Communication method, terminal device, and network device

Abstract

The present application relates to a communication method, a terminal device, and a network device. The method comprises: a terminal device initiating an advanced synchronization process, wherein a transmission power corresponding to the advanced synchronization process is determined on the basis of first information. By means of the embodiments of the present application, a transmission power corresponding to an advanced synchronization process is rationally determined, and the communication quality can thus be improved.

Description

Communication method, terminal device and network device Technical Field

[0001] The present application relates to the field of communications, and more specifically, to a communication method, terminal equipment, and network equipment. Background Art

[0002] The communication system supports handovers for connected user terminals. In some scenarios, to ensure communication continuity and service quality, the communication system may perform a handover. During the handover, the communication system can transfer the communication link between the user terminal and the original cell to a new cell. This reduces the interruption delay caused by the handover and improves communication quality.

[0003] Summary of the Invention

[0004] The embodiments of the present application provide a communication method, terminal equipment, and network equipment, which can improve communication quality.

[0005] An embodiment of the present application provides a communication method, including:

[0006] The terminal device initiates an early synchronization process, wherein the transmission power corresponding to the early synchronization process is determined based on the first information.

[0007] An embodiment of the present application provides a communication method, including:

[0008] The network device sends first information, which is used to determine the transmission power corresponding to the early synchronization process of the terminal device.

[0009] An embodiment of the present application provides a terminal device, including:

[0010] The sending unit is configured to initiate an early synchronization process, wherein a sending power corresponding to the early synchronization process is determined based on the first information.

[0011] An embodiment of the present application provides a network device, including:

[0012] The first sending unit is used to send first information, where the first information is used to determine the sending power corresponding to the early synchronization process of the terminal device.

[0013] An embodiment of the present application provides a terminal device, comprising a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory, so that the terminal device executes the above-mentioned communication method.

[0014] An embodiment of the present application provides a network device, comprising a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory, so that the network device executes the above-mentioned communication method.

[0015] The embodiment of the present application provides a chip for implementing the above-mentioned communication method. Specifically, the chip includes: a processor for calling and running a computer program from a memory, so that a device equipped with the chip executes the above-mentioned communication method.

[0016] An embodiment of the present application provides a computer-readable storage medium for storing a computer program, which, when executed by a device, enables the device to execute the above-mentioned communication method.

[0017] An embodiment of the present application provides a computer program product, including computer program instructions, which enable a computer to execute the above-mentioned communication method.

[0018] An embodiment of the present application provides a computer program, which, when executed on a computer, enables the computer to execute the above-mentioned communication method.

[0019] In the embodiments of the present application, the communication quality can be improved by reasonably determining the transmission power corresponding to the early synchronization process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG1 is a schematic diagram of an application scenario according to an embodiment of the present application.

[0021] FIG2 is a schematic diagram of a cell switching process across base stations according to an embodiment of the present application.

[0022] FIG3 is a schematic flowchart of a communication method according to an embodiment of the present application.

[0023] FIG4 is a schematic flowchart of a communication method according to another embodiment of the present application.

[0024] FIG5 is a schematic flowchart of a communication method according to another embodiment of the present application.

[0025] FIG6 is a schematic flowchart of a communication method according to another embodiment of the present application.

[0026] FIG7 is a schematic flowchart of a communication method according to another embodiment of the present application.

[0027] FIG8 is a schematic flowchart of a communication method according to another embodiment of the present application.

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

[0029] FIG10 is a schematic flowchart of a communication method according to another embodiment of the present application.

[0030] FIG11 is a schematic block diagram of a terminal device according to an embodiment of the present application.

[0031] FIG12 is a schematic block diagram of a terminal device according to another embodiment of the present application.

[0032] FIG13 is a schematic block diagram of a network device according to an embodiment of the present application.

[0033] FIG14 is a schematic block diagram of a network device according to another embodiment of the present application.

[0034] FIG15 is a flow chart of a communication method according to an application scenario of the present application.

[0035] FIG16 is a flow chart of a communication method according to another application scenario of the present application.

[0036] FIG17 is a schematic block diagram of a communication device according to an embodiment of the present application.

[0037] FIG18 is a schematic block diagram of a chip according to an embodiment of the present application.

[0038] FIG19 is a schematic block diagram of a communication system according to an embodiment of the present application. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0040] 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.

[0041] 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.

[0042] In one embodiment, the communication system in the embodiment of the present application can be applied to a carrier aggregation (CA) scenario, a dual connectivity (DC) scenario, and a standalone (SA) networking scenario.

[0043] In one embodiment, the communication system in the embodiment of the present application can be applied to an unlicensed spectrum, wherein 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, wherein the authorized spectrum can also be considered as an unshared spectrum.

[0044] 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.

[0045] The terminal device can be a station (STAION, ST) 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.

[0046] 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.).

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] FIG1 exemplarily illustrates a communication system 100. The communication system includes a network device 110 and two terminal devices 120. In one embodiment, the communication system 100 may include multiple network devices 110, and each network device 110 may include a different number of terminal devices 120 within its coverage area, which is not limited in this embodiment of the present application.

[0053] In one embodiment, the communication system 100 may further include other network entities such as a Mobility Management Entity (MME) and an Access and Mobility Management Function (AMF), which is not limited in this embodiment of the present application.

[0054] Among them, the network equipment may include access network equipment and core network equipment. That is, the wireless communication system also includes multiple core networks for communicating with the access network equipment. The access network equipment can be an evolutionary base station (evolutional node B, abbreviated as eNB or e-NodeB) macro base station, micro base station (also called "small base station"), pico base station, access point (AP), transmission point (TP) or new generation base station (new generation Node B, gNodeB), etc. in a long-term evolution (LTE) system, a next-generation (mobile communication system) (next radio, NR) system or an authorized auxiliary access long-term evolution (LAA-LTE) system.

[0055] 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 shown in Figure 1 as an example, the communication device may include a network device and a terminal device having a communication function. The network device and the terminal device may be specific devices in the embodiments of the present application and will not be described in detail here. The communication device may also include other devices in the communication system, such as a network controller, a mobility management entity, and other network entities, which are not limited in the embodiments of the present application.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] To facilitate understanding of the technical solutions of the embodiments of the present application, the relevant technologies of the embodiments of the present application are described below. The following relevant technologies can be arbitrarily combined with the technical solutions of the embodiments of the present application as optional solutions, and they all fall within the protection scope of the embodiments of the present application.

[0060] 1. Traditional switching process

[0061] Similar to LTE, NR systems support handovers for connected UEs. For example, when a user using network services moves from one cell to another, or due to wireless traffic load adjustments, activation and maintenance, or equipment failure, the system must transfer the user's communication link with the original cell to the new cell to ensure communication continuity and service quality. This is called a handover.

[0062] For example, FIG2 is a schematic diagram of a cell handover process across base stations, which may include the following processes:

[0063] S201. The source gNB triggers a handover based on the Layer 3 (L3) measurement results reported by the terminal and sends a handover request (HANDOVER REQUEST) to the target gNB (target cell) via the Xn interface.

[0064] S202. The target base station receives the handover request (Admission Control) from the source base station and provides the target cell's Radio Resource Control (RRC) configuration as part of the Handover Request Acknowledgement (HANDOVER REQUEST ACKNOWLEDGE) feedback to the source base station.

[0065] S203. The source base station sends an RRC reconfiguration message to the UE, instructing the UE to initiate a handover procedure, as well as RRC configuration information for accessing the target cell.

[0066] S204. The UE accesses the target cell, for example, switches to a new cell (Switch to New Cell), and sends an RRC Reconfiguration Complete message to the target cell.

[0067] 2. Layer 1 or Layer 2 triggered mobility (L1 / L2 triggered mobility, LTM)

[0068] To further reduce the interruption latency associated with handovers, LTM-triggered mobility (L1 / L2 triggered mobility) can be used. LTM is a handover process triggered by underlying signaling. To preconfigure multiple candidate cells for a UE, the UE performs Layer 1 (L1) measurements on these candidate cells and reports them to the network. The network determines the target cell based on the UE's measurement reports and sends a handover command to the UE, instructing it to perform the handover.

[0069] During the LTM process, to reduce the latency caused by the uplink synchronization process, the network can instruct the UE to initiate a random access procedure (also referred to as a RACH procedure) to the candidate cell when connected to the serving cell. When the candidate cell receives the preamble sent by the UE and is selected as the handover target cell, the timing advance (TA) can be indicated to the UE in the handover command. This eliminates the need for the UE to perform a random access procedure after receiving the handover command, thereby reducing handover interruption latency.

[0070] When the UE sends a random access process to a candidate cell, the network can support triggering through a physical downlink control channel (PDCCH) command (order). Unlike the traditional random access process, the random access process initiated by the UE to the LTM candidate cell does not need to receive a random access response (Random Access Response, RAR). If the candidate cell fails to successfully receive and calculate the TA due to insufficient power after the UE sends the preamble, the network needs to re-trigger the UE to send the preamble. The communication method of the embodiment of the present application can ensure that the UE maintains power climbing in subsequent preamble transmissions.

[0071] FIG3 is a schematic flow chart of a communication method according to an embodiment of the present application. The method 300 can optionally be applied to the system shown in FIG1 , but is not limited thereto. The method includes at least part of the following contents.

[0072] S310. The terminal device initiates an early synchronization process, wherein the transmission power corresponding to the early synchronization process is determined based on the first information.

[0073] In an embodiment of the present application, the terminal device may initiate an early synchronization process (also referred to as an early synchronization process) to one or more candidate cells. The early synchronization process may be before the switching process. For example, in a layer 1 or layer 2 triggered mobility (LTM) process, the candidate cell may be an LTM candidate cell. The terminal device may initiate an early synchronization process to the LTM candidate cell when connected to the serving cell. If an LTM candidate cell is selected as the switching target cell. The network may indicate the TA to the terminal device in the switching command. In this way, the terminal device does not need to perform a random access process (also referred to as a random access process) after receiving the switching command, thereby reducing the switching interruption delay and improving the communication quality.

[0074] In an embodiment of the present application, the transmission power (also referred to as transmit power) used by the information sent by the terminal device during the advance synchronization process can be determined based on the first information. The first information can be information maintained locally by the terminal device, or it can be information sent to the terminal device by the network device. The first information can include multiple types. For example, the first information can include the value of a counter, or it can include a power value, offset value, or climbing value indicated by the network device. It can also include whether the random access process is a new transmission or a retransmission, etc. The transmission type, etc., can be flexibly selected according to the needs of the actual application scenario.

[0075] In embodiments of the present application, communication quality can be improved by reasonably determining the transmit power corresponding to the early synchronization process. For example, based on the first information, it can be determined whether the transmit power corresponding to the early synchronization process needs to be increased, and the transmit power increase can be controlled in a timely manner to improve the success rate of information transmission, thereby improving communication quality. For example, in an early synchronization scenario, the UE can control the power increase of the preamble code transmission, thereby ensuring communication continuity and service quality.

[0076] Figure 4 is a schematic flow chart of a communication method according to another embodiment of the present application. Method 400 may include one or more features of the communication method of the above embodiment. In one embodiment, S310, the terminal device initiates an early synchronization process, including: S410, the terminal device initiates one or more first random access processes to one or more candidate cells.

[0077] In one embodiment, the transmission power of the second information in one or more first random access processes is determined based on the first information.

[0078] In one embodiment, the second information includes message 1, message A, or a preamble in the first random access process.

[0079] In this embodiment of the present application, the first random access process may be a random access process for early synchronization. The second information in the first random access process may be message 1 of the four-step random access, message A of the two-step random access, or a preamble in message 1 or message A.

[0080] For example, during the LTM process, the terminal device may initiate one or more random access processes to the LTM candidate cell when connected to the serving cell. During the random access process, the UE may send a preamble to the LTM candidate cell. The random access process initiated by the terminal device to the LTM candidate cell may not require receiving the RAR. The terminal device may determine whether the transmit power needs to be increased after each random access process based on the first information. For example, if the candidate cell fails to successfully receive and calculate the TA due to insufficient power after the UE sends the preamble, the UE may control the transmit power to increase based on the first information and resend the preamble, thereby improving the success rate of the preamble being received by the candidate cell.

[0081] In one embodiment, the first information includes the number of power climbs in the early synchronization process. For example, the number of power climbs in the first information can be obtained based on the number of transmissions of message 1, message A or the preamble during the early synchronization process. For example, the terminal device sends a preamble once to a candidate cell, and the number of power climbs corresponding to the candidate cell increases by 1. As the number of power climbs increases, the transmit power of the terminal device can be increased accordingly. The number of power climbs can correspond to a specific power value or a power offset value. For example, a power climb number of 2 corresponds to power 2, and a power climb number of 3 corresponds to power 3, wherein power 3 is greater than power 2. For another example, a power climb number of 2 corresponds to a power offset value of 2, and a power climb number of 3 corresponds to a power offset value of 3, wherein power offset value 3 is greater than power offset value 2.

[0082] In one embodiment, the first information includes the value of a first counter, and the value of the counter is used to indicate the number of power climbs during the early synchronization process. For example, the terminal device can locally maintain a counter for early synchronization. The value of the counter can indicate the number of power climbs or the number of information transmissions during the early synchronization process, etc. The initial value of the counter can be preconfigured or a default value. For example, the first random access process corresponds to the first counter. The initial value of the first counter is 0, and the preamble code is sent once during the first random access process, and the value of the first counter increases by 1. Alternatively, when the terminal device performs the initialization of the first random access process, the first counter can be set to 1, and the counter will be increased by 1 each time a preamble code is sent during subsequent retransmissions. In the embodiments of the present application, the values ​​of the counter such as 0 and 1 are only examples, not limitations, and the specific values ​​of the initial value, climb value, etc. of the counter can be set according to the actual scenario.

[0083] In one implementation, the first counter is a counter for early synchronization and random access multiplexing.

[0084] In one embodiment, the first counter is a counter dedicated to early synchronization. In this embodiment of the present application, when the terminal device triggers a new random access process, the counter multiplexed with early synchronization and random access may be reset, that is, restart counting from the initial value; the counter dedicated to early synchronization may not need to be reset.

[0085] In one embodiment, the first counter is a preamble power ramping counter. The preamble power ramping counter may be a counter multiplexed with advance synchronization and random access, such as PREAMBLE_POWER_RAMPING_COUNTER in random access.

[0086] In one embodiment, the first counter is a preamble power ramping counter of the LTM. For another example, the preamble power ramping counter of the LTM may be a counter dedicated to advance synchronization in the LTM process, such as PREAMBLE_POWER_RAMPING_COUNTER_LTM.

[0087] In one embodiment, as shown in FIG4 , the method 400 further includes:

[0088] S420. When the first counter is a counter dedicated to advance synchronization, the terminal device does not reset the first counter when triggering the second random access process to the same cell as the first random access process, and resets the first counter when triggering the second random access process to a cell different from the first random access process.

[0089] In the embodiment of the present application, the second random access procedure may be a random access procedure newly triggered after the first random access procedure. The second random access procedure may be a random access procedure triggered by other events, such as SR triggering, BFR triggering, uplink and downlink data arrival triggering, acquisition of system message triggering, etc. It may also be triggered by an early synchronization process, in which the early synchronization process may be initiated to the same candidate cell, and the early synchronization is used to initiate random access to other candidate cells.

[0090] For example, the value of the first counter is 3, indicating that the number of power ramps for the UE to send a preamble to candidate cell 1 is 3. If, in the newly triggered second random access process, the UE sends a preamble to candidate cell 1. In this case, the first counter T1 is not reset, and the value of the first counter T1 can continue to be used to initiate the second random access process to candidate cell 1. For another example, the value of the first counter is 3, indicating that the number of power ramps for the UE to send a preamble to candidate cell 1 is 3. If, in the newly triggered second random access process, the UE sends a preamble to candidate cell 2. In this case, the first counter T1 can be reset, for example, T1 can be reset to 1, and the second random access process can be initiated to candidate cell 2 using the preset initial power.

[0091] In one embodiment, as shown in FIG4 , the method 400 further includes: S430, in the case where the first counter is a counter multiplexed for advance synchronization and random access, the terminal device resets the first counter when triggering the second random access process. In an embodiment of the present application, if the first counter is used to indicate the number of power climbs of the preamble code in the advance synchronization process, and is also used to indicate the number of power climbs of the preamble code in the traditional random access process, the terminal device may reset the value of the first counter to the initial value when triggering a new second random access process. For example, if the value of the first counter is 3, it indicates that the number of power climbs of the preamble code sent by the UE to the candidate cell 1 is 3. If, in the newly triggered random access process, the UE sends a preamble code to the candidate cell 1, the value of the first counter is reset to an initial value such as 1 or 0.

[0092] Figure 5 is a schematic flow chart of a communication method according to another embodiment of the present application. The method 500 may include one or more features of the communication method of the above embodiment. In one embodiment, as shown in Figure 5, the method further includes: S510, after the terminal device completes the first random access process, the first timer is started, and the first timer is used to determine the first duration. The first duration can be used to control the first duration of the first operation allowed to be performed after the first random access process is completed. In one embodiment, the first operation is used to temporarily save the value of the first counter.

[0093] In S430 of the method, the terminal device performs a first operation, including: S520, the terminal device performs the first operation when the second random access process is triggered and the first timer is in a running state. For example, when the first timer is in a running state, that is, the second random access process is triggered within the first duration, the terminal device can perform the first operation to temporarily save the value of the first counter. The second random access process triggered subsequently can use the value of the first counter to determine the transmission power. If the first timer stops running, that is, exceeds the first duration, the value of the first counter can be reset. If the second random access process is triggered subsequently, the original accumulated value of the first counter is no longer used to determine the transmission power. Instead, the value of the reset first counter can be used to determine the transmission power.

[0094] In one embodiment, the first operation includes saving the value of the first counter to a temporary counter and / or assigning it to a first variable. For example, the UE saves the value of the first counter before initialization of the newly triggered random access procedure to a temporary counter, such as a temporary power counter. For another example, the UE assigns the value of the first counter before initialization of the newly triggered random access procedure to a new variable, such as a temporary preamble power ramping counter variable (PREAMBLE_POWER_RAMPING_COUNTER_TEMPORARY).

[0095] In one embodiment, the condition for performing the first operation includes at least one of the following:

[0096] The network device instructs to perform the first operation;

[0097] The second random access process occurs after the first random access process;

[0098] The second random access process occurs within a first time period after the first random access process is completed.

[0099] For example, if the terminal device receives information from the network device indicating that the value of the multiplexed counter is temporarily saved, the first operation can be performed, that is, the value of the first counter is saved in a temporary counter and / or assigned to a first variable. For another example, after the first random access process is triggered or completed, the second random access process is triggered. In this case, the terminal can autonomously perform the first operation or perform the first operation based on the instruction of the network device. For another example, if the second random access process is triggered within a first time period after the first random access process is completed, the first operation can be performed. If the second random access process is triggered after the first time period, the first operation may no longer be performed.

[0100] In one embodiment, the stop condition of the first timer includes: triggering the second random access procedure. In this embodiment of the present application, if the first timer is in a running state when the second random access procedure is triggered, the first timer can be stopped or reset after the first operation is performed.

[0101] In one embodiment, the method further includes: before performing initialization of the second random access process, the terminal device performs a first operation.

[0102] In the embodiment of the present application, if the counter multiplexed with random access is synchronized in advance, the original number of power ramp-up times can be obtained, and the value of the first counter can be temporarily saved and retrieved for use when needed later.

[0103] Figure 6 is a schematic flow chart of a communication method according to another embodiment of the present application. Method 600 may include one or more features of the communication method of the above embodiment. In one embodiment, the method further includes: S610: After performing the first operation, the terminal device starts a second timer, which is used to determine the validity period of the temporarily saved value of the first counter.

[0104] In one embodiment, as shown in Figure 6, the method also includes: S620, the terminal device receives a downlink command for early synchronization during the operation of the second timer, and the candidate index in the downlink command is the same as the candidate cell index corresponding to the first random access process, then in the initialization of the second random access process, the value of the second counter corresponding to the second random access process is set to the value of the temporary counter or the value of the first variable.

[0105] In some examples, the terminal device may maintain an independent counter for each candidate cell or each early synchronization process. For example, after the terminal device saves the value of the first counter (for example, 3) of the first random access process for a candidate cell (for example, indexed as C1) into a temporary counter and / or assigns it to a first variable, it starts the second timer. During the operation of the second timer, if the terminal device receives a downlink command for the candidate cell. For example, if the candidate index in the received downlink command is C1, the value of the second counter corresponding to the second random access process of the candidate cell C1 can be set to the value of the temporarily saved counter or variable, such as 3. In this case, the transmit power used for this second random access process is determined based on the value 3 of the second counter. Compared with performing the second random access process with the initial transmit power after resetting the counter, the transmit power determined by the temporarily saved value may be higher, which is beneficial to increasing the probability that the preamble is successfully received by a network device such as a candidate cell.

[0106] In one embodiment, as shown in FIG6 , the method further includes: S630: the terminal device deletes the value of the temporary counter or sets the value of the first variable to an initial value. For example, after the terminal device uses the value of the temporary counter or the value of the first variable to perform the second random access procedure, it may delete the value of the temporary counter, set the value of the temporary counter to an initial value such as 0 or 1, or set the value of the first variable to an initial value such as 0 or 1. In this way, a subsequent retriggered random access procedure can use the initial power to send a preamble.

[0107] Figure 7 is a schematic flow chart of a communication method according to another embodiment of the present application. The method 700 may include one or more features of the communication method of the above embodiment. In one embodiment, the first information includes power control information, which is used to determine the transmit power of the terminal device to transmit Message 1, Message A, or preamble of the first random access procedure. For example, the network device sends power control information to the terminal device to explicitly or implicitly indicate the transmit power used by the terminal device to initiate the first random access procedure.

[0108] In one embodiment, the power control information includes a power value, or the power control information includes an offset value and / or a climbing value for adjusting the current transmit power. For example, if the power control information includes a power value, the terminal device may adjust the transmit power used for sending the preamble during the first random access process to the power value. For another example, if the rate control information includes an offset value for transmit power, the terminal device may adjust the transmit power used for sending the preamble during the first random access process to the last transmit power plus or minus the offset value. For another example, if the rate control information includes a climbing value for transmit power, the terminal device may adjust the transmit power used for sending the preamble during the first random access process to the last transmit power plus the climbing value.

[0109] In one embodiment, the first information includes new transmission / retransmission indication information, which is used to indicate a new transmission or a retransmission. In this embodiment of the present application, the new transmission / retransmission indication information may include one or more bits to indicate a new transmission or a retransmission. For example, a bit value of 1 indicates a retransmission, and 0 indicates a new transmission. For another example, a bit value of 0 indicates a retransmission, and 1 indicates a new transmission.

[0110] For example, the new transmission and retransmission indication information sent by the network device to the terminal device may include a new transmission indication or an initial transmission indication. In this case, the terminal device may send Message 1 or Message A of the random access process to one or more candidate cells for the first time based on the new transmission indication or the initial transmission indication. Message 1 or Message A may include a preamble. Furthermore, the terminal device may set the value of the preamble power rise counter corresponding to the random access process or the preamble power rise counter of the LTM to 1.

[0111] In one embodiment, the new transmission retransmission indication information is used to indicate the number of retransmissions. For example, if the number of retransmissions indicated by the new transmission retransmission indication information is 2, it may indicate two retransmissions. After receiving the new transmission retransmission indication information, the terminal device may transmit the random access preamble code twice in succession. Furthermore, the transmit power may be increased each time the preamble is transmitted. The amount of the increase each time can be set based on the requirements of the actual application scenario.

[0112] In one embodiment, the method further includes: S710, the terminal device receives downlink control information, and the downlink control information is used to trigger the early synchronization process and / or one or more first random access processes. For example, the downlink control information may include an indication for triggering the early synchronization process and / or the random access process. For another example, the downlink control information may implicitly indicate the triggering of the early synchronization process and / or the random access process. In an embodiment of the present application, the above-mentioned power control information and / or the new transmission and retransmission indication information may be indicated by downlink control information such as a PDCCH command.

[0113] In one embodiment, the downlink control information is used to indicate at least one of the following: candidate cell index; power control information; new transmission and retransmission indication information; random access resource indication information; bandwidth part BWP indication information; transmission reception point TRP index.

[0114] In an embodiment of the present application, the downlink control information may explicitly or implicitly indicate one or more of the above information. For example, the downlink control information may include a candidate cell index and power control information. After receiving the downlink control information, the terminal device may determine the value of the first counter corresponding to the candidate cell that needs to be synchronized and / or randomly accessed in advance based on the candidate cell index. Then, based on the value of the first counter, determine the power used to send the random access preamble to the candidate cell. For another example, the downlink control information may include new transmission and retransmission indication information and random access resource indication information. If the new transmission and retransmission indication information includes a new transmission indication, then after the random access preamble is sent based on the resource corresponding to the random access resource indication information, the value of the first counter may not be increased or set to 1. If the new transmission and retransmission indication information includes a retransmission indication, then after the random access preamble is sent based on the resource corresponding to the random access resource indication information, the value of the first counter may be increased by 1 or increased by other values.

[0115] In one embodiment, the random access resource indication information includes at least one of the following: a random access preamble code index, an uplink indication, a supplementary uplink indication, a synchronization signal / physical broadcast channel block (Synchronization Signal / PBCH Block, SSB) index, and a physical random access channel mask index.

[0116] In one embodiment, the downlink control information includes a physical downlink control channel (PDCCH) command, and the PDCCH command is used to instruct the terminal device to initiate an early synchronization process to one or more candidate cells. For example, the PDCCH command instructs the terminal device to initiate a random access process to one or more candidate cells.

[0117] In one embodiment, as shown in FIG7 , in step S410, the terminal device initiates one or more first random access procedures to one or more candidate cells, including:

[0118] S720: When the received downlink control information includes a new transmission indication corresponding to the first random access procedure, the terminal device performs initialization of the first random access procedure;

[0119] S730: The terminal device sends second information of the first random access process to one or more candidate cells based on the preconfigured power, and sets the value of the first counter for power climbing to an initial value.

[0120] In an embodiment of the present application, the second information of the random access process may be a preamble code, message 1, or message A of the random access. For example, the network device sends a PDCCH command to the terminal device. If the new transmission and retransmission indication information in the PDCCH command includes a new transmission indication or an initial transmission indication, after receiving the PDCCH command, the terminal device may send the second information such as message 1, message A, or preamble code of the first random access process to the candidate cell corresponding to the candidate cell index in the PDCCH command. In addition, the terminal device may set the value of the first counter to an initial value, such as 1, at the same time as or after sending the second information for the first time.

[0121] In one embodiment, the preconfigured power is a target power for receiving a preamble of the second information. The transmission power that the terminal device may use when sending the second information for the first time may be the preconfigured target power for receiving a preamble.

[0122] In one embodiment, the step S410 terminal device initiates one or more first random access processes to one or more candidate cells, and further includes: when the received downlink control information includes a retransmission indication or a power climb indication corresponding to the first random access process, the terminal device retransmits the second information of the first random access process to one or more candidate cells and increases the value of the first counter.

[0123] For example, after the first transmission of the preamble of the first random access process, if the new transmission and retransmission indication information in the PDCCH command received by the terminal device includes a retransmission indication, or the power control information includes a power ramp indication, the terminal device may resend the second information, such as message 1, message A, or preamble of the first random access process, to the candidate cell corresponding to the candidate cell index in the PDCCH command after receiving the PDCCH command. Furthermore, the terminal device may increase the value of the first counter, for example, by adding 1, while or after resending the second information one or more times.

[0124] In one embodiment, the step S410 terminal device initiates one or more first random access processes to one or more candidate cells, and also includes: after the terminal device transmits or retransmits the second information of the first random access process, if the received downlink control information includes a new transmission indication corresponding to the first random access process, the terminal device does not increase the value of the first counter, and determines the transmission power of the second information based on the current value of the first counter.

[0125] For example, after transmitting the preamble of the first random access procedure one or more times, the new transmission and retransmission indication information in the PDCCH command received by the terminal device includes a new transmission indication. The multiple transmissions may include one new transmission and at least one retransmission. After receiving the PDCCH command, the terminal device may send second information such as message 1, message A, or the preamble of the first random access procedure to the candidate cell corresponding to the candidate cell index in the PDCCH command.

[0126] If the PDCCH command received by the terminal device indicates that early synchronization should be initiated to the same candidate cell as the previously transmitted or retransmitted signal, such as candidate cell 1, the terminal device may not increase the value of the first counter at the same time as or after sending the second message. For example, if the value of the first counter was 3 during the last transmission, upon receiving the next new transmission indication, the terminal device may send the second message to candidate cell 1 at the transmit power corresponding to the original value of the first counter, such as 3.

[0127] If the PDCCH command received by the terminal device indicates initiating early synchronization to a different cell than the previous new transmission or retransmission, such as candidate cell 2 or the serving cell, the terminal device may initialize the first counter simultaneously with or after sending the second information. For example, if the value of the first counter was 3 during the last transmission, upon receiving the next new transmission indication, the terminal device may reset the value of the first counter to 1.

[0128] In one embodiment, in step S410, the terminal device initiates one or more first random access processes to one or more candidate cells, including: the terminal device sends the second information of the first random access process to the one or more candidate cells multiple times in succession based on a preconfigured number of preamble code transmissions, and the transmission power increases once each time the second information is sent.

[0129] In an embodiment of the present application, the terminal device can autonomously trigger the early synchronization process. In this case, the early synchronization process can be triggered independently of the control information of the network device. For example, the number of preamble code transmissions preconfigured for a candidate cell is 3, and the terminal device can send the second information such as message 1, message A or preamble code of the first random access process to the candidate cell for three consecutive times. After the second information is sent for the first time, the value of the first counter corresponding to the candidate cell can be set to 1. After the second information is sent for the second time, the value of the first counter corresponding to the candidate cell can be set to 2. After the second information is sent for the third time, the value of the first counter corresponding to the candidate cell can be set to 3. Different first counter values ​​correspond to different transmission powers. For example, the larger the value of the first counter, the greater the corresponding transmission power.

[0130] FIG8 is a schematic flow chart of a communication method according to another embodiment of the present application. The method 800 may include one or more features of the communication method of the above embodiment. In one embodiment, the method further includes:

[0131] S810. The terminal device receives a cell handover command, where the cell handover command indicates a target cell for handover of the terminal device.

[0132] S820. The terminal device resets the counter corresponding to the target cell for early synchronization.

[0133] In an embodiment of the present application, after the advance synchronization process, one or more candidate cells may receive the index of the random access of the terminal device. The network device selects the candidate cell that can receive the index of the terminal device as the target cell for handover and sends a cell handover command to the terminal device. The cell handover command may include the target cell for handover selected by the network device for the terminal device. After receiving the cell handover command, the terminal device may perform a handover process to the target cell and may reset the counter for advance synchronization corresponding to the target cell, such as the value of the first counter and / or the second counter mentioned above.

[0134] In one embodiment, as shown in FIG8 , the method further includes: S830, the terminal device retains or resets the counters for early synchronization of other cells in the multiple candidate cells except the target cell. In an embodiment of the present application, one of the N candidate cells is the target cell, and the values ​​of the counters for early synchronization of the remaining N-1 cells can be retained or reset. For example, after receiving the cell switching command, the terminal device determines that candidate cell 1 is the target cell, and the timer T1 corresponding to candidate cell 1 can be reset to 1. The timer T2 corresponding to the remaining candidate cell 2 is retained at 2, and the timer T3 corresponding to candidate cell 3 is retained at 4. Subsequently, the preamble code is retransmitted to candidate cell 2 based on the transmission power corresponding to the value 2 of T2, and the preamble code is retransmitted to candidate cell 3 based on the transmission power corresponding to the value 4 of T3.

[0135] In one embodiment, as shown in FIG8 , the method further includes: S840, when the network device updates or releases a candidate cell, the terminal device resets the counter for early synchronization associated with the candidate cell. For example, when the network device notifies the terminal device to update candidate cell 2, the value of counter T2 corresponding to candidate cell 2 may be reset to 1. For another example, when the network device notifies the terminal device to release candidate cell 3, the value of counter T3 corresponding to candidate cell 3 may be reset to 1.

[0136] In one embodiment, the method further includes: the terminal device receiving candidate cell pre-configuration information. This step may be performed before S710. The terminal device may receive candidate cell pre-configuration information from the network device.

[0137] In one embodiment, the candidate cell pre-configuration information includes at least one of the following:

[0138] configuration of at least one candidate cell;

[0139] Resources and / or configuration for performing uplink synchronization to at least one candidate cell;

[0140] measurement configuration and / or reporting configuration of at least one candidate cell;

[0141] L1 measurement configuration and / or L3 measurement configuration;

[0142] L1 measurement reporting configuration and / or L3 measurement reporting configuration.

[0143] In one embodiment, the method further includes: the terminal device performs measurement and reporting on the candidate cell based on the candidate cell pre-configuration information, wherein the measurement includes L1 measurement and / or L3 measurement. The measurement report is carried by an RRC message, uplink control information (UCI) or a medium access control (MAC) control element (CE). This step can be performed before S710. After the terminal device receives the candidate cell pre-configuration information from the network device, it can perform measurement on the candidate cell based on the candidate cell pre-configuration information. For example, if the candidate cell pre-configuration information includes the configuration of multiple candidate cells, L1 measurement configuration and L1 measurement reporting configuration, the terminal device can perform L1 measurement on the multiple candidate cells based on the L1 measurement configuration, and report the measurement results based on the L1 measurement reporting configuration. The network device can send downlink control information based on the measurement results to trigger the early synchronization process of the candidate cell. For another example, if the candidate cell pre-configuration information includes configurations of multiple candidate cells, resources for performing uplink synchronization with the multiple candidate cells, and L3 measurement configurations, L3 measurements can be performed on the multiple candidate cells based on these resources to obtain measurement results. The terminal device can trigger an early synchronization process for the candidate cells based on the measurement results.

[0144] In one embodiment, the early synchronization process is triggered by the terminal device based on an instruction from the network device. For example, the network device may instruct the terminal device to initiate an early synchronization process with one or more candidate cells through downlink control information such as a PDCCH command.

[0145] In one embodiment, the early synchronization process is autonomously triggered by the terminal device. For example, the terminal device may determine to perform the early synchronization process on one or more candidate cells based on measurement results.

[0146] In one embodiment, the early synchronization process is triggered based on a measurement result of the terminal device, where the measurement result is determined based on a measurement event and / or a preconfigured threshold.

[0147] For example, the terminal device may trigger an early synchronization process based on a measurement event. If the terminal device detects that a measurement event has occurred, the early synchronization process may be triggered. Measurement events may include various types, such as the following:

[0148] Event A2: Serving becomes worse than absolute threshold;

[0149] Event A3: Neighbor becomes amount of offset better than PCell / PSCell;

[0150] Event A4: Neighbor becomes better than absolute threshold;

[0151] Event A5: PCell / PSCell becomes worse than absolute threshold 1 AND Neighbor / SCell becomes better than another absolute threshold 2.

[0152] For another example, the terminal device may determine whether to trigger the early synchronization process based on a preconfigured threshold. Specifically, if the measured strength of one signal is greater than the set threshold, the early synchronization process may be triggered. If the measured strength of another signal is less than the set threshold, the early synchronization process may also be triggered.

[0153] FIG9 is a schematic flow chart of a communication method according to an embodiment of the present application. The method 900 can optionally be applied to the system shown in FIG1 , but is not limited thereto. The method includes at least part of the following contents.

[0154] S910. The network device sends first information, where the first information is used to determine the transmission power corresponding to the advance synchronization process of the terminal device.

[0155] In one embodiment, the first information includes power control information, and the power control information is used to determine the transmission power of the terminal device to send message 1, message A or preamble code of the first random access process.

[0156] In one embodiment, the power control information includes a power value, or the power control information includes an offset value and / or a ramp-up value for adjusting the current transmission power.

[0157] In one embodiment, the first information includes new transmission and retransmission indication information, and the new transmission and retransmission indication information is used to indicate new transmission or retransmission.

[0158] In one embodiment, the new transmission retransmission indication information is used to indicate the number of retransmissions.

[0159] FIG10 is a schematic flow chart of a communication method according to another embodiment of the present application. The method 1000 may include one or more features of the communication method of the above embodiment. In one embodiment, as shown in FIG10 , the method further includes:

[0160] S1010: The network device sends candidate cell pre-configuration information. This step may be performed before S910.

[0161] In one embodiment, the candidate cell pre-configuration information includes at least one of the following:

[0162] configuration of at least one candidate cell;

[0163] Resources and / or configuration for performing uplink synchronization to at least one candidate cell;

[0164] measurement configuration and / or reporting configuration of at least one candidate cell;

[0165] L1 measurement configuration and / or L3 measurement configuration;

[0166] L1 measurement reporting configuration and / or L3 measurement reporting configuration.

[0167] In one embodiment, as shown in FIG10 , the method further includes:

[0168] S1020: The network device receives a report from the terminal device that the terminal device performs measurement on the candidate cell based on the candidate cell pre-configuration information, wherein the measurement includes L1 measurement and / or L3 measurement, and the measurement report is carried by an RRC message or UCI or MAC CE. This step can be performed before S910.

[0169] In one embodiment, the network device sends the first information, including:

[0170] S1030. The network device sends downlink control information, where the downlink control information is used to trigger the early synchronization process and / or one or more first random access processes. In this embodiment of the present application, the first information may be indicated by the downlink control information. For example, power control information, new transmission and retransmission indication information, etc. indicated by the downlink control information may be the first information.

[0171] In one embodiment, the downlink control information is used to indicate at least one of the following: candidate cell index; power control information; new transmission and retransmission indication information; random access resource indication information; BWP indication information; TRP index.

[0172] In one embodiment, the random access resource indication information includes at least one of the following: a random access preamble code index, an uplink indication, a supplementary uplink indication, an SSB index, and a physical random access channel mask index.

[0173] In one embodiment, the downlink control information includes a PDCCH command, and the PDCCH command is used to instruct the terminal device to initiate an early synchronization process to one or more candidate cells.

[0174] In one embodiment, as shown in FIG10 , the method further includes:

[0175] S1040. The network device sends a cell switching command, where the cell switching command indicates a target cell to which the terminal device switches.

[0176] For specific examples of the network device executing methods 900 and 1000 of this embodiment, reference can be made to the relevant descriptions of the network device, such as a base station, in the above methods 300 to 800 , which will not be repeated here for the sake of brevity.

[0177] FIG11 is a schematic block diagram of a terminal device according to an embodiment of the present application. The terminal device 1100 may include:

[0178] The sending unit 1101 is configured to initiate an early synchronization process, wherein a sending power corresponding to the early synchronization process is determined based on the first information.

[0179] In one embodiment, the sending unit is further configured to initiate one or more first random access procedures to one or more candidate cells;

[0180] The transmission power of the second information in the one or more first random access processes is determined based on the first information.

[0181] In one embodiment, the second information includes message 1, message A, or a preamble in the first random access process.

[0182] In one embodiment, the first information includes the number of power ramp-up times during the advance synchronization process.

[0183] In one embodiment, the first information includes a value of a first counter, where the value of the first counter is used to indicate the number of power ramp-up times during the advance synchronization process.

[0184] In one implementation, the first counter is a counter multiplexed with early synchronization and random access, or a counter dedicated to early synchronization.

[0185] In one embodiment, the first counter is a preamble power ramp-up counter, or a preamble power ramp-up counter of an LTM.

[0186] FIG12 is a schematic block diagram of a terminal device according to another embodiment of the present application. The terminal device 1200 may include one or more features of the terminal device of the above embodiment. In one embodiment, the terminal device 1200 further includes:

[0187] The first processing unit 1201 is configured to, when the first counter is a counter dedicated to early synchronization, not reset the first counter when the second random access procedure is triggered to the same cell as the first random access procedure, and reset the first counter when the second random access procedure is triggered to a cell different from the first random access procedure.

[0188] In one embodiment, as shown in FIG12 , the terminal device 1200 further includes:

[0189] The second processing unit 1202 is configured to reset the first counter when triggering the second random access procedure, if the first counter is a counter multiplexed with advance synchronization and random access.

[0190] In one embodiment, the second processing unit 1202 is further configured to perform a first operation before initializing the second random access procedure, where the first operation is configured to temporarily save the value of the first counter.

[0191] In one embodiment, the first operation includes saving the value of the first counter into a temporary counter and / or assigning the value to a first variable.

[0192] In one embodiment, the condition for performing the first operation includes at least one of the following:

[0193] The network device instructs to perform the first operation;

[0194] The second random access process occurs after the first random access process;

[0195] The second random access process occurs within a first time period after the first random access process is completed.

[0196] In one embodiment, the second processing unit 1202 is further configured to:

[0197] After completing the first random access process, starting a first timer, where the first timer is used to determine the first duration;

[0198] When the second random access procedure is triggered and the first timer is in a running state, the first operation is performed.

[0199] In one implementation, the stop condition of the first timer includes: triggering the second random access process.

[0200] In one embodiment, the second processing unit 1202 is further configured to start a second timer after executing the first operation, where the second timer is configured to determine a valid time of the temporarily saved value of the first counter.

[0201] In one embodiment, the second processing unit 1202 is also used to receive a downlink command for early synchronization during the operation of the second timer, and the candidate index in the downlink command is the same as the candidate cell index corresponding to the first random access process. In the initialization of the second random access process, the value of the second counter corresponding to the second random access process is set to the value of the temporary counter or the value of the first variable.

[0202] In one embodiment, the second processing unit 1202 is further configured to delete the value of a temporary counter or set the value of the first variable to an initial value.

[0203] In one embodiment, the first information includes power control information, and the power control information is used to determine the transmission power of the terminal device to send message 1, message A or preamble code of the first random access process.

[0204] In one embodiment, the power control information includes a power value, or the power control information includes an offset value and / or a ramp-up value for adjusting the current transmission power.

[0205] In one embodiment, the first information includes new transmission and retransmission indication information, and the new transmission and retransmission indication information is used to indicate new transmission or retransmission.

[0206] In one embodiment, the new transmission retransmission indication information is used to indicate the number of retransmissions.

[0207] In one embodiment, as shown in FIG12 , the terminal device 1200 further includes:

[0208] The first receiving unit 1203 is configured to receive downlink control information, where the downlink control information is used to trigger the early synchronization process and / or one or more first random access processes.

[0209] In one embodiment, the downlink control information is used to indicate at least one of the following: candidate cell index; power control information; new transmission and retransmission indication information; random access resource indication information; bandwidth part BWP indication information; transmission reception point TRP index.

[0210] In one embodiment, the random access resource indication information includes at least one of the following: a random access preamble code index, an uplink indication, a supplementary uplink indication, an SSB index, and a physical random access channel mask index.

[0211] In one embodiment, the downlink control information includes a PDCCH command, and the PDCCH command is used to instruct the terminal device to initiate an early synchronization process to one or more candidate cells.

[0212] In one embodiment, as shown in FIG12 , the terminal device 1200 further includes:

[0213] The third processing unit 1204 is configured to, when the received downlink control information includes a new transmission indication corresponding to the first random access procedure, perform initialization of the first random access procedure and set the value of the first counter for power ramping to an initial value;

[0214] The sending unit is further configured to send second information of the first random access process to one or more candidate cells based on preconfigured power.

[0215] In one implementation, the preconfigured power is a target power for receiving a preamble of the second information.

[0216] In one embodiment, as shown in FIG12 , the terminal device 1200 further includes:

[0217] The fourth processing unit 1205 is configured to, when the received downlink control information includes a retransmission indication or a power ramp-up indication corresponding to the first random access procedure, increase the value of the first counter;

[0218] The sending unit is further configured to retransmit the second information of the first random access process to one or more candidate cells.

[0219] In one embodiment, the fourth processing unit is also used to, after the second information of the first random access process is newly transmitted or retransmitted, when the received downlink control information includes a new transmission indication corresponding to the first random access process, not increase the value of the first counter, and determine the transmission power of the second information based on the current value of the first counter.

[0220] In one embodiment, the sending unit is further configured to send the second information of the first random access process to one or more candidate cells multiple times in succession based on a preconfigured number of preamble code transmissions, and the sending power increases each time the second information is sent.

[0221] In one embodiment, as shown in FIG12 , the terminal device 1200 further includes:

[0222] The second receiving unit 1206 is configured to receive a cell handover command, where the cell handover command indicates a target cell for handover of the terminal device;

[0223] The fifth processing unit 1207 is configured to reset the counter for early synchronization corresponding to the target cell.

[0224] In one embodiment, the fifth processing unit is further configured to retain or reset counters for early synchronization of cells other than the target cell among the multiple candidate cells.

[0225] In one embodiment, the fifth processing unit is further configured to reset a counter for early synchronization associated with a candidate cell when the network device updates or releases the candidate cell.

[0226] In one embodiment, the terminal device 1200 further includes:

[0227] The third receiving unit 1208 is configured to receive candidate cell pre-configuration information, where the candidate cell pre-configuration information includes at least one of the following:

[0228] configuration of at least one candidate cell;

[0229] Resources and / or configuration for performing uplink synchronization to at least one candidate cell;

[0230] measurement configuration and / or reporting configuration of at least one candidate cell;

[0231] L1 measurement configuration and / or L3 measurement configuration;

[0232] L1 measurement reporting configuration and / or L3 measurement reporting configuration.

[0233] In one embodiment, as shown in FIG12 , the terminal device 1200 further includes:

[0234] The sixth processing unit 1209 is configured to perform measurement and reporting on the candidate cell based on the candidate cell pre-configuration information, wherein the measurement includes L1 measurement and / or L3 measurement, and the measurement reporting is carried by an RRC message, UCI, or MAC CE.

[0235] In one embodiment, the early synchronization process is triggered based on an instruction from the terminal device based on a network device.

[0236] In one embodiment, the early synchronization process is autonomously triggered by the terminal device.

[0237] In one embodiment, the early synchronization process is triggered based on a measurement result of the terminal device, where the measurement result is determined based on a measurement event and / or a preconfigured threshold.

[0238] The terminal devices 1100 and 1200 of the embodiments of the present application can implement the corresponding functions of the terminal devices in the aforementioned method embodiments. The processes, functions, implementation methods and beneficial effects corresponding to the various modules (sub-modules, units or components, etc.) in the terminal devices 1100 and 1200 can be found in the corresponding descriptions in the aforementioned method embodiments and will not be repeated here. It should be noted that the functions described in the various modules (sub-modules, units or components, etc.) in the terminal devices 1100 and 1200 of the embodiment of the application can be implemented by different modules (sub-modules, units or components, etc.) or by the same module (sub-module, unit or component, etc.).

[0239] Figure 13 is a schematic block diagram of a network device according to an embodiment of the present application. The network device 1300 may include: a first sending unit 1301, configured to send first information, where the first information is used to determine the transmit power corresponding to the early synchronization process of the terminal device.

[0240] In one embodiment, the first information includes power control information, and the power control information is used to determine the transmission power of the terminal device to send message 1, message A or preamble code of the first random access process.

[0241] In one embodiment, the power control information includes a power value, or the power control information includes an offset value and / or a ramp-up value for adjusting the current transmission power.

[0242] In one embodiment, the first information includes new transmission and retransmission indication information, and the new transmission and retransmission indication information is used to indicate new transmission or retransmission.

[0243] In one embodiment, the new transmission retransmission indication information is used to indicate the number of retransmissions.

[0244] In one embodiment, the first sending unit is further configured to send downlink control information, where the downlink control information is used to trigger the early synchronization process and / or one or more first random access processes.

[0245] In one embodiment, the downlink control information is used to indicate at least one of the following: candidate cell index; power control information; new transmission and retransmission indication information; random access resource indication information; BWP indication information; TRP index.

[0246] In one embodiment, the random access resource indication information includes at least one of the following: a random access preamble code index, an uplink indication, a supplementary uplink indication, an SSB index, and a physical random access channel mask index.

[0247] In one embodiment, the downlink control information includes a physical downlink control channel PDCCH command, and the PDCCH command is used to instruct the terminal device to initiate an early synchronization process to one or more candidate cells.

[0248] Figure 14 is a schematic block diagram of a network device according to another embodiment of the present application. The network device 1400 may include one or more features of the network device of the above embodiment. In one embodiment, the network device 1400 further includes: a second sending unit 1401, configured to send a cell handover command, wherein the cell handover command indicates a target cell to which the terminal device is to handover.

[0249] In one embodiment, as shown in FIG14 , the network device 1400 further includes: a third sending unit 1402, configured to send candidate cell pre-configuration information, where the candidate cell pre-configuration information includes at least one of the following:

[0250] configuration of at least one candidate cell;

[0251] Resources and / or configuration for performing uplink synchronization to at least one candidate cell;

[0252] measurement configuration and / or reporting configuration of at least one candidate cell;

[0253] L1 measurement configuration and / or L3 measurement configuration;

[0254] L1 measurement reporting configuration and / or L3 measurement reporting configuration.

[0255] In one embodiment, the network device 1400 also includes: a receiving unit 1403, used to receive a report of the terminal device performing measurements on the candidate cell based on the candidate cell pre-configuration information, wherein the measurement includes L1 measurement and / or L3 measurement, and the measurement report is carried by an RRC message or UCI or MAC CE.

[0256] The network devices 1300 and 1400 of the embodiments of the present application can implement the corresponding functions of the network devices in the aforementioned method embodiments. The processes, functions, implementation methods, and beneficial effects corresponding to the various modules (sub-modules, units, or components, etc.) in the network devices 1300 and 1400 can be found in the corresponding descriptions in the aforementioned method embodiments and will not be repeated here. It should be noted that the functions described in the various modules (sub-modules, units, or components, etc.) in the network devices 1300 and 1400 of the embodiments of the application can be implemented by different modules (sub-modules, units, or components, etc.) or by the same module (sub-module, unit, or component, etc.).

[0257] Example 1: The UE maintains an independent counter / variable, and the network triggers it through a PDCCH order. As shown in Figure 15, this example may include one or more of the following steps:

[0258] S1501. The network provides candidate cell pre-configuration information to the UE. The candidate cell pre-configuration information may include at least one of the following:

[0259] configuration of at least one candidate cell;

[0260] Resources and / or configuration for the UE to perform uplink synchronization with at least one candidate cell;

[0261] measurement and / or reporting configuration of at least one candidate cell;

[0262] L1 measurement configuration and / or L3 measurement configuration;

[0263] L1 measurement reporting configuration and / or L3 measurement reporting configuration.

[0264] S1502: The UE performs measurement and reporting on the candidate cell based on pre-configured candidate cell configuration information. The measurement may be L1 measurement and / or L3 measurement. The measurement reporting may be implemented via RRC message, UCI, or MAC CE.

[0265] S1503: The UE triggers an early synchronization process. The early synchronization can be triggered by the UE itself or by the network.

[0266] For example, the network side may determine whether to trigger the early synchronization process. Optionally, the network determines to trigger the UE to initiate the early synchronization process to at least one candidate cell based on the UE's measurement report on the candidate cell.

[0267] For another example, the UE receives a PDCCH command sent by the network, and the PDCCH command is used to instruct the UE to initiate an early synchronization process with at least one candidate cell. Optionally, if the network instructs the UE to initiate an early synchronization process with multiple candidate cells, it can be triggered by a single signaling, such as carrying multiple candidate cell identifiers in the instruction signaling; or transmitted through multiple signalings. The PDCCH command can carry at least one of the following:

[0268] Candidate cell index;

[0269] Power control information is used to determine the transmit power of Message 1 (msg1), Message A (msgA), and the preamble transmitted by the UE. The power control information can explicitly indicate the power level or indicate the offset and / or ramping value used to adjust the previous power level.

[0270] New transmission and retransmission indication information, which may indicate a new transmission or a retransmission, and may optionally further indicate the number of retransmissions;

[0271] Random access resource indication information, such as random access preamble index, UL / SUL indicator, SSB index, PRACH mask index; BWP indicator; TRP index.

[0272] The UE may trigger an uplink synchronization procedure / random access procedure based on an indication from the network.

[0273] Scenario 1: If the PDCCH order indicates the initial / new transmission of early synchronization to the candidate cell, such as the first transmission of msg1 / msgA. The UE performs a random access initialization procedure and transmits msg1 / msgA based on the preconfigured power (e.g., preamble received target power, message A preamble received target power, etc.). The LTM preamble power ramp-up counter (PREAMBLE_POWER_RAMPING_COUNTER_LTM) is set to 1. This counter can be the preamble power ramp-up counter (PREAMBLE_POWER_RAMPING_COUNTER) in the relevant random access procedure, or it can be an independent counter used for LTM early synchronization.

[0274] After this transmission, the UE considers that the random access process is completed. If the PREAMBLE_POWER_RAMPING_COUNTER in the power ramping multiplexing related random access process is set, for the random access process triggered by early synchronization, the UE does not reset the counter after completing this transmission.

[0275] Scenario 2: If a new random access procedure is triggered, the UE needs to initialize the counter when the new random access is initialized. Before the new random access procedure is triggered, if the UE receives an instruction to retransmit msg1 / A or receives an instruction to power ramp up, the UE will increase the PREAMBLE_POWER_RAMPING_COUNTER by 1 and perform a retransmission of msg1 / msgA.

[0276] In one implementation, the UE may save the pre-initialized counter value to a temporary power counter, or assign the pre-initialized counter value to a new variable, such as a temporary preamble power ramping counter PREAMBLE_POWER_RAMPING_COUNTER_TEMPORARY. The conditions under which the UE performs the above-mentioned saving operation may include:

[0277] Based on network instructions;

[0278] The newly triggered random access process occurs after the random access process used for early synchronization (for the convenience of description, this process may be referred to as the first random access process);

[0279] The newly triggered random access procedure occurs within a first duration after the first random access procedure is completed. For example, after completing the first random access procedure, the UE starts a first timer. If the first timer is in a running state when the new random access procedure is triggered, the above operation is performed. In addition, the first timer stop condition includes: triggering a new random access procedure.

[0280] Optionally, after the UE performs the above-mentioned saving operation, it starts a second timer. If a PDCCH order for early synchronization is received during the operation of the second timer, and the candidate index (candidate index) contained in the PDCCH order is the same as the candidate cell index corresponding to the first random process, then when the RACH process is initialized, the value of PREAMBLE_POWER_RAMPING_COUNTER can be set to the value corresponding to the temporary power counter (temporary power counter), or the value corresponding to the variable PREAMBLE_POWER_RAMPING_COUNTER_TEMPORARY. Otherwise, the saved temporary power counter (temporary power counter) is deleted or the variable PREAMBLE_POWER_RAMPING_COUNTER_TEMPORARY is set to 1.

[0281] Optionally, the UE may set the value of the preamble power ramping counter (PREAMBLE_POWER_RAMPING_COUNTER) to the value corresponding to the temporary power counter (temporary power counter) or the value corresponding to a variable such as PREAMBLE_POWER_RAMPING_COUNTER_TEMPORARY), and then delete the saved temporary power counter or set the variable such as PREAMBLE_POWER_RAMPING_COUNTER_TEMPORARY to 1.

[0282] Scenario three: If the power ramp-up LTM synchronizes an independent counter in advance, such as PREAMBLE_POWER_RAMPING_COUNTER_LTM. The UE maintains an independent PREAMBLE_POWER_RAMPING_COUNTER_LTM for each candidate cell or each advance synchronization process. The UE continues to maintain the counter after the first transmission / after the random access process is completed. If the UE receives an indication to retransmit msg1 / message A or receives an indication to increase power, the UE will add 1 to PREAMBLE_POWER_RAMPING_COUNTER_LTM and perform retransmission of msg1 / msgA. If the UE receives an indication message instructing the UE to initiate a new transmission of msg1 / msgA to the candidate cell after the new transmission or retransmission, the UE may not add one to the counter and determine the target power based on the currently stored counter value.

[0283] S1504. If the UE receives an LTM cell switch command instructing the UE to switch to the target cell, the UE resets the counter. The counters of other candidate cells may be reset or retained. If the network updates or releases the candidate cell, the counters associated with the candidate cell also need to be reset.

[0284] In this embodiment of the present application, the UE may determine and / or transmit the transmit power of msg1 / msgA / preamble based on the following parameters:

[0285] Preamble Received Target Power: initial Random Access Preamble power for 4-step RA type;

[0286] msgA-Preamble Received Target Power: initial Random Access Preamble power for 2-step RA type);

[0287] Power Ramping Step: the power-ramping factor;

[0288] msgA-PreamblePowerRampingStep: the power ramping factor for MSGA preamble.

[0289] Example 2: UE maintains independent counters / variables and UE autonomous triggering.

[0290] As shown in FIG16 , this example may include one or more of the following steps:

[0291] S1601. The network provides candidate cell pre-configuration information to the UE. The candidate cell pre-configuration information includes at least one of the following:

[0292] configuration of at least one candidate cell;

[0293] Resources and / or configuration for the UE to perform uplink synchronization with at least one candidate cell;

[0294] measurement and / or reporting configuration of at least one candidate cell;

[0295] L1 measurement / L3 measurement and / or reporting configuration;

[0296] L1 measurement configuration and / or L3 measurement configuration;

[0297] L1 measurement reporting configuration and / or L3 measurement reporting configuration.

[0298] S1602: The UE monitors the candidate cell based on the pre-configured candidate cell configuration information. The monitoring of the candidate cell may be based on L1 measurement and / or L3 measurement.

[0299] S1603. The UE triggers an early synchronization process. This early synchronization can be triggered autonomously by the UE. The UE determines whether to perform an early synchronization process on at least one candidate cell based on the measurement results. Specifically, the early synchronization process can be triggered based on a measurement event or a preconfigured threshold.

[0300] S1604: The UE transmits message 1 / message A / preamble (msg1 / msgA / preamble) multiple times in succession based on a preconfigured number of preamble transmissions. Each time a transmission is performed, the power is ramped up. For example, the UE increments PREAMBLE_POWER_RAMPING_COUNTER_LTM by 1 and performs subsequent retransmissions of msg1 / msgA.

[0301] In the embodiment of the present application, the power control problem when retransmitting the preamble during the early synchronization process of LTM can be solved. In the early synchronization scenario provided in the embodiment of the present application, the UE maintains power ramp-up during subsequent preamble transmissions.

[0302] Figure 17 is a schematic structural diagram of a communication device 1700 according to an embodiment of the present application. The communication device 1700 includes a processor 1710, which can call and execute a computer program from a memory to enable the communication device 1700 to implement the method in the embodiment of the present application.

[0303] In one embodiment, the communication device 1700 may further include a memory 1720. The processor 1710 may call and execute a computer program from the memory 1720 to enable the communication device 1700 to implement the method in the embodiment of the present application.

[0304] The memory 1720 may be a separate device independent of the processor 1710 , or may be integrated into the processor 1710 .

[0305] In one embodiment, the communication device 1700 may further include a transceiver 1730 , and the processor 1710 may control the transceiver 1730 to communicate with other devices. Specifically, the transceiver 1730 may send information or data to other devices, or receive information or data sent by other devices.

[0306] The transceiver 1730 may include a transmitter and a receiver. The transceiver 1730 may further include an antenna, and the number of antennas may be one or more.

[0307] In one embodiment, the communication device 1700 may be a network device of an embodiment of the present application, and the communication device 1700 may implement the corresponding processes implemented by the network device in each method of the embodiment of the present application. For the sake of brevity, they will not be repeated here.

[0308] In one embodiment, the communication device 1700 may be a terminal device of an embodiment of the present application, and the communication device 1700 may implement the corresponding processes implemented by the terminal device in each method of the embodiment of the present application. For the sake of brevity, they will not be repeated here.

[0309] 18 is a schematic structural diagram of a chip 1800 according to an embodiment of the present application. The chip 1800 includes a processor 1810, which can call and execute a computer program from a memory to implement the method according to the embodiment of the present application.

[0310] In one embodiment, the chip 1800 may further include a memory 1820. The processor 1810 may call and execute a computer program from the memory 1820 to implement the method executed by the terminal device or the network device in the embodiment of the present application.

[0311] The memory 1820 may be a separate device independent of the processor 1810 , or may be integrated into the processor 1810 .

[0312] In one embodiment, the chip 1800 may further include an input interface 1830. The processor 1810 may control the input interface 1830 to communicate with other devices or chips, and specifically, may obtain information or data sent by other devices or chips.

[0313] In one embodiment, the chip 1800 may further include an output interface 1840. The processor 1810 may control the output interface 1840 to communicate with other devices or chips, and specifically, may output information or data to other devices or chips.

[0314] In one embodiment, the chip can be applied to the network device in the embodiments of the present application, and the chip can implement the corresponding processes implemented by the network device in each method of the embodiments of the present application. For the sake of brevity, they will not be repeated here.

[0315] In one embodiment, the chip can be applied to the terminal device in the embodiments of the present application, and the chip can implement the corresponding processes implemented by the terminal device in each method of the embodiments of the present application. For the sake of brevity, they will not be repeated here.

[0316] The chips used in the network device and the terminal device may be the same chip or different chips.

[0317] 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.

[0318] The processor mentioned above may be a general-purpose processor, a digital signal processor (DSP), a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or other programmable logic devices, transistor logic devices, discrete hardware components, etc. The general-purpose processor mentioned above may be a microprocessor or any conventional processor, etc.

[0319] The memory mentioned above may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. 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).

[0320] 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.

[0321] Figure 19 is a schematic block diagram of a communication system 1900 according to an embodiment of the present application. The communication system 1900 includes a terminal device 1910 and a network device 1920. The terminal device 1910 is used to initiate an early synchronization process, wherein the transmission power corresponding to the early synchronization process is determined based on the first information. The network device 1920 is used to send the first information, and the first information is used to determine the transmission power corresponding to the early synchronization process of the terminal device. The terminal device 1910 can be used to implement the corresponding functions implemented by the terminal device in the above method, and the network device 1920 can be used to implement the corresponding functions implemented by the network device in the above method. For the sake of brevity, it will not be repeated here.

[0322] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When software is used for implementation, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function in accordance with the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website, computer, server or data center by wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) mode to another website, computer, server or data center. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrations. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium (eg, a solid state disk (SSD)).

[0323] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0324] 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.

[0325] 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 modifications 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 within 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 communication method, comprising: The terminal device initiates an early synchronization process, wherein the transmission power corresponding to the early synchronization process is determined based on the first information.

2. The method according to claim 1, wherein: The terminal device initiates the early synchronization process, including: The terminal device initiates one or more first random access processes to one or more candidate cells; The transmission power of the second information in the one or more first random access processes is determined based on the first information.

3. The method according to claim 2, wherein: The second information includes message 1, message A or a preamble code in the first random access process.

4. The method according to any one of claims 1 to 3, wherein: The first information includes the number of power ramp-up times in the advance synchronization process.

5. The method according to any one of claims 1 to 4, wherein: The first information includes a value of a first counter, where the value of the first counter is used to indicate the number of power ramp-up times in the advance synchronization process.

6. The method according to claim 5, wherein: The first counter is a counter multiplexed with advance synchronization and random access, or a counter dedicated to advance synchronization.

7. The method according to claim 6, wherein: The first counter is a preamble power rise counter, or a preamble power rise counter of a mobility LTM triggered by layer 1 or layer 2.

8. The method according to any one of claims 5 to 7, wherein: The method further comprises: In the case where the first counter is a counter dedicated to advance synchronization, the terminal device does not reset the first counter when triggering the second random access process to the same cell as the first random access process, and resets the first counter when triggering the second random access process to a cell different from the first random access process.

9. The method according to any one of claims 5 to 8, wherein: The method further comprises: In the case where the first counter is a counter multiplexed with advance synchronization and random access, the terminal device resets the first counter when triggering the second random access process.

10. The method according to claim 8 or 9, wherein: The method further comprises: Before performing initialization of the second random access procedure, the terminal device performs a first operation, where the first operation is used to temporarily save the value of the first counter.

11. The method according to claim 10, wherein: The first operation includes saving the value of the first counter into a temporary counter and / or assigning the value to a first variable.

12. The method according to claim 10 or 11, wherein: The conditions for performing the first operation include at least one of the following: The network device instructs to execute the first operation; The second random access process occurs after the first random access process; The second random access process occurs within a first time period after the first random access process is completed.

13. The method according to claim 12, wherein: The method further comprises: After completing the first random access process, the terminal device starts a first timer, where the first timer is used to determine the first duration; The terminal device performs a first operation, including: the terminal device performs the first operation when the second random access process is triggered and the first timer is in a running state.

14. The method according to claim 13, wherein: The stop condition of the first timer includes: triggering the second random access process.

15. The method according to any one of claims 12 to 14, wherein: The method further comprises: After executing the first operation, the terminal device starts a second timer, where the second timer is used to determine the validity period of the temporarily saved value of the first counter.

16. The method according to claim 15, wherein: The method further comprises: During the operation of the second timer, the terminal device receives a downlink command for early synchronization, and the candidate index in the downlink command is the same as the candidate cell index corresponding to the first random access process. Then, in the initialization of the second random access process, the value of the second counter corresponding to the second random access process is set to the value of the temporary counter or the value of the first variable.

17. The method according to claim 16, wherein: The method further comprises: The terminal device deletes the value of the temporary counter or sets the value of the first variable to an initial value.

18. The method according to any one of claims 1 to 17, wherein: The first information includes power control information, and the power control information is used to determine the transmission power of message 1, message A or preamble code sent by the terminal device in the first random access process.

19. The method according to claim 18, wherein: The power control information includes a power value, or the power control information includes an offset value and / or a ramp-up value for adjusting the current transmission power.

20. The method according to any one of claims 1 to 19, wherein: The first information includes new transmission and retransmission indication information, and the new transmission and retransmission indication information is used to indicate new transmission or retransmission.

21. The method according to claim 20, wherein: The new transmission retransmission indication information is used to indicate the number of retransmissions.

22. The method according to any one of claims 1 to 21, wherein: The method further comprises: The terminal device receives downlink control information, where the downlink control information is used to trigger the early synchronization process and / or one or more first random access processes.

23. The method according to claim 22, wherein: The downlink control information is used to indicate at least one of the following: Candidate cell index; Power control information; New transmission and retransmission indication information; Random access resource indication information; Bandwidth part BWP indication information; Transmission reception point TRP index.

24. The method according to claim 23, wherein: The random access resource indication information includes at least one of the following: a random access preamble code index, an uplink indication, a supplementary uplink indication, a synchronization signal / physical broadcast channel block SSB index, and a physical random access channel mask index.

25. The method according to claim 23 or 24, wherein: The downlink control information includes a physical downlink control channel PDCCH command, and the PDCCH command is used to instruct the terminal device to initiate an early synchronization process to one or more candidate cells.

26. The method according to any one of claims 23 to 25, wherein: The terminal device initiates one or more first random access processes to one or more candidate cells, including: When the received downlink control information includes a new transmission indication corresponding to the first random access procedure, the terminal device performs initialization of the first random access procedure; The terminal device sends second information of the first random access process to one or more candidate cells based on the preconfigured power, and sets the value of the first counter used for power climbing to an initial value.

27. The method according to claim 26, wherein: The preconfigured power is a target power for receiving a preamble code of the second information.

28. The method according to any one of claims 22 to 27, wherein: The terminal device initiating one or more first random access processes to one or more candidate cells further includes: When the received downlink control information includes a retransmission indication or a power climbing indication corresponding to the first random access process, the terminal device retransmits the second information of the first random access process to one or more candidate cells and increases the value of the first counter.

29. The method according to claim 28, wherein: The terminal device initiates one or more first random access processes to one or more candidate cells, further comprising: After the terminal device newly transmits or retransmits the second information of the first random access process, if the received downlink control information includes a new transmission indication corresponding to the first random access process, the value of the first counter is not increased, and the transmission power of the second information is determined based on the current value of the first counter.

30. The method according to any one of claims 1 to 21, wherein: The terminal device initiates one or more first random access processes to one or more candidate cells, including: The terminal device sends the second information of the first random access process to the one or more candidate cells multiple times in succession based on the preconfigured number of preamble code transmissions, and the transmission power increases once each time the second information is sent.

31. The method according to any one of claims 1 to 30, wherein: The method further comprises: The terminal device receives a cell switching command, where the cell switching command indicates a target cell for switching of the terminal device; The terminal device resets the counter corresponding to the target cell for early synchronization.

32. The method according to claim 31, wherein: The method further comprises: The terminal device retains or resets counters for early synchronization of other cells among multiple candidate cells except the target cell.

33. The method according to claim 31 or 32, wherein: The method further comprises: When a network device updates or releases a candidate cell, the terminal device resets a counter for early synchronization associated with the candidate cell.

34. The method according to any one of claims 1 to 33, wherein: The method further comprises: The terminal device receives candidate cell pre-configuration information, where the candidate cell pre-configuration information includes at least one of the following: configuration of at least one candidate cell; Resources and / or configuration for performing uplink synchronization to at least one candidate cell; a measurement configuration and / or a reporting configuration of at least one candidate cell; L1 measurement configuration and / or L3 measurement configuration; L1 measurement reporting configuration and / or L3 measurement reporting configuration.

35. The method of claim 34, wherein: The method further comprises: The terminal device performs measurement and reporting on the candidate cell based on the pre-configuration information of the candidate cell, wherein the measurement includes L1 measurement and / or L3 measurement, and the measurement reporting is carried by an RRC message or UCI or MAC CE.

36. The method according to any one of claims 1 to 35, wherein: The advance synchronization process is triggered based on an instruction from the terminal device based on a network device.

37. The method according to any one of claims 1 to 35, wherein: The advance synchronization process is triggered autonomously by the terminal device.

38. The method according to claim 36 or 37, wherein: The advance synchronization process is triggered based on a measurement result of the terminal device, and the measurement result is determined based on a measurement event and / or a preconfigured threshold.

39. A communication method, comprising: The network device sends first information, where the first information is used to determine the transmission power corresponding to the early synchronization process of the terminal device.

40. The method of claim 39, wherein: The first information includes power control information, and the power control information is used to determine the transmission power of message 1, message A or preamble code sent by the terminal device in the first random access process.

41. The method of claim 40, wherein: The power control information includes a power value, or the power control information includes an offset value and / or a ramp-up value for adjusting the current transmission power.

42. The method according to any one of claims 39 to 41, wherein: The first information includes new transmission and retransmission indication information, and the new transmission and retransmission indication information is used to indicate new transmission or retransmission.

43. The method of claim 42, wherein: The new transmission retransmission indication information is used to indicate the number of retransmissions.

44. A method according to any one of claims 39 to 43, wherein: The network device sends first information, including: The network device sends downlink control information, where the downlink control information is used to trigger the early synchronization process and / or one or more first random access processes.

45. The method of claim 44, wherein: The downlink control information is used to indicate at least one of the following: Candidate cell index; Power control information; New transmission and retransmission indication information; Random access resource indication information; BWP instruction information; TRP index.

46. ​​The method of claim 45, wherein: The random access resource indication information includes at least one of the following: a random access preamble code index, an uplink indication, a supplementary uplink indication, an SSB index, and a physical random access channel mask index.

47. The method according to claim 45 or 46, wherein: The downlink control information includes a physical downlink control channel PDCCH command, and the PDCCH command is used to instruct the terminal device to initiate an early synchronization process to one or more candidate cells.

48. A method according to any one of claims 39 to 47, wherein: The method further comprises: The network device sends a cell switching command, where the cell switching command indicates a target cell to which the terminal device switches.

49. The method according to any one of claims 39 to 48, wherein: The method further comprises: The network device sends candidate cell pre-configuration information, where the candidate cell pre-configuration information includes at least one of the following: configuration of at least one candidate cell; Resources and / or configuration for performing uplink synchronization to at least one candidate cell; a measurement configuration and / or a reporting configuration of at least one candidate cell; L1 measurement configuration and / or L3 measurement configuration; L1 measurement reporting configuration and / or L3 measurement reporting configuration.

50. The method of claim 49, wherein: The method further comprises: The network device receives a report from the terminal device that the terminal device performs measurement on the candidate cell based on the candidate cell pre-configuration information, wherein the measurement includes L1 measurement and / or L3 measurement, and the measurement report is carried by an RRC message or UCI or MAC CE.

51. A terminal device, comprising: The sending unit is used to initiate an early synchronization process, wherein the sending power corresponding to the early synchronization process is determined based on the first information.

52. The terminal device according to claim 51, wherein: The sending unit is further used to initiate one or more first random access processes to one or more candidate cells; The transmission power of the second information in the one or more first random access processes is determined based on the first information.

53. The terminal device according to claim 52, wherein: The second information includes message 1, message A or a preamble code in the first random access process.

54. The terminal device according to any one of claims 51 to 53, wherein: The first information includes the number of power ramp-up times in the advance synchronization process.

55. The terminal device according to any one of claims 51 to 54, wherein: The first information includes a value of a first counter, where the value of the first counter is used to indicate the number of power ramp-up times in the advance synchronization process.

56. The terminal device according to claim 55, wherein: The first counter is a counter multiplexed with advance synchronization and random access, or a counter dedicated to advance synchronization.

57. The terminal device according to claim 56, wherein: The first counter is a preamble power rise counter, or a preamble power rise counter of an LTM.

58. The terminal device according to any one of claims 55 to 57, further comprising: A first processing unit is configured to, when the first counter is a counter dedicated to advance synchronization, not reset the first counter when a second random access procedure is triggered to the same cell as the first random access procedure, and reset the first counter when the second random access procedure is triggered to a cell different from the first random access procedure.

59. The terminal device according to any one of claims 55 to 58, further comprising: The second processing unit is configured to reset the first counter when triggering a second random access procedure if the first counter is a counter multiplexed with advance synchronization and random access.

60. According to the terminal device according to claim 58 or 59, the second processing unit is further used to perform a first operation before performing initialization of the second random access process, and the first operation is used to temporarily save the value of the first counter.

61. The terminal device according to claim 60, wherein: The first operation includes saving the value of the first counter into a temporary counter and / or assigning the value to a first variable.

62. The terminal device according to claim 60 or 61, wherein: The conditions for performing the first operation include at least one of the following: The network device instructs to execute the first operation; The second random access process occurs after the first random access process; The second random access process occurs within a first time period after the first random access process is completed.

63. The terminal device according to claim 62, wherein: The second processing unit is further configured to start a first timer after completing the first random access process, wherein the first timer is configured to determine the first duration; When the second random access procedure is triggered and the first timer is in a running state, the first operation is performed.

64. The terminal device according to claim 63, wherein: The stop condition of the first timer includes: triggering the second random access process.

65. According to the terminal device according to any one of claims 62 to 64, the second processing unit is also used to start a second timer after executing the first operation, and the second timer is used to determine the effective time of the value of the temporarily saved first counter.

66. According to the terminal device according to claim 65, the second processing unit is also used to receive a downlink command for early synchronization during the operation of the second timer, and the candidate index in the downlink command is the same as the candidate cell index corresponding to the first random access process. Then, in the initialization of the second random access process, the value of the second counter corresponding to the second random access process is set to the value of the temporary counter or the value of the first variable.

67. According to the terminal device according to claim 66, the second processing unit is also used to delete the value of the temporary counter or set the value of the first variable to an initial value.

68. The terminal device according to any one of claims 50 to 67, wherein: The first information includes power control information, and the power control information is used to determine the transmission power of message 1, message A or preamble code sent by the terminal device in the first random access process.

69. The terminal device according to claim 68, wherein: The power control information includes a power value, or the power control information includes an offset value and / or a ramp-up value for adjusting the current transmission power.

70. The terminal device according to any one of claims 51 to 69, wherein: The first information includes new transmission and retransmission indication information, and the new transmission and retransmission indication information is used to indicate new transmission or retransmission.

71. The terminal device according to claim 70, wherein: The new transmission retransmission indication information is used to indicate the number of retransmissions.

72. The terminal device according to any one of claims 51 to 71, further comprising: The first receiving unit is used to receive downlink control information, where the downlink control information is used to trigger the early synchronization process and / or one or more first random access processes.

73. The terminal device according to claim 72, wherein: The downlink control information is used to indicate at least one of the following: Candidate cell index; Power control information; New transmission and retransmission indication information; Random access resource indication information; Bandwidth part BWP indication information; Transmission reception point TRP index.

74. The terminal device according to claim 73, wherein: The random access resource indication information includes at least one of the following: a random access preamble code index, an uplink indication, a supplementary uplink indication, an SSB index, and a physical random access channel mask index.

75. The terminal device according to claim 73 or 74, wherein: The downlink control information includes a PDCCH command, and the PDCCH command is used to instruct the terminal device to initiate an early synchronization process to one or more candidate cells.

76. The terminal device according to any one of claims 73 to 75, wherein: The terminal device further includes: A third processing unit, configured to, when the received downlink control information includes a new transmission indication corresponding to the first random access procedure, perform initialization of the first random access procedure and set the value of the first counter for power climbing to an initial value; The sending unit is further configured to send second information of the first random access process to one or more candidate cells based on a preconfigured power.

77. The terminal device according to claim 76, wherein: The preconfigured power is a target power for receiving a preamble code of the second information.

78. The terminal device according to any one of claims 72 to 77, wherein: The terminal device further includes: A fourth processing unit, configured for the terminal device to increase the value of the first counter when the received downlink control information includes a retransmission indication or a power climbing indication corresponding to the first random access process; The sending unit is further configured to retransmit second information of the first random access process to one or more candidate cells.

79. The terminal device according to claim 78, wherein: The fourth processing unit is also used to, after the second information of the first random access process is newly transmitted or retransmitted, when the received downlink control information includes a new transmission indication corresponding to the first random access process, not increase the value of the first counter, and determine the transmission power of the second information based on the current value of the first counter.

80. The terminal device according to any one of claims 51 to 71, wherein: The sending unit is further configured to send second information of the first random access process to one or more candidate cells multiple times in succession based on a preconfigured number of preamble code transmissions, and each time the second information is sent, the sending power increases once.

81. The terminal device according to any one of claims 51 to 80, further comprising: A second receiving unit, configured to receive a cell switching command, wherein the cell switching command indicates a target cell for switching of the terminal device; The fifth processing unit is used to reset the counter for early synchronization corresponding to the target cell.

82. According to the terminal device of claim 81, the fifth processing unit is further used to retain or reset the counters used for early synchronization of other cells among the multiple candidate cells except the target cell.

83. According to the terminal device according to claim 81 or 82, the fifth processing unit is also used to reset the counter for early synchronization associated with a candidate cell when the network device updates or releases the candidate cell.

84. The terminal device according to any one of claims 51 to 83, further comprising: The third receiving unit is configured to receive candidate cell pre-configuration information, where the candidate cell pre-configuration information includes at least one of the following: configuration of at least one candidate cell; Resources and / or configuration for performing uplink synchronization to at least one candidate cell; a measurement configuration and / or a reporting configuration of at least one candidate cell; L1 measurement configuration and / or L3 measurement configuration; L1 measurement reporting configuration and / or L3 measurement reporting configuration.

85. The terminal device according to claim 84, further comprising: The sixth processing unit is configured to perform measurement and reporting on the candidate cell based on the pre-configuration information of the candidate cell, wherein the measurement includes L1 measurement and / or L3 measurement, and the measurement reporting is carried by an RRC message or UCI or MAC CE.

86. The terminal device according to any one of claims 51 to 85, wherein: The advance synchronization process is triggered based on an instruction from the terminal device based on a network device.

87. The terminal device according to any one of claims 51 to 85, wherein: The advance synchronization process is triggered autonomously by the terminal device.

88. The terminal device according to claim 86 or 87, wherein: The advance synchronization process is triggered based on a measurement result of the terminal device, where the measurement result is determined based on a measurement event and / or a preconfigured threshold.

89. A network device comprising: The first sending unit is used to send first information, where the first information is used to determine the sending power corresponding to the early synchronization process of the terminal device.

90. The network device according to claim 89, wherein: The first information includes power control information, and the power control information is used to determine the transmission power of message 1, message A or preamble code sent by the terminal device in the first random access process.

91. The network device according to claim 90, wherein: The power control information includes a power value, or the power control information includes an offset value and / or a ramp-up value for adjusting the current transmission power.

92. The network device according to any one of claims 89 to 91, wherein: The first information includes new transmission and retransmission indication information, and the new transmission and retransmission indication information is used to indicate new transmission or retransmission.

93. The network device according to claim 92, wherein: The new transmission retransmission indication information is used to indicate the number of retransmissions.

94. According to the network device according to any one of claims 89 to 93, the first sending unit is also used to send downlink control information, and the downlink control information is used to trigger the early synchronization process and / or one or more first random access processes.

95. The network device according to claim 94, wherein: The downlink control information is used to indicate at least one of the following: Candidate cell index; Power control information; New transmission and retransmission indication information; Random access resource indication information; BWP instruction information; TRP index.

96. The network device according to claim 95, wherein: The random access resource indication information includes at least one of the following: a random access preamble code index, an uplink indication, a supplementary uplink indication, an SSB index, and a physical random access channel mask index.

97. The network device according to claim 95 or 96, wherein: The downlink control information includes a physical downlink control channel PDCCH command, and the PDCCH command is used to instruct the terminal device to initiate an early synchronization process to one or more candidate cells.

98. The network device according to any one of claims 89 to 97, further comprising: The second sending unit is used to send a cell switching command, where the cell switching command indicates a target cell to which the terminal device switches.

99. The network device according to any one of claims 89 to 98, further comprising: The third sending unit is configured to send candidate cell pre-configuration information, where the candidate cell pre-configuration information includes at least one of the following: configuration of at least one candidate cell; Resources and / or configuration for performing uplink synchronization to at least one candidate cell; a measurement configuration and / or a reporting configuration of at least one candidate cell; L1 measurement configuration and / or L3 measurement configuration; L1 measurement reporting configuration and / or L3 measurement reporting configuration.

100. The network device according to claim 99, further comprising: A receiving unit is used to receive a report of the terminal device performing measurement on the candidate cell based on the pre-configuration information of the candidate cell, wherein the measurement includes L1 measurement and / or L3 measurement, and the measurement report is carried by an RRC message or UCI or MAC CE.

101. A terminal device, comprising: 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 so that the terminal device executes the method as claimed in any one of claims 1 to 38.

102. A network device comprising: 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 so that the network device executes the method as claimed in any one of claims 39 to 50.

103. A chip, comprising: A processor, configured to call and run a computer program from a memory so that a device equipped with the chip executes a method as claimed in any one of claims 1 to 38 or any one of claims 39 to 50.

104. A computer-readable storage medium for storing a computer program, which, when executed by a device, causes the device to perform a method as claimed in any one of claims 1 to 38 or any one of claims 39 to 50.

105. A computer program product comprising computer program instructions for causing a computer to perform a method as claimed in any one of claims 1 to 38 or any one of claims 39 to 50.

106. A computer program causing a computer to perform a method as claimed in any one of claims 1 to 38 or any one of claims 39 to 50.

107. A communication system comprising: A terminal device, configured to execute the method according to any one of claims 1 to 38; A network device, configured to execute the method as claimed in any one of claims 39 to 50.

Images