transitory computer-readable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer program code.

[0181] The present disclosure is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present disclosure. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0182] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0183] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0184] The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A method for obtaining cell timing advance information, applied to a terminal, comprising: receiving a radio resource control (RRC) reconfiguration message from a source cell, which carries configuration information related to random access of a candidate cell; Receiving a physical downlink control channel PDCCH command from a source cell, which carries a candidate cell identifier or index; Sending a random access preamble to the candidate cell according to the candidate cell identifier or index; The timing advance information of the target cell is obtained from the cell handover command sent by the source cell, or the timing advance information of the candidate cell is obtained from the random access response RAR.

2. According to the method of claim 1, acquiring the target cell timing advance information from the cell handover command sent by the source cell, or acquiring the candidate cell timing advance information from the random access response RAR comprises: If the configuration information indicates that the terminal has a RAR message, the terminal obtains the candidate cell timing advance information from the RAR; or, If the configuration information indicates that the terminal has no RAR message, the terminal obtains the candidate cell timing advance information from the cell handover command sent by the source cell; The terminal determines a timing advance value based on the timing advance information.

3. According to the method of claim 2, obtaining the candidate cell timing advance information from the RAR further comprises: In the case that the configuration information indicates that the terminal has a RAR, if the RAR is not received, the random access preamble is resent to the candidate cell according to the retransmission configuration information of the preamble in the configuration information.

4. According to the method according to any one of claims 1 to 3, obtaining the candidate cell timing advance information from the RAR comprises: receiving a RAR from a source cell or a candidate cell indicated by the RAR source indication information according to the RAR source indication information in the configuration information; The RAR received from the source cell is sent by the candidate cell to the source cell.

5. According to the method according to any one of claims 1 to 4, obtaining the candidate cell timing advance information from the RAR comprises: The RAR includes a candidate cell identifier or index and timing advance information, and the candidate cell timing advance information is obtained from the RAR.

6. According to the method according to any one of claims 1-5, the cell switching command includes target cell timing advance information, and the target cell timing advance information is obtained by the source cell by receiving the timing advance information sent by the candidate cell and determining the candidate cell as the target cell.

7. The method according to any one of claims 1-6, wherein the candidate cell identifier or index is indicated by a downlink control information DCI format Format 1-0 in a PDCCH command.

8. The method according to any one of claims 1-7, wherein the cell switching command is sent via a layer 2 signaling medium access control element MAC CE.

9. According to the method according to any one of claims 1 to 8, the RRC reconfiguration message comprises: Candidate cell identifier or index; Configuration information related to random access of the candidate cell includes configuration information related to the preamble code of the candidate cell and / or configuration information related to RAR.

10. The method according to claim 9, wherein the preamble-related configuration information comprises one or more of the following information: The root sequence index required to generate the preamble; Time-frequency resource location information for sending the preamble; Time information for sending the preamble; Preamble retransmission configuration information.

11. The method according to claim 10, wherein the retransmission configuration information of the preamble comprises one or more of the following information: Whether to retransmit; Maximum number of retransmissions; Initial transmission power; Power climbing strategy.

12. According to the method according to any one of claims 9 to 11, the RAR-related configuration information includes one or more of the following information: Whether there is RAR message indication information; RAR source indication information is used to indicate whether the terminal receives the RAR from the source cell or the candidate cell; The length of the RAR detection window.

13. The method according to any one of claims 1 to 12, wherein the candidate cell comprises one or more cells.

14. A method for obtaining cell timing advance information, applied to a base station, comprising: The base station of the source cell sends a radio resource control RRC reconfiguration message to the terminal, which carries configuration information related to random access of the candidate cell; The base station of the source cell sends a physical downlink control channel PDCCH command to the terminal, which carries a candidate cell identifier or index, and is used to instruct the terminal to send a random access preamble code to the candidate cell to obtain timing advance information.

15. The method according to claim 14, further comprising: If the configuration information indicates that the terminal has a RAR message, and the RAR source indication information in the configuration information indicates receiving the RAR from the source cell, the base station of the source cell receives the RAR sent by the base station of the candidate cell and forwards it to the terminal, and the RAR includes the candidate cell identifier or index and timing advance information.

16. The method according to any one of claims 14-15, further comprising: If the configuration information indicates that the terminal has a RAR message, and the RAR source indication information in the configuration information indicates receiving the RAR from the candidate cell, the base station of the candidate cell sends the RAR to the terminal, and the RAR includes the candidate cell identifier or index and timing advance information.

17. The method according to any one of claims 14 to 16, further comprising: If the configuration information indicates that the terminal has no RAR message, the base station of the source cell receives the candidate cell timing advance information sent by the base station of the candidate cell, and after determining the target cell, sends a cell switching command to the terminal, including the target cell timing advance information.

18. The method according to claim 17, wherein the cell switching command is sent via layer 2 signaling MAC CE.

19. The method according to any one of claims 14 to 18, wherein a downlink control information DCI format Format 1-0 in the PDCCH command indicates the candidate cell identifier or index.

20. According to the method according to any one of claims 14 to 19, the RRC reconfiguration message comprises: Candidate cell identifier or index; Configuration information related to random access of the candidate cell includes configuration information related to the preamble code of the candidate cell and / or configuration information related to RAR.

21. The method according to claim 20, wherein the preamble-related configuration information comprises one or more of the following information: The root sequence index required to generate the preamble; Time-frequency resource location information for sending the preamble; Time information for sending the preamble; Preamble retransmission configuration information.

22. The method according to claim 21, wherein the retransmission configuration information of the preamble comprises one or more of the following information: Whether to retransmit; Maximum number of retransmissions; Initial transmission power; Power climbing strategy.

23. According to the method according to any one of claims 20 to 22, the RAR-related configuration information includes one or more of the following information: Whether there is RAR message indication information; RAR source indication information is used to indicate whether the terminal receives the RAR from the source cell or the candidate cell; The length of the RAR detection window.

24. The method according to any one of claims 14 to 23, wherein the candidate cell comprises one or more cells.

25. A terminal, comprising: Memory; as well as A processor coupled to the memory, the processor being configured to execute the method for acquiring cell timing advance information according to any one of claims 1 to 13 based on instructions stored in the memory.

26. A terminal, comprising: A module for executing the method for obtaining cell timing advance information according to any one of claims 1 to 13.

27. A base station, comprising: Memory; as well as A processor coupled to the memory, the processor being configured to execute the method for acquiring cell timing advance information according to any one of claims 14 to 24 based on instructions stored in the memory.

28. A base station, comprising: A module for executing the method for obtaining cell timing advance information as described in any one of claims 14-24.

29. A system for obtaining cell timing advance information, comprising: A terminal, configured to execute the method for obtaining cell timing advance information according to any one of claims 1 to 13; as well as A base station, configured to execute the method for obtaining cell timing advance information according to any one of claims 14 to 24.

30. A non-transitory computer-readable storage medium having a computer program stored thereon, wherein when the program is executed by a processor, the steps of the method for obtaining cell timing advance information according to any one of claims 1 to 24 are implemented.

31. A computer program comprising: Instructions, when executed by a processor, cause the processor to perform the method according to any one of claims 1-24.

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