Initial access method and apparatus

Abstract

The present application relates to the field of wireless communications, and relates to an initial access method and apparatus. A terminal device may expect to acquire a PL between the terminal device and a first network device in a random access process. However, an existing terminal device performs power ramping when transmitting msg 1 multiple times, and the transmission power for each transmission of the msg 1 is different, causing a first network device to be unable to determine the transmission power of the received msg 1. In one solution of the present application, the transmission powers for transmitting the msg 1 multiple times by the terminal device are the same. In another solution, the transmission power of the msg 1 corresponds to a sequence in the msg 1 and / or a time-frequency resource used for transmitting the msg 1. In this way, for the msg1 successfully received by the first network device from the terminal device each time, the transmission power of the received msg 1 can be learned to calculate the PL, so that the terminal device can perform power control when transmitting information such as msg 3, thereby improving communication performance.

Description

Initial access method and device

[0001] This application claims priority to Chinese patent application filed on January 27, 2025, with application number 202510126711.1 and entitled "Initial Access Method and Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of wireless communication, and more specifically, to an initial access method and apparatus. Background Technology

[0003] In some communication systems, uplink (UL) density can increase network uplink capacity. For example, transmission reception points (TRPs) with only uplink reception can be deployed at different sites to increase the density of uplink reception points, thereby expanding the network's uplink capacity and enhancing the system's uplink transmission performance.

[0004] Currently, a terminal can send a sounding reference signal (SRS) to a Telephone Request Pointer (TRP) that only receives uplink signals. The TRP can measure the SRS and report its received power back to the macro base station. Based on the received power of the SRS and the pre-configured transmit power of the SRS for the terminal, the macro base station can obtain the path loss (PL) between the terminal and the TRP that only receives uplink signals, thereby improving the communication performance between the terminal and the TRP in subsequent communications. Summary of the Invention

[0005] This application provides an initial access method and apparatus that can further improve the communication performance between a terminal and a TRP that only receives uplink data.

[0006] Firstly, an initial access method is provided, which can be executed by a terminal device or by a module applied to the terminal device. For ease of understanding and description, the following description uses a terminal device as the executing entity. The method includes: after the terminal device sends a first random access sequence to a first network device with a first transmission power, it starts a first timer. Then, if the first timer times out, the terminal device again sends the first random access sequence to the first network device with the aforementioned first transmission power.

[0007] It is understandable that the terminal device uses the same transmission power when sending the first random access sequence twice, which is the aforementioned first transmission power.

[0008] As an example, the first network device mentioned above can be the network device that the terminal device wants to access. For example, only the uplink received TRP.

[0009] Based on the above scheme, the terminal device can transmit the same first random access sequence multiple times, all at the first transmission power. Thus, regardless of which first random access sequence the first network device (e.g., a TRP with only uplink reception) successfully receives from the terminal device, it can know that the transmission power of that first random access sequence is the first transmission power. The first network device or other network devices (e.g., the second network device described later) can determine the power level (PL) between the terminal device and the first network device based on the first transmission power and the received power of the first random access sequence, and indicate this PL to the terminal device. Alternatively, the first network device or other network devices (e.g., the second network device described later) can indicate the received power of the first random access sequence to the terminal device. The terminal device can determine the PL between itself and the first network device based on the received power of the first random access sequence and the first transmission power. Furthermore, the terminal device can use this PL to perform power control on the information to be transmitted in subsequent communications, thereby improving the communication performance between the terminal and the first network device in subsequent communications. It is understandable that the above scheme occurs during the initial access process. Therefore, compared with the scheme of obtaining PL through SRS, in the above scheme, the terminal device can obtain PL earlier, and then use PL to perform power control on SRS and information sent before SRS (e.g., random access messages), thereby further improving the communication quality between the terminal and the first network device while saving energy at the terminal.

[0010] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the terminal device receiving indication information from the second network device for a first PL, the first PL being a PL between the terminal device and the first network device.

[0011] For example, the indication information for the first PL can indicate the first PL. For instance, the indication information for the first PL can include the value of the first PL, so that the terminal device can obtain the value of the first PL from the aforementioned indication information. As another example, the indication information for the first PL can include the received power of the first random access sequence, so that the terminal device can determine the first PL based on the received power of the first random access sequence and the first transmitted power.

[0012] In conjunction with the first aspect, in some implementations of the first aspect, the indication information of the first PL sent by the second network device is carried in the random access response message. Further, the method also includes: in response to the random access response message, the terminal device sends a random access message to the first network device, wherein the transmission power of the random access message is determined based on the first PL.

[0013] For example, the random access message described above can be used to resolve conflicts during random access. For instance, the random access message could be message 3 (message 3, msg 3) or another message.

[0014] Based on the above scheme, the terminal device can use the first power level (PL) to perform power control on the random access message during the random access phase, thereby ensuring the communication quality between the terminal and the first network device while saving power. It is understood that the existing scheme obtains the PL through the signal received response (SRS), and the SRS is sent after random access; therefore, the terminal device cannot perform power control on the random access message using the existing scheme. Therefore, in the above scheme, the terminal device can obtain the PL earlier, thus using it earlier, and further improving the communication quality between the terminal and the first network device while saving power.

[0015] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: the terminal device receiving first configuration information from the second network device; and the terminal device determining the first transmission power based on the first configuration information.

[0016] In conjunction with the first aspect, in some implementations of the first aspect, the terminal device and the first network device only have uplink transmission. Here, the aforementioned uplink transmission can be understood as, or replaced by, uplink reception.

[0017] Secondly, an initial access method is provided. This method can be executed by the terminal device or by a module applied to the terminal device. For ease of understanding and description, the following description uses the terminal device as the executing entity.

[0018] For example, the method includes: a terminal device receiving second configuration information from a second network device; and the terminal device sending a first random access sequence to a first network device with a first transmission power based on the second configuration information.

[0019] The second configuration information can indicate the correspondence between N random access sequences and N transmission powers, or it can indicate the correspondence between N time-frequency resources and N transmission powers, or it can indicate the correspondence between N random access sequences, N time-frequency resources, and N transmission powers, where N is a positive integer. The N transmission powers may include the aforementioned first transmission power.

[0020] As an example, the first network device mentioned above can be the network device that the terminal device wants to access. For example, only the uplink received TRP.

[0021] Based on the above scheme, the terminal device can send a first random access sequence to the first network device based on the correspondence between time-frequency resources and / or random access sequences and transmit power configured in the second configuration information. In this way, the transmit power of the first random access sequence can be associated with the first random access sequence itself and / or the time-frequency resources used to transmit the first random access sequence. In some examples, the above scheme enables the first network device or the second network device to know the transmit power corresponding to the first random access sequence after the first network device receives it. Through the first transmit power and the received power of the first random access sequence, the terminal device can obtain the power level (PL) between itself and the first network device, thereby improving the communication performance between the terminal and the first network device in subsequent communications. It is understood that the above scheme occurs during the initial access process. Therefore, compared to the scheme of obtaining the PL through SRS, in the above scheme, the terminal device can obtain the PL earlier and use it earlier, thereby further improving the communication quality between the terminal and the first network device while saving energy.

[0022] In conjunction with the second aspect, in some implementations of the second aspect, the second configuration information includes a first power ramp value.

[0023] For example, the terminal device sending a first random access sequence to the first network device with a first transmission power based on the second configuration information may include: the terminal device determining the first transmission power based on the first power ramp value; and the terminal device sending the first random access sequence to the first network device with the first transmission power on the first time-frequency resource.

[0024] The first time-frequency resource and the first random access sequence can correspond to the first transmission power.

[0025] For example, when the second configuration information indicates the correspondence between N random access sequences and N transmission powers, the first random access sequence corresponds to the first transmission power, which can be understood as the first random access sequence being determined based on the first transmission power. Similarly, the first time-frequency resource corresponds to the first transmission power, which can be understood as the transmission power of the random access sequence transmitted on the first time-frequency resource being the first transmission power.

[0026] For example, when the second configuration information indicates the correspondence between N time-frequency resources and N transmission powers, the first time-frequency resource corresponds to the first transmission power, which can be understood as the first time-frequency resource being determined based on the first transmission power. Similarly, the first random access sequence corresponds to the first transmission power, which can be understood as the transmission power of the first random access sequence being the first transmission power.

[0027] For example, when the second configuration information indicates the correspondence between N random access sequences, N time-frequency resources, and N transmission powers, the first random access sequence corresponds to the first transmission power, which can be understood as the first random access sequence being determined based on the first transmission power. Similarly, the first time-frequency resource corresponds to the first transmission power, which can be understood as the first time-frequency resource being determined based on the first transmission power.

[0028] In conjunction with the second aspect, in some implementations of the second aspect, the method further includes: receiving indication information from the second network device for a first PL, the first PL being a PL between the terminal device and the first network device.

[0029] For example, the indication information for the first PL can indicate the first PL. For instance, the indication information for the first PL can include the value of the first PL, so that the terminal device can obtain the value of the first PL from the aforementioned indication information. As another example, the indication information for the first PL can include the received power of the first random access sequence, so that the terminal device can determine the first PL based on the received power of the first random access sequence and the first transmitted power.

[0030] In conjunction with the second aspect, in some implementations of the second aspect, the indication information of the first PL sent by the second network device is carried in the random access response message. The method may further include: in response to the random access response message, the terminal device sending a random access message to the first network device. The transmission power of the random access message may be determined based on the first PL.

[0031] For example, the random access message described above can be used to resolve conflicts during random access. For instance, the random access message could be msg 3 or another message.

[0032] Based on the above scheme, the terminal device can use the first power level (PL) to perform power control on the random access message during the random access phase, thereby ensuring the communication quality between the terminal and the first network device while saving power. It is understood that the existing scheme obtains the PL through the signal received response (SRS), and the SRS is sent after random access; therefore, the terminal device cannot perform power control on the random access message using the existing scheme. Therefore, in the above scheme, the terminal device can obtain the PL earlier, thus using it earlier, and further improving the communication quality between the terminal and the first network device while saving power.

[0033] In conjunction with the second aspect, in some implementations of the second aspect, the terminal device and the first network device only have uplink transmission. Here, the aforementioned uplink transmission can be understood as, or replaced by, uplink reception.

[0034] Thirdly, an initial access method is provided. This method can be executed by a network device (e.g., a first network device) or by a module applied to the network device (e.g., the first network device). For ease of understanding and description, the following description uses the first network device as the executing entity.

[0035] For example, the method includes: a first network device receiving a first random access sequence from a terminal device; and then, the first network device sending first information to a second network device. The first information may indicate the transmission power of the first random access sequence.

[0036] Based on the above scheme, the first network device can indicate the transmission power of the first random access sequence to the second network device based on the received first random access sequence. In this way, the second network device can enable the terminal device to obtain the power level (PL) between the terminal device and the first network device based on the transmission power of the first random access sequence, thereby further improving the communication quality between the terminal and the first network device while saving energy at the terminal.

[0037] In conjunction with the third aspect, in some implementations of the third aspect, the first information includes an identifier of the first random access sequence, and / or an identifier of the time-frequency resources used to receive the first random access sequence.

[0038] Based on the above scheme, the second network device can determine the transmission power of the first random access sequence based on the identifier of the first random access sequence and / or the identifier of the time-frequency resource used to receive the first random access sequence.

[0039] Fourthly, an initial access method is provided. This method can be executed by a network device (e.g., a second network device) or by a module applied to the network device (e.g., the second network device). For ease of understanding and description, the following description uses the second network device as the executing entity.

[0040] For example, the method includes: a second network device receiving first information from a first network device. The first information may indicate the transmission power of the first random access sequence. Then, based on the first information, the second network device sends indication information of a first power level (PL) to a terminal device. The first PL may be a power level (PL) between the terminal device and the first network device.

[0041] Based on the above scheme, the first network device can enable the terminal device to obtain the PL between the terminal device and the first network device based on the first information, thereby further improving the communication quality between the terminal and the first network device while saving energy in the terminal.

[0042] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the first information includes an identifier of the first random access sequence, and / or an identifier of the time-frequency resources used to receive the first random access sequence.

[0043] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the indication information of the first PL includes: the value of the first PL; the identifier of the first random access sequence; and / or, the identifier of the time-frequency resource used to receive the first random access sequence.

[0044] The beneficial effects of the fourth aspect and any implementation thereof can be found in the third aspect and the intentional effects of the corresponding implementation thereof, which will not be repeated here.

[0045] Fifthly, a communication device is provided, which may be a terminal device or a module applied to a terminal device. For example, the module applied to the terminal device may include a processor, a chip, a chip system, or may include a logic node, logic module, or software capable of implementing all or part of the functions of the terminal device.

[0046] In one exemplary design, the communication device includes a processing unit and a transceiver unit. After transmitting a first random access sequence to a first network device at a first transmission power, the processing unit is configured to: start a first timer. If the first timer times out, the transceiver unit is configured to transmit the first random access sequence to the first network device at the first transmission power.

[0047] In conjunction with the above design of the fifth aspect, in some implementations of the fifth aspect, the transceiver unit is also used to receive indication information from the first PL of the second network device.

[0048] In conjunction with the design described above in the fifth aspect, in some implementations of the fifth aspect, the indication information of the first PL sent by the second network device is carried in a random access response message. The transceiver unit is further configured to: in response to the random access response message, send a random access message to the first network device.

[0049] In conjunction with the above design of the fifth aspect, in some implementations of the fifth aspect, the transceiver unit is further configured to: receive first configuration information from the second network device; the processing unit is further configured to: determine the first transmission power based on the first configuration information.

[0050] The communication device in the above design can implement the technical solution of the first aspect and any implementation thereof, and the beneficial effects are similar to those achieved by the first aspect and corresponding implementation of this application, and will not be repeated here. Furthermore, some implementations of the communication device in the above design can be found in the implementation of the first aspect, and will not be repeated here.

[0051] In another exemplary design, the communication device includes a transceiver unit and a processing unit. The transceiver unit is configured to receive second configuration information from a second network device; the processing unit is configured to, based on the second configuration information, control the transceiver unit to transmit a first random access sequence to the first network device at a first transmission power.

[0052] In conjunction with the above design of the fifth aspect, in some implementations of the fifth aspect, the processing unit is specifically used to: determine the first transmission power based on the first power ramp value; and control the transceiver unit to send the first random access sequence to the first network device on the first time-frequency resource at the first transmission power.

[0053] In conjunction with the above design of the fifth aspect, in some implementations of the fifth aspect, the transceiver unit is also used to: receive indication information from the first PL of the second network device.

[0054] In conjunction with the design described above in the fifth aspect, in some implementations of the fifth aspect, the indication information of the first PL sent by the second network device is carried in a random access response message. The transceiver unit is further configured to: in response to the random access response message, send a random access message to the first network device.

[0055] The communication device in the above design can implement the technical solution of the second aspect and any of its implementations, and the beneficial effects are similar to those achieved by the second aspect and its corresponding implementations of this application, and will not be repeated here. Furthermore, some implementations of the communication device in the above design can be found in the implementations of the second aspect, and will not be repeated here.

[0056] Sixthly, a communication device is provided. This communication device may be a network device or a module applied to a network device. For example, the module applied to the network device may include a processor, a chip, a chip system, or may include logical nodes, logical modules, or software capable of implementing all or part of the functions of the network device.

[0057] In one exemplary design, the communication device includes a transceiver unit. The transceiver unit is configured to: receive a first random access sequence from a terminal device; and send first information to a second network device.

[0058] The communication device in the above design can implement the technical solution of the third aspect and any of its implementations, and the beneficial effects are similar to those achieved by the third aspect and its corresponding implementations of this application, and will not be repeated here. Furthermore, some implementations of the communication device in the above design can be found in the implementations of the third aspect, and will not be repeated here.

[0059] In another exemplary design, the communication device includes a transceiver unit and a processing unit. The transceiver unit is configured to receive first information from a first network device. The processing unit is configured to, based on the first information, control the transceiver unit to send a first PL instruction to a terminal device.

[0060] The communication device in the above design can implement the technical solution of the fourth aspect and any of its implementations, and the beneficial effects are similar to those achieved by the fourth aspect and its corresponding implementations of this application, and will not be repeated here. Furthermore, some implementations of the communication device in the above design can be found in the implementations of the fourth aspect, and will not be repeated here.

[0061] In a seventh aspect, a communication device is provided, comprising: a processor and an interface circuit, the interface circuit being configured to receive signals from other communication devices and transmit them to the processor or to send signals from the processor to other communication devices, the processor being configured to execute the method described in any aspect and any possible implementation thereof via logic circuits or executable code instructions.

[0062] Eighthly, a computer-readable storage medium is provided that stores a computer program (also referred to as code or instructions) that, when executed on a computer, causes the computer to perform the methods in any possible implementation of any of the preceding aspects.

[0063] Ninthly, a computer program product is provided, the computer program product comprising: a computer program (also referred to as code or instructions), which, when the computer program is run, causes a computer to perform a method in any possible implementation of any of the above aspects.

[0064] In a tenth aspect, a chip system is provided, the chip system including one or more processors, the one or more processors being configured to invoke computer instructions to cause the electronic device to perform a method in any possible implementation of any of the above aspects, for example, processing information involved in the above method.

[0065] In one possible design, the chip system also includes a memory for storing computer programs and data, which may be located inside or outside the processor.

[0066] The chip system can consist of chips or include chips and other discrete components.

[0067] One possible design is that the chip system also includes a power supply circuit for supplying power to the chip system.

[0068] Eleventhly, a processor is provided, comprising: an input circuit, an output circuit, and a processing circuit. The processing circuit is configured to receive signals through the input circuit and transmit signals through the output circuit, causing the processor to execute the method in any possible implementation of any of the preceding aspects.

[0069] In specific implementation, the processor can be one or more chips, the input circuit can be input pins, the output circuit can be output pins, and the processing circuit can be transistors, gate circuits, flip-flops, and various logic circuits. The input signal received by the input circuit can be received and input by, for example, but not limited to, a receiver, and the signal output by the output circuit can be, for example, but not limited to, output to and transmitted by a transmitter. Furthermore, the input circuit and the output circuit can be the same circuit, which is used as both the input circuit and the output circuit at different times. This application does not limit the specific implementation of the processor and various circuits.

[0070] In a twelfth aspect, a communication system is provided, comprising the communication apparatus of the fifth aspect and the communication apparatus of the sixth aspect described above. The communication apparatus of the fifth aspect is used to perform the method in any possible implementation of the second aspect, and the communication apparatus of the sixth aspect is used to perform the method in any possible implementation of the third or fourth aspect.

[0071] The beneficial effects of the features corresponding to the first to fourth aspects in the fifth to twelfth aspects can be referred to the relevant descriptions of the first to fourth aspects above. Attached Figure Description

[0072] Figure 1 is a schematic diagram of the architecture of the mobile communication system used in the embodiments of this application;

[0073] Figure 2 is a schematic diagram of a scenario with dense UL deployment corresponding to a co-location site;

[0074] Figure 3 is a schematic diagram of a scenario of dense UL deployment corresponding to different sites, as exemplified in this application.

[0075] Figure 4 is a schematic flowchart of an initial access method provided in an embodiment of this application;

[0076] Figure 5 is a schematic flowchart of another initial access method provided in an embodiment of this application;

[0077] Figure 6 is a schematic diagram of the correspondence between transmission power and random access sequence or time-frequency resources provided in the embodiments of this application;

[0078] Figure 7 is a schematic flowchart of another initial access method 700 provided in an embodiment of this application;

[0079] Figure 8 is a schematic block diagram of a communication device provided in an embodiment of this application;

[0080] Figure 9 is a schematic block diagram of another communication device provided in an embodiment of this application. Detailed Implementation

[0081] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0082] Figure 1 is a schematic diagram of the architecture of a communication system 1000 provided in an embodiment of this application. As shown in Figure 1, the communication system 1000 includes a radio access network (RAN) 100, wherein the RAN 100 includes at least one RAN node (110a and 110b in Figure 1, collectively referred to as 110), and may also include at least one terminal (120a-120j in Figure 1, collectively referred to as 120). The RAN 100 may also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in Figure 1). The terminal 120 is wirelessly connected to the RAN node 110. Terminals and RAN nodes can be interconnected via wired or wireless means. The communication system 1000 may also include a core network 200. The RAN node 110 is connected to the core network 200 via wireless or wired means. The core network equipment in core network 200 and the RAN node 110 in RAN 100 can be independent and different physical devices, or they can be the same physical device that integrates the logical functions of the core network equipment and the logical functions of the RAN node. Communication system 1000 may also include Internet 300.

[0083] RAN 100 can be an evolved universal terrestrial radio access (E-UTRA) system, a new radio (NR) system, or a future radio access system beyond NR as defined in the 3rd generation partnership project (3GPP), or it can be a Wi-Fi system. RAN 100 can also include two or more of the above-mentioned different radio access systems. RAN 100 can also be an open RAN (O-RAN).

[0084] RAN nodes, also known as radio access network devices, RAN entities, or access nodes, are used to help terminals access communication systems wirelessly. In one application scenario, an RAN node can be a base station, an evolved NodeB (eNodeB), a TRP (Transmission Repository Program), a high-frequency base station, a next-generation NodeB (gNB) in a 5th-generation (5G) mobile communication system, a next-generation base station in future mobile communication systems after 5G, or an access node in a Wi-Fi system. Unless otherwise specified, an RAN node can be a macro base station (as shown in Figure 1, 110a), a micro base station or an indoor station (as shown in Figure 1, 110b), a relay node, or a donor node.

[0085] In another application scenario, multiple RAN nodes can collaborate to help terminals achieve wireless access, with different RAN nodes implementing different functions of the base station. For example, a RAN node can be a central unit (CU), a distributed unit (DU), or a radio unit (RU). Here, the CU performs the functions of the base station's Radio Resource Control (RRC) and Packet Data Convergence Protocol (PDCP), and can also perform the functions of the Service Data Adaptation Protocol (SDAP). The DU performs the functions of the base station's Radio Link Control (RANC) and Medium Access Control (MAC) layers, and can also perform some or all of the physical layer functions. For specific descriptions of these protocol layers, refer to the relevant 3GPP technical specifications. The RU can be used to implement radio frequency signal transmission and reception. The CU and DU can be two independent RAN nodes or integrated into the same RAN node, such as within a baseband unit (BBU). The RU can be included in radio frequency equipment, such as in a remote radio unit (RRU) or an active antenna unit (AAU). The CU can be further divided into two types of RAN nodes: CU-control plane and CU-user plane.

[0086] In different systems, RAN nodes may have different names. For example, in an O-RAN system, a CU can be called an open CU (O-CU), a DU can be called an open DU (O-DU), and an RU can be called an open RU (O-RU). The RAN nodes in the embodiments of this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules. For example, a RAN node can be a server loaded with the corresponding software modules. The embodiments of this application do not limit the specific technology or device form used in the RAN nodes. For ease of description, a base station is used as an example of a RAN node in the following description.

[0087] A terminal is a device with wireless transceiver capabilities, capable of sending signals to or receiving signals from a base station. Terminals can also be called terminal equipment, user equipment (UE), mobile station, mobile terminal, etc. Terminals can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, etc. Terminals can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, airplanes, ships, robots, robotic arms, smart home devices, etc. The embodiments of this application do not limit the specific technology or device form used in the terminal.

[0088] Base stations and terminals can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can be deployed on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of the base stations and terminals.

[0089] The roles of base stations and terminals can be relative. For example, the helicopter or drone 120i in Figure 1 can be configured as a mobile base station. For terminals 120j that access the wireless access network 100 through 120i, terminal 120i is a base station; however, for base station 110a, 120i is a terminal, meaning that 110a and 120i communicate via a wireless air interface protocol. Of course, 110a and 120i can also communicate via a base station-to-base station interface protocol. In this case, relative to 110a, 120i is also a base station. Therefore, both base stations and terminals can be collectively referred to as communication devices. 110a and 110b in Figure 1 can be called communication devices with base station functions, and 120a-120j in Figure 1 can be called communication devices with terminal functions.

[0090] Communication between base stations and terminals, between base stations, and between terminals can be conducted using licensed spectrum, unlicensed spectrum, or both simultaneously. Communication can be conducted using spectrum below 6 GHz, spectrum above 6 GHz, or both simultaneously. The embodiments of this application do not limit the spectrum resources used for wireless communication.

[0091] In the embodiments of this application, the functions of the base station can be executed by modules (such as chips) within the base station, or by a control subsystem that includes base station functions. This control subsystem, including base station functions, can be a control center in the aforementioned application scenarios such as smart grids, industrial control, intelligent transportation, and smart cities. Similarly, the functions of the terminal can be executed by modules (such as chips or modems) within the terminal, or by a device that includes terminal functions.

[0092] In this application, the base station sends downlink signals or downlink information to the terminal, with the downlink information carried on the downlink channel; the terminal sends uplink signals or uplink information to the base station, with the uplink information carried on the uplink channel. To communicate with the base station, the terminal needs to establish a radio connection on a cell controlled by the base station. The cell with which the terminal has established a radio connection is called the terminal's serving cell. When the terminal communicates with this serving cell, it is also susceptible to interference from signals from neighboring cells.

[0093] To better understand the embodiments of this application, the following is an introduction to the technical terms involved in the embodiments of this application.

[0094] 1. Supplementary UL (SUL).

[0095] Supplementary Uplink (SUL) can also be replaced with Super Uplink (Super UL, SUL). For ease of description, it will be referred to as SUL below without distinction.

[0096] SUL enables uplink capacity expansion. In SUL, the frequency domain resources of a cell consist of normal downlink (NDL) carriers on band B1, normal uplink (NUL) carriers on band B1, and SUL carriers on band B0. NUL and NDL are in the same frequency band, while the frequency band of SUL can be lower than that of NUL.

[0097] For example, the macro base station is configured with a NUL, and the TRP is configured with a SUL. As an example, the SUL can be a carrier on a new high-frequency bandwidth (e.g., 4.9 GHz) or a low-frequency bandwidth, thereby forming more and denser uplink transmissions and expanding uplink capacity.

[0098] In this application, SUL is used only as an example and can be any other name. For example, SUL can be replaced by extended cell or enhanced uplink cell. The aforementioned extended cell or enhanced uplink cell can be a cell containing only uplink carriers or a cell having only uplink transmission resources.

[0099] In this application, uplink transmission can be understood as or replaced by uplink reception.

[0100] 2. Dense deployment of UL.

[0101] In some communication systems (e.g., 5G communication systems), dense uplink capacity deployment can be achieved by supplementing uplink SUL. For example, supplementing uplink can be done in two ways: co-located and dissimilar to each other, which will be described below.

[0102] In a co-site deployment scenario, a macro base station is deployed in uplink frequency bands that include both the NUL and SUL bands. To facilitate understanding, an example of co-site deployment is described below with reference to Figure 2.

[0103] Figure 2 is a schematic diagram of a dense UL deployment scenario corresponding to a co-located site. As shown in Figure 2, for a macro base station, when uplink capacity expansion is required, the SUL carrier and NUL carrier are configured as a single cell within the macro base station. For example, if a terminal is configured with multiple carriers in a single cell, one of these carriers is an NUL, and the others are supplementary uplink carriers (SUL1 and SUL2 in Figure 2). SUL2 can be a carrier on a new high-frequency bandwidth. As an example, the supplementary uplink carriers (SUL1 and SUL2) and the ordinary uplink carrier NUL can operate on the same band and use the same timing advancement (TA), downlink offset, and PL.

[0104] It is understood that Figure 2 is a schematic diagram for ease of understanding. When the embodiments of this application are applied to dense UL deployments corresponding to co-site locations, the number of additional uplink carriers deployed is not limited.

[0105] In some examples, within the dense UL deployment corresponding to the aforementioned co-location, sites other than the macro base station can be uplink-only sites (e.g., TRPs). In other words, the macro base station can have both uplink and downlink transmission capabilities. Other sites, however, only have uplink transmission capabilities and no downlink transmission capabilities. As an example, the macro base station and the uplink-only TRP can share the same frequency band. In other words, an uplink-only TRP exists within the coverage area of ​​the macro base station, and the macro base station uses the same uplink frequency band as the uplink-only TRP.

[0106] In this application, uplink transmission can be understood as or replaced by uplink reception. Downlink transmission can be understood as or replaced by downlink reception.

[0107] In this application, TRPs that can only receive uplinks, TRPs that can only receive uplinks (UL only TRP), points that can only receive uplinks (UL only receive point, UL only rx point), points that can only receive uplinks (UL only reception point), or UL reception points can be interchanged. This application does not limit the name of the site that can only receive uplinks.

[0108] In a cross-site deployment scenario, a site independent of a macro base station can be deployed within the coverage area of ​​that macro base station. This site and the macro base station do not necessarily need to be located in the same location. For ease of understanding, an example of cross-site deployment is described below with reference to Figure 3.

[0109] Figure 3 is a schematic diagram of a scenario of dense UL deployment corresponding to different sites, as illustrated in this application. As shown in Figure 3, sites (e.g., TRPs) for uplink reception can be deployed within the coverage area of ​​the macro base station. Exemplarily, the macro base station is configured with an additional uplink carrier SUL1 and a normal uplink carrier NUL, and the TRP is configured with an additional uplink carrier SUL2. As an example, SUL2 can be a carrier on a new high-frequency bandwidth (e.g., 4.9 GHz) or a low-frequency bandwidth, thereby forming more and denser uplink transmissions and expanding uplink capacity.

[0110] It is understandable that the aforementioned off-site deployment also provides supplementary uplink transmission for the macro base station. For example, this scenario can be used in factory area coverage scenarios. As an example, the TRP in Figure 3 could be the TRP of a small cell.

[0111] It is understood that Figure 3 is a schematic diagram for ease of understanding. When the embodiments of this application are applied to dense UL deployments corresponding to different sites, the number of additional uplink carriers deployed is not limited.

[0112] In some examples, in the dense UL deployment scenarios corresponding to the aforementioned off-site locations, the sites other than the macro base station can be uplink-only sites (e.g., TRPs). The macro base station and the uplink-only TRP can use different frequency bands. In other words, there is an uplink-only TRP under the coverage of the macro base station, and the uplink frequency band of the macro base station is different from that of the uplink-only TRP.

[0113] 3. PL.

[0114] In scenarios where UL is not densely deployed, the terminal can obtain the received power of the base station's downlink reference signal (e.g., SSB) by measuring the base station's downlink reference signal, thereby determining the power level (PL) between the terminal and the base station.

[0115] In the aforementioned scenario of dense UL deployment (e.g., see Figure 2 or Figure 3), there is no downlink reference signal (e.g., SSB) transmitted for TRPs that cannot perform downlink transmission. Therefore, the terminal cannot measure the downlink reference signal based on the reference signal transmitted by the TRP within the coverage area of ​​the TRP, and thus cannot directly determine the PL of the link with the TRP.

[0116] In one possible scenario, the terminal can transmit an SRS (Signal Support Response); the macro base station can detect the signal strength of the SRS (denoted as signal strength #1). Furthermore, only the uplink receiving TRP can detect the signal strength of the SRS (denoted as signal strength #2) and feed this signal strength #2 back to the macro base station. Thus, the macro base station can determine the PL (PL#1) between the terminal and the TRP based on the difference between signal strength #1 and signal strength #2, or determine the PL offset between PL#1 and the PL between the macro base station and the terminal (denoted as PL#2), and send this PL#1, or the PL offset between PL#1 and PL#2, to the terminal. The terminal can obtain the PL#1 of the link on the side of the uplink receiving TRP, or it can obtain PL#1 based on the aforementioned PL offset.

[0117] However, the above scheme requires the terminal to obtain the PL by sending an SRS, and the terminal cannot obtain the PL before the SRS is sent. Therefore, how to enable the terminal to obtain the PL earlier, thereby improving the communication performance with the TRP that only receives uplink data, is an urgent problem to be solved.

[0118] In view of this, embodiments of this application provide some solutions that enable a terminal to acquire a PL during random access with a TRP that only receives uplink data, thereby improving the communication performance between the terminal and the TRP earlier. It is understood that embodiments of this application can also be applied to other network devices that the terminal needs to randomly access; in other words, the PL acquired in embodiments of this application can also be the PL between the terminal and other network devices that need to randomly access.

[0119] For ease of description, the network device that the terminal will randomly connect to will be referred to as the first network device. The first network device can be a TRP that only receives uplink data, but is not limited to a TRP that only receives uplink data.

[0120] As an example, the power level (PL) between the terminal and the first network device can be determined based on the transmission power and reception power of the random access sequence. However, in existing schemes, if the terminal does not receive message 2 (msg 2) within a certain time window after transmitting a random access sequence, it will perform power ramping and retransmit the random access sequence. That is, the transmission power used by the terminal to transmit the random access sequence is different each time. However, the first network device cannot know which number of times the received random access sequence was transmitted by the terminal, nor can the terminal know which number of random access sequences was successfully received by the first network device. Thus, neither the terminal nor the first network device can know the transmission power of the random access sequence received by the first network device, and therefore the PL between the terminal and the first network device cannot be determined.

[0121] This application provides two types of initial access methods, enabling a first network device or other network devices on the network side to know the transmission power of the random access sequence received by the first network device. Furthermore, the terminal, the first network device, or other network devices can determine the power level (PL) between the terminal and the first network device based on the transmission power and reception power of the random access sequence.

[0122] In the first type of initial access method, the transmission power of the random access sequence sent by the terminal multiple times can be the same, so that the first network device can know the transmission power of any random access sequence received.

[0123] In the second type of initial access method, the transmission power of the terminal transmitting the random access sequence is associated with the random access sequence and / or the time-frequency resources used to transmit the random access sequence. In this way, the first network device can determine the transmission power of the random access sequence through the random access sequence and / or the time-frequency resources used to transmit the random access sequence.

[0124] In various embodiments of this application, "transmission power" can be understood as or replaced with "transmission power", which will not be elaborated further below.

[0125] The first type of initial access method described above will be introduced below with reference to Figure 4.

[0126] Figure 4 is a schematic flowchart of an initial access method 400 provided in an embodiment of this application. Optional operations in method 400 are shown in Figure 4 with dashed lines. For ease of understanding, two possible application scenarios of method 400 are first introduced below.

[0127] Scenario 1: A terminal device wants to connect to a first network device. This first network device only has uplink receiving capability and no downlink transmission capability; or, the terminal device and the first network device only have an uplink connection and no downlink connection; or, the terminal device and the first network device only have uplink resources configured and no downlink resources configured. Before method 400 is executed, the terminal device has already connected to a second network device. The second network device has both uplink receiving and downlink transmission capabilities; or, the terminal device and the second network device have both uplink and downlink connections; or, the terminal device and the second network device have both uplink and downlink resources configured. As an example, the second network device can be a macro base station, and the first network device can be a TRP (Transport Repository Program) connected to the macro base station that only has uplink receiving capability. Exemplarily, the first network device and the second network device can communicate via an X2 interface.

[0128] In this application, the first network device only has uplink receiving capability, which can also be understood as: the resources configured in the first network device are only used for uplink receiving, or only the resources configured in the first network device for uplink receiving are activated. The first network device does not have downlink transmission capability, which can also be understood as: the resources configured in the first network device are not used for downlink transmission, or the resources configured in the first network device for downlink transmission are deactivated or not activated.

[0129] Scenario 2: A terminal device wants to connect to a first network device. This first network device has uplink receiving capability and downlink transmission capability.

[0130] The following section describes the various operations of method 400 with reference to Figure 4.

[0131] S420, the terminal device sends a first random access sequence to the first network device at a first transmit power.

[0132] For example, the first random access sequence can be used to request a TA or for initial synchronization. For instance, the first random access sequence can be a preamble. As another example, the first random access sequence can be carried in message 1 (msg 1). The aforementioned msg 1 can be msg 1 in the random access process. In some examples, the first random access sequence can be called a first preamble, a first sequence, or other names, which are not limited in this application. In other examples, the first random access sequence can be replaced by msg 1.

[0133] In the example of Scenario 1, there is only uplink transmission between the terminal device and the first network device. In other words, there is no downlink transmission between the first network device and the terminal device. In other words, in the communication between the terminal device and the first network device, the terminal device only performs uplink transmission and does not perform downlink reception. For example, the first network device could be the aforementioned TRP that only performs uplink reception. In the example of Scenario 2, there is downlink transmission between the first network device and the terminal device. In other words, in the communication between the terminal device and the first network device, the terminal device performs both uplink transmission and downlink reception.

[0134] The link between the terminal device and the first network device can be referred to as the first link. The first link can correspond to the first network device. The above S420 can also be understood as the terminal device transmitting a first random access sequence at a first transmission power on the first link. In the example of scenario 1, the first link only has uplink transmission, or in other words, the first link can only perform uplink transmission. In the example of scenario 2, the first link has both uplink and downlink transmission, or in other words, the first link can perform both uplink and downlink transmission.

[0135] In some possible implementations, prior to S420, method 400 further includes: the terminal device selecting a UL access path based on the signal strength of a downlink reference signal (e.g., DL SSB) transmitted by a network device (e.g., the second network device in scenario 1, or the first network device in scenario 2). If the signal strength of the downlink reference signal measured by the terminal device is less than or equal to a certain access threshold, the terminal device can randomly access the first link. Here, S420 may be the first time the terminal device transmits the first random access sequence on the first link, or it may not be the first time it transmits the first random access sequence on the first link; this application does not limit this.

[0136] For example, the first transmission power may be the initial transmission power used to transmit the first random access sequence. It is understood that this application does not limit S420 to which number the terminal device transmits the first random access sequence. Even if the terminal device is not transmitting the first random access sequence for the first time, in some examples, the transmission power of the first random access sequence may also be the aforementioned initial transmission power.

[0137] In some examples, the first transmit power can be predefined by the protocol, preconfigured, or determined by other means. In other examples, the first transmit power can be configured by the network device. For example, in scenario 1, the second network device can configure the first transmit power via radio resource control (RRC) signaling. For example, in scenario 1, the terminal device may execute S410 and S415. S410 and S415 are described in detail below.

[0138] In some possible implementations, prior to S420, method 400 further includes: S410, whereby the terminal device receives first configuration information from the second network device; and S415, whereby the terminal device determines the first transmission power based on the first configuration information. As an example, downlink transmission may exist between the second network device and the terminal device. Uplink transmission may exist between the terminal device and the second network device. In some possible scenarios, the second network device may be a macro base station, and the aforementioned first network device may be a TRP (Transmission Point Resource) connected to the macro base station that only receives uplink data. The link between the terminal device and the second network device can be referred to as the second link. The second link may correspond to the second network device. S410 can also be understood as the terminal device receiving the first configuration information on the second link.

[0139] As an example, the first configuration information can be carried in an RRC message (or RRC signaling), a medium access control (MAC) control element (CE), downlink control information (DCI), system messages, or other messages. This application does not limit the message carried by the first configuration information. The first configuration information can indicate a first transmission power. For example, the first configuration information can include a numerical value of the first transmission power. The terminal device can find the numerical value of the first transmission power based on the first configuration information. As another example, the first configuration information can include some or all of the parameters used to determine the first transmission power. The terminal device can determine the numerical value of the first transmission power based on the parameters in the first configuration information. Alternatively, the terminal device can determine the numerical value of the first transmission power based on the parameters in the first configuration information and parameters from other information.

[0140] After the terminal device executes S420, the terminal device can execute S425.

[0141] S425, the terminal device starts the first timer.

[0142] In some examples, the terminal device can make random access based on a first timer.

[0143] As an example, if the terminal device receives a random access response (RAR) message from a network device (e.g., the second network device in scenario 1, or the first network device in scenario 2) within a first timer, the terminal device can send a message to the first network device to resolve conflicts in random access. For example, the message used to resolve conflicts in random access could be msg 3.

[0144] This application does not limit the specific name of the aforementioned RAR message; for example, the RAR message may be msg 2. The aforementioned msg 2 could be msg 2 during a random access procedure. Furthermore, this application does not limit the specific name of the first timer; for example, the aforementioned first timer may be called a RAR window or other names.

[0145] As another example, if the terminal device does not receive a RAR message from a network device (e.g., the second network device in scenario 1, or the first network device in scenario 2) before the first timer expires, the terminal device can execute S430.

[0146] S430, if the first timer times out, the terminal device again sends the first random access sequence to the first network device at the first transmission power.

[0147] In method 400, the first random access sequence is a general term for the sequence used for random access sent by the terminal device to the first network device at a first transmission power. When the terminal device sends the first random access sequence multiple times, the first random access sequence sent each time can be exactly the same or different; this application does not impose any limitation. For example, in S420 and S430, the terminal device sends the first random access sequence twice; these two first random access sequences can contain the same elements or different elements.

[0148] Understandably, similar to S410, in S430, the terminal device still transmits the first random access sequence to the first network device at the first transmission power. That is, the terminal device transmits the first random access sequence multiple times at the same transmission power. One possible scenario is that the first network device and the terminal device are relatively close. Therefore, the terminal device does not need to perform power ramping and can repeatedly transmit the first random access sequence at the original first transmission power, and the first network device may still receive the first random access sequence. Furthermore, the uplink beams of the first network device and the terminal device may not be aligned, and the first network device may fail to successfully receive the first random access sequence transmitted by the terminal device each time. Therefore, the terminal device may need to transmit the first random access sequence multiple times.

[0149] In Scenario 1, depending on the number of timers configured on the terminal device, there are two examples, referred to as Timer Example 1 and Timer Example 2 in Scenario 1, which will be introduced below.

[0150] Example 1 of timers in scenario 1: The terminal device may only be configured with a first timer, without configuring any other timers.

[0151] In the timer example 1 above, the first timer can be used for the terminal device to randomly access the first network device and the second network device. For example, the terminal device can use the first timer during the process of randomly accessing the second network device; the first timer can also be used during the process of randomly accessing the first network device (i.e., during the execution of method 400).

[0152] In timer example 1, when the terminal device determines that the network device for random access is the first network device, as the counter corresponding to the first timer increases, the terminal device can always use the first transmission power to send the first random access sequence to the first network device; or, to put it another way, the terminal device can choose not to perform power ramping; or, to put it another way, the power ramping value for the terminal device is 0; or, to put it another way, the terminal device does not perform power ramping according to the normal random access channel (RACH) configuration. In this way, the terminal device can use the same transmission power in multiple transmissions of the first random access sequence (e.g., in S420 and S430).

[0153] For example, each time the first timer times out, the counter corresponding to the first timer can be incremented by 1. The counter corresponding to the first timer can also be understood as the counter corresponding to the first random access sequence. For example, each time the terminal device sends the first random access sequence, the counter corresponding to the first random access sequence can be incremented by 1.

[0154] For example, the configuration of the above-described ordinary RACH can include: a conventional RACH configuration. For example, a RACH configuration with a power ramp value that is not 0.

[0155] For example, the power ramp value described above can be expressed as a difference (delta). As an example, the power ramp value can be configured for a link (or network device), or for a terminal device or cell; this application does not limit this. The power ramp value can represent the difference between the transmission power of two consecutive transmissions of the first random access sequence by the terminal device.

[0156] Example 2 of the timer in scenario 1: The terminal device can be configured with a first timer and a second timer. The second timer is different from the first timer.

[0157] In the timer example 2 above, the first timer can be for the first network device, or it can be understood as the first timer being for the first link. For example, the first timer can be used for a terminal device to randomly access the first network device. As an example, the terminal device can use the first timer during the process of randomly accessing the first network device (i.e., during the execution of method 400).

[0158] In the above timer example 2, the behavior of the terminal device corresponding to the first timer may include: as the counter corresponding to the first timer increases, the terminal device always uses the first transmit power to transmit the first random access sequence; or it can be understood that the terminal device may not perform power ramping; or it can be understood that the power ramping value of the terminal device is 0; or it can be understood that the terminal device does not perform power ramping according to the normal RACH configuration.

[0159] In the timer example 2 above, the second timer can be for the second network device, or it can be understood as the second timer being for the second link. For example, the second timer can be used for a terminal device to randomly access the second network device. As an example, the terminal device can use the second timer during the process of randomly accessing the second network device.

[0160] In the timer example 2 above, the behavior of the terminal device corresponding to the second timer may include: as the counter corresponding to the first timer increases, the terminal device performs power ramping according to the normal RACH configuration.

[0161] For example, the size of the second timer is smaller than the size of the first timer. In other words, compared to randomly accessing the second network device, the terminal device waits longer to detect RAR messages during the process of randomly accessing the first network device.

[0162] In Scenario 1, based on the number of power ramp values ​​configured for the terminal device, there can be two examples, referred to as Power Ramp Example 1 in Scenario 1 and Power Ramp Example 2 in Scenario 1, which will be described below.

[0163] Example 1 of power ramp value in scenario 1: The terminal device can be configured with only one power ramp value, which is not 0.

[0164] In the power ramp value example 1 above, this power ramp value can be used for the terminal device to randomly access the second network device. For example, the terminal device can use the power ramp value configured above when randomly accessing the second network device. However, the power ramp value configured above can be omitted when the terminal device randomly accesses the first network device.

[0165] In example 1 of the power ramp value, when the terminal device determines that the network device for random access is the first network device, as the counter corresponding to the first random access sequence increases, the terminal device can always use the first transmission power to send the first random access sequence to the first network device; or, in other words, the terminal device can choose not to perform power ramping; or, in other words, the terminal device does not use the configured power ramp value for power ramping; or, in other words, the terminal device does not perform power ramping according to the normal RACH configuration. In this way, the terminal device can use the same transmission power in multiple transmissions of the first random access sequence (e.g., in S420 and S430).

[0166] Example 2 of power ramp value in Scenario 1: The terminal device can be configured with power ramp value #1 and power ramp value #2. Among them, power ramp value #1 is 0. Power ramp value #2 is not 0.

[0167] In the power ramp value example 2 above, the power ramp value #1 can be applied to the first network device, or it can be understood that the power ramp value #1 can be applied to the first link. For example, the power ramp value #1 can be used for a terminal device to randomly access the first network device. As an example, the terminal device can use the power ramp value #1 during the process of randomly accessing the first network device (i.e., during the execution of method 400).

[0168] In the above timer example 2, as the counter corresponding to the first random access sequence increases, the terminal device always transmits the first random access sequence using the first transmit power; or it can be understood that the terminal device may not perform power ramping; or it can be understood that the terminal device uses power ramping value #1 for power ramping; or it can be understood that the terminal device does not perform power ramping according to the normal RACH configuration.

[0169] For example, each time the terminal device sends the first random access sequence, the counter corresponding to the first random access sequence can be incremented by 1.

[0170] In the timer example 2 above, the power ramp value #2 can be applied to the second network device, or it can be understood as the power ramp value #2 being applied to the second link. For example, the power ramp value #2 can be used when a terminal device randomly accesses the second network device. As an example, the terminal device can use the power ramp value #2 during the process of randomly accessing the second network device.

[0171] In the above timer example 2, as the counter corresponding to the first random access sequence increases, the terminal device performs power ramping according to the power ramping value #2.

[0172] In scenario 2, the terminal device can be configured with a first timer and a power ramp value #1. This first timer and power ramp value #1 can be used for the terminal device to randomly access the first network device. This application does not limit whether the terminal device is configured with other timers or other power ramp values.

[0173] Based on the above scheme, the terminal device can transmit the same first random access sequence multiple times, all at the first transmission power. Thus, regardless of which first random access sequence the first network device (e.g., a TRP with only uplink reception) successfully receives, it can know that the transmission power of that first random access sequence is the first transmission power. The first or second network device can determine the power level (PL) between the terminal device and the first network device based on the first transmission power and the received power of the first random access sequence, and indicate this PL to the terminal device. Alternatively, the first or second network device can indicate the received power of the first random access sequence to the terminal device. The terminal device can determine the PL between itself and the first network device based on the received power of the first random access sequence and the first transmission power. Furthermore, the terminal device can use this PL to perform power control on the information to be transmitted in subsequent communications, thereby improving the communication performance between the terminal and the first network device in subsequent communications. It is understandable that the above scheme occurs during the initial access process. Therefore, compared with the scheme of obtaining PL through SRS, in the above scheme, the terminal device can obtain PL earlier, and then use PL to perform power control on SRS and the information sent before SRS (e.g., msg 3), thereby improving the communication quality between the terminal and the first network device while saving energy at the terminal.

[0174] It is understood that S420, S425, and S430 described above are some examples of the random access of the terminal device to the first network device in method 400, and are not intended to limit this application. S420, S425, and S430 described above can be understood as the process of the terminal device sending the first random access sequence in any two adjacent transactions.

[0175] In other examples, after S425 (starting the first timer), the terminal device may detect a RAR message from a network device (e.g., the second network device in scenario 1, or the first network device in scenario 2) within the first timer. In this case, the terminal device may not execute S430, but instead send a message (e.g., msg 3) to the first network device to resolve conflicts in random access.

[0176] In some other examples, after S430, the terminal device will restart the first timer. If the first timer expires, the terminal device will send the first random access sequence to the first network device again with the first transmission power. That is, after S430, the terminal device may send the first random access sequence to the first network device with the same transmission power.

[0177] In other words, in method 400, the first timer can be started after each time the terminal device sends the first random access sequence.

[0178] In some possible implementations, the terminal device can be configured with a maximum number of transmissions of the first random access sequence (denoted as X, where X is a positive integer). Thus, if the first timer times out, the terminal device can increment the counter corresponding to the first timer (or, more accurately, the counter corresponding to the first random access sequence) by 1 and compare it with the maximum number of transmissions X. If the incremented counter is less than or equal to (or, alternatively, less than) X, the terminal device can retransmit the first random access sequence to the first network device at the first transmission power. If the incremented counter is greater than (or, alternatively, equal to) X, the terminal device can abandon access to the first network device. This can also be understood as the terminal device not detecting the first network device. Further, in scenario 1, this can be understood as the terminal device not detecting the path to the UL access point.

[0179] As an example, the maximum number of transmissions X mentioned above can be configured by the network device (e.g., the second network device in scenario 1, or the first network device in scenario 2), predefined by the protocol, or pre-configured in the terminal device. This application does not limit the configuration method of the maximum number of transmissions X mentioned above.

[0180] The operation of the first network device and the second network device in Scenario 1 is described below. It is understood that the first network device may receive any first random access sequence sent by the terminal device; this application does not limit this. Furthermore, method 400 also includes: S440.

[0181] S440, the first network device measures the first random access sequence and determines the received power of the first random access sequence.

[0182] It is understood that if the first network device receives the first random access sequence from the terminal device in S420, the first network device executes S440 after S420. For example, the terminal device may omit S425 and S430 in the above scenario. Furthermore, if the first network device receives the first random access sequence from the terminal device in S430, the first network device executes S440 after S430.

[0183] As an example, a first network device can detect a random access sequence on random access resources. If the detected signal strength is greater than or equal to a detection threshold, the first network device can determine that the signal strength is the received power of the first random access sequence. In this application, measurement or reception can be understood as detection, and received power can be understood as received signal strength or detected signal strength.

[0184] In some possible implementations, for scenario 1, after S440, method 400 also includes: S445 and S450.

[0185] S445, the first network device sends first indication information to the second network device. The first indication information may include the received power of the first random access sequence, or, may include the value of the first power level (PL). Correspondingly, the second network device receives the first indication information from the first network device.

[0186] For example, the first PL can be the PL between the terminal device and the first network device.

[0187] In some examples, if the first indication information includes a value of the first PL, then before S445, method 400 may further include: the first network device calculating the first PL based on the received power and the first transmitted power of the first random access sequence, thereby carrying the value of the first PL in the first indication information. This application does not limit the method by which the first network device obtains the first transmitted power. For example, the first network device may obtain the first transmitted power from the second network device before S445. As another example, the first transmitted power may be predefined by the protocol or pre-configured in the first network device.

[0188] In other examples, the first indication information may include the received power of the first random access sequence. The received power of the first random access sequence may be the received power measured by the first network device in S440.

[0189] S450, the second network device sends the indication information of the first PL to the terminal device. Correspondingly, the terminal device receives the indication information of the first PL from the second network device.

[0190] For example, the indication information for the first PL can indicate the first PL. For instance, the indication information for the first PL can include the value of the first PL, so that the terminal device can obtain the value of the first PL from the aforementioned indication information. As another example, the indication information for the first PL can include the received power of the first random access sequence, so that the terminal device can determine the first PL based on the received power of the first random access sequence and the first transmitted power.

[0191] The value of the first PL can be the absolute value of the first PL or the offset between the first PL and the second PL. For example, the second PL can be the PL between the terminal device and the second network device. Two examples are given below when the indication information of the first PL includes the value of the first PL.

[0192] In one example, if the first indication information in S445 indicates the received power of the first random access sequence, then before S450, method 400 may further include: the second network device calculating the first PL based on the received power and the first transmit power of the first random access sequence. This application does not limit the method by which the second network device obtains the first transmit power. For example, the second network device may determine the first transmit power and configure it to the terminal device before S450. As another example, the first transmit power may be predefined by the protocol or pre-configured in the second network device.

[0193] In another example, if the first indication information in S445 indicates the value of the first PL, the second network device can carry the value of the first PL in the indication information of the first PL in S450.

[0194] When the indication information of the first PL includes the received power of the first random access sequence, the first indication information in the aforementioned S445 can indicate the received power of the first random access sequence. In this way, the second network device can carry the received power of the first random access sequence in the indication information of the first PL in S450.

[0195] The above S445 and S450 can be examples for scenario 1. For scenario 2, after S440, method 400 further includes: S450', whereby the first network device sends indication information of the first PL to the terminal device (not shown in FIG4). Correspondingly, the terminal device receives the indication information from the first PL.

[0196] For example, the indication information of the first PL can indicate the first PL. For instance, the indication information of the first PL may include the value of the first PL or the received power of the first random access sequence, as described in the description of S450, which will not be repeated here.

[0197] If the indication information for the first PL includes a value for the first PL, the first network device can calculate the first PL based on the received power and the first transmitted power of the first random access sequence before sending the indication information. Then, the first network device can include the value of the first PL in the indication information for the first PL in S450'.

[0198] In some possible implementations, the indication information of the first PL is carried in a RAR message. The solutions applicable to scenario 1 or scenario 2 are described below.

[0199] For example, in scenario 1, the above S450 may include: the second network device sending a RAR message to the terminal device, the RAR message including indication information of the first PL. Correspondingly, the terminal device receives the RAR message from the second network device. Exemplarily, the above RAR message may be triggered by the first indication information sent by the first network device; in other words, the second network device may determine to send the RAR message to the terminal device based on the first indication information sent by the first network device.

[0200] For example, in scenario 2, S450' may include: a first network device sending a RAR message to a terminal device, the RAR message including indication information of a first PL. Correspondingly, the terminal device receives the RAR message from the first network device. Exemplarily, the RAR message may be triggered by a first random access sequence received by the first network device; in other words, the first network device may determine to send the RAR message to the terminal device based on the received first random access sequence.

[0201] The following describes a solution applicable to both Scenario 1 and Scenario 2. As an example, the aforementioned RAR message can be used to schedule terminal devices to send random access messages. Furthermore, in some possible implementations, the method may also include: S460.

[0202] S460, in response to the RAR message, the terminal device sends a random access message to the first network device. Correspondingly, the first network device receives the random access message from the terminal device.

[0203] For example, the above-described random access message can be used to resolve conflicts during random access. This application does not limit the specific name of the random access message in S460; for example, the random access message in S460 can also be called msg 3. The above-described msg 3 can be msg 3 during the random access process.

[0204] As an example, the transmission power of the random access message is determined based on the first power level (PL). For instance, the terminal device can obtain the first PL through S450 and use it to determine the transmission power of the random access message sent to the first network device, or, in other words, use the first PL to perform power control on the random access message.

[0205] In some possible implementations, prior to S460, method 400 further includes: S455, whereby the terminal device can determine the transmission power of the random access message based on the first PL and the target receive power of the first network device. The target receive power of the first network device can also be understood as the target receive power on the first link. As an example, the terminal device can determine that the transmission power of the random access message is equal to the sum of the target receive power on the first link and the first PL.

[0206] This application does not limit the method by which the terminal device obtains the target received power of the first network device. For example, the target received power of the first network device may be predefined by the protocol or pre-configured in the terminal device. As another example, the target received power of the first network device may be configured by the network device (e.g., the second network device in scenario 1, or the first network device in scenario 2) to the terminal device.

[0207] Based on the above scheme, the terminal device can use the first power level (PL) to perform power control on the random access messages during the random access phase, thereby ensuring communication quality between the terminal and the first network device while saving power. It is understood that existing schemes obtain the PL through the signal relay (SRS), and the SRS is sent after random access; therefore, the terminal device cannot perform power control on the random access messages using existing schemes. Therefore, in the above scheme, the terminal device can obtain the PL earlier, thus using it earlier, thereby further improving the communication quality between the terminal and the first network device while saving power.

[0208] In some possible implementations, after S450 or S450', other information sent by the terminal device to the first network device (e.g., SRS, or uplink data, etc.) may also be power controlled based on the aforementioned first PL.

[0209] The first type of initial access method has been described above with reference to Figure 4. In the second type of initial access method, the transmission power of the random access sequence sent by the terminal is associated with the random access sequence and / or the time-frequency resources used to send the random access sequence. Thus, the first network device can determine the transmission power of the random access sequence through the random access sequence and / or the time-frequency resources used to send the random access sequence. For ease of understanding, the second type of initial access method is described below with reference to Figures 5 and 6.

[0210] Figure 5 is a schematic flowchart of another initial access method 500 provided in an embodiment of this application. Optional operations in method 500 are shown in Figure 5 with dashed lines. Method 500 can also be applied to scenario 1 or scenario 2; please refer to the relevant description of method 400 for details, which will not be repeated here. The various operations of method 500 are described below with reference to Figure 5.

[0211] S510, the second network device sends second configuration information to the terminal device. Correspondingly, the terminal device receives the second configuration information from the second network device. For example, the second configuration information can be used to configure the transmission power of the terminal device when transmitting random access sequences. Three possible indication methods for the second configuration information are described below, denoted as indication method example 1 to indication method example 3.

[0212] Example 1 of the indication method: The second configuration information can indicate the correspondence between N random access sequences and N transmission powers.

[0213] Where N can be a positive integer. As an example, there can be a one-to-one correspondence between the N random access sequences and the N transmit powers. For instance, random access sequence #n can correspond to transmit power #n. Thus, the terminal device can transmit random access sequence #n at transmit power #n. Here, n can be a positive integer less than or equal to N. Exemplarily, n can be taken from 1 to N.

[0214] As an example, N random access sequences can be used to request a TA or for initial synchronization. In Indication Method Example 1, any two random access sequences among the N random access sequences can be different. For example, the N random access sequences can be N different preambles. As another example, the N random access sequences can be carried in N msg 1 messages, where any two msg 1 messages can be different. These msg 1 messages can be msg 1 messages during the random access process. In some examples, the N random access sequences can be called N preambles, N sequences, or other names; this application does not limit this. In other examples, the N random access sequences can be replaced with N msg 1 messages.

[0215] In Example 1 of the indication method, N transmission powers can be used to transmit N random access sequences. The N transmission powers can be the same or different. For example, all N transmission powers can be the same. Another example is that two of the N transmission powers are different. Yet another example is that any two of the N transmission powers are different.

[0216] Example of indication method 2: This second configuration information can indicate the correspondence between N time-frequency resources and N transmission powers.

[0217] Where N can be a positive integer. As an example, there can be a one-to-one correspondence between N time-frequency resources and N transmission powers. For instance, time-frequency resource #n can correspond to transmission power #n. Thus, the terminal device can transmit a random access sequence on time-frequency resource #n with transmission power #n. Here, n can be a positive integer less than or equal to N. For example, n can be taken from 1 to N.

[0218] For example, N time-frequency resources can be used to transmit a random access sequence; in other words, N time-frequency resources can be the time-frequency resources of a random access sequence. A description of the random access sequence can be found above, for example, in the description of indication method example 1, and will not be repeated here.

[0219] As an example, one of the N time-frequency resources can be understood as a time-domain resource and / or a frequency-domain resource. For example, a time-domain resource may include a time-domain symbol, a slot, a sub-frame, a frame, a millisecond (ms), a second (s), or other time-domain resources. In the embodiments of this application, a time-domain symbol may be an orthogonal frequency division multiplexing (OFDM) symbol or a discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbol. Unless otherwise specified, the symbols in the embodiments of this application refer to time-domain symbols. For example, a frequency-domain resource may include a carrier, a sub-carrier, a component carrier (CC), or other frequency-domain resources.

[0220] As an example, one of the N time-frequency resources can also be understood as a RACH occasion (RO). RO can also be called a physical random access channel (PRACH) occasion, PRACH transmission occasion, or other names; this application does not limit its scope. Furthermore, one of the N time-frequency resources in this application can also be understood as a time-frequency resource used for transmitting random access sequences in a future communication system. In a future communication system, the time-frequency resource used for transmitting random access sequences can be called RO, or it may have other names; this application does not limit the name of this time-frequency resource.

[0221] In Example 2 of the indication method, any two time-frequency resources among the N time-frequency resources can be different. For example, any two time-frequency resources among the N time-frequency resources may have different frequency domain resources and / or different time domain resources. Another example is that the N time-frequency resources can each be a different RO.

[0222] In Example 2 of the indication method, N transmission powers can be used to transmit random access sequences on N time-frequency resources. The N transmission powers can be the same or different. For example, all N transmission powers can be the same. Another example is that two of the N transmission powers are different. Yet another example is that any two of the N transmission powers are different.

[0223] Example of indication method 3: The second configuration information can indicate the correspondence between N random access sequences and N time-frequency resources and N transmission powers.

[0224] Where N can be a positive integer. As an example, there can be a one-to-one correspondence between N random access sequences, N time-frequency resources, and N transmit powers. For instance, there can be a correspondence between random access sequence #n, time-frequency resource #n, and transmit power #n. Thus, the terminal device can transmit random access sequence #n on time-frequency resource #n with transmit power #n. Here, n can be a positive integer less than or equal to N. For example, n can be taken from 1 to N.

[0225] As an example, N random access sequences can be used to request a TA or for initial synchronization. For instance, N random access sequences can be N preambles. Alternatively, N random access sequences can be carried within N msg 1 messages. These msg 1 messages can be msg 1 during the random access process. In some examples, N random access sequences can be called N preambles, N sequences, or other names; this application does not limit the terminology. In other examples, N random access sequences can be replaced with N msg 1 messages.

[0226] As an example, N time-frequency resources can be used to transmit N random access sequences; in other words, the N time-frequency resources can be the time-frequency resources of random access sequences. A description of one of the N time-frequency resources can be found above, for example, in the description of indication method example 2, and will not be repeated here.

[0227] In Example 3 of the indication method, the time-frequency resource and / or random access sequence corresponding to one of the N transmission powers can be different from the time-frequency resource and / or random access sequence corresponding to another of the N transmission powers. For example, suppose transmission power #1 corresponds to time-frequency resource #1 and random access sequence #1; transmission power #2 corresponds to time-frequency resource #2 and random access sequence #2. Wherein, time-frequency resource #1 is different from time-frequency resource #2; or, random access sequence #1 is different from random access sequence #2; or, time-frequency resource #1 is different from time-frequency resource #2, and random access sequence #1 is different from random access sequence #2.

[0228] As an example, N transmit powers can be used to transmit N random access sequences on N time-frequency resources respectively. For example, a terminal device can transmit a random access sequence #n on time-frequency resource #n with transmit power #n. Here, n can be a positive integer less than or equal to N. Exemplarily, n can be from 1 to N. The N transmit powers can be the same or different. For example, all N transmit powers can be the same. Another example is that two of the N transmit powers are different. Yet another example is that any two of the N transmit powers are different.

[0229] The above introduced examples 1 to 3 of the instruction method. Below, we continue with other examples of S510. As an example, downlink transmission can exist between the second network device and the terminal device. Uplink transmission can exist between the terminal device and the second network device. In some possible scenarios, the second network device can be a macro base station, and the aforementioned first network device can be a TRP (Transportation Resource Planning) connected to the macro base station that only receives uplink data. The link between the terminal device and the second network device can be referred to as the second link. The second link can correspond to the second network device. S510 can also be understood as the terminal device receiving second configuration information on the second link.

[0230] As an example, the second configuration information can be carried in an RRC message, MAC CE, DCI, system message, or other message. This application does not limit the message carried by the second configuration information. The second configuration information can indicate at least one correspondence among the above-mentioned indication method example 1, indication method example 2, or indication method example 3. For example, the second configuration information may include a mapping table or key-value pairs of the above-mentioned correspondence. As another example, the second configuration information may include an index of the above-mentioned correspondence, and the terminal device can determine the above-mentioned correspondence based on the index and the pre-stored association between the index and the above-mentioned correspondence.

[0231] It is understandable that S510 described above can be the operation of the second network device in scenario 1. In scenario 2, S510 can be replaced by S510', where the first network device sends second configuration information to the terminal device. Correspondingly, the terminal device receives the second configuration information from the first network device. The description of the second configuration information is consistent with the previous description and will not be repeated here.

[0232] In other examples, the second configuration information may be predefined by the protocol or pre-configured in the terminal device. In the above cases, S510 or S510' may not be executed.

[0233] S520, the terminal device, based on the second configuration information, sends a first random access sequence to the first network device at a first transmission power. Correspondingly, the first network device receives the first random access sequence. The first transmission power can be one of the N transmission powers indicated by the second configuration information.

[0234] For example, the first random access sequence can be used to request a TA or for initial synchronization. For instance, the first random access sequence can be a preamble. As another example, the first random access sequence can be carried in msg 1. The aforementioned msg 1 can be msg 1 during the random access process. In some examples, the first random access sequence can be called a first preamble, a first sequence, or other names, which are not limited in this application. In other examples, the first random access sequence can be replaced by msg 1.

[0235] In the case where the terminal device sends multiple random access sequences, the aforementioned first random access sequence can be understood as the random access sequence sent by the terminal device when the first network device successfully receives the random access sequence.

[0236] When the second configuration information uses indication method example 1 or indication method example 3 to indicate the correspondence, the first random access sequence can be the random access sequence corresponding to the first transmission power among N random access sequences.

[0237] In the case where the second configuration information adopts the indication method example 2, the first random access sequence can be a random access sequence selected by the terminal device according to the configuration of the network device (e.g., the second network device in scenario 1, or the first network device in scenario 2), or a configuration predefined by the protocol. In the above case, S520 can include: the terminal device, based on the second configuration information, transmits the first random access sequence to the first network device at a first transmission power on a first time-frequency resource. The first time-frequency resource can be a time-frequency resource corresponding to the first transmission power among N time-frequency resources.

[0238] In the example of Scenario 1, there is only uplink transmission between the terminal device and the first network device. In other words, there is no downlink transmission between the first network device and the terminal device. In other words, in the communication between the terminal device and the first network device, the terminal device only performs uplink transmission and does not perform downlink reception. For example, the first network device could be the aforementioned TRP that only performs uplink reception. In the example of Scenario 2, there is downlink transmission between the first network device and the terminal device. In other words, in the communication between the terminal device and the first network device, the terminal device performs both uplink transmission and downlink reception.

[0239] The link between the terminal device and the first network device can be referred to as the first link. The first link can correspond to the first network device. The above S520 can also be understood as the terminal device transmitting a first random access sequence at a first transmission power on the first link. In the example of scenario 1, the first link only has uplink transmission, or in other words, the first link can only perform uplink transmission. In the example of scenario 2, the first link has both uplink and downlink transmission, or in other words, the first link can perform both uplink and downlink transmission.

[0240] In some possible implementations, prior to S520, method 500 further includes: the terminal device selecting a UL access path based on the signal strength of a downlink reference signal (e.g., DL SSB) transmitted by a network device (e.g., the second network device in scenario 1, or the first network device in scenario 2). If the signal strength of the downlink reference signal measured by the terminal device is less than or equal to a certain access threshold, the terminal device may randomly access the first link. Here, S520 may be the first time the terminal device transmits a random access sequence on the first link, or it may not be the first time it transmits a random access sequence on the first link; this application does not limit this.

[0241] In some examples, the second configuration information in S510 or S510' includes a first power ramp value. In other examples, the first power ramp value may be predefined in the protocol or pre-configured in the terminal device; this application does not impose any limitations on this.

[0242] In method 500, the first power ramp value can be 0 or not, and is not limited here. For example, the first power ramp value can represent the difference between the transmission power of two consecutive transmissions of random access sequences by the terminal device.

[0243] In some possible implementations, the aforementioned S520 may include S522 and S524.

[0244] S522, the terminal device determines the first transmission power based on the first power ramp value.

[0245] As an example, the terminal device can determine the first transmission power based on the counter's count, the first power ramp-up value, and the initial transmission power. The counter can be used to indicate the number of times the terminal device transmits the random access sequence. For example, each time the terminal device transmits the random access sequence, it can start a first timer; if the first timer expires, the counter's count increases by 1. Alternatively, the counter can increase by 1 each time the terminal device transmits the random access sequence.

[0246] In some examples, the initial transmit power may be predefined by the protocol, preconfigured, or determined by other means. In other examples, the initial transmit power may be network-configured. For example, the terminal device may determine the initial transmit power based on second configuration information. Exemplarily, the terminal device may add the initial transmit power to the product of a counter count and a first power ramp-up value to obtain the first transmit power. However, this application is not limited, and the terminal device may also determine the first transmit power in other ways.

[0247] S524, the terminal device transmits a first random access sequence to the first network device on the first time-frequency resource at the first transmission power. Correspondingly, the first network device receives the first random access sequence.

[0248] In some possible implementations, prior to S524, method 500 may further include: the terminal device determining a first time-frequency resource and / or a first random access sequence based on a first transmit power. For ease of understanding, an example of the terminal device determining the first time-frequency resource and / or the first random access sequence is described below with reference to Figure 6.

[0249] Figure 6 is a schematic diagram illustrating the correspondence between transmission power and random access sequence or time-frequency resources provided in an embodiment of this application. The following section, referring to Figure 6(a), describes an example of a terminal device determining the first random access sequence.

[0250] Referring to Figure 6(a), there is a one-to-one correspondence between x random access sequence groups and x transmit powers. Here, x can be a positive integer. Each random access sequence group may include one or more random access sequences. Any two random access sequence groups within the x random access sequence groups may contain different random access sequences.

[0251] For example, the one-to-one correspondence between x random access sequence groups and x transmission powers can be understood as a one-to-one correspondence between x random access sequence groups and x counter counts. For instance, in Figure 6(a), "initial transmission power" can be understood as a counter count of 0; "initial transmission power + 1 power ramp" can be understood as a counter count of 1.

[0252] When the second configuration information uses the indication method example 1 to indicate the correspondence, the N random access sequences can each belong to the x random access sequence groups in Figure 6(a). For example, the second configuration information can be understood as indicating a one-to-one correspondence between the x random access sequence groups and the x transmission powers (or, counter counts).

[0253] When x equals N, there is a one-to-one correspondence between the N random access sequences and the x random access sequence groups; or, in other words, the N time-frequency resources belong to the x random access sequence groups respectively. When x is greater than N, the N random access sequences can be one-to-one corresponded to the N random access sequence groups within the x random access sequence groups; or, in other words, the N time-frequency resources belong to the N random access sequence groups within the x random access sequence groups respectively.

[0254] For example, assuming the terminal device determines in S522 that the first transmission power is "initial transmission power + 1 power ramp-up", then the terminal device can further determine that the first random access sequence is a random access sequence in random access sequence group 2. Further, the terminal device can execute S524, that is, on the first time-frequency resource, transmit the aforementioned first random access sequence to the first network device at the first transmission power. In the above example, the first time-frequency resource can be the time-frequency resource used by the terminal device to transmit the first random sequence; the specific selection method of the first time-frequency resource is not limited here.

[0255] The following example, illustrated in Figure 6(b), illustrates how a terminal device determines the first time-frequency resource. Referring to Figure 6(b), x RACH time-frequency resource groups can be one-to-one corresponded to x transmit powers. Here, x can be a positive integer. Each RACH time-frequency resource group may include one or more time-frequency resources (e.g., one or more ROs). Any two RACH time-frequency resource groups among the x RACH time-frequency resource groups may include different time-frequency resources.

[0256] For example, the one-to-one correspondence between x RACH time-frequency resource groups and x transmit powers can be understood as the one-to-one correspondence between x RACH time-frequency resource groups and x counter counts. For instance, in Figure 6(b), "initial transmit power" can be understood as the counter count being 0; "initial transmit power + 1 power ramp" can be understood as the counter count being 1.

[0257] When the second configuration information uses the indication method example 2 to indicate the correspondence, the N time-frequency resources can belong to the x RACH time-frequency resource groups in Figure 6(b). For example, the second configuration information can be understood as indicating a one-to-one correspondence between the x RACH time-frequency resource groups and the x transmit powers (or, the counts of the counters).

[0258] When x equals N, there is a one-to-one correspondence between the N time-frequency resources and the x RACH time-frequency resource groups; or, in other words, the N time-frequency resources belong to the x RACH time-frequency resource groups respectively. When x is greater than N, the N time-frequency resources can be one-to-one corresponded to the N RACH time-frequency resource groups within the x RACH time-frequency resource groups; or, in other words, the N time-frequency resources belong to the N RACH time-frequency resource groups within the x RACH time-frequency resource groups.

[0259] For example, assuming the terminal device determines in S522 that the first transmission power is "initial transmission power + 1 power ramp-up", then the terminal device can further determine that the first time-frequency resource is a time-frequency resource in RACH time-frequency resource group 2. Further, the terminal device can execute S524, that is, on the aforementioned first time-frequency resource, transmit a first random access sequence to the first network device at the first transmission power. In the above example, the first random access sequence can be a random access sequence transmitted by the terminal device on the first time-frequency resource; the specific selection method of the first random access sequence is not limited here.

[0260] The following example, illustrated in Figure 6(c), illustrates how a terminal device determines the first time-frequency resource and the first random access sequence. Referring to Figure 6(c), there is a one-to-one correspondence between x random access sequence groups, x RACH time-frequency resource groups, and x transmit powers. Here, x can be a positive integer. Any two transmit powers among the x transmit powers correspond to different random access sequence groups, and / or different RACH time-frequency resource groups. For example, taking "initial transmit power" and "initial transmit power + 1 power ramp" as examples, RACH time-frequency resource group 1 and RACH time-frequency resource group 2 include different time-frequency resources, and / or, random access sequence group 1 and random access sequence group 2 include different random access sequences.

[0261] For example, the x transmission powers in the above correspondence can be understood as a one-to-one correspondence between the counts of x counters. For instance, in Figure 6(c), "initial transmission power" can be understood as a counter count of 0; "initial transmission power + 1 power ramp" can be understood as a counter count of 1.

[0262] When the second configuration information uses the indication method example 3 to indicate the correspondence, N time-frequency resources can belong to x RACH time-frequency resource groups in Figure 6(c), and N random access sequences can belong to x random access sequence groups in Figure 6(c). For example, the second configuration information can be understood as indicating a one-to-one correspondence between x RACH time-frequency resource groups, x random access sequence groups, and x transmit powers (or, counter counts).

[0263] When x equals N, there is a one-to-one correspondence between the N time-frequency resources, the N random access sequences, and the x RACH time-frequency resource groups; or, to put it another way, the N time-frequency resources belong to the x RACH time-frequency resource groups, and the N time-frequency resources belong to the x random access sequence groups. When x is greater than N, there is a one-to-one correspondence between the N time-frequency resources and the N RACH time-frequency resource groups, and the N random access sequences can also correspond one-to-one with the N random access sequence groups within the x random access sequence groups; or, to put it another way, the N time-frequency resources belong to the N RACH time-frequency resource groups within the x RACH time-frequency resource groups, and the N time-frequency resources belong to the N random access sequence groups within the x random access sequence groups.

[0264] For example, assuming the terminal device determines in S522 that the first transmission power is "initial transmission power + 1 power ramp-up", then the terminal device can further determine that the first time-frequency resource is a time-frequency resource in RACH time-frequency resource group 2, and the first random access sequence is a random access sequence in random access sequence group 2. Further, the terminal device can execute S524, that is, on the aforementioned first time-frequency resource, transmit the aforementioned first random access sequence to the first network device at the first transmission power.

[0265] The operation of the first network device and the second network device in Scenario 1 is described below. Furthermore, method 500 also includes S525 and S530, which are described below.

[0266] S525, the first network device sends first information to the second network device. Correspondingly, the second network device receives the first information from the first network device.

[0267] Optionally, the first information is used to indicate the transmission power of the first random access sequence (i.e., the first transmission power).

[0268] In some examples, the first information may carry a numerical value of the first transmission power, an index of the first transmission power, or a count of a counter corresponding to the first transmission power. The index of the first transmission power may correspond to the first transmission power, and the second network device may determine the first transmission power based on this index.

[0269] In some possible implementations, prior to S525, the first network device may determine the value, index, or counter count of the first transmit power based on the first random access sequence received in S520 and / or the first time-frequency resources used to receive the first random access sequence.

[0270] As a specific example, when the second configuration information uses the aforementioned indication method example 1 to indicate the correspondence, the first network device can obtain the above correspondence and, based on the correspondence between N random access sequences and N transmission powers, and the first random access sequence, determine the value, index, or counter count of the first transmission power.

[0271] As another specific example, when the second configuration information uses the aforementioned indication method example 2 to indicate the correspondence, the first network device can obtain the above correspondence and, based on the correspondence between N time-frequency resources and N transmission powers, and the first time-frequency resources used to receive the first random access sequence, determine the value, index, or counter count of the first transmission power.

[0272] As another specific example, when the second configuration information uses the aforementioned indication method example 3 to indicate the correspondence, the first network device can obtain the above correspondence and, based on the correspondence between N random access sequences and N time-frequency resources and N transmission powers, as well as the first random access sequence and / or the first time-frequency resource, determine the value, index, or counter count of the first transmission power.

[0273] In other examples, the first information may include an identifier of a first random access sequence, and / or an identifier of the time-frequency resource used to receive the first random access sequence (i.e., the identifier of the first time-frequency resource). The second network device determines the first transmission power based on the correspondence indicated by the first information and the second configuration information, thereby realizing that the first information indirectly indicates the first transmission power.

[0274] In some possible implementations, after S520, method 500 further includes: a first network device measuring a first random access sequence and determining the received power of the first random access sequence; the first network device sending indication information of the received power of the first random access sequence to a second network device. Thus, the second network device can determine a first power level (PL) based on the first transmission power and the received power of the first random access sequence. This first PL can be the PL between the terminal device and the first network device.

[0275] As an example, the first network device can detect a random access sequence on random access resources. If the detected signal strength is greater than or equal to a detection threshold, the first network device can determine that the signal strength is the received power of the first random access sequence.

[0276] Optionally, the first information is used to indicate the first power level (PL). For example, the first information includes a numerical value of the first PL. In some possible implementations, the first network device may determine the first transmit power based on the first random access sequence received in S520 and / or the first time-frequency resources used to receive the first random access sequence; the first network device may measure the first random access sequence to determine the receive power of the first random access sequence. Further, the first network device may determine the first PL based on the first transmit power and the receive power of the first random access sequence. Specific examples of the first network device determining the first transmit power are given in other parts of S525, and will not be repeated here.

[0277] S530, the second network device sends an indication message for the first PL to the terminal device based on the first information. Correspondingly, the terminal device receives the indication message for the first PL from the second network device.

[0278] For example, the indication information of the first PL can indicate the first PL. In some examples, the indication information of the first PL can include the value of the first PL, so that the terminal device can obtain the value of the first PL from the above indication information. In some possible implementations, S530 includes: the second network device determining the first PL based on the first information; the second network device sending the indication information of the first PL to the terminal device. The indication information of the first PL can include the value of the first PL.

[0279] As an example, the first information can be used to indicate the transmission power of the first random access sequence.

[0280] For example, the first information may carry the value of the first transmission power, the index of the first transmission power, or the count of the counter corresponding to the first transmission power. In this way, the first network device can directly determine the value of the first transmission power; or, based on the index, determine that the value corresponding to the index is the value of the first transmission power; or, based on the counter count, the initial transmission power, and the first power ramp-up value, determine the value of the first transmission power.

[0281] For example, the first information may carry the identifier of the first random access sequence, and / or the identifier of the time-frequency resource used to receive the first random access sequence (i.e., the identifier of the first time-frequency resource). Thus, the second network device determines the first transmission power based on the correspondence indicated by the first information and the second configuration information.

[0282] As a specific example, when the second configuration information uses the aforementioned indication method example 1 to indicate the correspondence, the second network device can determine the first transmission power based on the correspondence between N random access sequences and N transmission powers, as well as the identifier of the first random access sequence.

[0283] As another specific example, when the second configuration information uses the aforementioned indication method example 2 to indicate the correspondence, the second network device can determine the first transmission power based on the correspondence between N time-frequency resources and N transmission powers, as well as the identifier of the first time-frequency resource.

[0284] As another specific example, when the second configuration information uses the aforementioned indication method example 3 to indicate the correspondence, the second network device can determine the first transmission power based on the correspondence between N random access sequences and N time-frequency resources and N transmission powers, as well as the identifier of the first random access sequence and / or the identifier of the first time-frequency resource.

[0285] Furthermore, in some possible implementations, the second network device can obtain the received power of the first random access sequence from the first network device, thereby determining the first PL based on the received power and the first transmitted power.

[0286] In other examples, the indication information for the first power level (PL) may include the received power of the first random access sequence and indication information for the first transmit power. Thus, the terminal device can determine the first PL based on the received power and the first transmit power of the first random access sequence. The indication information for the first transmit power can be used to indicate the first transmit power.

[0287] As an example, the indication information for the first transmit power may be a numerical value of the first transmit power. Thus, the terminal device can obtain the first transmit power from this indication information. As another example, the indication information for the first transmit power may include an identifier of the first random access sequence and / or an identifier of the first time-frequency resource. Thus, the terminal device can determine the first transmit power based on the second configuration information, and determine the first power level (PL) based on the first transmit power and the received power of the first random access sequence.

[0288] Understandably, the terminal device may transmit the random access sequence multiple times. In method 500, the transmission power of the random access sequence transmitted by the terminal device each time can be the same or different. The terminal device can obtain the transmission power corresponding to the first random access sequence successfully received by the first network device through the indication information of the first transmission power, and thus perform the calculation of the first PL.

[0289] Based on the above scheme, the terminal device can send a first random access sequence to the first network device based on the correspondence between time-frequency resources and / or random access sequences and transmit power configured in the second configuration information. In this way, the transmit power of the first random access sequence can be associated with the first random access sequence itself and / or the time-frequency resources used to transmit the first random access sequence. In some examples, the above scheme enables the first network device or the second network device to know the transmit power corresponding to the first random access sequence after the first network device receives it. Through the first transmit power and the received power of the first random access sequence, the terminal device can obtain the power level (PL) between itself and the first network device, thereby improving the communication performance between the terminal and the first network device in subsequent communications. It is understood that the above scheme occurs during the initial access process. Therefore, compared to the scheme of obtaining the PL through SRS, in the above scheme, the terminal device can obtain the PL earlier and use it earlier, thereby further improving the communication quality between the terminal and the first network device while saving energy.

[0290] The above-described S525 and S530 can be examples for scenario 1. For scenario 2, after S520, method 500 further includes: S530', whereby the first network device sends indication information of the first PL to the terminal device (not shown in FIG5). Correspondingly, the terminal device receives the indication information from the first PL.

[0291] For example, the indication information of the first PL can indicate the first PL. For instance, the indication information of the first PL can include the value of the first PL. As another example, the indication information of the first PL can include the identifier of the first random access sequence, and / or the identifier of the time-frequency resource used to receive the first random access sequence (i.e., the identifier of the first time-frequency resource). See the description of S530 for details, which will not be repeated here.

[0292] If the indication information for the first PL includes a value for the first PL, the first network device can calculate the first PL based on the received power and the first transmitted power of the first random access sequence before sending the indication information. Then, the first network device can include the value of the first PL in the indication information for the first PL in S530'.

[0293] In some possible implementations, the indication information of the first PL is carried in a RAR message. The solutions applicable to scenario 1 or scenario 2 are described below.

[0294] For example, in scenario 1, S530 above may include: the second network device sending a RAR message to the terminal device, the RAR message including indication information of the first PL. Correspondingly, the terminal device receives the RAR message from the second network device. Exemplarily, the RAR message may be triggered by first information sent by the first network device; in other words, the second network device may determine to send the RAR message to the terminal device based on the first information sent by the first network device. As an example, the first information may include an identifier of the time-frequency resource (e.g., RO identifier) ​​for receiving the first random access sequence, enabling the second network device to determine the beam used to send the RAR message based on the association between the beam and the time-frequency resource (e.g., RO) for receiving the first random access sequence, and to determine a scrambled random access-radio network temporary identifier (RA-RNTI) for scheduling control information of the RAR message.

[0295] For example, in scenario 2, S530' above may include: a first network device sending a RAR message to a terminal device, the RAR message including indication information of a first PL. Correspondingly, the terminal device receives the RAR message from the first network device. Exemplarily, the RAR message may be triggered by a first random access sequence received by the first network device; in other words, the first network device may determine to send the RAR message to the terminal device based on the received first random access sequence. As an example, the first network device may determine the beam used to send the RAR message based on the association between the beam and the time-frequency resources used to receive the first random access sequence, and determine the scrambled RA-RNTI for the control information used to schedule the RAR message.

[0296] The following describes a solution applicable to both Scenario 1 and Scenario 2. As an example, the terminal device can determine the RA-RNTI based on the first time-frequency resource used to send the first random access sequence; use the RA-RNTI to descramble control information used for scheduling RAR messages; and receive RAR messages based on the aforementioned control information. As an example, the aforementioned RAR messages can be used to schedule the terminal device to send random access messages. Further, in some possible implementations, the method may also include: S540.

[0297] S540, in response to the RAR message, the terminal device sends a random access message to the first network device.

[0298] In some possible implementations, prior to S540, method 500 further includes: the terminal device determining the transmission power of the random access message based on the first PL and the target receive power of the first network device. As an example, the aforementioned RAR message also includes the terminal device's TA. Thus, the terminal device can transmit the aforementioned random access message based on the aforementioned TA. Furthermore, the terminal device can determine the beam used to transmit the random access message based on the association between the beam and the time-frequency resources used to receive the first random access sequence. Other examples of S540 and the above determination of the transmission power of the random access message are described in the relevant section of S460 above, and will not be repeated here.

[0299] Based on the above scheme, the terminal device can use the first power level (PL) to perform power control on the random access messages during the random access phase, thereby ensuring communication quality between the terminal and the first network device while saving power. It is understood that existing schemes obtain the PL through the signal relay (SRS), and the SRS is sent after random access; therefore, the terminal device cannot perform power control on the random access messages using existing schemes. Therefore, in the above scheme, the terminal device can obtain the PL earlier, thus using it earlier, thereby further improving the communication quality between the terminal and the first network device while saving power.

[0300] In some possible implementations, after S530 or S530', other information sent by the terminal device to the first network device (e.g., SRS, or uplink data, etc.) can be power controlled based on the aforementioned first PL.

[0301] In other examples, if the first random access sequence sent by the terminal device in S520 is not successfully received by the first network device, the network device (e.g., the second network device in scenario 1, or the first network device in scenario 2) will not send msg 2. In the above situation, after executing S520, the terminal device can start a first timer. If the first timer times out, the terminal device can determine a second transmission power based on a first power ramp-up value. The difference between the second transmission power and the first transmission power can be the aforementioned first power ramp-up value.

[0302] Furthermore, in indication method example 1, the terminal device can determine the second random access sequence based on the second configuration information and the second transmission power, and transmit the second random access sequence at the second transmission power. In indication method example 2, the terminal device can determine the second time-frequency resource based on the second configuration information and the second transmission power, and transmit the random access sequence on the second time-frequency resource at the second transmission power. In indication method 3, the terminal device can determine the second time-frequency resource and the second random access sequence based on the second configuration information and the second transmission power, and transmit the second random access sequence on the second time-frequency resource at the second transmission power.

[0303] Based on the above scheme, even if the terminal device changes its transmission power (i.e., the first power ramp value is not zero), the first network device or the second network device can determine the transmission power of the received random access sequence based on the received random access sequence and / or the time-frequency resources used to receive the random access sequence. Alternatively, the first network device or the second network device can indicate the identifier of the received random access sequence and / or the identifier of the time-frequency resources used to receive the random access sequence to the terminal device, enabling the terminal device to determine the transmission power of the random access sequence received by the network side.

[0304] Figure 7 is a schematic flowchart of another initial access method 700 provided in an embodiment of this application. Optional operations in method 700 are shown in Figure 7 with dashed lines. Method 700 can also be applied to scenario 1 or scenario 2; please refer to the relevant description of method 400 for details, which will not be repeated here. The various operations of method 700 are described below with reference to Figure 7.

[0305] S720, the terminal device sends a first random access sequence to the first network device with a first transmit power.

[0306] For a description of the first network device, the first random access sequence, and the triggering method in S720, please refer to S420, which will not be repeated here.

[0307] In some examples, the first transmission power can be predefined by the protocol, preconfigured, or determined by other means. In other examples, the first transmission power can be network-configured. For example, in scenario 1, the terminal device may execute S510, i.e., receive second configuration information from the second network device. See the description of S510 for details, which will not be repeated here. In some possible implementations, method 700 also includes S522 before S720. In some possible implementations, S720 includes S524. See the descriptions of S522 and S524 for details, which will not be repeated here.

[0308] After the terminal device executes S720, the terminal device can execute S725.

[0309] S725, the terminal device starts the first timer. For a description of S725, please refer to the previous text, such as the relevant content of S425, which will not be repeated here.

[0310] S730, if the first timer times out, the terminal device transmits a second random access sequence to the first network device at a second transmission power. The second random access sequence is different from the first random access sequence; and / or, the first time-frequency resource is different from the second time-frequency resource. The first time-frequency resource is used to transmit the first random access sequence, and the second time-frequency resource is used to transmit the second random access sequence.

[0311] The first transmission power and the second transmission power may be the same or different, and this application does not limit this.

[0312] For example, when the second configuration information adopts the correspondence indicated by the indication method example 1, the first random access sequence is different from the second random access sequence. The first time-frequency resource and the second time-frequency resource may be the same or different; this is not limited here.

[0313] For example, when the second configuration information uses the correspondence indicated in Example 2, the first time-frequency resource is different from the second time-frequency resource. The first random access sequence and the second random access sequence may be the same or different; this is not limited here.

[0314] For example, in the case where the second configuration information adopts the correspondence indicated by the indication method example 3, the first time-frequency resource is different from the second time-frequency resource, and / or the first random access sequence is different from the second random access sequence.

[0315] The first network device may fail to successfully receive the first random access sequence sent by the terminal device each time. Possible reasons include: the first network device is far from the terminal device; the terminal device initially uses low transmit power; the signal strength (or receive power) at the first network device is weak; and / or, the uplink beam of the first network device may not be aligned with the uplink beam of the terminal device. Therefore, the terminal device may need to send the random access sequence multiple times.

[0316] It is understood that S720, S725, and S730 described above are some examples of the random access of the terminal device to the first network device in method 700, and are not intended to limit this application. S720, S725, and S730 described above can be understood as the process of the terminal device sending the first random access sequence in any two adjacent transactions.

[0317] In other examples, after S725 (starting the first timer), the terminal device may detect a RAR message from a network device (e.g., the second network device in scenario 1, or the first network device in scenario 2) within the first timer. In this case, the terminal device may not execute S730, but instead send a message (e.g., msg 3) to the first network device to resolve conflicts in random access.

[0318] In some further examples, after S730, the terminal device will restart the first timer. If this first timer expires, the terminal device will send a third random access sequence to the first network device at a third transmission power. The relationship between the third transmission power and the second transmission power is similar to that between the second and first transmission power, and will not be repeated here. The relationship between the third random access sequence and the second random access sequence is similar to that between the second and first random access sequences, and will not be repeated here. The relationship between the third time-frequency resource used to send the third random access sequence and the second time-frequency resource is similar to that between the second and first time-frequency resources, and will not be repeated here.

[0319] In other words, in method 700, the first timer can be started after each time the terminal device sends the first random access sequence.

[0320] In some possible implementations, the terminal device can be configured with a maximum number of transmissions of the first random access sequence (denoted as X, where X is a positive integer). Thus, if the first timer times out, the terminal device can increment the counter corresponding to the first timer (or, more accurately, the counter corresponding to the first random access sequence) by 1 and compare it with the maximum number of transmissions X. If the incremented counter is less than or equal to (or, alternatively, less than) X, the terminal device can transmit the third random access sequence to the first network device at a third transmission power. If the incremented counter is greater than (or, alternatively, equal to) X, the terminal device can abandon access to the first network device. This can also be understood as the terminal device not detecting the first network device. Further, in scenario 1, this can be understood as the terminal device not detecting the path to the UL access point.

[0321] As an example, the maximum number of transmissions X mentioned above can be configured by the network device (e.g., the second network device in scenario 1, or the first network device in scenario 2), predefined by the protocol, or pre-configured in the terminal device. This application does not limit the configuration method of the maximum number of transmissions X mentioned above.

[0322] The operation of the first network device and the second network device in Scenario 1 is described below. It is understood that the first network device may receive any random access sequence sent by the terminal device at any time; this application does not limit this. Furthermore, method 700 also includes: S740.

[0323] S740, the first network device measures the received random access sequence and determines the received power of the random access sequence.

[0324] It is understood that if the first network device receives a first random access sequence from the terminal device in S720, the first network device executes S740 after S720. For example, the terminal device may omit S725 and S730 in the above scenario. Furthermore, if the first network device receives a second random access sequence from the terminal device in S730, the first network device executes S740 after S730.

[0325] As an example, the first network device can detect a random access sequence on random access resources. If the detected signal strength is greater than or equal to a detection threshold, the first network device can determine that the signal strength is the received power of the random access sequence. In some possible implementations, for scenario 1, after S740, method 700 further includes S745 and S750.

[0326] S745, the first network device sends second information to the second network device. Correspondingly, the second network device receives the second information from the first network device.

[0327] S750, the second network device sends an indication message of the first PL to the terminal device based on the second information. Correspondingly, the terminal device receives the indication message of the first PL from the second network device.

[0328] The above-described S745 and S750 can be examples for scenario 1. For scenario 2, after S740, method 700 further includes: S750', whereby the first network device sends indication information of the first PL (not shown in FIG7) to the terminal device. Correspondingly, the terminal device receives the indication information from the first PL.

[0329] In some possible implementations, the indication information of the first PL is carried in a RAR message. As an example, the aforementioned RAR message can be used to schedule the terminal device to send a random access message. Further, in some possible implementations, the method may also include: S760.

[0330] S760, in response to the RAR message, the terminal device sends a random access message to the first network device.

[0331] Method 700 can be combined with the aforementioned Method 500. For example, specific examples of S745, S750, S750', and S760 are similar to the descriptions under S525, S530, S530', and S540, respectively. Specifically, in S525, "first information" can be replaced with "second information," "first transmission power (or transmission power of the first random access sequence)" can be replaced with "transmission power of the random access sequence received by the first network device," and "first time-frequency resource" can be replaced with "time-frequency resource used to transmit the random access sequence received by the first network device." The rest of the content remains essentially the same. For the sake of brevity, further details are omitted here.

[0332] In some possible implementations, after S750 or S750', other information sent by the terminal device to the first network device (e.g., SRS, or uplink data, etc.) can be power controlled based on the aforementioned first PL.

[0333] It is understood that, in order to achieve the functions in the above embodiments, the base station and terminal include hardware structures and / or software modules corresponding to perform each function. Those skilled in the art should readily recognize that, based on the units and method steps described in conjunction with the embodiments disclosed in this application, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0334] Figures 8 and 9 are schematic diagrams of possible communication devices provided in the embodiments of this application. These communication devices can be used to implement the functions of the terminal or base station in the above method embodiments, and thus can also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the communication device can be the terminal 120 shown in Figure 1, the base station 110 shown in Figure 1, or a module (such as a chip) applied to the terminal or base station.

[0335] As shown in Figure 8, the communication device 1300 includes a processing unit 1310 and a transceiver unit 1320. The communication device 1300 is used to implement the functions of a terminal or base station in the method embodiments shown in Figures 4, 5, or 7.

[0336] When the communication device 1300 is used to implement the function of the terminal device in the method embodiment shown in FIG4: after sending the first random access sequence to the first network device with the first transmission power, the processing unit 1310 is used to start the first timer; if the first timer times out, the transceiver unit 1320 is used to send the first random access sequence to the first network device again with the first transmission power.

[0337] When the communication device 1300 is used to implement the function of the terminal device in the method embodiment shown in FIG5: the transceiver unit 1320 is used to receive second configuration information from the second network device; the processing unit 1310 is used to control the transceiver unit 1320 to send a first random access sequence to the first network device with a first transmission power based on the second configuration information.

[0338] When the communication device 1300 is used to implement the function of the first network device in the method embodiment shown in FIG5: the transceiver unit 1320 is used to receive the first random access sequence from the terminal device; the transceiver unit 1320 is also used to send the first information to the second network device.

[0339] When the communication device 1300 is used to implement the function of the second network device in the method embodiment shown in FIG5: the transceiver unit 1320 is used to receive first information from the first network device; the processing unit 1310 is used to control the transceiver unit 1320 to send the first PL instruction information to the terminal device based on the first information.

[0340] When the communication device 1300 is used to implement the function of the terminal device in the method embodiment shown in FIG7: after sending the first random access sequence to the first network device with the first transmission power, the processing unit 1310 is used to start the first timer; if the first timer times out, the transceiver unit 1320 is used to send the second random access sequence to the first network device with the second transmission power.

[0341] For a more detailed description of the processing unit 1310 and the transceiver unit 1320, please refer to the relevant descriptions in the method embodiments shown in Figures 4, 5 or 7.

[0342] As shown in Figure 9, the communication device 1400 includes a processor 1410 and an interface circuit 1420. The processor 1410 and the interface circuit 1420 are coupled to each other. It is understood that the interface circuit 1420 can be a transceiver or an input / output interface. Optionally, the communication device 1400 may also include a memory 1430 for storing instructions executed by the processor 1410, or storing input data required by the processor 1410 to execute instructions, or storing data generated after the processor 1410 executes instructions. Sometimes, the interface circuit 1420 can also be understood as part of the processor 1410, in which case the communication device 1400 includes the processor 1410.

[0343] When the communication device 1400 is used to implement the method shown in FIG4, FIG5 or FIG7, the processor 1410 is used to implement the function of the processing unit 1310, and the interface circuit 1420 is used to implement the function of the transceiver unit 1320.

[0344] When the aforementioned communication device is a chip applied to a terminal, the terminal chip implements the functions of the terminal in the above method embodiments. The terminal chip receives information from the base station, which can be understood as the information being first received by other modules in the terminal (such as an RF module or antenna), and then sent to the terminal chip by these modules. The terminal chip sends information to the base station, which can be understood as the information being first sent to other modules in the terminal (such as an RF module or antenna), and then sent to the base station by these modules.

[0345] When the aforementioned communication device is a chip applied to a base station, the base station chip implements the functions of the base station in the above method embodiments. The base station chip receives information from the terminal, which can be understood as the information being first received by other modules in the base station (such as an RF module or antenna), and then sent to the base station chip by these modules. The base station chip sends information to the terminal, which can be understood as the information being sent down to other modules in the base station (such as an RF module or antenna), and then sent to the terminal by these modules.

[0346] In this application, entity A sends information to entity B, either directly or indirectly through other entities. Similarly, entity B receives information from entity A, either directly or indirectly through other entities. Entities A and B can be RAN nodes or terminals, or modules within RAN nodes or terminals. Information transmission and reception can be between RAN nodes and terminals, such as between a base station and a terminal; between two RAN nodes, such as between a CU and a DU; or between different modules within a single device, such as between a terminal chip and other modules of the terminal, or between a base station chip and other modules of the base station.

[0347] It is understood that the processor in the embodiments of this application can be a central processing unit, or other general-purpose processors, digital signal processors, application-specific integrated circuits, field-programmable gate arrays, or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

[0348] The method steps in the embodiments of this application can be implemented in hardware or in software instructions executable by a processor. The software instructions can consist of corresponding software modules, which can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, portable hard disks, optical discs, or any other form of storage medium well known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. The storage medium can also be a component of the processor. The processor and the storage medium can reside in an application-specific integrated circuit (ASIC). Alternatively, the ASIC can reside in a base station or terminal. The processor and the storage medium can also exist as discrete components in the base station or terminal.

[0349] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are performed entirely or partially. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. 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 integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video optical disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both types of storage media.

[0350] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0351] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. In the textual description of this application, the character " / " generally indicates an "or" relationship between the preceding and following related objects; in the formulas of this application, the character " / " indicates a "division" relationship between the preceding and following related objects. "Including at least one of A, B, and C" can mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B, and C.

[0352] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The order of the process numbers described above does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.

[0353] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

Claims

1. An initial access method, characterized in that, The method is executed by a terminal device or by a module applied to a terminal device, the method comprising: After sending the first random access sequence to the first network device at the first transmission power, the first timer is started; If the first timer times out, the first random access sequence is sent to the first network device again at the first transmission power.

2. The method according to claim 1, characterized in that, The method further includes: The terminal device receives indication information of a first path loss from a second network device, wherein the first path loss is the path loss between the terminal device and the first network device.

3. The method according to claim 2, characterized in that, The indication information of the first path loss is carried in the random access response message, wherein the method further includes: In response to the random access response message, a random access message is sent to the first network device, wherein the transmission power of the random access message is determined based on the first path loss.

4. The method according to any one of claims 1 to 3, characterized in that, The method further includes: Receive first configuration information from the second network device; The first transmission power is determined based on the first configuration information.

5. The method according to any one of claims 1 to 4, characterized in that, The terminal device and the first network device only have uplink transmission.

6. A communication device, characterized in that, Includes a module for performing the method according to any one of claims 1 to 5.

7. A communication device, characterized in that, include: A processor configured to execute a computer program or instructions to cause the method of any one of claims 1 to 5 to be performed.

8. The communication device according to claim 7, characterized in that, The communication device further includes a memory for storing the computer program or the instructions.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program or instructions that, when executed by a communication device, cause the communication device to perform the method as described in any one of claims 1 to 5.

10. A computer program product, characterized in that, It includes a computer program or instructions that, when executed by a communication device, cause the communication device to perform the method as described in any one of claims 1 to 5.

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