Timing advance obtaining method and device, terminal and network side equipment

Abstract

The invention discloses a timing advance obtaining method and device, a terminal and network side equipment, and belongs to the technical field of communication, and the timing advance obtaining method comprises the steps that the terminal determines a target candidate cell from at least one candidate cell based on first information; the first information is used for representing whether an association relationship exists between the candidate cell and a service cell of the terminal; and the terminal executes advanced random access to the target candidate cell to obtain a timing advance (TA).

Description

Technical Field

[0001] This application belongs to the field of communication technologies, and particularly relates to a method, apparatus, terminal, and network-side device for obtaining a Timing Advance (TA). Background Art

[0002] In the L1 / L2-triggered mobility (LTM) scenario, an early TA acquisition process triggered by a Physical Downlink Control Channel (PDCCH) order is supported. That is, the User Equipment (UE) of the source serving cell performs an early Random Access Channel (RACH) procedure (only sending msg1) in the LTM candidate cell to obtain the TA of the candidate cell in advance.

[0003] In the related art, LTM supports handovers between the source serving cell and the candidate cell within the same central unit (intra-CU) and between the source serving cell and the candidate cell of different central units (inter-CU). Among them, intra-CU includes the same distributed unit (intra-DU) and the same central unit, and there are two types of handover scenarios for different distributed units (intra-CU, inter-DU). Considering the delay between interfaces, not all candidate cells are worth the UE performing the early RACH procedure to obtain the TA in advance.

[0004] Therefore, how to determine which candidate cells the UE obtains the TA in advance for is an urgent problem to be solved currently. Summary of the Invention

[0005] Embodiments of this application provide a method, apparatus, terminal, and network-side device for obtaining a timing advance, which can solve the problem of which candidate cells the UE obtains the TA in advance for.

[0006] In a first aspect, a method for obtaining a timing advance is provided, which is executed by a terminal. The method includes:

[0007] The terminal determines a target candidate cell from at least one candidate cell based on first information; the first information is used to characterize whether there is an association relationship between the candidate cell and the serving cell of the terminal;

[0008] The terminal performs an early random access to the target candidate cell to obtain a timing advance TA.

[0009] Second aspect, a method for obtaining timing advance is provided, which is executed by a network-side device. The method includes:

[0010] The network-side device sends candidate configuration information to the terminal; the candidate configuration information is used to assist the terminal in determining first information, and based on the first information, determine a target candidate cell from at least one candidate cell; the first information is used to characterize whether there is an association relationship between the candidate cell and the serving cell of the terminal; the target candidate cell is used for the terminal to perform early random access to obtain a timing advance TA.

[0011] Third aspect, an apparatus for obtaining timing advance is provided, including:

[0012] A first determination module, configured to determine a target candidate cell from at least one candidate cell based on first information; the first information is used to characterize whether there is an association relationship between the candidate cell and the serving cell of the terminal;

[0013] An obtaining module, configured to perform early random access to the target candidate cell to obtain a timing advance TA.

[0014] Fourth aspect, an apparatus for obtaining timing advance is provided, including:

[0015] A sending module, configured to send candidate configuration information to the terminal; the candidate configuration information is used to assist the terminal in determining first information, and based on the first information, determine a target candidate cell from at least one candidate cell; the first information is used to characterize whether there is an association relationship between the candidate cell and the serving cell of the terminal; the target candidate cell is used for the terminal to perform early random access to obtain a timing advance TA.

[0016] Fifth aspect, a terminal is provided. The terminal includes a processor and a memory. The memory stores a program or instruction that can run on the processor. When the program or instruction is executed by the processor, the steps of the method described in the first aspect are implemented.

[0017] Sixth aspect, a terminal is provided, including a processor and a communication interface. The processor is configured to determine a target candidate cell from at least one candidate cell based on first information; the first information is used to characterize whether there is an association relationship between the candidate cell and the serving cell of the terminal; perform early random access to the target candidate cell to obtain a timing advance TA.

[0018] Seventh aspect, a network-side device is provided. The network-side device includes a processor and a memory. The memory stores a program or instruction that can run on the processor. When the program or instruction is executed by the processor, the steps of the method described in the second aspect are implemented.

[0019] In an eighth aspect, a network-side device is provided, including a processor and a communication interface. The communication interface is configured to send candidate configuration information to a terminal. The candidate configuration information is used to assist the terminal in determining first information, and based on the first information, determine a target candidate cell from at least one candidate cell. The first information is used to represent whether there is an association relationship between the candidate cell and the serving cell of the terminal. The target candidate cell is used for the terminal to perform early random access to obtain a timing advance (TA).

[0020] In a ninth aspect, a readable storage medium is provided. A program or instruction is stored on the readable storage medium. When the program or instruction is executed by a processor, the steps of the method described in the first aspect are implemented, or the steps of the method described in the second aspect are implemented.

[0021] In a tenth aspect, a wireless communication system is provided, including: a terminal and a network-side device. The terminal can be used to execute the steps of the method described in the first aspect, and the network-side device can be used to execute the steps of the method described in the second aspect.

[0022] In an eleventh aspect, a chip is provided. The chip includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is configured to run a program or instruction to implement the method described in the first aspect, or implement the method described in the second aspect.

[0023] In a twelfth aspect, a computer program / program product is provided. The computer program / program product is stored in a storage medium. The program / program product is executed by at least one processor to implement the steps of the method described in the first aspect, or implement the steps of the method described in the second aspect.

[0024] In an embodiment of the present application, based on the first information, the terminal determines whether there is an association relationship between at least one candidate cell and the serving cell of the terminal, and determines the cell having an association relationship with the serving cell from at least one candidate cell as the target candidate cell, so that the terminal can determine that it needs to perform an early RACH procedure on the target candidate cell to obtain TA in advance, thereby avoiding unnecessary early RACH procedures. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A block diagram of a wireless communication system to which an embodiment of the present application can be applied is shown;

[0026] Figure 2 is a schematic diagram of the architecture of CU-DU in the prior art;

[0027] Figure 3is a signaling interaction schematic diagram of LTM in the prior art;

[0028] Figure 4 is one of the flow schematic diagrams of the method for obtaining timing advance provided by the embodiments of the present application;

[0029] Figure 5 is another flow schematic diagram of the method for obtaining timing advance provided by the embodiments of the present application;

[0030] Figure 6 is one of the structural schematic diagrams of the device for obtaining timing advance provided by the embodiments of the present application;

[0031] Figure 7 is another structural schematic diagram of the device for obtaining timing advance provided by the embodiments of the present application;

[0032] Figure 8 is a communication device provided by the embodiments of the present application;

[0033] Figure 9 is a hardware structural schematic diagram of a terminal for implementing the embodiments of the present application;

[0034] Figure 10 is a network-side device provided by the embodiments of the present application. Detailed implementation manners

[0035] Next, the technical solutions in the embodiments of the present application will be clearly described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application belong to the scope of protection of the present application.

[0036] The terms "first", "second", etc. in the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first" and "second" are usually of the same type, and the number of objects is not limited. For example, the first object can be one or multiple. In addition, "or" in the present application means at least one of the connected objects. For example, "A or B" covers three scenarios, namely, Scenario 1: including A and not including B; Scenario 2: including B and not including A; Scenario 3: including both A and B. The character " / " generally indicates an "or" relationship between the associated objects before and after.

[0037] The term "indication" in this application can be either a direct indication (or an explicit indication) or an indirect indication (or an implicit indication). Among them, a direct indication can be understood as that the sender clearly informs the receiver of specific information, operations to be performed, request results, etc. in the sent indication; an indirect indication can be understood as that the receiver determines the corresponding information according to the indication sent by the sender, or makes a judgment and determines the operations to be performed or request results, etc. according to the judgment result.

[0038] It should be noted that the technology described in the embodiments of this application is not limited to the Long Term Evolution (LTE) / LTE-Advanced (LTE-A) system, and can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency-Division Multiple Access (SC-FDMA), or other systems. The terms "system" and "network" in the embodiments of this application are often used interchangeably, and the described technology can be used in the above-mentioned systems and radio technologies, as well as in other systems and radio technologies. The following description describes the New Radio (NR) system for example purposes, and uses NR terms in most of the following descriptions, but these technologies can also be applied to systems other than the NR system, such as the 6th Generation (6G) communication system. th Generation, 6G) communication system.

[0039] Figure 1The block diagram of a wireless communication system to which the embodiments of the present application can be applied is shown. The wireless communication system includes a terminal 11 and a network-side device 12. Among them, the terminal 11 can be a mobile phone, a tablet personal computer, a laptop computer, a notebook computer, a personal digital assistant (PDA), a handheld computer, a netbook, an ultra-mobile personal computer (UMPC), a mobile internet device (MID), an augmented reality (AR), a virtual reality (VR) device, a robot, a wearable device, a flight vehicle, a vehicle user equipment (VUE), a shipborne device, a pedestrian user equipment (PUE), a smart home (home appliances with wireless communication functions, such as refrigerators, TVs, washing machines, or furniture, etc.), a game console, a personal computer (PC), a teller machine, or a self-service machine, etc. Wearable devices include: smart watches, smart bracelets, smart earphones, smart glasses, smart jewelry (smart bracelets, smart bracelets, smart rings, smart necklaces, smart anklets, smart ankle chains, etc.), smart wristbands, smart clothing, etc. Among them, the vehicle user equipment can also be called a vehicle terminal, a vehicle controller, a vehicle module, a vehicle component, a vehicle chip, or a vehicle unit, etc. It should be noted that the specific type of the terminal 11 is not limited in the embodiments of the present application. The network-side device 12 can include an access network device or a core network device. Among them, the access network device can also be called a radio access network (RAN) device, a radio access network function, or a radio access network unit. The access network device can include a base station, a wireless local area network (WLAN) access point (AP), or a wireless fidelity (WiFi) node, etc.Among them, the base station can be referred to as Node B (NB), Evolved Node B (eNB), the next generation Node B (gNB), New Radio Node B (NR Node B), access point, Relay Base Station (RBS), Serving Base Station (SBS), Base Transceiver Station (BTS), radio base station, radio transceiver, Basic Service Set (BSS), Extended Service Set (ESS), home Node B (HNB), home evolved Node B, Transmission Reception Point (TRP), or some other suitable term in the art. As long as the same technical effect is achieved, the base station is not limited to specific technical terms. It should be noted that in the embodiments of this application, only the base station in the NR system is taken as an example for introduction, and the specific type of the base station is not limited.

[0040] To facilitate a clearer understanding of the technical solutions provided by the embodiments of this application, some related knowledge is introduced as follows.

[0041] In the Release 18 (hereinafter referred to as R18) mobility enhancement project, for LTM, intra-DU and intra-CU, inter-DU two types of handover scenarios are supported. In Release 19 (hereinafter referred to as R19), inter-CU LTM will be supported.

[0042] In the LTM of R18, the early TA acquisition process triggered by PDCCH order is supported, that is, the UE of the source serving cell executes the RACH procedure in the LTM candidate cell to obtain the TA value of the candidate cell in advance. All LTMs in R18 are handovers between cells within the same CU. It does not take much time for the DU corresponding to the serving cell to obtain the TA value calculated by the DU corresponding to the candidate cell, that is, the time consumed for transmitting and obtaining the TA value between multiple DUs under the same CU is short. However, R19 LTM can include handovers between inter-CUs. Considering the latency between interfaces, not all candidate cells are worth the UE executing the early RACH procedure to obtain the TA in advance.

[0043] The following introduces the CU-DU architecture. Refer to Figure 2 as shown in Figure 2 which is a schematic diagram of the CU-DU architecture in the prior art.

[0044] The 5G core network (5GC) is connected to the next-generation radio access network (NG-RAN) through the NG interface. The NG-RAN splits the base station (gNB) into a central unit (gNB-CU) and a distributed unit (gNB-DU), and connects them through the F1 interface.

[0045] Among them, one gNB only contains one gNB-CU, contains one or more gNB-DUs, and one gNB-DU contains one or more cells.

[0046] The gNB-CU contains the protocol stack above the Packet Data Convergence Protocol (PDCP), and the gNB-DU contains the protocol stack below the PDCP layer, such as the Radio Link Control (RLC), Media Access Control (MAC), and Physical Layer (PHY).

[0047] On the control plane, the gNB-CU contains the Radio Resource Control (RRC) and the PDCP on the control plane (PDCP-C). On the user plane, the gNB-CU contains the Service Data Adaptation Protocol (SDAP) and the PDCP on the user plane (PDCP-U).

[0048] The following introduces LTM.

[0049] In the R18 mobility enhancement project, LTM was introduced. Specifically, the serving base station determines the target cell based on the UE's layer 1 measurement results, and uses the MAC Control Element (MACCE) to trigger the UE to switch the primary cell or the primary and secondary cells (or the primary cell group or the secondary cell group) to the target cell (or the target cell group). During the LTM process, the network side prepares multiple candidate cells in advance, and sends the configuration information of the candidate cells to the UE through the RRC signaling. And when the UE changes the cell, the configuration information of the candidate cells saved by the UE will not be actively released. R18 LTM only supports cell switching under the same CU. R19 LTM will study cell switching across CUs. Refer to Figure 3 as shown in Figure 3 which is a schematic diagram of the signaling interaction of LTM in the prior art, such asFigure 3 As shown, it includes an LTM preparation stage, an Early sync stage, an LTM execution stage, and an LTM completion stage. Among them, the LTM preparation stage includes steps 1 - 3; the Early sync stage includes steps 4a and 4b; the LTM execution stage includes steps 5 - 7; the LTM completion stage includes step 8. Specifically:

[0050] Step 1: When the UE is in the RRC_CONNECTED state, it sends a Measurement report to the base station (gNB). The gNB performs LTM candidate preparation.

[0051] Step 2: The gNB sends an RRC reconfiguration message to the UE, including an LTM candidate configuration.

[0052] Step 3: The UE sends an RRC reconfiguration complete message to the gNB.

[0053] Step 4a: DL synchronization with candidate cells.

[0054] Step 4b: UL synchronization with candidate cells.

[0055] Step 5: The UE sends an L1 measurement report to the gNB. The gNB performs an LTM decision.

[0056] Step 6: The gNB sends a Cell Switch command to the UE through MAC CE.

[0057] Step 7: The UE executes the RACH Procedure.

[0058] Step 8: LTM completion.

[0059] The following is an introduction to Early TA acquisition.

[0060] To reduce the latency of cell change, during the LTM process, the network (NW) can trigger the UE to acquire the TA of candidate cells in advance. Here, the TA is used for the UE's uplink transmission, aiming to ensure that the UE's uplink data packets reach the base station within the desired time. Specifically, the NW sends a PDCCH order to the UE, which carries the identifier of the candidate cell. After receiving the PDCCH order, the UE sends a preamble to the candidate cell indicated by the PDCCH order, and the candidate cell calculates the UE's TA based on the preamble. Table 1 shows the parameters included in the PDCCH order.

[0061] Table 1

[0062]

[0063] The R18 mobility enhance project agrees to carry the indication information of the candidate cell and the configuration information of the random access opportunity of the candidate cell in the PDCCH order that triggers the acquisition of the TA of the candidate cell in advance. In addition, there is 1 bit in the PDCCH order to explicitly configure whether the PRACH is an initial transmission or a retransmission.

[0064] Regarding whether the UE maintains the TA value of the candidate cell: The UE does not maintain the TA value of the candidate cell. The serving base station maintains the TA value of the candidate cell. When the serving base station uses the MAC CE to trigger the UE to perform LTM, if the serving base station maintains a valid TA value of the target cell, the TA value will be carried in the LTM cell switch MAC CE. After receiving the MAC CE, the UE can obtain the TA value of the target cell, so it does not need to trigger the RACH process to the target cell, and thus can perform a cell switch based on RACH-less.

[0065] Currently, there can only be one running RACH process in a MAC entity. For the RACH process triggered by the PDCCH order to acquire the TA value of the candidate cell in advance, after the UE sends the preamble to the corresponding candidate cell, it will consider this RACH process to have ended.

[0066] In summary, in the related art, early TA acquisition is triggered by the serving DU / cell using the PDCCH order, and the TA value of the UE in the candidate cell is also maintained by the serving DU. For Rel-19 LTM, one possible enhancement direction is for the candidate cell to configure Contention Free Random Access (CFRA) resources specific to early TA acquisition for the UE, such as for supporting conditional LTM scenarios. The UE triggers the early TA acquisition process for the candidate cell under the serving DU by itself, including the UE sending a preamble to the candidate DU / cell based on the preconfigured CFRA resources by itself, and the candidate DU sending the TA calculated based on the preamble sent by the UE to the serving DU, and the serving DU sending the TA to the UE through RAR or MAC CE. In this case, if the interface latency between the serving DU and the candidate DU is too large, performing early RACH will cause a long interruption of the UE data. Since the UE does not know the latency between the serving DU and the candidate DU, it cannot decide whether it can perform the early TA acquisition process for the candidate DU.

[0067] In summary, in view of the above problems, the embodiments of the present application provide a method, apparatus, terminal, and network-side device for acquiring timing advance, which can solve the problem of which candidate cells the UE acquires TA in advance.

[0068] The method for acquiring timing advance provided by the embodiments of the present application will be described in detail below with reference to the accompanying drawings and through some embodiments and their application scenarios.

[0069] Figure 4 is one of the flow diagrams of the method for acquiring timing advance provided by the embodiments of the present application. As Figure 4 shown, the method includes steps 401 - step 402; where:

[0070] Step 401, the terminal determines a target candidate cell from at least one candidate cell based on first information; the first information is used to characterize whether there is an association relationship between the candidate cell and the serving cell of the terminal.

[0071] It should be noted that the embodiments of the present application can be applied to scenarios where the UE performs the early RACH process in advance to obtain the TA in advance. The terminal includes but is not limited to the types of the terminal 11 listed above, and the network-side device includes but is not limited to the types of the network-side device 12 listed above. The present application can be applied to the LTM scenario, including the intra-CU and inter-CU handover scenarios, and can also be applied to non-LTM scenarios, such as Conditional Handover (CHO) and Conditional PSCell Addition / Change (CPAC), etc. The embodiments of the present application are not limited thereto.

[0072] In the embodiments of the present application, in order to determine which candidate cell the terminal performs early random access to obtain the TA, first, it is necessary to determine a target candidate cell associated with the serving cell from at least one candidate cell based on the first information. In practical applications, the target candidate cell can be one or more, or there may be no target candidate cell.

[0073] It should be noted that in the case where there is no target candidate cell, the terminal may not perform the early RACH, or may perform the early RACH to other candidate cells.

[0074] That is, if there is a target candidate cell, the terminal performs the early RACH (also referred to as the first early RACH) to the target candidate cell; specifically, the terminal uses the resources corresponding to the first early RACH to perform the first early RACH to the target candidate cell. In the case where there is no target candidate cell, the terminal performs the second early RACH to other candidate cells; specifically, the terminal uses the resources corresponding to the second early RACH to perform the second early RACH to other candidate cells.

[0075] The specific processes of the terminal performing the first early RACH to the target candidate cell and the terminal performing the second early RACH to other candidate cells will be introduced in subsequent embodiments and will not be elaborated here.

[0076] The terminal determines the target candidate cell from at least one candidate cell based on the first information, including the following situations:

[0077] Situation 1: The terminal determines whether there is an association relationship between each candidate cell and the serving cell based on the first information.

[0078] Scenario 2: The terminal first selects some candidate cells from all candidate cells according to the Reference Signal Received Power (RSRP) or other conditions, and then determines whether there is an association relationship between each candidate cell in the selected candidate cells and the serving cell based on the first information.

[0079] Step 402: The terminal performs early random access to the target candidate cell to obtain the timing advance (TA).

[0080] In the embodiments of the present application, each candidate cell is allocated CFRA resources related to early random access (early RACH) for the terminal. After the terminal determines the target candidate cell, it performs early RACH to the target candidate cell to obtain the TA.

[0081] In the method for obtaining the timing advance provided by the embodiments of the present application, the terminal determines whether there is an association relationship between at least one candidate cell and the serving cell of the terminal based on the first information, and determines the cell having an association relationship with the serving cell from at least one candidate cell as the target candidate cell, so that the terminal can determine that it needs to perform the early RACH process to the target candidate cell to obtain the TA in advance, thereby avoiding unnecessary early RACH processes.

[0082] Optionally, before the terminal determines the target candidate cell from at least one candidate cell based on the first information, the terminal also needs to perform the following steps:

[0083] The terminal determines the first information based on the candidate configuration information.

[0084] In the embodiments of the present application, the candidate configuration information is sent by the network side device to the terminal based on the RRC message.

[0085] Optionally, in one implementation, the candidate configuration information includes the configuration information of the candidate cell and may also include the configuration information of the serving cell; where:

[0086] The configuration information of the candidate cell includes at least one of the following:

[0087] 1) The first index value in the RACH configuration information corresponding to the candidate cell.

[0088] Specifically, the candidate cell allocates CFRA resources related to early RACH for the terminal through the RACH configuration information, and the configuration information of each candidate cell corresponds to 1 or 0 RACH configuration information. Optionally, in addition to the first index value, the RACH configuration information further includes at least one of the following:

[0089] [a], RACH configuration information identifier, also known as Early RACH configuration identifier.

[0090] [b], Frequency domain related information.

[0091] [c], Bandwidth (Bandwidth Part, BWP) information.

[0092] [d], Random Access Preamble index, used to indicate one or more specific preamble indexes available for early RACH.

[0093] [e], Synchronization Signal (SS) / Physical Broadcast Channel (PBCH) index.

[0094] [f], The number of Synchronization Signal Blocks (SSBs) associated with a RACH occasion.

[0095] [g], Physical Random Access Channel Mask index PRACH Mask index.

[0096] [h], The first threshold value. When the RSRP of the SSB or CSI Reference Signal (CSI-RS) related to the candidate cell exceeds the first threshold value, the UE decides to select the corresponding SSB or CSI-RS.

[0097] [i], Random Access Response (RAR) window RAR Window, used to receive the RAR of early RACH.

[0098] [j], RACH occasion related parameters.

[0099] [k], Preamble power related parameters.

[0100] [l], Maximum number of preamble transmissions.

[0101] [m], Configuration information identifier of the candidate cell, or identifier of the candidate cell.

[0102] 2) The second index value corresponding to the candidate cell.

[0103] The configuration information of the serving cell includes at least one of the following:

[0104] 1) The fourth index value corresponding to the serving cell;

[0105] 2) The second list corresponding to the serving cell, where the second list includes the fifth index values corresponding to at least one of the candidate cells.

[0106] Optionally, any one of the first index value, the second index value, the fourth index value, and the fifth index value includes:

[0107] At least one of a cell identifier (IDentity, ID), the ID of the candidate configuration information, the RACH configuration information corresponding to the candidate cell, a Master Node (MN) ID, a Secondary Node (Service Node, SN) ID, an MN group (set) ID, an SN set ID, a CU ID, a CU set ID, a DU ID, a DU set ID, and a set identifier.

[0108] Optionally, in another implementation, the candidate configuration information includes:

[0109] At least one first list, where the first list includes the third index values corresponding to at least one cell, and the at least one cell includes at least one of the candidate cell and the serving cell of the terminal.

[0110] Optionally, the third index value includes:

[0111] At least one of a cell ID, the ID of the candidate configuration information, the RACH configuration information corresponding to the candidate cell, an MN ID, an SN ID, an MN set ID, an SN set ID, a CU ID, a CU set ID, a DU ID, a DU set ID, and a set identifier.

[0112] Optionally, the terminal determines a target candidate cell from at least one candidate cell based on first information, and specifically, it can be implemented in any of the following ways:

[0113] Way 1: The terminal compares the first index value corresponding to the candidate cell with the fourth index value, and determines the candidate cell with the same first index value and fourth index value as the target candidate cell.

[0114] Specifically, the terminal compares the first index value in the RACH configuration information corresponding to the candidate cell with the fourth index value corresponding to the serving cell, and determines the candidate cell with the same first index value and fourth index value as the target candidate cell.

[0115] It should be noted that in the above-mentioned Method 1, the first index value includes at least one of: MN ID, SN ID, MN set ID, SN set ID, CU ID, CU set ID, DU ID, DU set ID, and set identifier.

[0116] For example, the first index value corresponding to candidate cell 1 is: MN ID = 1; the first index value corresponding to candidate cell 2 is: MN ID = 2; the fourth index value corresponding to the serving cell is: MN ID = 1. If the MN ID corresponding to candidate cell 1 is the same as the MN ID corresponding to the serving cell, then candidate cell 1 is determined as the target candidate cell.

[0117] Another example, the first index value corresponding to candidate cell 1 is: CU ID = 1; the first index value corresponding to candidate cell 2 is: CU ID = 2; the fourth index value corresponding to the serving cell is: CU ID = 2. If the CU ID corresponding to candidate cell 2 is the same as the CU ID corresponding to the serving cell, then candidate cell 2 is determined as the target candidate cell.

[0118] Optionally, when the terminal successfully switches from the source serving cell to the target cell, the terminal replaces the first index value corresponding to the target cell with the fourth index value.

[0119] Specifically, the RRC message sent by the network side device to the terminal includes candidate configuration information, which also includes the configuration information of the serving cell, and the configuration information of the serving cell includes the fourth index value corresponding to the serving cell. After the terminal successfully switches from the source serving cell to the target cell, the target cell becomes the serving cell of the terminal. Therefore, it is necessary to replace the first index value corresponding to the target cell with the fourth index value corresponding to the serving cell. It should be noted that the target cell can be any one of the target candidate cells or a cell outside the target candidate cells.

[0120] When the target cell is any one of the target candidate cells, the first index value corresponding to the target candidate cell is the same as the fourth index value corresponding to the serving cell. Therefore, after the terminal successfully switches to the target cell, the first index value can be replaced with the fourth index value, or the first index value can not be replaced.

[0121] When the target cell is a cell outside the target candidate cells, after the terminal successfully switches to the target cell, it is necessary to replace the first index value corresponding to the target cell with the fourth index value corresponding to the serving cell.

[0122] For example, the first index value corresponding to the target cell is: MN ID = 2; the fourth index value corresponding to the serving cell is: MN ID = 1. Then, the first index value is replaced with the fourth index value, that is, the replaced first index value is: MN ID = 1.

[0123] Through the above method, when the terminal needs to determine other target candidate cells from at least one candidate cell to perform early RACH at a future moment, the first index value corresponding to the candidate cell can be compared with the replaced fourth index value, thereby ensuring the continuity of the early RACH execution.

[0124] Method 2: The terminal compares the second index value corresponding to the candidate cell with the fourth index value, and determines the candidate cell with the same second index value and fourth index value as the target candidate cell.

[0125] Specifically, in the embodiment of the present application, the second index value is configured outside the RACH configuration information corresponding to the candidate cell. That is, in the candidate configuration information sent by the network side device to the terminal, it includes the RACH configuration information corresponding to the candidate cell and the second index value corresponding to the candidate cell. The terminal compares the second index value with the fourth index value corresponding to the serving cell, and determines the candidate cell with the same second index value and fourth index value as the target candidate cell.

[0126] It should be noted that in the above Method 2, the second index value includes at least one of: MN ID, SN ID, MN set ID, SN set ID, CU ID, CU set ID, DU ID, DU set ID, and set identifier.

[0127] Optionally, in the case where the terminal successfully switches from the source serving cell to the target cell, the terminal replaces the second index value corresponding to the target cell with the fourth index value. It should be noted that the target cell can be any one of the target candidate cells or a cell outside the target candidate cells.

[0128] Through the above method, when the terminal needs to determine other target candidate cells from at least one candidate cell to perform early RACH at a future moment, the second index value corresponding to the candidate cell can be compared with the replaced fourth index value, thereby ensuring the continuity of the early RACH execution.

[0129] Method 3 is specifically implemented through the following steps 1)-2):

[0130] Step 1: The terminal compares the first index value corresponding to the candidate cell with the fifth index value in the second list;

[0131] Step 2), the terminal determines the target candidate cell based on the comparison result; the first index value corresponding to the target candidate cell is the same as the fifth index value.

[0132] Specifically, the terminal compares the first index value in the RACH configuration information corresponding to the candidate cell with at least one fifth index value in the second list corresponding to the serving cell, and determines the candidate cell with the same first index value and fifth index value as the target candidate cell.

[0133] For example, the first index value corresponding to candidate cell 1 is: MN ID = 1; the first index value corresponding to candidate cell 2 is MN ID = 2; the first index value corresponding to candidate cell 3 is MN ID = 3; the second list includes the fifth index value corresponding to candidate cell 1: MN ID = 1; the fifth index value corresponding to candidate cell 2: MN ID = 2. Then the second list contains the index values of candidate cell 1 and candidate cell 2, and candidate cell 1 and candidate cell 2 are determined as the target candidate cells.

[0134] Optionally, when the terminal successfully switches from the source serving cell to the target cell, the terminal replaces the third list in the candidate configuration information corresponding to the target cell with the second list; the third list includes at least one sixth index value corresponding to the candidate cell.

[0135] Specifically, the RRC message sent by the network side device to the terminal includes candidate configuration information, which also includes the configuration information of the serving cell, and the second list corresponding to the serving cell is included in the configuration information of the serving cell. After the terminal successfully switches from the source serving cell to the target cell, the target cell becomes the serving cell of the terminal. Therefore, it is necessary to replace the third list in the candidate configuration information corresponding to the target cell with the second list corresponding to the serving cell. It should be noted that the target cell can be any one of the target candidate cells or a cell outside the target candidate cells.

[0136] For example, the third list corresponding to the target cell includes: the sixth index value corresponding to candidate cell 1: MN ID = 1; the sixth index value corresponding to candidate cell 5: MN ID = 5. After the terminal successfully switches to the target cell, the third list corresponding to the target cell is replaced with the second list corresponding to the serving cell, that is, the replaced third list includes: the sixth index value corresponding to candidate cell 1: MN ID = 1; the sixth index value corresponding to candidate cell 5: MN ID = 5.

[0137] It should be noted that in the embodiments of the present application, the third list in the candidate configuration information is configured in the RACH configuration information corresponding to the candidate cell.

[0138] Through the above method, when the terminal needs to determine other target candidate cells from at least one candidate cell to perform early RACH at a future moment, it can compare the first index value corresponding to the candidate cell with the above-mentioned replaced second list, thereby ensuring the continuity of the execution of early RACH.

[0139] Method 4 is specifically implemented through the following steps 1)-2):

[0140] Step 1), the terminal compares the second index value corresponding to the candidate cell with the fifth index value in the second list;

[0141] Step 2), the terminal determines the target candidate cell based on the comparison result; the second index value corresponding to the target candidate cell is the same as the fifth index value.

[0142] Specifically, the second index value is configured outside the RACH configuration information corresponding to the candidate cell. That is, in the candidate configuration information sent by the network-side device to the terminal, it includes the RACH configuration information corresponding to the candidate cell and the second index value corresponding to the candidate cell. The terminal compares the second index value with at least one fifth index value in the second list corresponding to the serving cell, and determines the candidate cell with the same second index value and fifth index value as the target candidate cell.

[0143] Optionally, when the terminal successfully switches from the source serving cell to the target cell, the terminal replaces the third list in the candidate configuration information corresponding to the target cell with the second list; the target cell can be any one of the target candidate cells or a cell outside the target candidate cells, and the third list includes at least one sixth index value corresponding to the candidate cell.

[0144] It should be noted that in the embodiments of the present application, the third list is directly configured in the candidate configuration information.

[0145] Through the above method, when the terminal needs to determine other target candidate cells from at least one candidate cell to perform early RACH at a future moment, it can compare the first index value corresponding to the candidate cell with the above-mentioned replaced second list, thereby ensuring the continuity of the execution of early RACH.

[0146] Method 5, the terminal determines the target candidate cell based on the first list; where:

[0147] The third index value corresponding to the target candidate cell and the third index value corresponding to the serving cell are in the same first list.

[0148] In an embodiment of the present application, the first list includes third index values corresponding to multiple cells. When the third index value corresponding to a candidate cell and the third index value corresponding to the serving cell are in the same first list, the candidate cell is determined as the target candidate cell.

[0149] For example, the first list includes the third index value corresponding to candidate cell 1 and the third index value corresponding to the serving cell. Then, candidate cell 1 is determined as the target candidate cell.

[0150] Optionally, the terminal performs early random access to the target candidate cell to obtain TA, which can be specifically implemented through the following steps:

[0151] Step 1): When the terminal meets the first condition, the terminal sends a preamble to the at least one target candidate cell.

[0152] Optionally, the terminal sends a preamble to the target candidate cell on the Physical Random Access Channel (PRACH) occasion corresponding to the target candidate cell according to the RACH configuration information of the target candidate cell.

[0153] Specifically, the first condition includes at least one of the following:

[0154] a) For any target candidate cell, at least one of the following is satisfied: the L1-RSRP of the SSB corresponding to the target candidate cell exceeds the threshold value corresponding to the target candidate cell, and the L1-RSRP of the CSI-RS corresponding to the target candidate cell exceeds the threshold value corresponding to the target candidate cell;

[0155] b) The terminal has no current data transmission.

[0156] For example, the terminal is in Discontinuous Reception (DRX) time and has no uplink transmission; or, it is currently during the measurement gap of the terminal.

[0157] Step 2): Case 1: The terminal considers the early RACH to end after sending the preamble to the target candidate cell N times;

[0158] Or,

[0159] Case 2: The terminal opens the RAR window and listens for the physical PDCCH in the RAR window.

[0160] Specifically, for Scenario 1: After the terminal sends N preambles to the target candidate cell, it considers the early RACH to end, that is, the terminal does not need to listen for the RAR. Here, N is configured by the network or determined by the terminal based on the quality of the SSB or CSI-RS corresponding to the early RACH. For example, if the SSB or CSI-RS corresponding to the early RACH is higher than a network-configured threshold, the terminal considers the early RACH to end after sending the preamble.

[0161] In this solution, if the handover command contains a TA value, the UE performs a RACH-less cell handover; otherwise, the UE performs a RACH-based cell handover.

[0162] For Scenario 2: After the terminal sends the preamble, it opens the RAR window and listens for the PDCCH in the RAR window to obtain the TA of the target candidate cell.

[0163] In practical applications, the terminal can open the RAR window at the first PDCCH occasion after sending the preamble.

[0164] Alternatively, the terminal opens the RAR window after the first timer expires. For example, the terminal opens the RAR window at the first PDCCH occasion after the first timer expires. Here, the first timer can be configured in the RACH configuration information of the target candidate cell or stipulated by the protocol.

[0165] Step 3: If the terminal receives a PDCCH scrambled with a Cell Radio Network Temporary Identifier (C-RNTI) in the RAR window and the terminal successfully decodes the content carried in the downlink allocation indicated by the PDCCH, such as the RAR or MAC CE, the terminal considers the early RACH to be successfully completed.

[0166] Otherwise, the terminal sets the current preamble transmission count to the current preamble transmission count + 1. If the current preamble transmission count of the terminal is less than the pre-configured maximum transmission count + 1, the terminal re-executes the early RACH procedure for the target candidate cell; otherwise, the terminal considers this RACH to be a failure. Optionally, the terminal indicates the reason corresponding to the RACH failure to the serving cell.

[0167] Figure 5 It is the second flow diagram of the timing advance acquisition method provided by the embodiments of the present application. As Figure 5 shown, this method includes Step 501; where:

[0168] The network - side device sends candidate configuration information to the terminal; the candidate configuration information is used to assist the terminal in determining first information, and based on the first information, the terminal determines a target candidate cell from at least one candidate cell; the first information is used to characterize whether there is an association relationship between the candidate cell and the serving cell of the terminal; the target candidate cell is used for the terminal to perform early random access to obtain the timing advance (TA).

[0169] It should be noted that the embodiments of this application can be applied to scenarios where the UE performs an early RACH process in advance to obtain TA early. The terminal includes, but is not limited to, the types of terminal 11 listed above, and the network - side device includes, but is not limited to, the types of network - side device 12 listed above. This application can be applied to LTM scenarios, including intra - CU and inter - CU handover scenarios, and can also be applied to non - LTM scenarios, such as CHO and CPAC, etc. The embodiments of this application do not limit this.

[0170] In the embodiments of this application, in order to determine which candidate cell the terminal performs early random access to obtain TA, the network - side device needs to send candidate configuration information to the terminal, so that the terminal determines the first information based on the candidate configuration information, and then determines the target candidate cell based on the first information, so as to perform early random access to the target candidate cell to obtain TA.

[0171] In the method for obtaining the timing advance provided by the embodiments of this application, the network - side device sends candidate configuration information to the terminal, so that the terminal determines the first information based on the candidate configuration information, and then the terminal determines, based on the first information, whether there is an association relationship between at least one candidate cell and the serving cell of the terminal, and determines the cell with an association relationship with the serving cell from at least one candidate cell as the target candidate cell, so that the terminal can determine that it needs to perform an early RACH process on the target candidate cell to obtain TA early, thereby avoiding unnecessary early RACH processes.

[0172] Optionally, the candidate configuration information includes the configuration information of the candidate cell, and the configuration information of the candidate cell includes at least one of the following:

[0173] a) The first index value in the RACH configuration information corresponding to the candidate cell;

[0174] b) The second index value corresponding to the candidate cell.

[0175] Optionally, the candidate configuration information includes:

[0176] At least one first list, where the first list includes third index values corresponding to at least one cell, and the at least one cell includes at least one of the candidate cell and the serving cell of the terminal.

[0177] Optionally, the candidate configuration information further includes the configuration information of the serving cell, and the configuration information of the serving cell includes at least one of the following:

[0178] a) A fourth index value corresponding to the serving cell;

[0179] b) A second list corresponding to the serving cell, and the second list includes fifth index values corresponding to at least one of the candidate cells.

[0180] Optionally, any one of the first index value, the second index, the fourth index value, and the fifth index value includes:

[0181] At least one of a cell ID, an ID of the candidate configuration information, RACH configuration information corresponding to the candidate cell, an MN ID, an SN ID, an MN set ID, an SN set ID, a CU ID, a CU set ID, a DU ID, a DU set ID, and a set ID.

[0182] Optionally, the third index value includes:

[0183] At least one of a cell ID, an ID of the candidate configuration information, RACH configuration information corresponding to the candidate cell, an MN ID, an SN ID, an MN set ID, an SN set ID, a CU ID, a CU set ID, a DU ID, a DU set ID, and a set ID.

[0184] The method for obtaining the timing advance provided by the present invention will be further described below in conjunction with specific embodiments.

[0185] Embodiment 1: Carry a first index value in the RACH configuration information related to early acquisition of TA.

[0186] First, the UE receives a first RRC message sent by a network-side device; where:

[0187] The first RRC message includes one or more candidate configuration information, the candidate configuration information includes the configuration information of a candidate cell, the configuration information of the candidate cell includes RACH configuration information, and the candidate cell allocates early RACH-related CFRA resources based on the RACH configuration information. The configuration information of each candidate cell corresponds to 1 or 0 RACH configuration information.

[0188] The RACH configuration information includes one or more of the following:

[0189] a) Early RACH configuration identifier;

[0190] b) Frequency domain related information;

[0191] c) BWP;

[0192] d) Random Access Preamble index, which is used to indicate one or more specific preamble indexes available for early RACH;

[0193] e) SS / PBCH index;

[0194] f) The number of SSBs associated with one RACH occasion;

[0195] g) PRACH Mask index;

[0196] h) Threshold 1. When the RSRP of the SSB or CSI-RS related to the candidate cell exceeds the threshold, the UE decides to execute the selection of the corresponding SSB or CSI-RS;

[0197] i) RAR window, which is used to receive the RAR of early RACH;

[0198] j) RACH occasion related parameters;

[0199] k) Preamble power related parameters;

[0200] l) Maximum number of preamble transmissions;

[0201] m) Candidate configuration identifier or candidate cell identifier;

[0202] n) The first index value, which can be any one of MN ID, SN ID, MN set ID, SN set ID, CUID, CU set ID, DU ID, and DU set ID.

[0203] It should be noted that the first RRC message also includes the fourth index value corresponding to the serving cell of the terminal, which is used for the UE to determine whether to perform the early RACH procedure of other candidate cells in the serving cell; the UE stores or updates the fourth index value (if the UE has stored the fourth index value before, it is updated, otherwise it is stored). After the UE switches to a target cell, it replaces the first index value corresponding to the target cell with the stored fourth index value.

[0204] When the first index value of candidate cell 1 is the same as the second index value, the UE decides to perform the first early RACH to candidate cell 1 in the serving cell. When the first index value of candidate cell 1 is different from the second index value, the UE's behavior towards candidate cell 1 includes any one of the following:

[0205] a) The serving cell will not perform early RACH to candidate cell 1;

[0206] b) The serving cell performs the second early RACH to candidate cell 1.

[0207] That is, if the first index value of candidate cell 1 is the same as the second index value, then candidate cell 1 is the target candidate cell, and the terminal performs the first early RACH using the resources corresponding to the first early RACH to candidate cell 1; otherwise, the terminal performs the second early RACH using the resources corresponding to the second early RACH to candidate cell 1.

[0208] Specifically, the first early RACH includes that after the UE sends the preamble, it opens the RAR window and receives the C-RNTI scrambled RAR or MAC CE sent by the serving cell.

[0209] The second early RACH includes that after the UE sends the preamble, it opens the RAR window and receives the RAR scrambled by the random access RNTI (RA-RNTI) sent by the candidate cell.

[0210] For the NW side, when the NW side device of the candidate cell receives the preamble on the first early RACH resource or receives the preamble associated with the first early RACH resource, it sends the calculated TA value to the network side device of the UE's serving cell; when the network side device of the candidate cell receives the preamble on the second early RACH resource or receives the preamble associated with the second early RACH resource, it sends the RAR to the UE.

[0211] The following introduces the UE performing the first early RACH or the second early RACH from the serving cell to candidate cell 1.

[0212] Specifically, under the condition of meeting the first condition, the UE performs the first early RACH or the second early RACH from the serving cell to candidate cell 1, and the first condition includes at least one of the following:

[0213] a) The L1-RSRP of the SSB corresponding to candidate cell 1 exceeds the threshold, or the L1-RSRP of the CSI-RS corresponding to candidate cell 1 exceeds the threshold.

[0214] b) The UE has no current data transmission. For example, the UE is in the DRX inactive time and has no uplink data transmission; or it is currently during the measurement gap of the UE.

[0215] Optionally, the UE performs the first early RACH or the second early RACH from the serving cell to candidate cell 1, including:

[0216] The UE sends a preamble to candidate cell 1 on the PRACH occasion corresponding to candidate cell 1 according to the RACH configuration information of candidate cell 1.

[0217] The UE performing the first early RACH from the serving cell to candidate cell 1 includes that after the UE sends the preamble, the UE behavior includes any one of the following:

[0218] a) After the UE sends the preamble N times, the UE considers the first early RACH to end.

[0219] Specifically, after the UE sends the preamble N times to the target candidate cell (i.e., candidate cell 1), it considers the first early RACH to end. The N is configured by the network or determined by the UE based on the quality of the SSB or CSI-RS corresponding to the first early RACH. For example, if the SSB or CSI-RS corresponding to the first early RACH is higher than a network-configured threshold, the UE considers the first early RACH to end after sending the preamble.

[0220] In this solution, if the handover command contains the TA value, the UE performs a RACH-less cell handover; otherwise, the UE performs a RACH-based cell handover.

[0221] b) The UE opens the RAR window and listens for the PDCCH in the RAR window to obtain the TA value of candidate cell 1.

[0222] Specifically, the UE opens the RAR window at the first PDCCH occasion after sending the preamble; or, the UE opens the RAR window after the first timer expires. For example, the UE opens the RAR window at the first PDCCH occasion after the first timer expires. The first timer can be configured in the RACH configuration information of candidate cell 1 or stipulated by the protocol.

[0223] If the UE receives a PDCCH scrambled with the C-RNTI within the RAR window and the UE successfully decodes the content carried in the downlink allocation indicated by the PDCCH, such as the RAR or the MAC CE, the UE considers that the first early RACH is successfully completed. Otherwise, the UE sets the current preamble transmission count of the UE to the current preamble transmission count + 1. If the current preamble transmission count of the UE is less than the preconfigured maximum transmission count + 1, the UE re-executes the first early RACH procedure for candidate cell 1; otherwise, the UE considers that this RACH fails. Optionally, the UE indicates the RACH problem to the serving cell.

[0224] The UE performs the second early RACH to candidate cell 1 in the serving cell. After the UE sends the preamble, the UE behavior includes:

[0225] The UE opens the RAR window and listens for the PDCCH in the RAR window to obtain the TA value of candidate cell 1.

[0226] Specifically, the UE opens the RAR window at the first PDCCH occasion after sending the preamble; or, the UE opens the RAR window after the expiration of the first timer. For example, the UE opens the RAR window at the first PDCCH occasion after the expiration of the first timer. The first timer can be configured in the RACH configuration information of candidate cell 1 or stipulated by the protocol.

[0227] If the UE receives a PDCCH scrambled with the RA-RNTI within the RAR window and the UE successfully decodes the content carried in the downlink allocation indicated by the PDCCH, such as the RAR or the MAC CE, the UE considers that the second early RACH is successfully completed. Otherwise, the UE sets the current preamble transmission count of the UE to the current preamble transmission count + 1. If the current preamble transmission count of the UE is less than the preconfigured maximum transmission count + 1, the UE re-executes the second early RACH procedure for candidate cell 1; otherwise, the UE considers that this RACH fails. Optionally, the UE indicates the RACH problem to the serving cell.

[0228] Embodiment 2: A third list that can perform early RACH is carried in the RACH configuration information related to the TA obtained in advance.

[0229] First, the UE receives the first RRC message sent by the network side device; where:

[0230] The first RRC message contains one or more pieces of candidate configuration information, which includes the configuration information of candidate cells. The configuration information of candidate cells includes RACH configuration information, and the candidate cells allocate CFRA resources related to early RACH for the UE based on the RACH configuration information. The configuration information of each candidate cell corresponds to one or zero pieces of RACH configuration information.

[0231] The RACH configuration information includes one or more of the following:

[0232] a) Early RACH configuration identifier;

[0233] b) Frequency domain related information;

[0234] c) BWP;

[0235] d) Random Access Preamble index, which is used to indicate one or more specific preamble indexes available for early RACH;

[0236] e) SS / PBCH index;

[0237] f) The number of SSBs associated with one RACH occasion;

[0238] g) PRACH Mask index;

[0239] h) Threshold 1, when the RSRP of the SSB or CSI-RS related to the candidate cell exceeds the threshold, the UE decides to perform the selection corresponding to the SSB or CSI-RS;

[0240] i) RAR window, which is used to receive the RAR of early RACH;

[0241] j) RACH occasion related parameters;

[0242] k) Preamble power related parameters;

[0243] l) Maximum number of preamble transmissions;

[0244] m) Candidate configuration identifier or candidate cell identifier;

[0245] n) The first index value, which can be at least one of cell identifier, candidate configuration information identifier, RACH configuration information corresponding to the candidate cell, MN ID, SN ID, MN set ID, SN set ID, CU ID, CU set ID, DU ID, DU set ID, and set ID.

[0246] o) The third list, including a sixth index value, which can be at least one of a cell identifier, an identifier of candidate configuration information, RACH configuration information corresponding to a candidate cell, MN ID, SN ID, MN set ID, SN set ID, CU ID, CU set ID, DU ID, DU set ID, and set ID.

[0247] It should be noted that the first RRC message also includes a second list corresponding to the serving cell of the terminal, which is used for the UE to determine whether to perform an early RACH procedure for other candidate cells in the serving cell; the UE stores or updates the second list (if the UE has stored a second list before, it is updated, otherwise it is stored). After the UE switches to a target cell, it replaces the third list corresponding to the target cell with the stored second list.

[0248] When the first index value in candidate cell 1 is the same as the fifth index value in the second list, the UE decides to perform an early RACH to candidate cell 1 in the serving cell.

[0249] It should be noted that the process of the UE performing an early RACH to candidate cell 1 in the serving cell is the same as or similar to that in Embodiment 1. To avoid repetition, it will not be elaborated here.

[0250] Embodiment 3: Determine whether to perform an early RACH according to a second index value outside the RACH configuration information.

[0251] First, the UE receives a first RRC message sent by a network-side device; wherein:

[0252] The first RRC message includes one or more pieces of candidate configuration information, and the candidate configuration information includes the configuration information of a candidate cell. The configuration information of the candidate cell includes RACH configuration information, and the candidate cell allocates CFRA resources related to the early RACH to the UE based on the RACH configuration information. The configuration information of each candidate cell corresponds to 1 or 0 pieces of RACH configuration information.

[0253] The candidate configuration information includes at least one of the following:

[0254] a) A second index value.

[0255] b) RACH configuration information; wherein, the RACH configuration information includes at least one of the following:

[0256] Early RACH configuration identifier; frequency domain related information; BWP; Random Access Preamble index; SS / PBCH index; number of SSBs associated with a RACH occasion; PRACH Mask index; threshold 1; RAR window; RACH occasion related parameters; preamble power related parameters; maximum number of preamble transmissions; candidate configuration identifier or candidate cell identifier.

[0257] It should be noted that the first RRC message also includes a fourth index value corresponding to the serving cell of the terminal, which is used by the UE to determine whether to perform the early RACH procedure for other candidate cells in the serving cell; the UE stores or updates the fourth index value (if the UE has previously stored the fourth index value, it is updated, otherwise it is stored). After the UE switches to a target cell, it replaces the second index value corresponding to the target cell with the stored fourth index value.

[0258] It should be noted that the process of the UE performing early RACH from the serving cell to candidate cell 1 is the same as or similar to that in Embodiment 1-2. To avoid repetition, it will not be elaborated here.

[0259] Embodiment 4: Determine whether to perform early RACH according to the third list outside the RACH configuration information.

[0260] First, the UE receives a first RRC message sent by the network device; where:

[0261] The first RRC message includes one or more candidate configuration information, and the candidate configuration information includes the configuration information of the candidate cell. The configuration information of the candidate cell includes RACH configuration information, and the candidate cell allocates CFRA resources related to early RACH for the UE based on the RACH configuration information. The configuration information of each candidate cell corresponds to 1 or 0 RACH configuration information.

[0262] The candidate configuration information includes:

[0263] a) Second index value.

[0264] b) The RACH configuration information includes at least one of the following:

[0265] Early RACH configuration identifier; frequency domain related information; BWP; Random Access Preamble index; SS / PBCH index; number of SSBs associated with a RACH occasion; PRACH Mask index; threshold 1; RAR window; RACH occasion related parameters; preamble power related parameters; maximum number of preamble transmissions; candidate configuration identifier or candidate cell identifier.

[0266] c) The third list includes a sixth index value, and the sixth index value can be at least one of a cell identifier, an identifier of candidate configuration information, RACH configuration information corresponding to a candidate cell, MN ID, SN ID, MN set ID, SN set ID, CU ID, CU set ID, DU ID, DU set ID, and set ID.

[0267] It should be noted that the first RRC message also includes a second list corresponding to the serving cell of the terminal, which is used for the UE to determine whether to perform the early RACH procedure for other candidate cells in the serving cell; the UE stores or updates the second list (if the UE has stored the second list before, it is updated, otherwise it is stored). After the UE switches to a target cell, it replaces the third list corresponding to the target cell with the stored second list.

[0268] When the second index value of candidate cell 1 is the same as the fifth index value in the second list, the UE decides to perform early RACH on candidate cell 1 in the serving cell.

[0269] It should be noted that the process of the UE performing early RACH on candidate cell 1 in the serving cell is the same as or similar to those in Embodiments 1-3. To avoid repetition, it will not be elaborated here.

[0270] Embodiment 5: Determine whether to perform early RACH according to the first list outside the RACH configuration information. The first list includes third index values corresponding to multiple cells.

[0271] For example, when the third index value corresponding to candidate cell 1 and the third index value corresponding to the serving cell are in the same first list, the UE decides to perform early RACH on candidate cell 1 in the serving cell.

[0272] It should be noted that the process of the UE performing early RACH on candidate cell 1 in the serving cell is the same as or similar to those in Embodiments 1-4. To avoid repetition, it will not be elaborated here.

[0273] The method for obtaining timing advance provided by the embodiments of the present application may be executed by a timing advance obtaining device. In the embodiments of the present application, taking the timing advance obtaining device executing the timing advance obtaining method as an example, the timing advance obtaining device provided by the embodiments of the present application is described.

[0274] Figure 6 is one of the structural schematic diagrams of the timing advance obtaining device provided by the embodiments of the present application. As Figure 6 shown, the timing advance obtaining device 600 is applied to a terminal and includes:

[0275] A first determination module 601, configured to determine a target candidate cell from at least one candidate cell based on first information; the first information is used to characterize whether there is an association relationship between the candidate cell and the serving cell of the terminal.

[0276] An obtaining module 602, configured to perform an early random access to the target candidate cell to obtain a timing advance TA.

[0277] In the timing advance obtaining device provided by the embodiments of the present application, based on the first information, it is determined whether there is an association relationship between at least one candidate cell and the serving cell of the terminal, and the cell having an association relationship with the serving cell is determined as the target candidate cell from at least one candidate cell, so that the terminal can determine that it is necessary to perform an early RACH procedure to the target candidate cell to obtain TA in advance, thereby avoiding unnecessary early RACH procedures.

[0278] Optionally, the device further includes:

[0279] A second determination module, configured to determine the first information based on candidate configuration information.

[0280] Optionally, the candidate configuration information includes the configuration information of the candidate cell, and the configuration information of the candidate cell includes at least one of the following:

[0281] The first index value in the random access channel RACH configuration information corresponding to the candidate cell;

[0282] The second index value corresponding to the candidate cell.

[0283] Optionally, the candidate configuration information includes:

[0284] At least one first list, where the first list includes third index values corresponding to at least one cell, and the at least one cell includes at least one of the candidate cell and the serving cell of the terminal.

[0285] Optionally, the candidate configuration information further includes the configuration information of the serving cell, and the configuration information of the serving cell includes at least one of the following:

[0286] The fourth index value corresponding to the serving cell;

[0287] The second list corresponding to the serving cell, where the second list includes the fifth index values corresponding to at least one of the candidate cells.

[0288] Optionally, the first determination module 601 is further configured to:

[0289] Compare the first index value corresponding to the candidate cell with the fourth index value, and determine the candidate cell with the same first index value and the fourth index value as the target candidate cell.

[0290] Optionally, the apparatus further includes:

[0291] The first replacement module is configured to replace the first index value corresponding to the target cell with the fourth index value when the terminal successfully switches from the source serving cell to the target cell.

[0292] Optionally, the first determination module 601 is further configured to:

[0293] Compare the second index value corresponding to the candidate cell with the fourth index value, and determine the candidate cell with the same second index value and the fourth index value as the target candidate cell.

[0294] Optionally, the apparatus further includes:

[0295] The second replacement module is configured to replace the second index value corresponding to the target cell with the fourth index value when the terminal successfully switches from the source serving cell to the target cell.

[0296] Optionally, the first determination module 601 is further configured to:

[0297] Compare the first index value corresponding to the candidate cell with the fifth index value in the second list;

[0298] Based on the comparison result, determine the target candidate cell; the first index value corresponding to the target candidate cell is the same as the fifth index value.

[0299] Optionally, the first determination module 601 is further configured to:

[0300] Compare the second index value corresponding to the candidate cell with the fifth index value in the second list;

[0301] Based on the comparison result, determine the target candidate cell; the second index value corresponding to the target candidate cell is the same as the fifth index value.

[0302] Optionally, the apparatus further includes:

[0303] A third replacement module, configured to replace the third list in the candidate configuration information corresponding to the target cell with the second list when the terminal successfully switches from the source serving cell to the target cell; the third list includes sixth index values corresponding to at least one candidate cell.

[0304] Optionally, the first determination module 601 is further configured to:

[0305] Based on the first list, determine the target candidate cell; where:

[0306] The third index value corresponding to the target candidate cell and the third index value corresponding to the serving cell are in the same first list.

[0307] Optionally, any one of the first index value, the second index value, the fourth index value, and the fifth index value includes:

[0308] At least one of a cell identifier, an identifier of the candidate configuration information, RACH configuration information corresponding to the candidate cell, a master node MN identifier, a secondary node SN identifier, an MN group set identifier, an SN set identifier, a central unit CU identifier, a CU set identifier, a distributed unit DU identifier, a DU set identifier, and a set identifier.

[0309] Optionally, the third index value includes:

[0310] At least one of a cell identifier, an identifier of the candidate configuration information, RACH configuration information corresponding to the candidate cell, an MN identifier, an SN identifier, an MN set identifier, an SN set identifier, a CU identifier, a CU set identifier, a DU identifier, a DU set identifier, and a set identifier.

[0311] Optionally, the method further includes:

[0312] A receiving module, configured to receive the candidate configuration information sent by the network-side device.

[0313] Figure 7 It is the second schematic structural diagram of the timing advance acquisition apparatus provided by the embodiments of the present application. As Figure 7 shown, the timing advance acquisition apparatus 700 is applied to a network-side device and includes:

[0314] A sending module 701, configured to send candidate configuration information to a terminal; the candidate configuration information is used to assist the terminal in determining first information, and based on the first information, determine a target candidate cell from at least one candidate cell; the first information is used to characterize whether there is an association relationship between the candidate cell and the serving cell of the terminal; the target candidate cell is used for the terminal to perform early random access to obtain a timing advance (TA).

[0315] In the timing advance acquisition device provided in the embodiments of the present application, by sending candidate configuration information to a terminal, the terminal is enabled to determine first information based on the candidate configuration information, and further enabled the terminal to determine, based on the first information, whether there is an association relationship between at least one candidate cell and the serving cell of the terminal, and determine a cell having an association relationship with the serving cell from at least one candidate cell as the target candidate cell, so that the terminal can determine that it needs to perform an early RACH procedure on the target candidate cell to obtain TA in advance, thereby avoiding unnecessary early RACH procedures.

[0316] Optionally, the candidate configuration information includes configuration information of the candidate cell, and the configuration information of the candidate cell includes at least one of the following:

[0317] A first index value in the random access channel (RACH) configuration information corresponding to the candidate cell;

[0318] A second index value corresponding to the candidate cell.

[0319] Optionally, the candidate configuration information includes:

[0320] At least one first list, where the first list includes at least one third index value corresponding to at least one cell, and the at least one cell includes at least one of the candidate cell and the serving cell of the terminal.

[0321] Optionally, the candidate configuration information further includes configuration information of the serving cell, and the configuration information of the serving cell includes at least one of the following:

[0322] A fourth index value corresponding to the serving cell;

[0323] A second list corresponding to the serving cell, and the second list includes at least one fifth index value corresponding to at least one of the candidate cells.

[0324] Optionally, any one of the first index value, the second index, the fourth index value, and the fifth index value includes:

[0325] At least one of the cell identifier, the identifier of the candidate configuration information, the RACH configuration information corresponding to the candidate cell, the master node MN identifier, the secondary node SN identifier, the MN group set identifier, the SN set identifier, the central unit CU identifier, the CU set identifier, the distributed unit DU identifier, the DU set identifier, and the set identifier.

[0326] Optionally, the third index value includes:

[0327] At least one of the cell identifier, the identifier of the candidate configuration information, the RACH configuration information corresponding to the candidate cell, the MN identifier, the SN identifier, the MN set identifier, the SN set identifier, the CU identifier, the CU set identifier, the DU identifier, the DU set identifier, and the set identifier.

[0328] The timing advance acquisition device in the embodiments of the present application may be an electronic device, such as an electronic device with an operating system, or a component in an electronic device, such as an integrated circuit or a chip. The electronic device may be a terminal or other devices other than the terminal. Exemplarily, the terminal may include, but is not limited to, the types of the above-mentioned terminal 11, and other devices may be a server, a Network Attached Storage (NAS), etc., which are not specifically limited in the embodiments of the present application.

[0329] The timing advance acquisition device provided in the embodiments of the present application can implement Figures 4 to 5 each process implemented by the method embodiments and achieve the same technical effects. To avoid repetition, it will not be elaborated here.

[0330] As Figure 8 shown, the embodiments of the present application further provide a communication device 800, including a processor 801 and a memory 802. A program or instruction that can run on the processor 801 is stored on the memory 802. For example, when the communication device 800 is a terminal, when the program or instruction is executed by the processor 801, it implements each step of the timing advance acquisition method embodiment shown above Figure 4 and can achieve the same technical effects. When the communication device 800 is a network-side device, when the program or instruction is executed by the processor 801, it implements each step of the timing advance acquisition method embodiment shown above Figure 5 and can achieve the same technical effects. To avoid repetition, it will not be elaborated here.

[0331] The embodiments of the present application further provide a terminal, including a processor and a communication interface. The communication interface is coupled to the processor, and the processor is used to run a program or instruction to implement as Figure 4Steps in the method embodiments shown. This terminal embodiment corresponds to the above-mentioned terminal-side method embodiments. Each implementation process and realization manner of the above method embodiments can be applied to this terminal embodiment and can achieve the same technical effects. Specifically, Figure 9 It is a schematic diagram of the hardware structure of a terminal for implementing an embodiment of the present application.

[0332] The terminal 900 includes but is not limited to at least some components such as a radio frequency unit 901, a network module 902, an audio output unit 903, an input unit 904, a sensor 905, a display unit 906, a user input unit 907, an interface unit 908, a memory 909, and a processor 910.

[0333] Those skilled in the art can understand that the terminal 900 may further include a power source (such as a battery) for supplying power to each component. The power source can be logically connected to the processor 910 through a power management system, so as to implement functions such as management of charging, discharging, and power consumption management through the power management system. Figure 9 The terminal structure shown in does not constitute a limitation on the terminal. The terminal may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements, which will not be elaborated here.

[0334] It should be understood that in the embodiments of the present application, the input unit 904 may include a graphics processing unit (GPU) 9041 and a microphone 9042. The graphics processing unit 9041 processes the image data of static pictures or videos obtained by an image capture device (such as a camera) in a video capture mode or an image capture mode. The display unit 906 may include a display panel 9061, and the display panel 9061 may be configured in the form of a liquid crystal display, an organic light-emitting diode, etc. The user input unit 907 includes at least one of a touch panel 9071 and other input devices 9072. The touch panel 9071 is also called a touch screen. The touch panel 9071 may include two parts: a touch detection device and a touch controller. The other input devices 9072 may include but are not limited to a physical keyboard, function keys (such as volume control keys, switch keys, etc.), a trackball, a mouse, and a joystick, which will not be elaborated here.

[0335] In the embodiments of the present application, after receiving downlink data from a network-side device, the radio frequency unit 901 can transmit it to the processor 910 for processing; in addition, the radio frequency unit 901 can send uplink data to the network-side device. Generally, the radio frequency unit 901 includes but is not limited to an antenna, an amplifier, a transceiver, a coupler, a low-noise amplifier, a duplexer, etc.

[0336] The memory 909 can be used to store software programs or instructions as well as various data. The memory 909 may mainly include a first storage area for storing programs or instructions and a second storage area for storing data. Among them, the first storage area may store an operating system, application programs or instructions required for at least one function (such as a sound playback function, an image playback function, etc.). In addition, the memory 909 may include volatile memory or non-volatile memory. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), a static random access memory (SRAM), a dynamic random access memory (DRAM), a synchronous dynamic random access memory (SDRAM), a double data rate synchronous dynamic random access memory (DDR SDRAM), an enhanced synchronous dynamic random access memory (ESDRAM), a synchronous link dynamic random access memory (SLDRAM), and a direct rambus random access memory (DRRAM). The memory 909 in the embodiments of the present application includes, but is not limited to, these and any other suitable types of memory.

[0337] The processor 910 may include one or more processing units; optionally, the processor 910 integrates an application processor and a modem processor. Among them, the application processor mainly processes operations related to the operating system, user interface, and application programs, etc., and the modem processor mainly processes wireless communication signals, such as a baseband processor. It can be understood that the above-mentioned modem processor may not be integrated into the processor 910 either.

[0338] The embodiments of the present application also provide a network-side device, including a processor and a communication interface, the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the steps of the method embodiments as Figure 5 shown. This network-side device embodiment corresponds to the above-mentioned network-side device method embodiment. Each implementation process and implementation manner of the above method embodiment can be applied to this network-side device embodiment, and the same technical effects can be achieved.

[0339] Specifically, an embodiment of the present application further provides a network-side device. As Figure 10 shown, the network-side device 1000 includes: an antenna 101, a radio frequency device 102, a baseband device 103, a processor 104, and a memory 105. The antenna 101 is connected to the radio frequency device 102. In the uplink direction, the radio frequency device 102 receives information through the antenna 101 and sends the received information to the baseband device 103 for processing. In the downlink direction, the baseband device 103 processes the information to be sent and sends it to the radio frequency device 102. After processing the received information, the radio frequency device 102 sends it out through the antenna 101.

[0340] In the above embodiments, the method executed by the network-side device can be implemented in the baseband device 103, and the baseband device 103 includes a baseband processor.

[0341] The baseband device 103 may include, for example, at least one baseband board, and multiple chips are arranged on the baseband board. As Figure 10 shown, one of the chips is, for example, a baseband processor, which is connected to the memory 105 through a bus interface to call the program in the memory 105 and execute the operations of the network device shown in the above method embodiments.

[0342] The network-side device may further include a network interface 106, and the interface is, for example, a Common Public Radio Interface (CPRI).

[0343] Specifically, the network-side device 1000 of the embodiment of the present application further includes: instructions or programs stored on the memory 105 and executable on the processor 104. The processor 104 calls the instructions or programs in the memory 105 to execute Figure 5 the methods executed by the respective modules shown, and achieves the same technical effects. To avoid repetition, it will not be elaborated here.

[0344] An embodiment of the present application further provides a readable storage medium. Programs or instructions are stored on the readable storage medium, and when the programs or instructions are executed by a processor, the various processes of the embodiment of the method for obtaining the timing advance amount shown above Figure 4 or Figure 5 are implemented, and the same technical effects can be achieved. To avoid repetition, it will not be elaborated here.

[0345] Wherein, the processor is the processor in the terminal described in the above embodiments. The readable storage medium includes a computer-readable storage medium, such as a computer read-only memory ROM, a random access memory RAM, a magnetic disk, or an optical disc, etc. In some examples, the readable storage medium may be a non-transitory readable storage medium.

[0346] Another embodiment of the present application further provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor, and the processor is configured to run programs or instructions to implement the above Figure 4 or Figure 5 each process of the embodiment of the method for obtaining timing advance shown, and can achieve the same technical effects. To avoid repetition, details are not described herein again.

[0347] It should be understood that the chip mentioned in the embodiment of the present application may also be referred to as a system-on-chip, system chip, chip system, or system-on-chip, etc.

[0348] Another embodiment of the present application further provides a computer program / program product. The computer program / program product is stored in a storage medium and is executed by at least one processor to implement the above Figure 4 or Figure 5 each process of the embodiment of the method for obtaining timing advance shown, and can achieve the same technical effects. To avoid repetition, details are not described herein again.

[0349] The embodiment of the present application further provides a system for obtaining timing advance, including: a terminal and a network-side device. The terminal can be used to execute the above Figure 4 steps of the method for obtaining timing advance shown, and the network-side device can be used to execute the above Figure 5 steps of the method for obtaining timing advance shown.

[0350] It should be noted that in this article, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device. Without more limitations, the element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in a reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0351] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-described example methods can be implemented by means of computer software products plus a necessary general hardware platform, and of course, they can also be implemented by hardware. The computer software product is stored in a storage medium (such as ROM, RAM, magnetic disk, optical disk, etc.) and includes several instructions for causing a terminal or a network-side device to execute the methods described in various embodiments of the present application.

[0352] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms of embodiments without departing from the purpose of the present application and the scope protected by the claims. These embodiments are all within the protection scope of the present application.

Claims

1. A method for obtaining timing advance, characterized in that, it includes: The terminal determines a target candidate cell from at least one candidate cell based on first information; The first information is used to characterize whether there is an association relationship between the candidate cell and the serving cell of the terminal; The terminal performs early random access to the target candidate cell to obtain a timing advance TA.

2. The method for obtaining timing advance according to claim 1, characterized in that, the method further includes: The terminal determines the first information based on candidate configuration information.

3. The method for obtaining timing advance according to claim 2, characterized in that, the candidate configuration information includes the configuration information of the candidate cell, and the configuration information of the candidate cell includes at least one of the following: The first index value in the random access channel RACH configuration information corresponding to the candidate cell; The second index value corresponding to the candidate cell.

4. The method for obtaining timing advance according to claim 2, characterized in that, the candidate configuration information includes: At least one first list, and the first list includes a third index value corresponding to at least one cell, and the at least one cell includes at least one of the candidate cell and the serving cell of the terminal.

5. The method for obtaining timing advance according to claim 3, characterized in that, the candidate configuration information further includes the configuration information of the serving cell, and the configuration information of the serving cell includes at least one of the following: The fourth index value corresponding to the serving cell; The second list corresponding to the serving cell, and the second list includes a fifth index value corresponding to at least one of the candidate cells.

6. The method for obtaining timing advance according to claim 5, characterized in that, the terminal determines a target candidate cell from at least one candidate cell based on first information, including: The terminal compares the first index value corresponding to the candidate cell with the fourth index value, and determines the candidate cell with the same first index value and the fourth index value as the target candidate cell.

7. The method for obtaining timing advance according to claim 6, characterized in that, the method further includes: In the case where the terminal successfully switches from the source serving cell to the target cell, the terminal replaces the first index value corresponding to the target cell with the fourth index value.

8. The method for obtaining timing advance according to claim 5, characterized in that, the terminal determines a target candidate cell from at least one candidate cell based on first information, including: The terminal compares the second index value corresponding to the candidate cell with the fourth index value, and determines the candidate cell with the same second index value and the fourth index value as the target candidate cell.

9. The method for obtaining timing advance according to claim 8, characterized in that, the method further includes: In the case where the terminal successfully switches from the source serving cell to the target cell, the terminal replaces the second index value corresponding to the target cell with the fourth index value.

10. The method for obtaining timing advance according to claim 5, wherein, the terminal determines a target candidate cell from at least one candidate cell based on first information, including: the terminal compares the first index value corresponding to the candidate cell with the fifth index value in the second list; the terminal determines the target candidate cell based on the comparison result; the first index value corresponding to the target candidate cell is the same as the fifth index value.

11. The method for obtaining timing advance according to claim 5, wherein, the terminal determines a target candidate cell from at least one candidate cell based on first information, including: the terminal compares the second index value corresponding to the candidate cell with the fifth index value in the second list; the terminal determines the target candidate cell based on the comparison result; the second index value corresponding to the target candidate cell is the same as the fifth index value.

12. The method for obtaining timing advance according to claim 10 or 11, wherein, the method further includes: when the terminal successfully switches from a source serving cell to a target cell, the terminal replaces the third list in the candidate configuration information corresponding to the target cell with the second list; the third list includes sixth index values corresponding to at least one candidate cell.

13. The method for obtaining timing advance according to any one of claims 4, wherein, the terminal determines at least one target candidate cell from at least one candidate cell based on first information, including: the terminal determines the target candidate cell based on the first list; wherein: the third index value corresponding to the target candidate cell and the third index value corresponding to the serving cell are in the same first list.

14. The method for obtaining timing advance according to any one of claims 5 to 12, wherein, any one of the first index value, the second index value, the fourth index value and the fifth index value includes: at least one of a cell identifier, an identifier of the candidate configuration information, RACH configuration information corresponding to the candidate cell, a master node MN identifier, a secondary node SN identifier, an MN group set identifier, an SN set identifier, a central unit CU identifier, a CU set identifier, a distributed unit DU identifier, a DU set identifier and a set identifier.

15. The method for obtaining timing advance according to claim 4 or 13, wherein, the third index value includes: at least one of a cell identifier, an identifier of the candidate configuration information, RACH configuration information corresponding to the candidate cell, an MN identifier, an SN identifier, an MN set identifier, an SN set identifier, a CU identifier, a CU set identifier, a DU identifier, a DU set identifier and a set identifier.

16. The method for obtaining timing advance according to any one of claims 2 to 15, wherein, the method further includes: the terminal receives the candidate configuration information sent by the network side device.

17. A method for obtaining timing advance, characterized in that, it includes: The network side device sends candidate configuration information to the terminal; The candidate configuration information is used to assist the terminal in determining first information, and based on the first information, determine a target candidate cell from at least one candidate cell; The first information is used to characterize whether there is an association relationship between the candidate cell and the serving cell of the terminal; The target candidate cell is used for the terminal to perform early random access to obtain a timing advance TA.

18. The method for obtaining timing advance according to claim 17, characterized in that, The candidate configuration information includes the configuration information of the candidate cell, and the configuration information of the candidate cell includes at least one of the following: The first index value in the random access channel RACH configuration information corresponding to the candidate cell; The second index value corresponding to the candidate cell.

19. The method for obtaining timing advance according to claim 17, characterized in that, The candidate configuration information includes: At least one first list, and the first list includes third index values corresponding to at least one cell, and the at least one cell includes at least one of the candidate cell and the serving cell of the terminal.

20. The method for obtaining timing advance according to claim 18, characterized in that, The candidate configuration information further includes the configuration information of the serving cell, and the configuration information of the serving cell includes at least one of the following: The fourth index value corresponding to the serving cell; The second list corresponding to the serving cell, and the second list includes fifth index values corresponding to at least one of the candidate cells.

21. The method for obtaining timing advance according to claim 20, characterized in that, Any one of the first index value, the second index, the fourth index value, and the fifth index value includes: At least one of a cell identifier, an identifier of the candidate configuration information, RACH configuration information corresponding to the candidate cell, a master node MN identifier, a secondary node SN identifier, an MN group set identifier, an SN set identifier, a central unit CU identifier, a CU set identifier, a distributed unit DU identifier, a DU set identifier, and a set identifier.

22. The method for obtaining timing advance according to claim 19, characterized in that, The third index value includes: At least one of a cell identifier, an identifier of the candidate configuration information, RACH configuration information corresponding to the candidate cell, an MN identifier, an SN identifier, an MN set identifier, an SN set identifier, a CU identifier, a CU set identifier, a DU identifier, a DU set identifier, and a set identifier.

23. A device for obtaining timing advance, characterized in that, it includes: A first determination module, configured to determine a target candidate cell from at least one candidate cell based on first information; The first information is used to characterize whether there is an association relationship between the candidate cell and the serving cell of the terminal; An acquisition module, configured to perform early random access to the target candidate cell to obtain a timing advance TA.

24. A device for obtaining timing advance, It is characterized in that It includes: A sending module, configured to send candidate configuration information to a terminal; The candidate configuration information is used to assist the terminal in determining first information, and based on the first information, determine a target candidate cell from at least one candidate cell; The first information is used to characterize whether there is an association relationship between the candidate cell and the serving cell of the terminal; The target candidate cell is used for the terminal to perform early random access to obtain a timing advance (TA).

25. A terminal, It is characterized in that It includes a processor and a memory. The memory stores a program or instructions that can run on the processor. When the program or instructions are executed by the processor, the steps of the method for obtaining the timing advance as described in any one of claims 1 to 16 are implemented.

26. A network-side device, It is characterized in that It includes a processor and a memory. The memory stores a program or instructions that can run on the processor. When the program or instructions are executed by the processor, the steps of the method for obtaining the timing advance as described in any one of claims 17 to 22 are implemented.

27. A readable storage medium, It is characterized in that The readable storage medium stores a program or instructions. When the program or instructions are executed by a processor, the method for obtaining the timing advance as described in any one of claims 1 to 16 is implemented, or the steps of the method for obtaining the timing advance as described in any one of claims 17 to 22 are implemented.

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