Wireless communication method, terminal device and network device

Abstract

A wireless communication method, a terminal device and a network device, the method comprising: a terminal device receiving a first signaling sent by a first network device, the first signaling being used for instructing the terminal device to initiate a random access process to a target network device, the first signaling comprising first indication information, and the first indication information being used for indicating the terminal device to initiate a random access process to the target network device; the first indication information is used for indicating the target network equipment; the terminal device sends a physical random access channel (PRACH) to the target network device; and the terminal device receives a random access response RAR, the RAR comprising a target timing advance (TA) value, and the target TA value being a TA value of the terminal device to the target network device.

Description

Wireless communication method, terminal device and network device Technical Field

[0001] The embodiments of the present application relate to the field of communications, and specifically to a wireless communication method, terminal device, and network device. Background Art

[0002] In some scenarios, the terminal device may obtain an initial timing advance (TA) through a random access process, and further send an uplink channel or an uplink signal based on the initial TA.

[0003] In some scenarios, it is considered to support uplink transmission based on multiple Transmission Reception Points (TRPs). In this case, how the terminal device obtains a suitable TA for uplink transmission based on multiple TRPs is an urgent problem that needs to be solved.

[0004] Summary of the Invention

[0005] The present application provides a wireless communication method, terminal device and network device, which are conducive to the terminal device selecting a suitable TA.

[0006] In a first aspect, a method for wireless communication is provided, including: a terminal device receives first signaling sent by a first network device, the first signaling being used to instruct the terminal device to initiate a random access process to a target network device, wherein the first signaling includes first indication information, and the first indication information is used to indicate the target network device; the terminal device sends a physical random access channel PRACH to the target network device; the terminal device receives a random access response RAR, the RAR including a target timing advance TA value, and the target TA value is the TA value of the terminal device to the target network device.

[0007] In a second aspect, a method for wireless communication is provided, including: a first network device sends a first signaling to a terminal device, the first signaling being used to instruct the terminal device to initiate a random access process to a target network device, wherein the first signaling includes first indication information, and the first indication information is used to indicate the target network device.

[0008] In a third aspect, a terminal device is provided for executing the method in the above-mentioned first aspect or its various implementations.

[0009] Specifically, the terminal device includes a functional module for executing the method in the above-mentioned first aspect or its various implementation modes.

[0010] In a fourth aspect, a network device is provided for executing the method in the above second aspect or its various implementations.

[0011] Specifically, the network device includes a functional module for executing the method in the above-mentioned second aspect or its various implementation modes.

[0012] In a fifth aspect, a terminal device is provided, comprising a processor and a memory, wherein the memory is configured to store a computer program, and the processor is configured to call and execute the computer program stored in the memory to perform the method of the first aspect or its respective implementations.

[0013] In a sixth aspect, a network device is provided, comprising a processor and a memory, wherein the memory is configured to store a computer program, and the processor is configured to call and execute the computer program stored in the memory to perform the method of the second aspect or its respective implementations.

[0014] In a seventh aspect, a chip is provided for implementing the method in any one of the first to second aspects or their respective implementations.

[0015] Specifically, the chip includes: a processor for calling and running a computer program from a memory, so that a device equipped with the device executes the method in any one of the first to second aspects or their respective implementations.

[0016] In an eighth aspect, a computer-readable storage medium is provided for storing a computer program, which enables a computer to execute the method of any one of the first to second aspects or their respective implementations.

[0017] In a ninth aspect, a computer program product is provided, comprising computer program instructions, wherein the computer program instructions enable a computer to execute the method of any one of the first to second aspects or their respective implementations.

[0018] In a tenth aspect, a computer program is provided, which, when executed on a computer, enables the computer to execute the method of any one of the first to second aspects or their respective implementations.

[0019] Through the above technical solution, the first network device can trigger the terminal device to initiate random access to the target network device through the first signaling. Further, the terminal device can send PRACH to the target network device, receive the random access response RAR, and obtain the TA value of the terminal device to the target network device from the RAR. Therefore, in an embodiment of the present application, by designing the first signaling, the terminal device can initiate random access to a specific network device, and then obtain the TA of the terminal device to the specific network device, that is, the acquisition of the TA with the granularity of the specific network device is realized, which is conducive to the terminal device to obtain the appropriate TA. For example, in uplink transmission based on multiple TRPs, due to the different distances between multiple TRPs and terminal devices, the use of a unified TA will lead to a large uplink synchronization error. Therefore, the TRP synchronized with the uplink of the terminal device can trigger the terminal device to initiate random access to other TRPs to obtain the TA value of the terminal device to other TRPs. Here, when performing uplink transmission, the terminal device can use the TA value corresponding to each TRP to initiate uplink transmission to each TRP, which is conducive to ensuring uplink synchronization between the terminal device and each TRP. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG1 is a schematic diagram of a communication system architecture provided in an embodiment of the present application.

[0021] FIG2 is a schematic diagram of a format of a MAC CE for differential adjustment of a TA.

[0022] FIG3 is a schematic diagram of the format of a MAC CE indicating the absolute value of TA.

[0023] FIG4 is a schematic diagram of the format of MAC RAR signaling carrying TA.

[0024] FIG5 is a schematic diagram of timing advance for downlink reception and uplink transmission.

[0025] FIG6 is a scenario diagram of uplink transmission based on multiple TRPs and multiple DCI scheduling.

[0026] FIG7 is a schematic diagram of a four-step random access process.

[0027] FIG8 is a schematic interaction diagram of a wireless communication method provided according to an embodiment of the present application.

[0028] FIG9 is a schematic interaction diagram of a wireless communication method according to an embodiment of the present application.

[0029] FIG10 is a schematic interaction diagram of another wireless communication method according to an embodiment of the present application.

[0030] FIG11 is a schematic interaction diagram of yet another wireless communication method according to an embodiment of the present application.

[0031] FIG12 is a schematic interaction diagram of a wireless communication method according to another embodiment of the present application.

[0032] FIG13 is a schematic interaction diagram of another wireless communication method according to another embodiment of the present application.

[0033] FIG14 is a schematic interaction diagram of yet another wireless communication method according to another embodiment of the present application.

[0034] FIG15 is a schematic interaction diagram of a wireless communication method according to yet another embodiment of the present application.

[0035] FIG16 is a schematic interaction diagram of another wireless communication method according to yet another embodiment of the present application.

[0036] FIG17 is a schematic interaction diagram of yet another wireless communication method according to yet another embodiment of the present application.

[0037] Figure 18 is a schematic interaction diagram of another wireless communication method provided according to an embodiment of the present application.

[0038] FIG19 is a schematic interaction diagram of a method for wireless communication according to an embodiment of the present application.

[0039] FIG20 is a schematic interaction diagram of a method for wireless communication according to an embodiment of the present application.

[0040] Figure 21 is a schematic block diagram of a terminal device provided according to an embodiment of the present application.

[0041] Figure 22 is a schematic block diagram of a network device provided according to an embodiment of the present application.

[0042] Figure 23 is a schematic block diagram of another network device provided according to an embodiment of the present application.

[0043] Figure 24 is a schematic block diagram of another terminal device provided according to an embodiment of the present application.

[0044] Figure 25 is a schematic block diagram of another network device provided according to an embodiment of the present application.

[0045] Figure 26 is a schematic block diagram of a communication device provided according to an embodiment of the present application.

[0046] Figure 27 is a schematic block diagram of a chip provided according to an embodiment of the present application.

[0047] Figure 28 is a schematic block diagram of a communication system provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0048] The following will describe the technical solutions in the embodiments of this application in conjunction with the drawings in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of the embodiments. With respect to the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0049] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: Global System of Mobile communication (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, Advanced Long Term Evolution (LTE-A) system, New Radio (NR) system, NR system evolution system, LTE on unlicensed spectrum (LTE-U) system, NR on unlicensed spectrum (NR-U) system, Non-Terrestrial Networks (NTN) system, Universal Mobile Telecommunication System (UMTS), Wireless Local Area Networks (WLAN), Wireless Fidelity (Wireless Fidelity) system. Fidelity, WiFi), fifth-generation communication (5th-Generation, 5G) system or other communication systems, etc.

[0050] Generally speaking, traditional communication systems support a limited number of connections and are easy to implement. However, with the development of communication technology, mobile communication systems will not only support traditional communications, but will also support, for example, device-to-device (D2D) communication, machine-to-machine (M2M) communication, machine-type communication (MTC), vehicle-to-vehicle (V2V) communication, or vehicle-to-everything (V2X) communication, etc. The embodiments of the present application can also be applied to these communication systems.

[0051] Optionally, the communication system in the embodiment of the present application can be applied to a carrier aggregation (CA) scenario, a dual connectivity (DC) scenario, or a standalone (SA) networking scenario.

[0052] Optionally, the communication system in the embodiment of the present application can be applied to an unlicensed spectrum, where the unlicensed spectrum can also be considered as a shared spectrum; or, the communication system in the embodiment of the present application can also be applied to an authorized spectrum, where the authorized spectrum can also be considered as an unshared spectrum.

[0053] The embodiments of the present application describe various embodiments in conjunction with network devices and terminal devices, wherein the terminal device may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device, etc.

[0054] The terminal device can be a station (STA) in a WLAN, a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA) device, a handheld device with wireless communication capabilities, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a next-generation communication system such as an NR network, or a terminal device in a future evolved Public Land Mobile Network (PLMN) network, etc.

[0055] In an embodiment of the present application, the terminal device can be deployed on land, including indoors or outdoors, handheld, wearable or vehicle-mounted; it can also be deployed on the water surface (such as ships, etc.); it can also be deployed in the air (such as airplanes, balloons and satellites, etc.).

[0056] In an embodiment of the present application, the terminal device may be a mobile phone, a tablet computer, a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal device in industrial control, a wireless terminal device in self-driving, a wireless terminal device in remote medical, a wireless terminal device in a smart grid, a wireless terminal device in transportation safety, a wireless terminal device in a smart city, or a wireless terminal device in a smart home, etc.

[0057] As an example and not a limitation, in the embodiment of the present application, the terminal device may also be a wearable device. Wearable devices may also be called wearable smart devices, which are a general term for wearable devices that are intelligently designed and developed using wearable technology for daily wear, such as glasses, gloves, watches, clothing, and shoes. A wearable device is a portable device that is worn directly on the body or integrated into the user's clothes or accessories. Wearable devices are not only hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are fully functional, large in size, and can achieve complete or partial functions without relying on smartphones, such as smart watches or smart glasses, as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0058] In an embodiment of the present application, the network device may be a device for communicating with a mobile device. The network device may be an access point (AP) in WLAN, a base station (BTS) in GSM or CDMA, a base station (NodeB, NB) in WCDMA, an evolved base station (eNB or eNodeB) in LTE, or a relay station or access point, or a vehicle-mounted device, a wearable device, and a network device (gNB) in an NR network, or a network device in a future evolved PLMN network or a network device in an NTN network, etc.

[0059] As an example and not a limitation, in an embodiment of the present application, the network device may have a mobile feature, for example, the network device may be a mobile device. Alternatively, the network device may be a satellite or a balloon station. For example, the satellite may be a low earth orbit (LEO) satellite, a medium earth orbit (MEO) satellite, a geostationary earth orbit (GEO) satellite, a high elliptical orbit (HEO) satellite, etc. Optionally, the network device may also be a base station set up in a location such as land or water.

[0060] In an embodiment of the present application, the network device can provide services for a cell, and the terminal device communicates with the network device through the transmission resources used by the cell (for example, frequency domain resources, or spectrum resources). The cell can be a cell corresponding to the network device (for example, a base station). The cell can belong to a macro base station or a base station corresponding to a small cell. The small cells here may include: metro cells, micro cells, pico cells, femto cells, etc. These small cells have the characteristics of small coverage and low transmission power, and are suitable for providing high-speed data transmission services.

[0061] For example, a communication system 100 used in an embodiment of the present application is shown in FIG1 . The communication system 100 may include a network device 110, which may be a device that communicates with a terminal device 120 (or a communication terminal or terminal). The network device 110 may provide communication coverage for a specific geographic area and may communicate with terminal devices within the coverage area.

[0062] FIG1 exemplarily shows a network device and two terminal devices. Optionally, the communication system 100 may include multiple network devices and each network device may include other numbers of terminal devices within its coverage area, which is not limited in this embodiment of the present application.

[0063] Optionally, the communication system 100 may further include other network entities such as a network controller and a mobility management entity, which is not limited in the embodiment of the present application.

[0064] It should be understood that in the embodiments of the present application, a device having a communication function in a network / system may be referred to as a communication device. Taking the communication system 100 shown in FIG1 as an example, the communication device may include a network device 110 and a terminal device 120 having a communication function. The network device 110 and the terminal device 120 may be the specific devices described above and will not be described in detail here. The communication device may also include other devices in the communication system 100, such as a network controller, a mobility management entity, and other network entities, which are not limited in the embodiments of the present application.

[0065] It should be understood that the terms "system" and "network" are often used interchangeably herein. The term "and / or" is simply a description of an association between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " generally indicates that the related objects are in an "or" relationship.

[0066] It should be understood that the "indication" mentioned in the embodiments of this application can be a direct indication, an indirect indication, or an indication of an association. For example, "A indicates B" can mean that A directly indicates B, for example, B can be obtained through A; it can also mean that A indirectly indicates B, for example, A indicates C, and B can be obtained through C; it can also mean that there is an association between A and B.

[0067] In the description of the embodiments of the present application, the term "corresponding" may indicate a direct or indirect correspondence between the two, or an association relationship between the two, or a relationship between indication and being indicated, configuration and being configured, etc.

[0068] In the embodiments of the present application, "pre-defined" may be implemented by pre-storing corresponding codes, tables, or other methods that can be used to indicate relevant information in a device (e.g., a terminal device or a network device). The present application does not limit the specific implementation method. For example, pre-defined may refer to information defined in a protocol.

[0069] In the embodiments of the present application, the "protocol" may refer to a standard protocol in the communication field, for example, it may include an LTE protocol, an NR protocol, and related protocols used in future communication systems, and this application does not limit this.

[0070] To facilitate understanding of the technical solutions of the embodiments of the present application, the timing advance (TA) related to the present application is explained.

[0071] In some scenarios, in a cell group (CG), the UE can be configured with up to 4 timing advance groups (TAGs). TAG can be configured through Radio Resource Control (RRC). Optionally, a CG can include multiple serving cells, and each serving cell will be assigned a TAG identifier (Timing Advance Group Identity, TAG-Id). Each TAG will have a time alignment timer (TimeAlignmentTimer), and the UE will count the time alignment timer. When this timer times out, the UE will consider that the TAG is out of uplink synchronization. When the network device adjusts the TA value through the Media Access Control Control Element (MAC CE) or other signaling during the operation of the timer, the timer will be reset, and the UE will consider that the TAG is in uplink synchronization state. For example, if the value of TimeAlignmentTimer is configured to 500ms, that is, the network device needs to update (adjust) the UE's TA value once within 500ms. Otherwise, the UE may consider the uplink out of synchronization and may initiate a random access process when uplink data arrives.

[0072] In some scenarios, the UE's TA can be calculated using the following formula. The UE's TA is based on the first path of the downlink channel received by the UE, that is, the first symbol of the time slot where the channel is located, as the downlink reference, and advance transmission is performed on this basis:

[0073] (N TA +N TA,offset )*T C

[0074] In a CG, each serving cell can be pre-configured with a timing advance offset (TA offset), for example, through the high-level parameter (n-TimingAdvanceOffset), that is, N in the formula TA,offset . Among them, TA adjustment amount (N TA) is performed based on the pre-configured TA offset. C is the minimum time unit in the NR system, T C =1 / (4096*480kHz). N TA The MAC CE of the network device can provide differential adjustment, that is, the current TA adjustment (new) is based on the previous TA (old), adjusted forward or backward in time. The calculation formula is as follows:

[0075]

[0076] The MAC CE format for differential adjustment of TA is shown in Figure 2, where the adjustment of TA is based on the adjustment of T A The minimum time unit is TAG, and the granularity of TA adjustment is TAG.

[0077] In other scenarios, the network device may indicate to the UE the absolute value of the TA for uplink transmission. For example, the network device may directly indicate the absolute value of the TA N via the MAC CE command shown in FIG3. TA , its value range is 0 to 3846, and its length is 12 bits. According to the formula N TA =T A *16*64*2 μ The TA indication range can be determined. Furthermore, the MAC CE command applies to the Primary Timing Advance Group (PTAG) corresponding to the corresponding MAC entity, i.e., the PTAG is defined to include special cells (SpCells). Because the MAC CE applies only to PTAGs, it does not need to include a TAG-Id.

[0078] In some scenarios, during the UE's initial access (to a cell), after sending a Physical Random Access Channel (PRACH) to a network device, the UE expects the network device to provide the UE with a TA indication via a Media Access Control Random Access Response (MAC RAR) within a certain time window. Figure 4 shows a format for MAC RAR signaling carrying a TA. Based on the MAC RAR, the UE can obtain an initial TA absolute value of 12 bits.

[0079] If the UE operates in single TRP (sTRP) mode, the reference point of the UE timing advance is calculated from the downlink reception time point and advanced forward (NTA +N TA,offset )*T C The uplink channel or uplink signal is sent at a specific time, as shown in Figure 5.

[0080] In some scenarios, repetition of the Physical Uplink Control Channel (PUCCH) or Physical Uplink Shared Channel (PUSCH) based on multiple TRPs (multi-TRP, mTRP) is supported to enhance uplink coverage and transmission reliability. The UE needs to send PUCCH or PUSCH carrying the same content to different TRPs. For repeated transmission of multiple PUSCHs (multi-PUSCH) based on single downlink control information (DCI, sDCI), the UE can use one TA to sequentially send PUSCHs to different TRPs; for repeated transmission of multi-PUSCH based on multiple DCI (multi-DCI, mDCI), since there may not be a sufficiently ideal backhaul as a connection between multiple TRPs, multiple TRPs independently schedule the UE. This operation may cause temporal overlap of PUSCH / PUCCH for different TRPs, so different TA updates or indications need to be supported for different TRPs.

[0081] In some scenarios, mechanisms are being considered to support PUCCH / PUSCH transmissions from multiple antenna panels to multiple TRPs simultaneously. However, even with multiple uplink transmit antenna panels and multiple TRPs configured, a UE can only use one TA for early transmission within a serving cell. This limitation should clearly be overcome by supporting TRP-specific TA acquisition and indication.

[0082] For example, in the scenario of mDCI-mTRP within a cell, TRP#1 and TRP#2 use the same PCI, as shown in Figure 6. Each TRP can schedule PDSCH / PUSCH transmission on the TRP through its own DCI. It is worth noting that in the operation of mDCI-mTRP, the control resource set (CORESET) is grouped by the RRC parameter control resource set pool index (CORESETPoolIndex). For example, a CORESET with a CORESETPoolIndex of "0" is grouped into one group, corresponding to one TRP; a CORESET with a CORESETPoolIndex of "1" is grouped into another group, corresponding to another TRP. When the network device does not configure CORESETPoolIndex for a CORESET, its default value is "0".

[0083] In the inter-cell mDCI-mTRP scenario, TRP#1 in Figure 6 can be understood as the reference TRP, that is, the TRP to which the UE initially accesses. The UE has achieved uplink and downlink synchronization, and it has a dedicated physical cell identifier (PCI) #1. As for other TRPs, since the network device can select one TRP from up to 7 TRPs to provide additional uplink transmission services for the UE, these TRPs have different PCIs from the service TRP, and often have not established uplink and downlink synchronization with the UE in advance.

[0084] In some scenarios, the concept of Transmission Configuration Indicator (TCI) state is proposed for downlink spatial domain quasi-co-located (QCL) (beam) indication and the transmission of QCL information in the time and frequency domains. Specifically, the quasi-co-located (QCL) relationship can be simply described as the relationship of large-scale fading from a source reference signal to a target reference signal. For beam indication, after the UE obtains the QCL relationship between the two source reference signals and the target reference signal from the network device, it can use the receive beam that previously received the source reference signal when receiving the target reference signal.

[0085] In some scenarios, the TCI state indication mechanism only applies to downlink channels and signals. For uplink beam indication, the concept of spatial relation is defined to express the spatial relationship between two reference signals.

[0086] In some scenarios, to provide a unified uplink and downlink beam management mechanism for the communication system, the concept of a unified TCI state is proposed based on the design of the TCI state. The important functions it adds are as follows:

[0087] 1. Three unified TCI state modes are designed. The joint TCI state applies to both uplink and downlink channels and signals; the downlink (DL) TCI state applies only to downlink channels and signals; and the uplink (DL) TCI state applies only to uplink channels and signals.

[0088] 2. Downlink channels (part of the Physical Downlink Control Channel (PDCCH), the Physical Downlink Shared Channel (PDSCH)) and signals (the aperiodic Channel State Information Reference Signal (CSI-RS)) use the same downlink transmit beam, for example, using the DL TCI state or joint TCI state.

[0089] 3. Uplink channels (e.g., PUCCH, PUSCH) and signals (e.g., Sounding Reference Signal (SRS)) use the same uplink transmit beam and use the UL TCI state or joint TCI state.

[0090] 4. Unified TCI state can be dynamically updated and indicated using MAC CE and / or DCI.

[0091] 5. Applicable to the scenario of carrier aggregation, the beam indication on a single component carrier (CC) can be applicable to multiple different CCs.

[0092] 6. The uplink beam indication can be given simultaneously with the uplink power control parameters through the UL TCI state or joint TCI state.

[0093] 7. Support beam management function between cells.

[0094] In some scenarios, the terminal device can use a random access procedure to obtain a TA. The random access procedure can include network-triggered and UE-initiated random access procedures. For example, a network-triggered random access procedure is triggered by the network device sending a PDCCH order (PDCCH order), in which the network device provides sufficient information to enable the UE to transmit a PRACH. A UE-initiated random access procedure is triggered by the expiration of the TA timer on the UE side.

[0095] Figure 7 shows a schematic diagram of a four-step random access process. The four-step random access process includes the following steps:

[0096] Step 1: The terminal device sends a random access preamble (Preamble, also known as Msg 1) to the network device.

[0097] Specifically, the terminal device can select the Physical Random Access Channel (PRACH) resource. The network device sends random access-related parameters to the terminal device through the System Information Block (SIB), including the Reference Signal Receiving Power (RSRP) threshold (rsrp-ThresholdSSB) used to select the appropriate Synchronization Signal Block (SSB). The terminal device compares the RSRP measurement results under each SSB with the rsrp-ThresholdSSB and selects the SSB with a measurement value higher than the threshold value for access.

[0098] It should be noted that SSB can also be called synchronization signal / physical broadcast channel block (SS / PBCH block).

[0099] Among them, each SSB corresponds to a set of random access preamble code (Preamble) resources and random access opportunity (RACH Occasion, RO) resources, and the terminal device sends PRACH according to the Preamble and RO resources corresponding to the selected SSB.

[0100] Step 2: The network device sends a random access response (Random Access Response, RAR, also known as Msg 2) to the terminal device.

[0101] After the terminal device sends the Preamble to the network device, it can open a random access response window (ra-ResponseWindow) and detect the corresponding physical downlink control channel (PDCCH) within the ra-ResponseWindow according to the random access radio network temporary identifier (RA-RNTI). If the terminal device detects the PDCCH scrambled by the RA-RNTI, it can obtain the physical downlink shared channel (PDSCH) scheduled by the PDCCH. The PDSCH includes the RAR corresponding to the Preamble.

[0102] Step 3: The terminal device sends Msg 3.

[0103] After receiving the RAR message, the terminal device determines whether the RAR is its own RAR message. For example, the terminal device can use the preamble code index to check. After determining that it is its own RAR message, it can generate Msg 3 at the RRC layer and send Msg 3 to the network device, which needs to carry the identification information of the terminal device, etc.

[0104] In step 4, the network device sends a contention resolution message (Msg 4) to the terminal device.

[0105] The network device sends Msg 4 to the terminal device, and the terminal device correctly receives Msg 4 to complete contention resolution. For example, during the RRC connection establishment process, Msg 4 can carry the RRC connection establishment message.

[0106] During random access, after the terminal device sends a PRACH, it receives the RAR sent by the network device in the RAR receiving window. If the terminal device does not receive the RAR, it will send the PRACH again on the next available PRACH resource.

[0107] In summary, when the UE is uplink synchronized with TRP#0 and the UE is out of uplink synchronization with TRP#1, for the random access process triggered by TRP#0, the UE can obtain the TA value corresponding to TRP#0 in the uplink synchronization state, but cannot obtain the TA value corresponding to TRP#1 in the uplink out-of-sync state; for the random access process triggered by the TA timer, the SSB selected by the UE should be sent from the TRP in the uplink out-of-sync state, and should not be sent from the TRP in the uplink synchronization state, but the UE does not know which TRP the SSB comes from. Therefore, the UE cannot obtain a suitable TA, which in turn affects the uplink transmission based on multiple TRPs.

[0108] To facilitate understanding of the technical solutions of the embodiments of the present application, the technical solutions of the present application are described in detail below through specific embodiments. The above related technologies can be combined arbitrarily with the technical solutions of the embodiments of the present application as optional solutions, and all of them fall within the scope of protection of the embodiments of the present application. The embodiments of the present application include at least part of the following contents.

[0109] FIG8 is a schematic interaction diagram of a wireless communication method 200 according to an embodiment of the present application. As shown in FIG8 , the method 200 includes at least part of the following:

[0110] S210: The terminal device receives first signaling sent by a first network device, where the first signaling is used to instruct (or trigger) the terminal device to initiate a random access process to a target network device, wherein the first signaling includes first indication information, and the first indication information is used to indicate the target network device;

[0111] S220, the terminal device sends a physical random access channel PRACH to the target network device;

[0112] S230, the terminal device receives a target timing advance TA value, where the target TA value is the TA value of the terminal device to the target network device.

[0113] In some embodiments, the first network device may be a network device initially accessed by the terminal device, or a network device in an uplink synchronization state. The terminal device has obtained a TA value of the terminal device for the first network device, for example, the terminal device obtains the TA value of the terminal device for the first network device through an initial access process.

[0114] In some embodiments, the first network device is a network device associated with a specific search space, such as a network device associated with a common search space (CSS).

[0115] In some embodiments, the target network device may be a network device that is about to perform uplink synchronization, or a network device that is in an uplink out-of-sync state. That is, the terminal device has not yet obtained the TA value of the terminal device for the target network device, or the TA value of the terminal device for the target network device has expired or is out of date.

[0116] In some embodiments, each network device may be configured with a TAG, for example, a TAG ID. Therefore, the network device is associated with (or corresponds to) the configured TAG ID, and the terminal device's TA value for the network device (i.e., the target TA value) may be considered to be the TA value associated with (or corresponding to) the TAG ID.

[0117] In some embodiments, each network device may be associated with (or correspond to) a CORESETPoolIndex, and the TA value (ie, target TA value) of the terminal device to the network device may be considered to be the TA value corresponding to the CORESETPoolIndex.

[0118] In some embodiments, when a first network device schedules a terminal device to transmit uplink information to multiple network devices, the first network device may trigger the terminal device to initiate random access to a target network device to obtain the target TA value. The multiple network devices include the target network device. Optionally, the uplink information may include PUSCH and / or PUCCH.

[0119] Optionally, the multiple network devices may be multiple network devices within a cell (intra-cell), or multiple network devices between cells (inter-cell). For example, the multiple network devices may be multiple TRPs. Therefore, the embodiment of the present application may be applicable to uplink transmission of multiple TRPs within a cell, or may also be applicable to uplink transmission of multiple TRPs between cells.

[0120] Since the distances from different network devices to the terminal device are different, and there may be large uplink synchronization errors between multiple network devices, the terminal device sends uplink information to multiple network devices based on a unified TA, which will cause uplink desynchronization between the terminal device and the network device. Therefore, it is necessary for the terminal device to obtain the TA value of the network device granularity (such as TRP-specific).

[0121] In some embodiments, the first network device and the target network device are the same network device, or different network devices.

[0122] For example, the first network device may trigger the terminal device to initiate random access to the first network device to obtain the TA value of the terminal device to the first network device.

[0123] For another example, the first network device may trigger the terminal device to initiate random access to other network devices to obtain the TA value of the terminal device to the other network devices.

[0124] In some embodiments, the first network device may be a network device in a serving cell, or may be a network device in a non-serving cell.

[0125] In some embodiments, the target network device may be a network device in a serving cell, or may be a network device in a non-serving cell.

[0126] Optionally, when the first network device and the target network device are not the same network device, the first network device and the network device may both be network devices under the service cell, or one may be a network device under the service cell and the other may be a network device under the non-service cell. This application does not limit this.

[0127] In some embodiments, the first network device and the target network device may be TRPs.

[0128] For example, the first network device is TRP#0 and the target network device is TRP#1.

[0129] For another example, the first network device is TRP#0, and the target network device is TRP#0.

[0130] In some embodiments, the first signaling may be DCI signaling.

[0131] In some embodiments, the first signaling may be a PDCCH order.

[0132] For example, when DCI format 1_0 is scrambled by a cell radio network temporary identifier (Cell RNTI, C-RNTI) and the frequency domain resource assignment (Frequency domain resource assignment, FDRA) field is all 1s, the DCI is understood as a PDCCH order.

[0133] In some embodiments, the first signaling may include parameters used by the terminal device to send PRACH, such as a preamble index, an SSB index, a RO (PRACH mask index), etc.

[0134] In some embodiments, the first signaling may be transmitted through a specific control resource set (CORESET), such as CORESET#0, where the default CORESETPoolIndex of CORESET#0 is 0, and the first signaling may also be considered to be transmitted through a specific control resource set pool.

[0135] In some embodiments, the first signaling may be transmitted through a specific search space, for example, the first signaling is transmitted through a CSS.

[0136] In some embodiments, after receiving the first signaling sent by the first network device, the terminal device may determine to initiate random access to the target network device based on the first indication information in the first signaling, and further, may send a PRACH to the target network device. For example, the PRACH is sent using the parameters for sending the PRACH indicated in the first signaling.

[0137] Furthermore, the terminal device may receive a target TA value. For example, the terminal device may obtain the target TA value through RAR.

[0138] In some embodiments, the target TA value is sent by the second network device to the terminal device.

[0139] Optionally, the second network device may be a target network device, or a network device associated with a CSS, or a network device associated with a specific CORESET, such as a network device associated with CORESET#0, or a network device associated with CORESETPoolIndex#0.

[0140] In some embodiments, for the four-step random access process, the terminal device may also send Msg3 to the target network device.

[0141] Furthermore, the terminal device can also receive Msg4 sent by the second network device.

[0142] For example, the terminal device may receive Msg4 sent by the target network device, or may receive Msg4 sent by a network device associated with the CSS.

[0143] It should be understood that in the embodiment of the present application, the first indication information can directly or indirectly indicate the target network device, and the present application does not limit the specific indication method.

[0144] For example, if the first information can uniquely identify a network device, the first network device can indicate the target network device through the first information, that is, the first indication information can be used to indicate the first information. Further, the terminal device can determine which network device to initiate random access to based on the first information.

[0145] Optionally, the first indication information may be identification information of the target network device, and the terminal device may determine to which network device to initiate random access according to the identification information of the target network device.

[0146] In some embodiments, the first indication information may also indicate, through a bitmap, which network device the terminal device is triggered to initiate random access to.

[0147] As an example, the first indication information may include multiple bits, each bit corresponds to a network device, and the value of each bit is used to indicate whether to trigger the terminal device to initiate random access to the corresponding network device. For example, the value of the bit is 1, which indicates triggering, otherwise it indicates not triggering.

[0148] Optionally, the number of the multiple bits is determined based on the maximum number of multiple TRPs in the uplink transmission based on multiple TRPs.

[0149] For example, the multiple TRPs include 2 TRPs (i.e., TRP#0 and TRP#1), and the multiple bits can be 2 bits, corresponding to TRP#0 and TRP#1 respectively. When the bit corresponding to TRP takes the value of 1, it means that the terminal device is triggered to initiate random access to the TRP, otherwise, it means that the terminal device is not triggered to initiate random access to the TRP.

[0150] The specific implementation of the first indication information is described below in conjunction with specific embodiments.

[0151] Example 1

[0152] In this embodiment 1, the first indication information is used to indicate a first control resource set pool index (CORESETPoolIndex), and the first control resource pool index is associated with the target network device, or in other words, the target network device belongs to the control resource set pool identified by the first control resource set pool index.

[0153] Optionally, in this embodiment 1, the control resource set pool index is associated with the TAG ID.

[0154] Optionally, the control resource set pool index and the TAG ID may correspond one to one.

[0155] Optionally, the association relationship may be predefined or configured by the network device.

[0156] It should be understood that in the embodiment of the present application, in the above-mentioned association relationship, the TAG ID can also be replaced by other information that can uniquely associate or indicate the network device, and the present application does not limit this.

[0157] In some embodiments, the first CORESETPoolIndex is associated with the first TAG ID, and the first TAG ID is associated with the target network device. Therefore, when the first CORESETPoolIndex is associated with the first TAG ID, and the first TAG ID is associated with the target network device, the first network device can indicate the target network device through the first CORESETPoolIndex.

[0158] In some embodiments, the first network device is TRP#0, the target network device is TRP#1, TRP#0 is associated with CORESETPoolIndex#0, and TRP#1 is associated with CORESETPoolIndex#1. Then, TRP#0 associated with CORESETPoolIndex#0 can trigger the terminal device to initiate random access to TRP#1 associated with CORESETPoolIndex of 1.

[0159] In some embodiments, the first signaling includes a first information field, and the first information field can be used to indicate a CORESETPoolIndex associated with the target network device.

[0160] Optionally, the value of the first information field is used to indicate a CORESETPoolIndex associated with the network device.

[0161] Optionally, the length of the first information field may be determined according to the number of CORESETPoolIndex supported by the terminal device and / or the length of CORESETPoolIndex.

[0162] For example, the number of CORESETPoolIndex is 2, which are 0 and 1 respectively, and the first information field can be 1 bit.

[0163] For another example, if the number of CORESETPoolIndex is 4, which are 0 to 3 respectively, the first information field can be 2 bits.

[0164] For another example, if the number of CORESETPoolIndex is 8, which are 0 to 7 respectively, the first information field may be 3 bits.

[0165] Optionally, when the random access preamble index is not all zero, the first information field is used to indicate CORESETPoolIndex; otherwise, the first information field is a reserved field. The CORESETPoolIndex is used to determine the TAG ID to which the PRACH is sent, that is, to which network device associated with the TAG ID the PRACH is sent.

[0166] In the following, in combination with Embodiment 1-1, Embodiment 1-2 and Embodiment 1-3, the specific implementation process of Embodiment 1 is described by taking the first signaling being the PDCCH order as an example.

[0167] Example 1-1:

[0168] In this embodiment 1-1, the first network device is TRP#0, and the target network device is TRP#0.

[0169] As shown in FIG9 , the following steps may be included:

[0170] Step 1: TRP#0 sends a PDCCH order to the UE, where the PDCCH order carries the CORESETPoolIndex associated with TRP#0. The PDCCH order also carries parameters for sending PRACH, such as the preamble index, SSB index, and RO (PRACH mask index).

[0171] Step 2: The UE sends PRACH to TRP#0 according to the CORESETPoolIndex carried in the PDCCH order.

[0172] Specifically, PRACH is sent to TRP#0 according to the parameters for sending PRACH carried in the PDCCH order.

[0173] Step 3: TRP#0 sends a RAR to the UE, where the RAR includes the target TA value.

[0174] For example, TRP#0 can calculate the TA value of the UE for TRP#0, that is, the target TA value, based on the arrival time of the PRACH.

[0175] Optionally, the RAR also includes the CORESETPoolIndex or TAG ID associated with the target TA value, or the CORESETPoolIndex or TAG ID associated with TRP#0.

[0176] Optionally, the contention-based four-step random access process may further include the following steps:

[0177] Step 4: UE sends Msg 3 to TRP#0.

[0178] Step 5: TRP#0 sends Msg 4 to UE.

[0179] Example 1-2:

[0180] In this embodiment 1-2, the first network device is TRP#0 and the target network device is TRP#1.

[0181] As shown in FIG10 , the following steps may be included:

[0182] Step 1: TRP#0 sends a PDCCH order to the UE, where the PDCCH order carries the CORESETPoolIndex associated with TRP#1. The PDCCH order also carries parameters for sending PRACH, such as the preamble index, SSB index, and RO (PRACH mask index).

[0183] Step 2: The UE sends PRACH to TRP#1 according to the CORESETPoolIndex carried in the PDCCH order.

[0184] Specifically, PRACH is sent to TRP#1 according to the parameters for sending PRACH carried in the PDCCH order.

[0185] Step 3: TRP#1 sends RAR to UE, where the RAR includes the target TA value.

[0186] For example, TRP#1 can calculate the UE's TA value for TRP#1, that is, the target TA value, based on the arrival time of PRACH.

[0187] Optionally, the RAR also includes the CORESETPoolIndex or TAG ID associated with the target TA value, or the CORESETPoolIndex or TAG ID associated with TRP#1.

[0188] Optionally, the contention-based four-step random access process may further include the following steps:

[0189] Step 4: UE sends Msg 3 to TRP#1.

[0190] Step 5: TRP#1 sends Msg 4 to UE.

[0191] It should be noted that in the above-mentioned Examples 1-1 and 1-2, the RAR is replied by the target network device. That is, the network device to which the terminal device sends the PRACH responds to the UE, and the network device responds to the UE with the RAR, which also carries the target TA value. Unlike Examples 1-1 and 1-2, in Example 1-3, the RAR and / or Msg4 are sent by the network device associated with the CSS.

[0192] Example 1-3:

[0193] In this embodiment 1-3, the first network device is TRP#0, the target network device is TRP#1, and TRP#0 is the TRP associated with the CSS.

[0194] As shown in FIG11 , the following steps may be included:

[0195] Step 1: TRP#0 sends a PDCCH order to the UE, where the PDCCH order carries the CORESETPoolIndex associated with TRP#1. The PDCCH order also carries parameters for sending PRACH, such as the preamble index, SSB index, and RO (PRACH mask index).

[0196] Step 2: The UE sends PRACH to TRP#1 according to the CORESETPoolIndex carried in the PDCCH order.

[0197] Specifically, PRACH is sent to TRP#1 according to the parameters for sending PRACH carried in the PDCCH order.

[0198] Optionally, TRP#1 can calculate the UE's TA value for TRP#1, that is, the target TA value, based on the arrival time of PRACH.

[0199] Further, TRP#1 sends the target TA value to TRP#0, and TRP#0 sends RAR to the UE, where the RAR carries the target TA value.

[0200] Step 3: TRP#0 sends a RAR to the UE, where the RAR includes the target TA value.

[0201] Optionally, the RAR also includes the CORESETPoolIndex or TAG ID associated with the target TA value, or the CORESETPoolIndex or TAG ID associated with TRP#1.

[0202] Optionally, the contention-based four-step random access process may further include the following steps:

[0203] Step 4: UE sends Msg 3 to TRP#1.

[0204] Step 5: TRP#0 sends Msg 4 to UE.

[0205] Example 2

[0206] In this embodiment 2, the first indication information is used to indicate first spatial information, and the first spatial information is associated with the target network device.

[0207] Optionally, the first spatial information may be information related to the spatial domain, for example, information related to a reference signal, information related to a beam, etc.

[0208] For example, the first signaling may indicate to which network device the PRACH is to be sent by indicating an uplink beam to the terminal device.

[0209] In some embodiments, the first signaling may be used to indicate a spatial filter for sending the PRACH, that is, a transmit filter of the PRACH.

[0210] In some embodiments, the first signaling may also be used to indicate a spatial filter for receiving the RAR, that is, a receiving filter of the RAR.

[0211] In the embodiment of the present application, the transmit filter is also called a transmit beam, and the receive filter is also called a receive beam.

[0212] Optionally, in this embodiment 2, the spatial information is associated with the TAG ID.

[0213] Optionally, the association relationship may be predefined or configured by the network device.

[0214] Optionally, the association relationship between the spatial information and the TAG ID may be one-to-one.

[0215] It should be understood that in the embodiment of the present application, in the above-mentioned association relationship, the TAG ID can also be replaced by other information that can uniquely associate or indicate the network device, and the present application does not limit this.

[0216] In some embodiments, the first spatial information is associated with a first TAG ID, and the first TAG ID is associated with the target network device. Therefore, when the first spatial information and the first TAG ID are associated, and the first TAG ID is associated with the target network device, the first network device can indicate the target network device through the first spatial information.

[0217] In some embodiments, the first spatial information includes a first TCI state and / or first spatial relation information.

[0218] In some embodiments, the first TCI state is associated with a first TAG ID, and the first TAG ID is associated with the target network device. Optionally, the first TCI state is a UL TCI state or a Joint TCI state.

[0219] In some embodiments, the first spatial relationship information is associated with a first TAG ID, and the first TAG ID is associated with the target network device.

[0220] In some embodiments, the transmit beam of the PRACH may be indicated using the first TCI state or the first spatial relationship information.

[0221] For example, the first TCI state can be used to indicate a reference signal resource index, such as an SSB resource index, a CSI-RS resource index, or an SRS resource index. If the first TCI state indicates a downlink reference signal resource index, such as an SSB resource index or a CSI-RS resource index, the terminal device can use the transmit beam corresponding to the receive beam for receiving the reference signal resource indicated by the first TCI state as the transmit beam of the PRACH; or, if the first TCI state indicates an uplink reference signal resource index, such as an SRS resource index, the terminal device can use the transmit beam for receiving the reference signal resource indicated by the first TCI state as the transmit beam of the PRACH.

[0222] For another example, the first spatial relationship information can be used to indicate a reference signal resource index, such as an SSB resource index, a CSI-RS resource index, or an SRS resource index. If the first spatial relationship information indicates a downlink reference signal resource index, such as an SSB resource index or a CSI-RS resource index, the terminal device can use the transmit beam corresponding to the receive beam that receives the reference signal resource indicated by the first spatial relationship information as the transmit beam of the PRACH; or, if the first spatial relationship information indicates an uplink reference signal resource index, such as an SRS resource index, the terminal device can use the transmit beam that receives the reference signal resource indicated by the first spatial relationship information as the transmit beam of the PRACH.

[0223] In some embodiments, the first signaling may include an SSB resource index for measuring the downlink reference time.

[0224] In some embodiments, when the first spatial information is used to indicate a reference signal resource index (e.g., an SSB index), the first spatial information is used for both downlink reference time measurement and for indicating a PRACH transmit beam. Optionally, in this case, the first spatial information may reuse the SSB resource index field in the first signaling.

[0225] In some embodiments, the first signaling further includes:

[0226] The second indication information is used to instruct the terminal device to use a spatial filter to receive a random access response RAR.

[0227] For example, the second indication information is used to indicate a second TCI state, where the second TCI state is a DL TCI state or a Joint TCI state.

[0228] In some embodiments, the first signaling may include a second information field for indicating the first spatial information.

[0229] Optionally, the length of the second information field may be determined according to the number of first spatial information, such as the number of TCI states, the number of spatial relationships, etc.

[0230] As an example, the second information field may be 3 bits, or may be other bit lengths, which is not limited in this application.

[0231] In some embodiments, the first signaling may include a third information field for indicating the second TCI state.

[0232] Optionally, the length of the third information field can be determined according to the number of TCI states, etc.

[0233] As an example, the third information field may be 3 bits, or may be other bit lengths, which is not limited in this application.

[0234] In some embodiments, the first signaling may include the following fields:

[0235] SS / PBCH index, used to indicate the SS / PBCH (i.e., SSB), which is used to determine the RO for sending PRACH;

[0236] The second information field is used to indicate the first TCI state or the first Spatial relation;

[0237] The third information field (optional) is used to indicate the second TCI state.

[0238] Optionally, when the second information field is used to indicate the reference signal resource index, the second information field can be multiplexed with the information bits of the SS / PBCH index to carry it. That is, the second information field can be used to determine to which network device the PRACH is sent, and can also be used to determine the RO resource for sending the PRACH.

[0239] Optionally, when the random access preamble index is not all zero, the second information field is used to indicate the first TCI state or the first Spatial relation; otherwise, the second information field is a reserved field.

[0240] Optionally, when the random access preamble code index is not all zero, the third information field is used to indicate the second TCI state; otherwise, the third information field is a reserved field.

[0241] It should be understood that the indication method of the PRACH transmit beam and the RAR receive beam in Example 2 can also be applied to Example 1 and the subsequent Example 3.

[0242] For example, in Example 1, the first signaling may include a first information field for indicating the first CORESETPoolIndex. Furthermore, the first signaling may also include a second information field for indicating the first TCI state or the first Spatial relation, or may also include a third information field for indicating the second TCI state.

[0243] For another example, in Example 3, the first signaling may include a fourth information field for indicating the first PCI. Furthermore, the first signaling may also include a second information field for indicating the first TCI state or the first Spatial relation, or may also include a third information field for indicating the second TCI state.

[0244] In the following, in combination with Embodiment 2-1, Embodiment 2-2 and Embodiment 2-3, the specific implementation process of Embodiment 2 is described by taking the first signaling being the PDCCH order as an example.

[0245] Example 2-1:

[0246] In this embodiment 2-1, the first network device is TRP#0, and the target network device is TRP#0.

[0247] As shown in FIG12 , the following steps may be included:

[0248] Step 1: TRP#0 sends a PDCCH order to the UE. This PDCCH order carries spatial information associated with TRP#0, such as the TCI state or spatial relation. The PDCCH order also carries parameters for transmitting the PRACH, such as the preamble index, SSB index, and RO (PRACH mask index).

[0249] Step 2: The UE sends PRACH to TRP#0 according to the spatial information carried in the PDCCH order.

[0250] Optionally, the UE may send PRACH to TRP#0 according to the transmit beam indicated by the spatial information.

[0251] Step 3: TRP#0 sends a RAR to the UE, where the RAR includes the target TA value.

[0252] For example, TRP#0 can calculate the TA value of the UE for TRP#0, that is, the target TA value, based on the arrival time of the PRACH.

[0253] Optionally, the UE may receive the RAR according to the RAR receiving beam indicated in the PDCCH order.

[0254] Optionally, the RAR also includes the CORESETPoolIndex or TAG ID associated with the target TA value, or the CORESETPoolIndex or TAG ID associated with TRP#0.

[0255] Optionally, the contention-based four-step random access process may further include the following steps:

[0256] Step 4: UE sends Msg 3 to TRP#0.

[0257] Step 5: TRP#0 sends Msg 4 to UE.

[0258] Example 2-2:

[0259] In this embodiment 2-2, the first network device is TRP#0 and the target network device is TRP#1.

[0260] As shown in FIG13 , the following steps may be included:

[0261] Step 1: TRP#0 sends a PDCCH order to the UE. This PDCCH order carries spatial information associated with TRP#1, such as the TCI state or spatial relation. The PDCCH order also carries parameters for transmitting the PRACH, such as the preamble index, SSB index, and RO (PRACH mask index).

[0262] Step 2: The UE sends PRACH to TRP#1 according to the spatial information carried in the PDCCH order.

[0263] Optionally, the UE can send PRACH to TRP#1 according to the transmit beam indicated by the spatial information.

[0264] Step 3: TRP#1 sends RAR to UE, where the RAR includes the target TA value.

[0265] For example, TRP#1 can calculate the UE's TA value for TRP#1, that is, the target TA value, based on the arrival time of PRACH.

[0266] Optionally, the UE may receive the RAR according to the RAR receiving beam indicated in the PDCCH order.

[0267] Optionally, the RAR also includes the CORESETPoolIndex or TAG ID associated with the target TA value, or the CORESETPoolIndex or TAG ID associated with TRP#1.

[0268] Optionally, the contention-based four-step random access process may further include the following steps:

[0269] Step 4: UE sends Msg 3 to TRP#1.

[0270] Step 5: TRP#1 sends Msg 4 to UE.

[0271] It should be noted that in the above-mentioned Examples 2-1 and 2-2, the RAR is replied by the target network device, that is, the network device to which the terminal device sends the PRACH, and the network device replies to the UE with the RAR, and the target TA value is carried in the RAR. Unlike Examples 2-1 and 2-2, in Example 2-3, the RAR and / or Msg4 are sent by the network device associated with the CSS. Among them, TRP#0 is the TRP associated with the CSS.

[0272] Example 2-3:

[0273] In this embodiment 1-3, the first network device is TRP#0 and the target network device is TRP#1.

[0274] As shown in FIG14 , the following steps may be included:

[0275] Step 1: TRP#0 sends a PDCCH order to the UE, where the PDCCH order carries the spatial information associated with TRP#1. The PDCCH order also carries parameters for sending PRACH, such as the preamble index, SSB index, and RO (PRACH mask index).

[0276] Step 2: The UE sends PRACH to TRP#1 according to the spatial information carried in the PDCCH order.

[0277] Optionally, the UE can send PRACH to TRP#1 according to the transmit beam indicated by the spatial information.

[0278] Optionally, TRP#1 can calculate the UE's TA value for TRP#1, that is, the target TA value, based on the arrival time of PRACH.

[0279] Further, TRP#1 sends the target TA value to TRP#0, and TRP#0 sends RAR to the UE, where the RAR carries the target TA value.

[0280] Step 3: TRP#0 sends a RAR to the UE, where the RAR includes the target TA value.

[0281] Optionally, the UE may receive the RAR according to the RAR receiving beam indicated in the PDCCH order.

[0282] Optionally, the RAR also includes the CORESETPoolIndex or TAG ID associated with the target TA value, or the CORESETPoolIndex or TAG ID associated with TRP#1.

[0283] Optionally, the contention-based four-step random access process may further include the following steps:

[0284] Step 4: UE sends Msg 3 to TRP#1.

[0285] Step 5: TRP#0 sends Msg 4 to UE.

[0286] Example 3

[0287] In this embodiment 3, the first indication information is used to indicate a first PCI, where the first PCI is associated with the target network device.

[0288] In this embodiment 3, PCI and TAG ID are associated with each other.

[0289] Optionally, the association relationship may be predefined or configured by the network device.

[0290] Optionally, the PCI and the TAG ID may be in a one-to-one correspondence.

[0291] It should be understood that in the embodiment of the present application, in the above-mentioned association relationship, the TAG ID can also be replaced by other information that can uniquely associate or indicate the network device, and the present application does not limit this.

[0292] In some embodiments, the first PCI is associated with the target network device, which may include:

[0293] The first PCI is associated with the first TAG ID, and the first TAG ID is associated with the target network device; or

[0294] The first PCI is associated with a first CORESETPoolIndex, and the first CORESETPoolIndex is associated with the target network device.

[0295] Therefore, when the first PCI is associated with the first TAG ID or the first CORESETPoolIndex, and the first TAG ID or the first CORESETPoolIndex is associated with the target network device, the first network device may indicate the target network device through the first PCI.

[0296] In some embodiments, the first signaling may include a fourth information field, and the fourth information field may be used to indicate a PCI associated with the target network device.

[0297] Optionally, the value of the fourth information field is used to indicate the PCI associated with the network device.

[0298] Optionally, the length of the fourth information field may be determined according to the length of the PCI and / or the number of PCIs.

[0299] As an example, the fourth information field may be 10 bits, or may be other bit lengths.

[0300] In some embodiments, the target network device may be a network device in a non-serving cell. Before the terminal device communicates with the network device in the non-serving cell, it is necessary to first obtain the corresponding TA value. Since there are multiple network devices in the alternative non-serving cell, for example, up to seven, the terminal device wirelessly knows in advance which network device to synchronize with for uplink, and in this case, the PCI can be used to indicate this.

[0301] In some embodiments, when the target network device is a network device in a non-service cell, the terminal device needs to measure the reference signal in the non-service cell in advance, such as SSB, perform downlink synchronization, and find a suitable downlink receiving beam and a corresponding uplink transmitting beam.

[0302] In the following, in combination with Embodiment 3-1, Embodiment 3-2 and Embodiment 3-3, the specific implementation process of Embodiment 1 is described by taking the first signaling as the PDCCH order as an example.

[0303] Example 3-1:

[0304] In this embodiment 3-1, the PCI associated with the first network device is PCI#0, the PCI associated with the target network device is PCI#D, the first network device is a network device in a serving cell, and the target network device is a network device in a non-serving cell.

[0305] As shown in FIG15 , the following steps may be included:

[0306] Step 1: The first network device sends a PDCCH order to the UE, wherein the PDCCH order carries PCI#D and also carries parameters for sending PRACH.

[0307] Step 2: The UE sends a PRACH to the target network device according to the PCI#D carried in the PDCCH order.

[0308] Specifically, the PRACH is sent to the target network device according to the parameters for sending the PRACH carried in the PDCCH order.

[0309] Step 3: The target network device sends a RAR to the UE, where the RAR includes the target TA value.

[0310] For example, the target network device may calculate the TA value of the UE to the target network device, that is, the target TA value, according to the arrival time of the PRACH.

[0311] Optionally, the RAR further includes a CORESETPoolIndex or TAG ID associated with the target TA value, or in other words, a CORESETPoolIndex or TAG ID associated with the target network device.

[0312] Optionally, the contention-based four-step random access process may further include the following steps:

[0313] Step 4: The UE sends Msg 3 to the target network device.

[0314] Step 5: The target network device sends Msg 4 to the UE.

[0315] Example 3-2:

[0316] In this embodiment 3-2, the PCI associated with the first network device is PCI#D, and the PCI associated with the target network device is PCI#D. That is, the first network device and the target network device are the same network device, which is a network device in a non-serving cell.

[0317] As shown in FIG16 , the following steps may be included:

[0318] Step 1: The first network device sends a PDCCH order to the UE, where the PDCCH order carries PCI#D and also carries parameters for sending PRACH.

[0319] Step 2: The UE sends a PRACH to the first network device, ie, the target network device, according to the PCI#D carried in the PDCCH order.

[0320] Specifically, the PRACH is sent to the target network device according to the parameters for sending the PRACH carried in the PDCCH order.

[0321] Step 3: The target network device sends a RAR to the UE, where the RAR includes the target TA value.

[0322] For example, the target network device may calculate the TA value of the UE to the target network device, that is, the target TA value, according to the arrival time of the PRACH.

[0323] Optionally, the RAR further includes a CORESETPoolIndex or TAG ID associated with the target TA value, or in other words, a CORESETPoolIndex or TAG ID associated with the target network device.

[0324] Optionally, the contention-based four-step random access process may further include the following steps:

[0325] Step 4: The UE sends Msg 3 to the target network device.

[0326] Step 5: The target network device sends Msg 4 to the UE.

[0327] It should be noted that in the above-mentioned Examples 3-1 and 3-2, the RAR is replied by the target network device, that is, the network device to which the terminal device sends the PRACH, and which network device replies to the UE with the RAR, and the target TA value is carried in the RAR. Different from Examples 3-1 and 3-2, in Example 3-3, the RAR and / or Msg4 are sent by the network device associated with the CSS, wherein the network device associated with PCI#0 is the network device associated with the CSS.

[0328] Example 3-3:

[0329] In this embodiment 3-3, the PCI associated with the first network device is PCI#0, the PCI associated with the target network device is PCI#D, the first network device is a network device in a serving cell, and the target network device is a network device in a non-serving cell.

[0330] As shown in FIG17 , the following steps may be included:

[0331] Step 1: The first network device sends a PDCCH order to the UE, wherein the PDCCH order carries PCI#D and also carries parameters for sending PRACH.

[0332] Step 2: The UE sends a PRACH to the target network device according to the PCI#D carried in the PDCCH order.

[0333] Specifically, the PRACH is sent to the target network device according to the parameters for sending the PRACH carried in the PDCCH order.

[0334] For example, the target network device may calculate the TA value of the UE to the target network device, that is, the target TA value, according to the arrival time of the PRACH.

[0335] Furthermore, the target network device sends the target TA value to the first network device, and the first network device sends the RAR to the UE.

[0336] Step 3: The first network device sends a RAR to the UE, where the RAR includes a target TA value.

[0337] Optionally, the RAR further includes a CORESETPoolIndex or TAG ID associated with the target TA value, or in other words, a CORESETPoolIndex or TAG ID associated with the target network device.

[0338] Optionally, the contention-based four-step random access process may further include the following steps:

[0339] Step 4: The UE sends Msg 3 to the target network device.

[0340] Step 5: The first network device sends Msg 4 to the UE.

[0341] Therefore, in an embodiment of the present application, the first network device can trigger the terminal device to initiate random access to the target network device through the first signaling. Further, the terminal device can send PRACH to the target network device, receive the random access response RAR, and obtain the TA value of the terminal device to the target network device from the RAR. Therefore, in an embodiment of the present application, by designing the first signaling, the terminal device can initiate random access to a specific network device, and then obtain the TA of the terminal device to the specific network device, that is, the acquisition of TA with a specific network device granularity is realized, which is conducive to the terminal device obtaining a suitable TA.

[0342] For example, the target network device may be indicated by CORESETPoolIndex.

[0343] For another example, the target network device is indicated through spatial information such as TCI status or spatial relationship.

[0344] For another example, the target network device is indicated by PCI.

[0345] FIG18 is a schematic flow chart of another wireless communication method 300 according to an embodiment of the present application. As shown in FIG18 , the method 300 includes at least part of the following:

[0346] S310, when the first timing advance TA timer expires, the terminal device sends a physical random access channel PRACH to the target network device based on the target reference signal.

[0347] The first TA timer is associated with a first TAG ID, the target network device is associated with the first TAG ID, and the target reference signal is a reference signal associated with the target network device selected by the terminal device from multiple candidate reference signals.

[0348] In some embodiments, the first TAG ID may be a TAG ID corresponding to a TAG configured for the target network device.

[0349] In some embodiments, the first TA timer may be a timer configured for the TAG corresponding to the first TAG ID, or called a time alignment timer (TimeAlignmentTimer).

[0350] As mentioned above, in the related technology, when the terminal device selects a reference signal, it does not know which network device sends the reference signal. Therefore, the reference signal selected by the terminal device may be sent by a network device in an uplink synchronization state. In this case, the terminal device does not need to initiate random access to the network device.

[0351] In an embodiment of the present application, by associating a reference signal with a network device, when initiating random access, the terminal device can select the reference signal associated with the target network device to which it wants to initiate random access, further determine the PRACH resource corresponding to the reference signal, and then send the PRACH to the target network device based on the PRACH resource.

[0352] In some embodiments, the candidate reference signal may be SSB, CSI-RS or SRS, etc., which is not limited in this application.

[0353] It should be understood that the present application does not limit the specific manner of establishing the association relationship between the reference signal and the network device.

[0354] In some embodiments, multiple candidate reference signals may be divided into multiple reference signal groups, each reference signal group being associated with a network device, wherein each reference signal group includes one or more candidate reference signals.

[0355] Optionally, each reference signal group is associated with a network device, including:

[0356] Each reference signal group is associated with a TAG ID or CORESETPoolIndex, and the TAG ID or CORESETPoolIndex is associated with a network device.

[0357] In some embodiments, the plurality of reference signal groups are predefined, that is, the terminal device and the network device can obtain the grouping information without exchanging information.

[0358] In some embodiments, the plurality of reference signal groups are configured by a network device.

[0359] For example, as shown in FIG18 , the method 300 further includes:

[0360] S301, a terminal device receives first configuration information sent by a first network device, where the first configuration information is used to configure multiple reference signal groups, where each reference signal group is associated with a network device, for example, each reference signal group is associated with a TAG ID or CORESETPoolIndex.

[0361] In some embodiments, the first network device may be a network device in an uplink synchronization state, that is, the terminal device and the first network device have performed uplink and downlink synchronization.

[0362] In some embodiments, the first network device is a network device associated with a specific search space, such as a network device associated with a common search space (CSS).

[0363] In some embodiments, the first configuration information may be carried through RRC signaling, or may be carried through other downlink signaling, which is not limited in this application.

[0364] In some implementations, for each reference signal, the network device can configure a TAG ID or CORESETPoolIndex for it. In this way, by configuring corresponding TAG IDs or CORESETPoolIndex for different reference signals, multiple reference signal groups can be formed, where the TAG IDs or CORESETPoolIndex corresponding to the reference signals in each reference signal group are the same.

[0365] In some other implementations, the network device may configure a corresponding set of reference signals for each TAG ID or CORESETPoolIndex. For example, for TAG ID#0 or CORESETPoolIndex#0, {SSB#0, SSB#1, ..., SSB#31} may be configured, and for TAG ID#1 or CORESETPoolIndex#1, {SSB#32, SSB#1, ..., SSB#63} may be configured.

[0366] In some further implementations, multiple reference signal groups are divided according to preset rules. For example, multiple candidate reference signals are grouped according to their indices. That is, the indices of the reference signals in a reference signal group satisfy a certain relationship.

[0367] As an example, SSBs with even indexes are grouped together, corresponding to TAG ID#0 or CORESETPoolIndex#0; SSBs with odd indexes are grouped together, corresponding to TAG ID#1 or CORESETPoolIndex#1.

[0368] As another example, the SSBs of the first half of the SSB index are grouped together, corresponding to TAG ID#0 or CORESETPoolIndex#0; and the SSBs of the second half of the SSB index are grouped together, corresponding to TAG ID#1 or CORESETPoolIndex#1.

[0369] Therefore, after the first TA timer times out, the terminal device needs to select the reference signal in the corresponding reference signal group according to the TAG or CORESETPoolIndex corresponding to the first TA timer, for example, select the reference signal in the reference signal group that meets the RSRP threshold value, so as to avoid selecting the reference signal in the reference signal group corresponding to the network device in the uplink synchronization state.

[0370] In some embodiments, the sending a physical random access channel (PRACH) to the target network device based on the target reference signal includes:

[0371] Selecting a PRACH resource associated with the target reference signal from preconfigured PRACH resources, such as an RO resource, a Preamble;

[0372] The PRACH is sent to the target network device using the PRACH resource associated with the target reference signal.

[0373] In some embodiments, the method 300 further includes:

[0374] The terminal device receives a RAR, where the RAR includes a target TA value.

[0375] Optionally, the RAR further includes a CORESETPoolIndex or TAG ID associated with the target TA value, or in other words, a CORESETPoolIndex or TAG ID associated with the target network device.

[0376] In some embodiments, the RAR is sent by the second network device to the terminal device.

[0377] Optionally, the second network device may be the target network device, or a network device associated with a CSS, or a network device associated with a specific CORESET, such as a network device associated with CORESET#0, or a network device associated with CORESETPoolIndex#0.

[0378] In some embodiments, the first network device, the second network device, and the target network device may be TRPs.

[0379] The specific implementation process of the method 300 is described below with reference to FIG. 19 and FIG. 20 .

[0380] In the examples of Figures 19 and 20, multiple reference signal groups may include SSB group #0 and SSB group #1, where SSB group #0 is associated with TRP#0, SSB group #1 is associated with TRP#1, TRP#0 is associated with the first TAG ID, and the first TAG ID is associated with the first TA timer.

[0381] As shown in FIG19 , the following steps may be included:

[0382] Step 1: When the first TA timer times out and uplink data arrives, the UE selects the target SSB in SSB group #0 associated with TRP#0, and further uses the PRACH resources associated with the target SSB to send PRACH to TRP#0.

[0383] Step 2: TRP#0 sends a RAR to the UE, which includes the target TA value.

[0384] Optionally, TRP#0 may calculate the UE's TA value for TRP#1, ie, the target TA value, based on the arrival time of the PRACH.

[0385] Optionally, the RAR also includes the CORESETPoolIndex or TAG ID associated with the target TA value, or the CORESETPoolIndex or TAG ID associated with TRP#0.

[0386] Optionally, the contention-based four-step random access process may further include the following steps:

[0387] Step 3: UE sends Msg 3 to TRP#0.

[0388] Step 4: TRP#0 sends Msg 4 to UE.

[0389] It should be noted that in the example of Figure 19, the RAR is replied by the target network device. That is, the network device to which the terminal device sends the PRACH responds to the UE with the RAR, which also carries the target TA value. In the example of Figure 20, the RAR and / or Msg4 are sent by the network device associated with the CSS. TRP#1 is the TRP associated with the CSS.

[0390] As shown in FIG20 , the following steps may be included:

[0391] Step 1: When the first TA timer times out and uplink data arrives, the UE selects a target SSB in SSB group #0 associated with TRP#0, and further uses the PRACH resources associated with the target SSB to send PRACH to TRP#0.

[0392] Step 2: TRP#0 sends a RAR to the UE, which includes the target TA value.

[0393] Optionally, TRP#0 may calculate the UE's TA value for TRP#1, ie, the target TA value, based on the arrival time of the PRACH.

[0394] Optionally, the RAR also includes the CORESETPoolIndex or TAG ID associated with the target TA value, or the CORESETPoolIndex or TAG ID associated with TRP#0.

[0395] Further, TRP#0 sends the target TA value to TRP#1, and TRP#1 sends RAR to the UE, where the RAR carries the target TA value.

[0396] Optionally, the contention-based four-step random access process may further include the following steps:

[0397] Step 3: UE sends Msg 3 to TRP#0.

[0398] Step 4: TRP#1 sends Msg 4 to UE.

[0399] In summary, in an embodiment of the present application, multiple reference signals can be grouped, and each reference signal group is associated with a network device. In this way, when the TA timer corresponding to the TAG ID associated with the network device times out, the terminal device can select the target reference signal in the reference signal group associated with the network device, and further use the PRACH resource associated with the target reference signal to send PRACH to the target network device, thereby obtaining the TA value corresponding to the target network device.

[0400] The above text, in combination with Figures 8 to 20, describes in detail the method embodiment of the present application. The following text, in combination with Figures 21 to 28, describes in detail the device embodiment of the present application. It should be understood that the device embodiment and the method embodiment correspond to each other, and similar descriptions can refer to the method embodiment.

[0401] FIG21 shows a schematic block diagram of a terminal device 400 according to an embodiment of the present application. As shown in FIG21 , the terminal device 400 includes:

[0402] The communication unit 410 is used to receive a first signaling sent by a first network device, where the first signaling is used to instruct the terminal device to initiate random access to a target network device, wherein the first signaling includes first indication information, and the first indication information is used to indicate the target network device.

[0403] In some embodiments, the communication unit 410 is further configured to:

[0404] Sending a physical random access channel PRACH to the target network device;

[0405] A random access response RAR is received, where the RAR includes a target timing advance TA value, where the target TA value is a TA value of the terminal device to the target network device.

[0406] In some embodiments, the first indication information is used to indicate a first control resource pool index, wherein the first control resource pool index is associated with the target network device.

[0407] In some embodiments, the first control resource set pool index is associated with a first timing advance group identifier TAG ID, and the first TAG ID is associated with the target network device.

[0408] In some embodiments, the first indication information is used to indicate first spatial information, wherein the first spatial information is associated with the target network device.

[0409] In some embodiments, the first spatial information is associated with a first TAG ID, and the first TAG ID is associated with the target network device.

[0410] In some embodiments, the first spatial information is associated with a first control resource set pool index, and the first control resource set pool index is associated with the target network device.

[0411] In some embodiments, the first spatial information includes a first transmission configuration indication TCI state and / or first spatial relationship information.

[0412] In some embodiments, the first TCI state is associated with a first TAG ID, and the first TAG ID is associated with the target network device; and / or

[0413] The first spatial relationship information is associated with a first TAG ID, and the first TAG ID is associated with the target network device.

[0414] In some embodiments, the first spatial information is further used to instruct the terminal device to send a spatial filter for a physical random access channel PRACH.

[0415] In some embodiments, when the first spatial information indicates a synchronization signal block SSB resource index, the first spatial information is also used to indicate a spatial filter for the terminal device to send a PRACH.

[0416] In some embodiments, the first TCI state is an uplink TCI state or a joint TCI state.

[0417] In some embodiments, the first indication information is used to indicate a first physical cell identifier (PCI), wherein the first PCI is associated with the target network device.

[0418] In some embodiments, the first PCI is associated with a first TAG ID, and the first TAG ID is associated with the target network device; or

[0419] The first PCI is associated with a first control resource pool index, and the first control resource pool index is associated with the target network device.

[0420] In some embodiments, the first signaling further includes:

[0421] The second indication information is used to instruct the terminal device to use a spatial filter to receive a random access response RAR.

[0422] In some embodiments, the second indication information is used to indicate a second TCI state, wherein the second TCI state is a downlink TCI state or a joint TCI state.

[0423] In some embodiments, the RAR further includes a first TAG ID or a first control resource set pool index, where the first TAG ID or the first control resource set pool index is associated with the target network device.

[0424] In some embodiments, the target TA value is associated with the first TAG ID.

[0425] In some embodiments, the target TA value is received from a second network device, where the second network device is the target network device, or a network device associated with a common search space (CSS).

[0426] In some embodiments, the target network device and the first network device are the same network device, or the target network device and the first network device are not the same network device.

[0427] In some embodiments, when the target network device and the first network device are not the same network device,

[0428] The first network device and the target network device are both network devices in a serving cell; or, the first network device is a network device in a serving cell, and the target network device is a network device in a non-serving cell; or, the first network device is a network device in a non-serving cell, and the target network device is a network device in a non-serving cell.

[0429] In some embodiments, the first signaling is a physical downlink control channel (PDCCH) command.

[0430] In some embodiments, the first network device is a network device associated with a CSS.

[0431] Alternatively, in some embodiments, the communication unit may be a communication interface or a transceiver, or an input / output interface of a communication chip or a system on chip. The processing unit may be one or more processors.

[0432] It should be understood that the terminal device 400 according to the embodiment of the present application may correspond to the terminal device in the embodiment of the method of the present application, and the above-mentioned and other operations and / or functions of each unit in the terminal device 400 are respectively for realizing the corresponding processes of the terminal device in the method 200 shown in Figures 8 to 17. For the sake of brevity, they will not be repeated here.

[0433] FIG22 shows a schematic block diagram of a network device 500 according to an embodiment of the present application. As shown in FIG22 , the network device 500 includes:

[0434] The communication unit 510 is used to send a first signaling to the terminal device, where the first signaling is used to instruct the terminal device to initiate random access to the target network device, wherein the first signaling includes first indication information, and the first indication information is used to indicate the target network device.

[0435] In some embodiments, the first indication information is used to indicate a first control resource pool index, wherein the first control resource pool index is associated with the target network device.

[0436] In some embodiments, the first control resource set pool index is associated with a first timing advance group identifier TAG ID, and the first TAG ID is associated with the target network device.

[0437] In some embodiments, the first indication information is used to indicate first spatial information, wherein the first spatial information is associated with the target network device.

[0438] In some embodiments, the first spatial information is associated with a first TAG ID, and the first TAG ID is associated with the target network device.

[0439] In some embodiments, the first spatial information is associated with a first control resource set pool index, and the first control resource set pool index is associated with the target network device.

[0440] In some embodiments, the first spatial information includes a first transmission configuration indication TCI state and / or first spatial relationship information.

[0441] In some embodiments, the first TCI state is associated with a first TAG ID, and the first TAG ID is associated with the target network device; and / or

[0442] The first spatial relationship information is associated with a first TAG ID, and the first TAG ID is associated with the target network device.

[0443] In some embodiments, the first spatial information is further used to instruct the terminal device to send a spatial filter for a physical random access channel PRACH.

[0444] In some embodiments, when the first spatial information indicates a synchronization signal block SSB resource index, the first spatial information is also used to indicate a spatial filter for the terminal device to send a PRACH.

[0445] In some embodiments, the first TCI state is an uplink TCI state or a joint TCI state.

[0446] In some embodiments, the first indication information is used to indicate a first physical cell identifier (PCI), wherein the first PCI is associated with the target network device.

[0447] In some embodiments, the first PCI is associated with a first TAG ID, and the first TAG ID is associated with the target network device; or

[0448] The first PCI is associated with a first control resource pool index, and the first control resource pool index is associated with the target network device.

[0449] In some embodiments, the first signaling further includes:

[0450] The second indication information is used to instruct the terminal device to use a spatial filter to receive a random access response RAR.

[0451] In some embodiments, the second indication information is used to indicate a second TCI state, wherein the second TCI state is a downlink TCI state or a joint TCI state.

[0452] In some embodiments, the communication unit 510 is further configured to: send a RAR to the terminal device, where the RAR includes a target TA value.

[0453] In some embodiments, the RAR further includes a first TAG ID or a first control resource set pool index, where the first TAG ID or the first control resource set pool index is associated with the target network device.

[0454] In some embodiments, the target TA value is associated with the first TAG ID.

[0455] In some embodiments, the network device is a network device associated with a CSS.

[0456] In some embodiments, the target network device is the network device.

[0457] In some embodiments, the target network device and the network device are not the same network device.

[0458] In some embodiments, when the target network device and the network device are not the same network device,

[0459] The network device and the target network device are both network devices in a serving cell; or, the network device is a network device in a serving cell, and the target network device is a network device in a non-serving cell; or, the network device is a network device in a non-serving cell, and the target network device is a network device in a non-serving cell.

[0460] In some embodiments, the first signaling is a physical downlink control channel (PDCCH) command.

[0461] Optionally, in some embodiments, the communication unit may be a communication interface or a transceiver, or an input / output interface of a communication chip or a system on chip.

[0462] It should be understood that the network device 500 according to the embodiment of the present application may correspond to the first network device in the method embodiment of the present application, and the above-mentioned and other operations and / or functions of each unit in the network device 500 are respectively for implementing the corresponding processes of the first network device in the method 200 shown in Figures 8 to 17. For the sake of brevity, they will not be repeated here.

[0463] Figure 23 shows a schematic block diagram of a network device 800 according to an embodiment of the present application. As shown in Figure 23, the network device 800 includes:

[0464] The communication unit 810 is used to send a random access response RAR to the terminal device, where the RAR includes a target timing advance TA value, wherein the RAR is a response to a physical random access channel PRACH, the receiving end of the PRACH is the target network device, and the terminal device sending the PRACH to the target network device is triggered by the first network device.

[0465] In some embodiments, the RAR further includes a first TAG ID or a first control resource set pool index, where the first TAG ID or the first control resource set pool index is associated with the target network device.

[0466] In some embodiments, the target TA value is associated with the first TAG ID.

[0467] In some embodiments, the network device is the target network device or a network device associated with a common search space (CSS).

[0468] In some embodiments, the first network device is a network device associated with a CSS.

[0469] In some embodiments, the target network device and the first network device are the same network device, or the target network device and the first network device are not the same network device.

[0470] In some embodiments, when the target network device and the first network device are not the same network device,

[0471] The first network device and the target network device are both network devices in a serving cell; or

[0472] The first network device is a network device in a serving cell, and the target network device is a network device in a non-serving cell; or

[0473] The first network device is a network device in a non-serving cell, and the target network device is a network device in a non-serving cell.

[0474] Alternatively, in some embodiments, the communication unit may be a communication interface or a transceiver, or an input / output interface of a communication chip or a system on chip. The processing unit may be one or more processors.

[0475] It should be understood that the network device 800 according to the embodiment of the present application may correspond to the network device in the embodiment of the method of the present application, and the above-mentioned and other operations and / or functions of each unit in the network device 800 are respectively for implementing the corresponding processes of the network device in the method 200 shown in Figures 8 to 17. For the sake of brevity, they will not be repeated here.

[0476] FIG24 shows a schematic block diagram of a terminal device 1000 according to an embodiment of the present application. As shown in FIG24 , the terminal device 1000 includes:

[0477] The communication unit 1010 is configured to, when a first timing advance TA timer expires, send, by the terminal device, a physical random access channel PRACH to a target network device based on a target reference signal;

[0478] The first TA timer is associated with a first timing advance group identifier TAG ID, the target network device is associated with the first TAG ID, and the target reference signal is a reference signal associated with the target network device selected by the terminal device from multiple candidate reference signals.

[0479] In some embodiments, the multiple candidate reference signals are divided into multiple reference signal groups, each reference signal group is associated with a network device, and each reference signal group includes one or more candidate reference signals.

[0480] In some embodiments, each reference signal group is associated with a network device, including:

[0481] Each reference signal group is associated with a TAG ID, and the TAG ID is associated with a network device.

[0482] In some embodiments, the plurality of reference signal groups are predefined or configured by a network device.

[0483] In some embodiments, the network device 1000 further includes:

[0484] a processing unit, configured to select a PRACH resource associated with the target reference signal from preconfigured PRACH resources;

[0485] The communication unit 1010 is further configured to: send a PRACH to the target network device using the PRACH resource associated with the target reference signal.

[0486] In some embodiments, the communication unit 1010 is further configured to: receive a random access response sent by the second network device, where the random access response includes a target TA value.

[0487] In some embodiments, the second network device is the target network device, or a network device associated with a common search space (CSS).

[0488] In some embodiments, the RAR further includes a first TAG ID or a first control resource set pool index, where the first TAG ID or the first control resource set pool index is associated with the target network device.

[0489] In some embodiments, the target reference signal comprises a target synchronization channel block SSB.

[0490] Alternatively, in some embodiments, the communication unit may be a communication interface or a transceiver, or an input / output interface of a communication chip or a system on chip. The processing unit may be one or more processors.

[0491] It should be understood that the terminal device 1000 according to the embodiment of the present application may correspond to the terminal device in the embodiment of the method of the present application, and the above-mentioned and other operations and / or functions of each unit in the terminal device 1000 are respectively for realizing the corresponding processes of the terminal device in the method 300 shown in Figures 18 to 20. For the sake of brevity, they will not be repeated here.

[0492] Figure 25 shows a schematic block diagram of a network device 1100 according to an embodiment of the present application. As shown in Figure 25, the network device 1100 includes:

[0493] Communication unit 1110 is used to send first configuration information to the terminal device, where the first configuration information is used to configure an association relationship between multiple reference signal groups and multiple network devices, wherein each reference signal group includes one or more candidate reference signals, and the association relationship is used by the terminal device to determine the PRACH resources used to send a physical random access channel PRACH to a target network device.

[0494] In some embodiments, in the association relationship, each reference signal group is associated with one network device.

[0495] In some embodiments, each reference signal group is associated with a network device, including:

[0496] Each reference signal group is associated with a TAG ID, and the TAG ID is associated with a network device.

[0497] In some embodiments, the communication unit 1110 is further configured to: send a random access response to the terminal device, where the random access response includes a target TA value.

[0498] In some embodiments, the RAR further includes a first TAG ID or a first control resource set pool index, where the first TAG ID or the first control resource set pool index is associated with a target network device, and the target network device is a network device that initiates random access for the terminal device.

[0499] In some embodiments, the reference signal comprises a synchronization channel block SSB.

[0500] Alternatively, in some embodiments, the communication unit may be a communication interface or a transceiver, or an input / output interface of a communication chip or a system on chip. The processing unit may be one or more processors.

[0501] It should be understood that the network device 1100 according to the embodiment of the present application may correspond to the first network device in the method embodiment of the present application, and the above-mentioned and other operations and / or functions of each unit in the network device 1100 are respectively for implementing the corresponding processes of the first network device in the method 300 shown in Figures 18 to 20. For the sake of brevity, they will not be repeated here.

[0502] Figure 26 is a schematic structural diagram of a communication device 600 provided in an embodiment of the present application. The communication device 600 shown in Figure 26 includes a processor 610, which can call and run a computer program from a memory to implement the method in the embodiment of the present application.

[0503] Optionally, as shown in FIG26 , the communication device 600 may further include a memory 620. The processor 610 may call and execute a computer program from the memory 620 to implement the method in the embodiment of the present application.

[0504] The memory 620 may be a separate device independent of the processor 610 , or may be integrated into the processor 610 .

[0505] Optionally, as shown in FIG26 , the communication device 600 may further include a transceiver 630 , and the processor 610 may control the transceiver 630 to communicate with other devices, specifically, to send information or data to other devices, or to receive information or data sent by other devices.

[0506] The transceiver 630 may include a transmitter and a receiver. The transceiver 630 may further include an antenna, and the number of antennas may be one or more.

[0507] Optionally, the communication device 600 may specifically be the first network device or the second network device of the embodiment of the present application, and the communication device 600 may implement the corresponding processes implemented by the first network device or the second network device in each method of the embodiment of the present application. For the sake of brevity, they will not be repeated here.

[0508] Optionally, the communication device 600 may specifically be a mobile terminal / terminal device in an embodiment of the present application, and the communication device 600 may implement the corresponding processes implemented by the mobile terminal / terminal device in each method in the embodiment of the present application. For the sake of brevity, they will not be repeated here.

[0509] Figure 27 is a schematic structural diagram of a chip according to an embodiment of the present application. The chip 700 shown in Figure 27 includes a processor 710, which can call and run a computer program from a memory to implement the method according to the embodiment of the present application.

[0510] Optionally, as shown in FIG27 , the chip 700 may further include a memory 720. The processor 710 may call and execute a computer program from the memory 720 to implement the method in the embodiment of the present application.

[0511] The memory 720 may be a separate device independent of the processor 710 , or may be integrated into the processor 710 .

[0512] Optionally, the chip 700 may further include an input interface 730. The processor 710 may control the input interface 730 to communicate with other devices or chips, and specifically, may obtain information or data sent by other devices or chips.

[0513] Optionally, the chip 700 may further include an output interface 740. The processor 710 may control the output interface 740 to communicate with other devices or chips, and specifically, may output information or data to other devices or chips.

[0514] Optionally, the chip can be applied to the first network device or the second network device in the embodiments of the present application, and the chip can implement the corresponding processes implemented by the first network device or the second network device in the various methods of the embodiments of the present application. For the sake of brevity, they will not be repeated here.

[0515] Optionally, the chip can be applied to the mobile terminal / terminal device in the embodiments of the present application, and the chip can implement the corresponding processes implemented by the mobile terminal / terminal device in the various methods of the embodiments of the present application. For the sake of brevity, they will not be repeated here.

[0516] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0517] FIG28 is a schematic block diagram of a communication system 900 provided in an embodiment of the present application. As shown in FIG28 , the communication system 900 includes a terminal device 910 and a network device 920 .

[0518] Among them, the terminal device 910 can be used to implement the corresponding functions implemented by the terminal device in the above method, and the network device 920 can be used to implement the corresponding functions implemented by the first network device and / or the second network device in the above method. For the sake of brevity, they will not be repeated here.

[0519] It should be understood that the processor of the embodiments of the present application may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiment can be completed by hardware integrated logic circuits in the processor or software instructions. The above processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The various methods, steps, and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the embodiments of the present application can be directly embodied as being executed by a hardware decoding processor, or can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium mature in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0520] It is understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. 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), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct RAM bus random access memory (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0521] It should be understood that the above-mentioned memories are exemplary but not restrictive. For example, the memories in the embodiments of the present application may also be static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct RAM RAM (DR RAM), etc. In other words, the memories in the embodiments of the present application are intended to include, but are not limited to, these and any other suitable types of memories.

[0522] An embodiment of the present application also provides a computer-readable storage medium for storing a computer program.

[0523] Optionally, the computer-readable storage medium can be applied to the first network device in the embodiment of the present application, and the computer program enables the computer to execute the corresponding processes implemented by the first network device in the various methods of the embodiment of the present application. For the sake of brevity, they are not repeated here.

[0524] Optionally, the computer-readable storage medium can be applied to the second network device in the embodiment of the present application, and the computer program enables the computer to execute the corresponding processes implemented by the second network device in the various methods of the embodiment of the present application. For the sake of brevity, they are not repeated here.

[0525] Optionally, the computer-readable storage medium can be applied to the mobile terminal / terminal device in the embodiments of the present application, and the computer program enables the computer to execute the corresponding processes implemented by the mobile terminal / terminal device in the various methods of the embodiments of the present application. For the sake of brevity, they will not be repeated here.

[0526] An embodiment of the present application also provides a computer program product, including computer program instructions.

[0527] Optionally, the computer program product can be applied to the first network device in the embodiment of the present application, and the computer program instructions enable the computer to execute the corresponding processes implemented by the first network device in the various methods of the embodiment of the present application. For the sake of brevity, they are not repeated here.

[0528] Optionally, the computer program product can be applied to the second network device in the embodiment of the present application, and the computer program instructions enable the computer to execute the corresponding processes implemented by the second network device in the various methods of the embodiment of the present application. For the sake of brevity, they are not repeated here.

[0529] Optionally, the computer program product can be applied to the mobile terminal / terminal device in the embodiments of the present application, and the computer program instructions enable the computer to execute the corresponding processes implemented by the mobile terminal / terminal device in the various methods of the embodiments of the present application. For the sake of brevity, they will not be repeated here.

[0530] The embodiment of the present application also provides a computer program.

[0531] Optionally, the computer program can be applied to the first network device in the embodiment of the present application. When the computer program runs on a computer, the computer executes the corresponding processes implemented by the first network device in the various methods of the embodiment of the present application. For the sake of brevity, they are not repeated here.

[0532] Optionally, the computer program can be applied to the second network device in the embodiment of the present application. When the computer program runs on the computer, the computer executes the corresponding processes implemented by the second network device in the various methods of the embodiment of the present application. For the sake of brevity, they are not repeated here.

[0533] Optionally, the computer program can be applied to the mobile terminal / terminal device in the embodiments of the present application. When the computer program runs on the computer, the computer executes the corresponding processes implemented by the mobile terminal / terminal device in the various methods of the embodiments of the present application. For the sake of brevity, they will not be repeated here.

[0534] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0535] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0536] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0537] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0538] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0539] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0540] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A wireless communication method, characterized in that: include: The terminal device receives a first signaling sent by a first network device, where the first signaling is used to instruct the terminal device to initiate random access to a target network device, wherein the first signaling includes first indication information, and the first indication information is used to indicate the target network device; The terminal device sends a physical random access channel PRACH to the target network device; The terminal device receives a random access response RAR, where the RAR includes a target timing advance TA value, and the target TA value is a TA value of the terminal device to the target network device.

2. The method according to claim 1, characterized in that The first indication information is used to indicate a first control resource pool index, wherein the first control resource pool index is associated with the target network device.

3. The method according to claim 2, characterized in that The first control resource set pool index is associated with a first timing advance group identifier TAG ID, and the first TAG ID is associated with the target network device.

4. The method according to any one of claims 1 to 3, characterized in that The first indication information is used to indicate first spatial information, where the first spatial information is associated with the target network device.

5. The method according to claim 4, characterized in that The first spatial information is associated with a first TAG ID, and the first TAG ID is associated with the target network device.

6. The method according to claim 4, characterized in that The first space information is associated with a first control resource set pool index, and the first control resource set pool index is associated with the target network device.

7. The method according to any one of claims 4 to 6, characterized in that The first spatial information includes a first transmission configuration indication TCI state and / or first spatial relationship information.

8. The method according to claim 7, characterized in that The first TCI state is associated with a first TAG ID, and the first TAG ID is associated with the target network device; and / or The first spatial relationship information is associated with a first TAG ID, and the first TAG ID is associated with the target network device.

9. The method according to claim 7 or 8, characterized in that The first spatial information is also used to instruct the terminal device to send a spatial filter for a physical random access channel PRACH.

10. The method according to claim 9, characterized in that When the first spatial information indicates a synchronization signal block SSB resource index, the first spatial information is also used to indicate a spatial filter for the terminal device to send a PRACH.

11. The method according to any one of claims 7 to 10, characterized in that The first TCI state is an uplink TCI state or a combined TCI state.

12. The method according to any one of claims 1 to 11, characterized in that The first indication information is used to indicate a first physical cell identifier (PCI), where the first PCI is associated with the target network device.

13. The method according to claim 12, characterized in that The first PCI is associated with a first TAG ID, and the first TAG ID is associated with the target network device; or The first PCI is associated with a first control resource pool index, and the first control resource pool index is associated with the target network device.

14. The method according to any one of claims 1 to 13, characterized in that The first signaling further includes: The second indication information is used to instruct the terminal device to use a spatial filter to receive a random access response RAR.

15. The method according to claim 14, characterized in that The second indication information is used to indicate a second TCI state, where the second TCI state is a downlink TCI state or a combined TCI state.

16. The method according to any one of claims 1 to 15, characterized in that The RAR further includes a first TAG ID or a first control resource pool index, where the first TAG ID or the first control resource pool index is associated with the target network device.

17. The method according to claim 16, characterized in that The target TA value is associated with the first TAG ID.

18. The method according to any one of claims 1 to 17, characterized in that The target TA value is received from a second network device, where the second network device is the target network device, or a network device associated with a common search space CSS.

19. The method according to any one of claims 1 to 18, characterized in that The target network device and the first network device are the same network device, or the target network device and the first network device are not the same network device.

20. The method according to claim 19, characterized in that In the case that the target network device and the first network device are not the same network device, The first network device and the target network device are both network devices in a serving cell; or The first network device is a network device in a serving cell, and the target network device is a network device in a non-serving cell; or The first network device is a network device in a non-serving cell, and the target network device is a network device in a non-serving cell.

21. The method according to any one of claims 1 to 20, characterized in that The first signaling is a physical downlink control channel PDCCH command.

22. The method according to any one of claims 1 to 21, characterized in that The first network device is a network device associated with a CSS.

23. A wireless communication method, characterized in that: include: The first network device sends a first signaling to the terminal device, where the first signaling is used to instruct the terminal device to initiate random access to the target network device, wherein the first signaling includes first indication information, and the first indication information is used to indicate the target network device.

24. The method according to claim 23, wherein The first indication information is used to indicate a first control resource pool index, wherein the first control resource pool index is associated with the target network device.

25. The method according to claim 24, characterized in that The first control resource set pool index is associated with a first timing advance group identifier TAG ID, and the first TAG ID is associated with the target network device.

26. The method according to any one of claims 23 to 25, characterized in that The first indication information is used to indicate first spatial information, where the first spatial information is associated with the target network device.

27. The method according to claim 26, characterized in that The first spatial information is associated with a first TAG ID, and the first TAG ID is associated with the target network device.

28. The method according to claim 26, characterized in that The first space information is associated with a first control resource set pool index, and the first control resource set pool index is associated with the target network device.

29. The method according to any one of claims 26 to 28, characterized in that The first spatial information includes a first transmission configuration indication TCI state and / or first spatial relationship information.

30. The method according to claim 29, wherein The first TCI state is associated with a first TAG ID, and the first TAG ID is associated with the target network device; and / or The first spatial relationship information is associated with a first TAG ID, and the first TAG ID is associated with the target network device.

31. The method according to claim 29 or 30, characterized in that The first spatial information is also used to instruct the terminal device to send a spatial filter for a physical random access channel PRACH.

32. The method according to claim 31, characterized in that When the first spatial information indicates a synchronization signal block SSB resource index, the first spatial information is also used to indicate a spatial filter for the terminal device to send a PRACH.

33. The method according to any one of claims 29 to 32, characterized in that The first TCI state is an uplink TCI state or a combined TCI state.

34. The method according to any one of claims 23 to 33, wherein: The first indication information is used to indicate a first physical cell identifier (PCI), where the first PCI is associated with the target network device.

35. The method according to claim 34, wherein The first PCI is associated with a first TAG ID, and the first TAG ID is associated with the target network device; or The first PCI is associated with a first control resource pool index, and the first control resource pool index is associated with the target network device.

36. The method according to any one of claims 23 to 35, wherein: The first signaling further includes: The second indication information is used to instruct the terminal device to use a spatial filter to receive a random access response RAR.

37. The method according to claim 36, wherein The second indication information is used to indicate a second TCI state, where the second TCI state is a downlink TCI state or a combined TCI state.

38. The method according to any one of claims 23 to 37, wherein: The method further comprises: The first network device sends a RAR to the terminal device, where the RAR includes a target TA value.

39. The method according to claim 38, characterized in that The RAR further includes a first TAG ID or a first control resource pool index, where the first TAG ID or the first control resource pool index is associated with the target network device.

40. The method according to claim 38 or 39, characterized in that The target TA value is associated with the first TAG ID.

41. The method according to any one of claims 23 to 40, wherein: The first network device is a network device associated with a CSS.

42. The method according to any one of claims 23 to 41, wherein: The target network device is the first network device.

43. The method according to any one of claims 23 to 41, wherein The target network device and the first network device are not the same network device.

44. The method according to claim 43, wherein In the case that the target network device and the first network device are not the same network device, The first network device and the target network device are both network devices in a serving cell; or The first network device is a network device in a serving cell, and the target network device is a network device in a non-serving cell; or The first network device is a network device in a non-serving cell, and the target network device is a network device in a non-serving cell.

45. The method according to any one of claims 23 to 44, wherein The first signaling is a physical downlink control channel PDCCH command.

46. ​​A method of wireless communication, characterized in that: include: The second network device sends a random access response RAR to the terminal device, where the RAR includes a target timing advance TA value, wherein the RAR is a response to a physical random access channel PRACH, the receiving end of the PRACH is the target network device, and the sending of the PRACH by the terminal device to the target network device is triggered by the first network device.

47. The method according to claim 46, wherein The RAR further includes a first TAG ID or a first control resource pool index, where the first TAG ID or the first control resource pool index is associated with the target network device.

48. The method according to claim 47, wherein The target TA value is associated with the first TAG ID.

49. The method according to any one of claims 46 to 48, wherein The second network device is the target network device or a network device associated with a common search space (CSS).

50. The method according to any one of claims 46 to 49, wherein The first network device is a network device associated with a CSS.

51. The method according to any one of claims 46 to 50, wherein: The target network device and the first network device are the same network device, or the target network device and the first network device are not the same network device.

52. The method according to claim 51, characterized in that In the case that the target network device and the first network device are not the same network device, The first network device and the target network device are both network devices in a serving cell; or The first network device is a network device in a serving cell, and the target network device is a network device in a non-serving cell; or The first network device is a network device in a non-serving cell, and the target network device is a network device in a non-serving cell.

53. A wireless communication method, characterized in that: include: When the first timing advance TA timer expires, the terminal device sends a physical random access channel PRACH to the target network device based on the target reference signal; The first TA timer is associated with a first timing advance group identifier TAG ID, the target network device is associated with the first TAG ID, and the target reference signal is a reference signal associated with the target network device selected by the terminal device from multiple candidate reference signals.

54. The method according to claim 53, wherein The multiple candidate reference signals are divided into multiple reference signal groups, each reference signal group is associated with a network device, and each reference signal group includes one or more candidate reference signals.

55. The method according to claim 54, characterized in that Each reference signal group is associated with a network device, including: Each reference signal group is associated with a TAG ID, and the TAG ID is associated with a network device.

56. The method according to claim 54 or 55, characterized in that The multiple reference signal groups are predefined or configured by the network device.

57. The method according to any one of claims 53 to 56, wherein: The sending a physical random access channel (PRACH) to a target network device based on a target reference signal includes: A PRACH resource associated with the target reference signal is selected from preconfigured PRACH resources, and the PRACH resource associated with the target reference signal is used to send the PRACH to the target network device.

58. The method according to any one of claims 53 to 57, wherein: The method further comprises: The terminal device receives a random access response sent by the second network device, where the random access response includes a target TA value.

59. The method according to claim 58, characterized in that The second network device is the target network device, or a network device associated with a common search space CSS.

60. The method according to claim 58 or 59, characterized in that The RAR further includes a first TAG ID or a first control resource pool index, where the first TAG ID or the first control resource pool index is associated with the target network device.

61. The method according to any one of claims 53 to 60, wherein: The target reference signal includes a target synchronization channel block SSB.

62. A method of wireless communication, characterized in that: include: A first network device sends first configuration information to a terminal device, where the first configuration information is used to configure an association relationship between multiple reference signal groups and multiple network devices, wherein each reference signal group includes one or more candidate reference signals, and the association relationship is used by the terminal device to determine a PRACH resource used to send a physical random access channel PRACH to a target network device.

63. The method according to claim 62, characterized in that In the association relationship, each reference signal group is associated with one network device.

64. The method according to claim 63, wherein Each reference signal group is associated with a network device, including: Each reference signal group is associated with a TAG ID, and the TAG ID is associated with a network device.

65. The method according to any one of claims 62 to 64, wherein: The method further comprises: The first network device sends a random access response to the terminal device, where the random access response includes a target TA value.

66. The method according to claim 65, characterized in that The RAR also includes a first TAG ID or a first control resource set pool index, where the first TAG ID or the first control resource set pool index is associated with a target network device, and the target network device is a network device that initiates random access by the terminal device.

67. The method according to any one of claims 62 to 66, wherein: The reference signal includes a synchronization channel block SSB.

68. A terminal device, characterized in that: include: A communication unit, configured to receive a first signaling sent by a first network device, where the first signaling is used to instruct the terminal device to initiate random access to a target network device, wherein the first signaling includes first indication information, and the first indication information is used to indicate the target network device; Sending a physical random access channel PRACH to the target network device; and A random access response RAR is received, where the RAR includes a target timing advance TA value, where the target TA value is a TA value of the terminal device to the target network device.

69. A network device, characterized in that include: A communication unit is used to send a first signaling to a terminal device, where the first signaling is used to instruct the terminal device to initiate random access to a target network device, wherein the first signaling includes first indication information, and the first indication information is used to indicate the target network device.

70. A network device, characterized in that include: A communication unit is used to send a random access response RAR to a terminal device, where the RAR includes a target timing advance TA value, wherein the RAR is a response to a physical random access channel PRACH, the receiving end of the PRACH is a target network device, and the sending of the PRACH by the terminal device to the target network device is triggered by the first network device.

71. A terminal device, characterized in that: include: A communication unit, configured to send a physical random access channel PRACH to a target network device based on a target reference signal when a first timing advance TA timer expires; The first TA timer is associated with a first timing advance group identifier TAG ID, the target network device is associated with the first TAG ID, and the target reference signal is a reference signal associated with the target network device selected by the terminal device from multiple candidate reference signals.

72. A network device, characterized in that include: A communication unit, configured to send first configuration information to a terminal device, wherein the first configuration information is used to configure an association relationship between multiple reference signal groups and multiple network devices, wherein each reference signal group includes one or more candidate reference signals, and the association relationship is used by the terminal device to determine the PRACH resources used to send a physical random access channel PRACH to a target network device.

73. A terminal device, characterized in that: include: A processor and a memory, the memory being used to store a computer program, the processor being used to call and run the computer program stored in the memory to execute the method according to any one of claims 1 to 22, or the method according to any one of claims 53 to 61.

74. A network device, characterized in that include: A processor and a memory, the memory being used to store a computer program, the processor being used to call and run the computer program stored in the memory to perform the method according to any one of claims 23 to 45, or the method according to any one of claims 46 to 52, or the method according to any one of claims 62 to 67.

75. A chip, characterized in that include: A processor for calling and running a computer program from a memory so that a device equipped with the chip performs the method according to any one of claims 1 to 22, or the method according to any one of claims 23 to 45, or the method according to any one of claims 46 to 52, or the method according to any one of claims 53 to 61, or the method according to any one of claims 62 to 67.

76. A computer-readable storage medium, characterized in that Used to store a computer program, the computer program causing a computer to perform the method according to any one of claims 1 to 22, or the method according to any one of claims 23 to 45, or the method according to any one of claims 46 to 52, or the method according to any one of claims 53 to 61, or the method according to any one of claims 62 to 67.

77. A computer program product, characterized in that Comprising computer program instructions which cause a computer to perform the method of any one of claims 1 to 22, or the method of any one of claims 23 to 45, or the method of any one of claims 46 to 52, or the method of any one of claims 53 to 61, or the method of any one of claims 62 to 67.

78. A computer program, characterized in that The computer program causes a computer to perform the method of any one of claims 1 to 22, or the method of any one of claims 23 to 45, or the method of any one of claims 46 to 52, or the method of any one of claims 53 to 61, or the method of any one of claims 62 to 67.

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