Random access method and related apparatus

Abstract

This application provides a random access method and associated apparatus that helps solve the problem of a method for triggering multi-PRACH transmissions, thereby reducing the complexity of implementing terminal devices. The method is applied to terminal devices. The method includes the steps of determining that a trigger condition is met and transmitting a first message that is randomly accessed based on multiple transmission beams. The trigger condition includes at least one of the following: a network device allows a terminal device to perform multiple physical random access channel (PRACH) transmissions based on multiple transmission beams; the service type of the terminal device is a pre-configured service type; and the maximum value of multiple synchronization signals and reference signal received power (RSRP) of PBCH blocks (SSBs) detected by the terminal device is less than a first threshold.

Description

Technical Field

[0001] This application claims the priority of Chinese Patent Application No. 202310480944.2, entitled "Random Access Method and Related Device", filed with the China National Intellectual Property Administration on April 27, 2023, and is hereby incorporated by reference in its entirety.

[0002] This application relates to the field of communication technologies, and particularly to a random access method and related devices.

Background Art

[0003] In a wireless communication system, the energy attenuation of a wireless signal in the propagation process deteriorates as the carrier center frequency of the signal increases. Under the same propagation environment and transmission distance, the higher the frequency of the signal, the faster the signal energy attenuation, and as a result, the signal coverage range is more significantly reduced. Since the terminal device is limited by the transmission power, the coverage problem of the uplink signal is more obvious.

[0004] Currently, one of the research objectives of the 3rd Generation Partnership Project (3GPP (registered trademark, the same hereinafter)) R18 is to expand the coverage of the physical random access channel (PRACH). To improve the coverage performance, a multi-PRACH transmission scheme is considered. The multi-PRACH transmission scheme includes using a plurality of different transmission beams to perform repeated transmission of the PRACH.

[0005] However, currently, the problem of the method for triggering multi-PRACH transmission has not been solved.

Summary of the Invention

Means for Solving the Problems

[0006] This application provides a random access method and related apparatus that helps solve the problem of how to trigger multi-PRACH transmissions, thereby reducing the complexity of implementation in terminal devices.

[0007] According to a first embodiment, a random access method applicable to a terminal device is provided. The method includes the steps of determining that a trigger condition is met and transmitting a first message that is randomly accessed based on a plurality of transmission beams. The trigger condition includes at least one of the following: a network device allows the terminal device to perform a plurality of PRACH transmissions based on a plurality of transmission beams; the service type of the terminal device is a pre-configured service type; and the maximum reference signal receiving power (RSRP) of a plurality of synchronization signals and PBCH blocks (SSBs) detected by the terminal device is less than a first threshold.

[0008] In this application, the step of performing multiple PRACH transmissions may represent multiple transmissions of a first message. The first message may be Message 1 (Msg 1) in a four-step random access process. Pre-configured service types may include delay-sensitive service types and cell switching service types.

[0009] Based on the technical solution of this application, a terminal device may use a coverage expansion scheme that transmits a first message randomly accessed based on multiple transmission beams when a trigger condition is met, instead of using a coverage expansion scheme that transmits a first message randomly accessed based on multiple transmission beams in any case, thereby helping to reduce the complexity of the implementation of the terminal device.

[0010] Referring to the first aspect, in some implementations of the first aspect, the method further includes the step of receiving first instruction information used to indicate whether a network device permits a terminal device to perform multiple PRACH transmissions based on multiple transmission beams.

[0011] Referring to the first embodiment, in some implementations of the first embodiment, the first instruction information is placed in a system information block (SIB) message.

[0012] Referring to the first embodiment, in some implementations of the first embodiment, the method further includes the step of determining, for each transmission of the first message, the number of transmissions of the first message and the transmission power. The step of transmitting the first message randomly accessed based on a plurality of transmission beams includes the step of transmitting the first message once based on the first transmission beam in the plurality of transmission beams, with the transmission power for this transmission of the first message at the RACH occasion (RO) for this transmission of the first message, wherein the first transmission beam is any one of the plurality of transmission beams. In this way, the terminal device can transmit the first message multiple times based on a plurality of transmission beams, thereby helping to improve the success rate of the transmission of the first message.

[0013] Referring to the first embodiment, in some implementations of the first embodiment, the method further includes the steps of receiving a plurality of SSBs and selecting at least one SSB from the plurality of SSBs. The number of transmission beams is equal to the number of at least one SSB, and the number of transmissions of the first message is equal to the number of at least one SSB. In this way, the terminal device can transmit the first message once in a single transmission beam, and as a result, the implementation is simple.

[0014] Referring to the first embodiment, in some implementations of the first embodiment, the RSRP of each SSB among at least one SSB is greater than the second threshold.

[0015] Referring to the first embodiment, in some implementations of the first embodiment, the direction of the downlink transmission beam associated with at least one SSB is different. In this way, the direction of the uplink transmission beam selected by the terminal device according to the downlink transmission beam is different, thereby helping to improve the success probability of transmitting the first message.

[0016] Referring to the first embodiment, in some implementations of the first embodiment, in a single PRACH transmission cycle, each of the multiple SSBs is mapped to random access opportunities in all frequency domains within the same time period. In this way, different SSBs are mapped to different time periods, and different SSBs perform PRACH transmissions over different time periods, thereby helping to reduce power consumption of terminal devices.

[0017] According to a second aspect, the present application provides a terminal device, the terminal device comprising a processor and memory, the memory storing computer executable instructions, and the processor executing the computer executable instructions stored in memory to cause the terminal device to perform the method according to the first aspect.

[0018] According to a third aspect, the present application provides a computer-readable storage medium. The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, it performs the method according to the first aspect.

[0019] According to a fourth aspect, the present application provides a computer program product. The computer program product includes a computer program that, when executed on a computer, causes the computer to perform the method according to the first aspect.

[0020] According to the fifth aspect, the present application provides a chip. The chip includes a processor, and the processor is configured to call a computer program stored in a memory to execute the method according to the first aspect.

[0021] It should be understood that the second to fifth aspects of the present application correspond to the technical solutions of the first aspect of the present application, and the beneficial effects obtained by each aspect and the corresponding realizable implementation forms are the same. Details will not be described again in this specification.

Brief Description of Drawings

[0022] [Figure 1] It is a schematic structural diagram of a terminal device applicable to an embodiment of the present application. [Figure 2] It is a schematic diagram of the signal coverage range provided in an embodiment of the present application. [Figure 3] It is a schematic flowchart of a four-step random access method provided in an embodiment of the present application. [Figure 4] It is a schematic diagram in which different transmission beams are used to perform repeated transmission of PRACH provided in an embodiment of the present application. [Figure 5] It is a schematic architecture diagram of a communication system provided in an embodiment of the present application. [Figure 6] It is a schematic flowchart of a random access method provided in an embodiment of the present application. [Figure 7] It is a schematic flowchart of another random access method provided in an embodiment of the present application. [Figure 8] It is a schematic diagram of the mapping relationship between SSB and RO provided in an embodiment of the present application. [Figure 9] It is a schematic structural diagram of a random access device provided in an embodiment of the present application. [Figure 10] It is a schematic diagram of the hardware structure of another terminal device provided in an embodiment of the present application.

Modes for Carrying Out the Invention

[0023] The technical solutions in this application will be described below with reference to the attached drawings.

[0024] To facilitate a clear explanation of the technical solutions in the embodiments of this application, the relevant terms included in this application are first introduced in detail below.

[0025] In the embodiments of this application, words such as "first" and "second" are used to distinguish the same or similar items having essentially the same function and role, and the sequence is not limited. Those skilled in the art will understand that words such as "first" and "second" do not limit the number or order of execution, and that words such as "first" and "second" do not necessarily indicate a difference.

[0026] In this application, words such as “exemplary” or “for example” are used to indicate that an example, illustration, or explanation is being given. Any embodiment or design solution described “exemplary” or “for example” in this application should not be described as being preferable or having more advantages than another embodiment or design solution. More precisely, the use of words such as “exemplary” or “for example” is intended to present a related concept in a particular manner.

[0027] In addition, "at least one" means one or more, and "multiple" means two or more. "And / or" describes an association between related objects and indicates that three relationships may exist. For example, A and / or B may represent the following three cases: that only A exists, that both A and B exist, and that only B exists, and A and B may be singular or plural. The letter " / " generally indicates an "or" relationship between related objects. "At least one of the following items (elements)" or a similar expression means any combination of these items, including one item (element) or any combination of multiple items (elements). For example, at least one item (element) of a, b, and c may represent a, or b, or c, or a and b, or a and c, or b and c, or a, b, and c, and a, b, and c may be singular or plural.

[0028] Figure 1 is a schematic diagram of a terminal device applicable to one embodiment of this application. As shown in Figure 1, the terminal device 100 may include a processor 110, an external memory interface 120, internal memory 121, a USB interface 130, a charge management module 140, a power management module 141, a battery 142, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, a headset jack 170D, a sensor module 180, a key 190, a motor 191, an indicator 192, a camera 193, a display screen 194, a subscriber identity module (SIM) card interface 195, and the like.

[0029] It can be understood that the structures shown in this embodiment do not constitute any specific limitations on the terminal device 100. In some other embodiments of this application, the terminal device 100 may include more or fewer components than those shown in the figures, or may be a combination of some components, or a division of some components, or may have a different component arrangement. The components shown in the figures may be implemented by hardware, software, or a combination of software and hardware.

[0030] The processor 110 may include one or more processing units. For example, the processor 110 may include an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, a display processing unit (DPU), and / or a neural network processing unit (NPU). Different processing units may be separate devices or may be integrated into one or more processors. In some embodiments, the terminal device 100 may further include one or more processors 110. The processor may be the central center and command center of the terminal device 100. The processor may generate operation control signals based on instruction operation codes and timing signals to perform instruction fetching and instruction execution control. Memory may be further provided in the processor 110 for storing instructions and data. In some embodiments, the memory of the processor 110 is a cache. The memory can store instructions or data used or periodically used by the processor 110. If the processor 110 needs to use the instructions or data again, it can retrieve them directly from memory. In this way, repeated access is avoided, the latency of the processor 110 is reduced, and as a result, the efficiency of the terminal device 100 is improved.

[0031] The wireless communication function of the terminal device 100 can be realized through antennas 1 and 2, a mobile communication module 150, a wireless communication module 160, a modem processor, a baseband processor, and the like. Antennas 1 and 2 are configured to transmit and receive electromagnetic wave signals. Each antenna of the terminal device 100 may be configured to cover one or more communication frequency bands. Different antennas may be reused to improve antenna utilization. For example, antenna 1 may be reused as a diversity antenna in a wireless local area network. In some other embodiments, antennas may be used in combination with tuning switches.

[0032] The mobile communication module 150 is applied to a terminal 100 and can provide a wireless communication solution including 2G / 3G / 4G / 5G, etc. The mobile communication module 150 may include at least one filter, switch, power amplifier, low-noise amplifier, etc. The mobile communication module 150 can receive electromagnetic waves through antenna 1, perform processing such as filtering and amplification on the received electromagnetic waves, and transmit the electromagnetic waves to a modem processor for demodulation. The mobile communication module 150 may further amplify the signal modulated by the modem processor and convert the signal into electromagnetic waves for radiation through antenna 1. In some embodiments, at least some of the functional modules of the mobile communication module 150 may be located in the processor 110. In some embodiments, at least some of the functional modules of the mobile communication module 150 may be located in the same device as at least some of the modules of the processor 110.

[0033] The wireless communication module 160 can provide solutions applicable to the terminal device 100 for wireless communication including wireless local area networks (WLAN), Bluetooth® (BT), global navigation satellite systems (GNSS), frequency modulation (FM) technology, near field communication (NFC) technology, infrared (IR) technology, etc. The wireless communication module 160 may be one or more components with at least one communication processing module integrated. The wireless communication module 160 receives electromagnetic waves via antenna 2, performs frequency modulation and filtering on the electromagnetic wave signal, and transmits the processed signal to processor 110. The wireless communication module 160 may further receive the signal transmitted from processor 110, perform frequency modulation and amplification on the transmitted signal, and convert the transmitted signal into electromagnetic waves for radiation via antenna 2.

[0034] In some embodiments, in the terminal device 100, antenna 1 is coupled to a mobile communication module 150 and antenna 2 is coupled to a wireless communication module 160 so that the terminal device 100 can communicate with the network and other devices through wireless communication technology. Wireless communication technology may include GSM, GPRS, CDMA, WCDMA®, TD-SCDMA, LTE, GNSS, WLAN, NFC, FM, and / or IR technology. GNSS may include the global positioning system (GPS), global navigation satellite system (GLONASS), Bei Dou navigation satellite system (BDS), quasi-zenith satellite system (QZSS), and / or satellite-based augmentation systems (SBAS).

[0035] The display screen 194 is configured to display images, videos, etc. The display screen 194 includes a display panel. The display panel may be a liquid crystal display (LCD), an organic light-emitting diode (OLED), an active-matrix organic light-emitting diode or active-matrix organic light-emitting diode (AMOLED), a flexible light-emitting diode (FLED), a MiniLED, a MicroLED, a Micro-OLED, or a quantum dot light-emitting diode (QLED). In some embodiments, the terminal device 100 may include one or N display screens 194, where N is a positive integer greater than 1.

[0036] The external memory interface 120 may be configured to connect to an external memory card, such as a Micro SD card, in order to expand the storage capacity of the terminal device 100. The external memory card communicates with the processor 110 through the external memory interface 120 to implement data storage functions. For example, data files such as music, photos, and videos are stored on the external memory card.

[0037] The internal memory 121 may be configured to store one or more computer programs, each of which includes instructions. The processor 110 can execute instructions stored in the internal memory 121 to cause the terminal device 100 to perform various functional applications, data processing, etc. The internal memory 121 may include a program storage area and a data storage area. The program storage area may store the operating system. The program storage area may further store one or more applications (such as a gallery and contacts). The data storage area may store data created during use of the terminal device 100 (e.g., photos and contacts). In addition, the internal memory 121 may include high-speed random access memory, or it may include at least one disk storage device, flash memory device, or non-volatile memory such as universal flash storage (UFS). In some embodiments, the processor 110 can cause the terminal device 100 to perform various functional applications and data processing by executing instructions stored in the internal memory 121 and / or instructions stored in memory located in the processor 110.

[0038] The sensor module 180 may include a pressure sensor 180A, a gyroscope sensor 180B, a barometric pressure sensor 180C, a magnetic sensor 180D, an acceleration sensor 180E, a distance sensor 180F, a light proximity sensor 180G, a fingerprint sensor 180H, a temperature sensor 180J, a touch sensor 180K, an ambient light sensor 180L, a bone conduction sensor 180M, and the like.

[0039] In wireless communication systems, the energy attenuation of a radio signal during the propagation process worsens as the carrier center frequency of the signal increases. Under the same propagation environment and transmission distance, the higher the signal frequency, the faster the signal energy attenuation. This means that the coverage range of high-frequency signals is smaller than that of low-frequency signals, and the coverage range of signals in high-frequency bands (e.g., FR2 frequency bands) is more significantly reduced.

[0040] Figure 2 is a schematic diagram of the signal coverage range provided in one embodiment of this application. As shown in Figure 2, under the same propagation conditions, the downlink coverage range r1 for high-frequency signals is smaller than the downlink coverage range r2 for low-frequency signals. The uplink coverage range r3 for high-frequency signals in a terminal device is smaller than the downlink coverage range r1. Therefore, to extend the coverage range of uplink signals in a terminal device, it is necessary to design a coverage extension solution for uplink signals.

[0041] 3GPP R17 discusses coverage extensions for physical uplink shared channels (PUSCH), physical uplink control channels (PUCCH), and Message 3 (Msg 3) in random access (RA) processes, but does not discuss coverage extensions for PRACH. PRACH coverage extension is a bottleneck problem in uplink channel coverage and is extremely important in processes such as initial access and beam fault recovery.

[0042] The relevant technologies and concepts included in this application are first introduced below.

[0043] Typically, when a terminal device needs to establish communication with a network device, it must transmit information to the network device via a random access channel (RACH) to obtain uplink synchronization, acquire terminal device identification information, and prepare for subsequent scheduling of the terminal device by the network device.

[0044] The random access process involves a terminal device initiating an attempt to access the network by transmitting a preamble sequence through PRACH and successfully establishing a radio resource control (RRC) connection to the network. The preamble sequence may also be called a random access preamble or simply a preamble. PRACH is an uplink physical random access channel, and PRACH and RACH form a mapping relationship.

[0045] Typically, terminal devices and network devices interact to perform a random access process and implement uplink synchronization. Due to the different distances between terminal devices and network devices, the time delay of the uplink signals transmitted to reach the network device varies accordingly. To ensure that uplink signals transmitted by all terminal devices are aligned with the network device's frame time slot (10 ms frame) when they reach the network device, it is necessary to ensure that unused terminal devices transmit uplink data using different time advances (TA).

[0046] Random access types include competition-based random access and non-competition-based random access. In competition-based random access, competition may occur if multiple terminal devices transmit preamble sequences to a network device simultaneously. Since the network device cannot distinguish which preamble sequence is transmitted by which terminal device, terminal devices must transmit messages relevant to themselves to the network device. Thus, the network device can distinguish between preamble sequences transmitted by different terminal devices. In non-competition-based random access, the network device instructs terminal devices to perform random access at appropriate times. Therefore, competition does not occur.

[0047] In a possible random access scenario, an idle terminal device (RRC_IDLE) performs a cell discovery after power-on and, after discovering a cell, accesses the appropriate cell using a random access method. Using a scenario as an example, and referring to Figure 3, the following describes the race-based random access process used in the current standard, which may also be called a four-step random access process, relating to the interaction of four messages (Message) between the terminal device and the network device. The four messages include Message 1 (Msg 1), Message 2 (Msg 2), Message 3 (Msg 3), and Message 4 (Msg 4).

[0048] Figure 3 is a schematic flowchart of a four-step random access method 300 provided in one embodiment of this application. Method 300 includes S301 to S304, and the specific steps are as follows:

[0049] S301: The terminal device transmits the preamble sequence to the network device (preamble).

[0050] This step corresponds to the interaction of Msg 1 between the terminal device and the network device. In other words, the terminal device transmitting Msg 1 to the network device includes the terminal device transmitting a preamble sequence to the network device. Optionally, the terminal device transmits one or more preamble sequences to the network device.

[0051] Initial random access is initiated by the MAC sublayer of the terminal device. Prior to S301, the network device may notify all terminal devices via SIB messages which PRACH resources are permitted to transmit the preamble sequence. RACH is configured to transmit the preamble sequence as the uplink random access channel. PRACH is responsible for carrying RACH, is the physical channel to which RACH is mapped, and has a fixed time-frequency resource, which can be obtained via SIB messages.

[0052] A terminal device may obtain at least one of the following pieces of information in advance through an SIB message transmitted by a network device: (1) PRACH channel parameters: The preamble format, the transmission time of the PRACH (i.e., which system frame, which subframe, which time slot, and which start symbol), and the frequency domain resource offset of the PRACH (prach-RreqOffset) (which determines the frequency domain position of the PRACH) can be obtained through the preamble sequence configuration index (prach-ConfigIndex). (2) Random access groups and the available preamble sequences for each group. (3) Size of the random access response window. The terminal device controls the reception of Msg 2 through a window mechanism and stops receiving Msg 2 after the random access response window has sized. (4) Power rise coefficient. (5) Initial transmission power of the preamble sequence. (6) The maximum number of preamble sequences to be transmitted. (7) The maximum number of retransmissions of Msg 3. (8) Conflict resolution timer.

[0053] Each cell has up to 64 available preamble sequences, and each preamble sequence has an identification (ID) corresponding to that preamble sequence. In competition-based random access, a terminal device may randomly select one of several preamble sequences for transmission on PRACH. Therefore, multiple terminal devices may select the same preamble sequence. A preamble sequence typically carries 6 bits of information, 5 bits representing the random access-radio network temporary identity (RA-RNTI), which is used to identify the time-frequency resource on which the terminal device transmits the preamble sequence and may descramble physical downlink control channel (PDCCH) information, and 1 bit representing the size of the data being transmitted during Msg 3 uplink scheduling transmission. When transmitting a preamble sequence, a terminal device may calculate the RA-RNTI according to the subframe number and the location of the PRACH frequency resource for transmitting Msg 1.

[0054] S302: The network device transmits a random access response (RAR) to the terminal device.

[0055] This step corresponds to the interaction of Msg 2 between the terminal device and the network device. In other words, the transmission of Msg 2 from the network device to the terminal device includes the transmission of RAR from the network device to the terminal device.

[0056] After transmitting Msg 1, the terminal device monitors for a certain period of time (e.g., 3 ms) to see if the network device transmits Msg 2 via RA-RNTI. The time the terminal device continuously monitors for Msg 2 is the size of the random access response window. Illustratively, the random access response window is up to 10 ms.

[0057] After receiving Msg 1, the network device calculates the correlation peak value using the IDs of the 64 preamble sequences that have the detected preamble sequence. If the correlation peak value can be obtained by calculating the ID of the preamble sequence using the detected preamble sequence, then the preamble sequence is the preamble sequence transmitted by the terminal device. The time delay of data transmission between the terminal device and the network device can be further obtained through correlation peak detection.

[0058] After receiving Msg 1, the network device assigns a temporary cell-RNTI (TC-RNTI) and prepares to perform uplink and downlink scheduled transmissions. The network device then transmits Msg 2 on a downlink-shared channel (DL-SCH), carrying the preamble sequence ID, tracking area (TA), uplink grant (UL Grant), and TC-RNTI. Msg 2 may be transmitted to multiple terminal devices on a single DL-SCH.

[0059] S303: The terminal device transmits Message 3 to the network device.

[0060] The terminal device receives Msg 2 in the random access response window and detects Msg 2. If the ID of the preamble sequence carried in Msg 2 is the same as the ID of the preamble sequence transmitted by the terminal device, the terminal device considers the response successful.

[0061] The terminal device transmits Msg 3 to the network device. Msg 3 may include an RRC connection establishment request, a tracking area update (TAU), a scheduling request, an RRC connection re-establishment request, and may further include idle TC-RNTI and conflict resolution identification information.

[0062] The terminal device transmits Msg 3 via the uplink-shared channel (DL-SCH). The size of the transmission block may be specified by the UL Grant carried in Msg 2 received in S302, but it must be 80 bits or more.

[0063] Reasons for establishing an RRC connection may include, but are not limited to, the following scenarios: (1) Mobile originating calls (Mo-Data): A common scenario involves an RRC connection request carrying the reason value "Mo-Data" because the terminal device is idle and the service needs to be started again to reach the RRC connection state (RRC_CONNECTION). (2) Mobile originating signaling (Mo-Sig): Typical scenarios include initial attachment and TAU. (3) Mobile Terminal Access (MT-Access): Typical scenarios include access initiated by the terminal device in response to paging, or alternatively, service access triggered when paging is received. (4) Use of emergency calls.

[0064] It should be noted that multiple terminal devices may use the same preamble sequence. Therefore, after multiple terminal devices receive Msg 2, it can be assumed that multiple terminal devices will respond to Msg 1 transmitted by multiple terminal devices, thereby causing a conflict. The conflict can be resolved by transmitting Msg 4 through the network device.

[0065] S304: The network device transmits Message 4 to the terminal device.

[0066] Message 4 contains conflict resolution identifiers. After receiving Message 4, the terminal device compares the received conflict resolution identifiers with the conflict resolution identifiers carried by the terminal device in Message 3. If the conflict resolution identifiers in Message 3 and Message 4 are the same, the conflict is resolved and the random access process succeeds. Otherwise, the conflict fails, and the terminal device restarts the random access process.

[0067] The transmission of Msg 1 from a terminal device to a network device can be considered a PRACH transmission. When a terminal device is located in an area of ​​weak signal coverage, coverage can be enhanced in the following ways:

[0068] (1) The transmission of the preamble sequence is repeated multiple times during PRACH transmission, and the more repetitions performed, the greater the signal coverage range. However, the number of repetitions of preamble sequence transmission in PRACH transmission is limited, and random access failures may still occur in a single PRACH transmission. In particular, the scenario of frequency range 2 (FR 2) is more likely to result in insufficient uplink coverage. FR 2 includes the millimeter-wave frequency band from 24.25 GHz to 52.6 GHz.

[0069] (2) When PRACH transmission fails, for example, when a terminal device does not receive Msg 2, the terminal device may initiate PRACH retransmission. In the retransmission process, the transmission beam may be switched or the transmission power may be adjusted. However, different preamble sequences may be selected in the PRACH retransmission process, and as a result, the network device may not be able to perform diversity reception. In addition, retransmission after failure causes further random access time delays.

[0070] Currently, 3GPP R18 is beginning research to expand PRACH coverage, including the following: (1) Repeated transmission of PRACH is performed based on the same transmission beam in a 4-step random access process. (2) Repeated transmission of PRACH is performed based on different transmission beams in a 4-step random access process.

[0071] This embodiment of the present application primarily relates to performing repeated PRACH transmissions based on different transmission beams, or performing multiple PRACH transmissions based on different transmission beams, or repeatedly performing PRACH transmissions based on different transmission beams. Referring to the description in S301, in the process by which a terminal device transmits Msg 1 to a network device, the terminal device may perform repeated PRACH transmissions on different transmission beams. The network device may receive multiple PRACH transmissions on the same or different receiving beams. It should be understood that the transmission beam and receiving beam used herein refer to uplink transmissions. That is, the transmission beam refers to the uplink transmission beam of the terminal device, and the receiving beam refers to the uplink receiving beam of the network device.

[0072] Figure 4 is a schematic diagram showing that different transmission beams are used to perform repeated PRACH transmissions provided in one embodiment of the present application. As shown in Figure 4, a terminal device performs repeated PRACH transmissions using M transmission beams, the M transmission beams comprising Tx_1, Tx_2, ..., and Tx_M, where M is a positive integer greater than or equal to 2. The terminal device may perform one or more PRACH transmissions on each transmission beam. A network device may receive multiple PRACH transmissions on the same receiving beam Rx_n. In this way, the network device may receive multiple received PRACH transmissions in combination, thereby improving the signal interference noise ratio (SINR) of the received signal to achieve the objective of improving the probability of correct reception of random access signals.

[0073] For example, the number of PRACH transmissions performed by a terminal device based on different transmission beams can be any value of 2, 4, 6, and 8.

[0074] Consider an example where the transmission beams include Tx_1 and Tx_2, and the number of PRACH transmission repetitions is 2, the terminal device may perform one PRACH transmission for transmission beam Tx_1 and one PRACH transmission for transmission beam Tx_2.

[0075] Considering an example where the transmission beams include Tx_1 and Tx_2 and the number of PRACH transmission repetitions is 4, the terminal device may perform 2 PRACH transmissions for transmission beam Tx_1 and 2 PRACH transmissions for transmission beam Tx_2. Naturally, the terminal device may also perform 1 PRACH transmission for transmission beam Tx_1 and 3 PRACH transmissions for transmission beam Tx_2. Or, the terminal device may also perform 3 PRACH transmissions for transmission beam Tx_1 and 1 PRACH transmission for transmission beam Tx_2. This is not limited to the embodiments of this application.

[0076] Please understand that in each PRACH transmission, the terminal device may repeatedly transmit the preamble sequence based on the maximum number of preamble sequences that can be transmitted.

[0077] One purpose of performing multiple PRACH transmissions based on different transmission beams is to quickly find a relatively suitable uplink transmission beam for a terminal device or a relatively suitable uplink reception beam for a network device among multiple different transmission beams. A network device may transmit multiple SSBs on different downlink transmission beams, and a terminal device may select an SSB according to the RSRP of the multiple SSBs to determine the downlink reception beam, and then the terminal device may determine the uplink transmission beam using a beam alignment scheme.

[0078] When implementing a coverage extension scheme that performs PRACH repetition transmission based on different transmission beams, network devices need to perform combined reception of PRACH transmissions on multiple different beams. As a result, the probability of correct signal reception can be improved, but the complexity of the network device implementation increases to some extent. In either case, when a coverage extension scheme that performs PRACH repetition transmission based on different transmission beams is used, the load on network devices may increase. In addition, terminal devices need to switch to use different transmission beams, which also increases the complexity of the terminal device implementation.

[0079] Current protocols do not clearly define when a terminal device may use a coverage expansion scheme that performs PRACH repetition transmissions based on different transmission beams; in other words, there is currently a challenge in how to trigger a terminal device to perform PRACH repetition transmissions based on different transmission beams. In consideration of this, one embodiment of the present application provides a random access method in which, if trigger conditions are met, a terminal device may use a coverage expansion scheme that performs PRACH repetition transmissions based on different transmission beams.

[0080] Figure 5 is a schematic architectural diagram of a communication system 500 provided in one embodiment of the present application. The communication system 500 shown in Figure 5 includes a network device 501 and a terminal device 502. It should be understood that the communication system 500 represents one network device (e.g., a base station) and one terminal device (e.g., a mobile phone). However, the communication system 500 is not limited to one network device and one terminal device. The number and form of devices shown in Figure 5 are used as examples only and do not constitute a limitation to the embodiments of the present application. In actual use, two or more network devices and two or more terminal devices may be included.

[0081] The technical solutions in the embodiments of this application can be applied to fifth-generation (5G) systems or future evolutionary communication systems, and various communication systems such as vehicle-to-X (V2X), where V2X may include vehicle-to-network (V2N), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-pedestrian (V2P), long-term evolution-vehicle (LTE-V), vehicle internet, machine-type communication (MTC), Internet of Things (IoT), long-term evolution-machine (LTE-M), machine-to-machine (M2M), device-to-device (D2D), and the like.

[0082] The terminal device in the embodiments of this application may also be called a terminal, user equipment (UE), mobile station (MS), mobile terminal (MT), etc. The terminal device may be a mobile phone, personal computer (PC), smart TV, wearable device, tablet computer (Pad), computer with wireless transceiver function, virtual reality (VR) terminal device, augmented reality (AR) terminal device, wireless terminal for industrial control, wireless terminal for self-driving, wireless terminal for remote medical surgery, wireless terminal for smart grid, wireless terminal for transportation safety, wireless terminal for smart city, wireless terminal for smart home, etc.

[0083] As an example, and not an limitation, in the embodiments of this application, the terminal device may also be a wearable device. Wearable devices, sometimes called smart wearable devices, are a general term for wearable devices intelligently designed and developed for everyday wear using wearable technology, such as glasses, gloves, watches, clothing, and shoes. Wearable devices are portable devices that are worn directly on the human body or integrated into the user's clothing or accessories. Wearable devices are not merely hardware devices, but achieve powerful functionality through software support, data interaction, and cloud interaction. In a broad sense, smart wearable devices include full-featured large devices that can achieve full or partial functionality without relying on a smartphone, such as smartwatches or smart glasses, and devices that focus on specific types of application functionality and need to be used in conjunction with other devices such as smartphones, such as various smart bands or smart jewelry for monitoring physical signs.

[0084] In addition, terminal devices may also be terminal devices in IoT systems. IoT is an important part of the future development of information technology and has the main technological characteristic of connecting things to a network using communication technology to realize intelligent networks for human-machine interconnection and thing-to-thing interconnection. The specific form of terminal devices is not limited in this application.

[0085] In embodiments of this application, the terminal device may be an apparatus configured to implement the functions of the terminal device, or an apparatus capable of supporting the terminal device to implement the functions, such as a chip system. The apparatus may be mounted on the terminal. In embodiments of this application, the chip system may consist of a chip, or may include a chip and other separate devices.

[0086] The network device in the embodiments of this application may be any device having wireless transceiver functionality. The devices include, but are not limited to, evolved Node B (eNB), radio network controller (RNC), node base (NB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home evolved Node B, or home node B, HNB), base band unit (BBU), access point (AP) of a wireless fidelity (WIFI) system, radio relay node, radio backhaul node, transmission point (TP), or transmission and reception point (TRP), and may also be one or a group of antenna panels (including multiple antenna panels) of a 5G or 5G system base station such as an NR, gNB, or transmission point (TRP or TP), or may also be network nodes that constitute a gNB or transmission point such as a base band unit (BBU) or distributed unit (DU).

[0087] In embodiments of this application, the network device may be a device configured to implement the functions of a network device, or a device capable of supporting the network device in implementing its functions, such as a chip system. The device may be attached to the network device. It should be understood that all or part of the functions of the network device in this application may be implemented by software functions executed in hardware, or by virtualization functions instantiated on a platform (e.g., a cloud platform).

[0088] It should be understood that the network devices and terminal devices in the embodiments of this application may be deployed on land, on water, or in the air, including indoors, outdoors, handheld, or in-vehicle, or even in the air, such as on an aircraft, balloon, or satellite. The application scenarios for the network devices and terminal devices are not limited to the embodiments of this application.

[0089] Figure 6 is a schematic flowchart of a random access method 600 provided in one embodiment of the present application. Exemplary, the method 600 may be applied to the communication system 500 shown in Figure 5, and the steps of the method 600 may be performed by terminal devices of the communication system 500. The method 600 includes S601 and S602, and the specific steps are as follows:

[0090] S601: Determine that the trigger condition is met.

[0091] In this step, the trigger condition may include at least one of the following: the network device allows the terminal device to perform multiple PRACH transmissions based on multiple transmission beams; the service type of the terminal device is a pre-configured service type; and the maximum RSRP of multiple SSBs detected by the terminal device is less than a first threshold.

[0092] Referring to the explanation above, in this step, the network device allows the terminal device to perform multiple PRACH transmissions based on multiple transmission beams. In a random access process, it can be understood that the network device allows the terminal device to perform PRACH transmissions based on multiple transmission beams, and each transmission beam may perform one or more PRACH transmissions. Therefore, multiple PRACH transmissions may be performed based on multiple transmission beams.

[0093] A terminal device may decide whether to use a coverage extension scheme that transmits a first message randomly accessed based on multiple transmission beams according to service requirements. Pre-configured service types may include delay-sensitive service types and cell switching service types. Delay-sensitive service types may be understood as service types with relatively high delay requirements or service types with low delay requirements.

[0094] Latency-sensitive service types may include, for example, high-resolution video services based on the transmission control protocol (TCP), such as 4K / 8K high-resolution video live streaming and on-demand services, high-resolution video conferencing, and high-bandwidth services with very high requirements for real-time performance, such as virtual reality (VR). Another example of latency-sensitive service types may include several cloud services, such as cloud desktops and cloud payments.

[0095] The first threshold is the threshold required to trigger the terminal device to execute S602.

[0096] For example, a trigger condition may include any one of the conditions described above. For instance, the trigger condition may include a network device allowing a terminal device to perform multiple PRACH transmissions based on multiple transmission beams, or the trigger condition may include the service type of the terminal device being a pre-configured service type, or the trigger condition may include the maximum RSRP value of multiple SSBs detected by the terminal device being less than a first threshold.

[0097] In another example, the trigger condition includes any two of the conditions described above. For example, the trigger condition includes the network device allowing the terminal device to perform multiple PRACH transmissions based on multiple transmission beams and the service type of the terminal device being a pre-configured service type, or the trigger condition includes the network device allowing the terminal device to perform multiple PRACH transmissions based on multiple transmission beams and the maximum RSRP of multiple SSBs detected by the terminal device being less than a first threshold, or the trigger condition includes the service type of the terminal device being a pre-configured service type and the maximum RSRP of multiple SSBs detected by the terminal device being less than a first threshold.

[0098] In yet another example, the trigger condition includes three of the aforementioned conditions, namely, the trigger condition includes: the network device allowing the terminal device to perform multiple PRACH transmissions based on multiple transmission beams; the service type of the terminal device being a pre-configured service type; and the maximum RSRP of multiple SSBs detected by the terminal device being less than a first threshold.

[0099] Optionally, the trigger conditions in the embodiments of this application are pre-configured in the terminal device.

[0100] S602: The first message, which is accessed randomly, is transmitted based on multiple transmission beams.

[0101] In this step, the first message is Msg 1 as described in S301. Multiple transmission beams include multiple transmission beams having different transmission directions. When the terminal device determines that the trigger condition is met, the terminal device transmits the first message, which is accessed randomly based on the multiple transmission beams, transmitting the first message once or multiple times on each transmission beam, and thus the first message is transmitted multiple times across the multiple transmission beams. In this specification, transmission beams refer to the uplink transmission beams of the terminal device.

[0102] From the above description, it can be seen that the transmission of Msg 1 from a terminal device to a network device can be considered as a single PRACH transmission. The terminal device transmits a first message that is randomly accessed based on multiple transmission beams; that is, the terminal device performs multiple PRACH transmissions based on multiple transmission beams. In the embodiments of this application, the terminal device transmitting a first message that is randomly accessed based on multiple transmission beams is equivalent to the terminal device transmitting a first message that is randomly accessed based on multiple transmission beams.

[0103] For specific implementations in which a terminal device transmits a first message that is accessed randomly based on multiple transmission beams, please refer to the explanation in Figure 4, as further details are not provided herein.

[0104] In an optional embodiment, prior to S601, method 600 further includes receiving first instruction information used to indicate whether a network device permits a terminal device to perform multiple PRACH transmissions based on multiple transmission beams. Optionally, the first instruction information may be placed in an SIB message.

[0105] For example, a network device transmits an SIB message to a terminal device, the SIB message containing first instruction information, which is embodied in the form of information bits.

[0106] For example, if the information bit value is "false," it indicates that the terminal device is not permitted to perform multiple PRACH transmissions based on multiple transmission beams, and if the information bit value is "true," it indicates that the terminal device is permitted to perform multiple PRACH transmissions based on multiple transmission beams.

[0107] In another example, if the information bit value is "0", it indicates that the terminal device is permitted to perform multiple PRACH transmissions based on multiple transmission beams; if the information bit value is "1", it indicates that the terminal device is permitted to perform multiple PRACH transmissions based on one transmission beam; and if the information bit value is "2", it indicates that the terminal device is permitted to perform one PRACH transmission based on one transmission beam. When the information bit takes a value other than "0", it indicates that the network device does not permit the terminal device to perform multiple PRACH transmissions based on multiple transmission beams.

[0108] Figure 7 is a schematic flowchart of another random access method 700 provided in one embodiment of the present application. Method 700 includes S701 to S707, and the specific steps are as follows:

[0109] S701: The network device transmits multiple SSBs to the terminal device. In response, the terminal device receives multiple SSBs.

[0110] It should be noted that each of the multiple SSBs transmitted by a network device is associated with one downlink transmission beam, i.e., corresponding to one beam scanning direction. Ultimately, there is one SSB in each direction.

[0111] Optionally, S701 may be executed before S601 in method 600.

[0112] S702: The network device transmits PRACH resource configuration information to the terminal device. In response, the terminal device receives the PRACH resource configuration information.

[0113] PRACH resource configuration information may include mapping relationships between each SSB and the RO in multiple SSBs. Optionally, network devices may transmit PRACH resource configuration information to terminal devices via SIB messages.

[0114] Optionally, S702 may be performed before S601 in method 600.

[0115] Figure 8 is a schematic diagram of the mapping relationship between SSBs and ROs provided in one embodiment of the present application. In Figure 8, an example is used in which multiple SSBs include SSB_1, SSB_2, SSB_3, and SSB_4. When a network device allows a terminal device to perform multiple PRACH transmissions in different beams, the mapping relationship between SSBs and ROs can be set to a “time domain first, then frequency domain” mapping scheme. As shown in Figure 8, in one PRACH transmission cycle, one SSB is mapped to ROs in all frequency domains in the same time period. After selecting at least one SSB from multiple SSBs, the terminal device can determine the ROs associated with at least one SSB, i.e., it can determine the location of the time-frequency resources for each transmission of the first message.

[0116] S703: The terminal device selects at least one SSB from multiple SSBs.

[0117] After the terminal device has received multiple SSBs, it is determined whether the trigger condition is met if the aforementioned trigger condition includes the maximum RSRP value of the multiple SSBs detected by the terminal device being less than a first threshold. In addition, the terminal device may determine, according to the multiple SSBs, the number of transmission beams for each transmission of the first message, the number of transmissions of the first message, and the transmission power.

[0118] Before determining the number of transmission beams, the number of transmissions of the first message, and the transmission power for each transmission of the first message, the terminal device first selects at least one SSB from among several SSBs. The possible selection methods are as follows:

[0119] Method 1: The terminal device selects at least one SSB from among several SSBs in which the RSRP is greater than a second threshold.

[0120] Method 2: The terminal device selects an SSB from among multiple SSBs whose RSRP is greater than a third threshold, first selecting the SSB with the strongest RSRP from among the SSBs that meet the conditions, and then selecting a non-adjacent SSB.

[0121] Optionally, the second and third thresholds may be equal or unequal, and this is not limited to the embodiments of this application.

[0122] Non-adjacent SSBs in Method 2 may include SSBs with different directions, i.e., the directions of the downlink transmission beams associated with at least one selected SSB are different. Furthermore, the identification information (or beam numbers) of the downlink transmission beams associated with at least one SSB are not adjacent.

[0123] In one example, the RSRPs of SSB_1, SSB_2, SSB_3, and SSB_4 in multiple SSBs are all less than a third threshold. SSB_1 is associated with downlink transmission beam_1 having identification information 1, SSB_2 is associated with downlink transmission beam_2 having identification information 2, SSB_3 is associated with downlink transmission beam_3 having identification information 3, and SSB_4 is associated with downlink transmission beam_4 having identification information 4. The direction of downlink transmission beam_1 is 20°, the direction of downlink transmission beam_2 is 40°, the direction of downlink transmission beam_3 is 60°, and the direction of downlink transmission beam_4 is 80°. If the RSRP of SSB_1 is strongest, the terminal device may first select SSB_1 and then select downlink transmission beam_3 which is not adjacent to the identification information of downlink transmission beam_1. In this way, at least one SBB ultimately selected from multiple SSBs includes downlink transmission beam_1 and downlink transmission beam_3. The directions of downlink transmission beam_1 and downlink transmission beam_3 are different, and the identification information of downlink transmission beam_1 and downlink transmission beam_3 is not adjacent to each other.

[0124] S704: The terminal device determines the number of transmission beams.

[0125] After selecting at least one SBB, the terminal device may determine its downlink receive beam according to the downlink receive beam corresponding to at least one SSB, and further determine its uplink transmit beam according to the downlink receive beam in a beam alignment manner.

[0126] It should be noted that typically, one downlink receive beam corresponds to one uplink transmission beam. In addition, one downlink receive beam may correspond to multiple uplink transmission beams, or multiple downlink receive beams may correspond to one uplink transmission beam.

[0127] Assuming that the number of SBBs selected by the terminal device is 4, and one SBB is associated with one downlink transmission beam of the network device, i.e., with one downlink receive beam of the terminal device, and one downlink receive beam corresponds to one uplink transmission beam, the terminal device may determine that the number of uplink transmission beams is 4, i.e., that it can transmit a first message based on 4 uplink transmission beams. In this case, the number of uplink transmission beams of the terminal device is equal to the number of SBBs.

[0128] Assuming that the number of SBBs selected by the terminal device is 4, and one SBB is associated with one downlink transmission beam of the network device, i.e., with one downlink receive beam of the terminal device, and one downlink receive beam corresponds to two uplink transmission beams, and the other three downlink receive beams correspond to one uplink transmission beam, then the terminal device may determine that the number of uplink transmission beams is 5, i.e., it can transmit a first message based on 5 uplink transmission beams. In this case, the number of uplink transmission beams of the terminal device is greater than the number of SBBs.

[0129] Assuming that the number of SBBs selected by the terminal device is 4, and one SBB is associated with one downlink transmission beam of the network device, i.e., with one downlink receive beam of the terminal device, and two downlink receive beams correspond to the same uplink transmission beam, and the other two downlink receive beams correspond to one uplink transmission beam each, then the terminal device may determine that the number of uplink transmission beams is 3, i.e., it can transmit a first message based on 3 uplink transmission beams. In this case, the number of uplink transmission beams of the terminal device is less than the number of SBBs.

[0130] S705: The terminal device determines the number of messages to transmit in the first message.

[0131] The terminal device may determine the number of transmissions of the first message according to the number of transmission beams. Note that the number of transmissions of the first message must be greater than or equal to the number of transmission beams.

[0132] In a possible implementation, if the number of transmissions of the first message is equal to the number of transmission beams, the terminal device transmits the first message once in each transmission beam.

[0133] In another possible implementation, if the number of transmissions of the first message is greater than the number of transmission beams, the terminal device transmits the first message multiple times across some of the transmission beams. In this case, the terminal device may select a value greater than the number of transmission beams from a preset range of counts as the number of transmissions of the first message. For example, if the number of transmission beams is 4 and the preset range of counts includes 2, 4, 6, and 8, then the number of transmissions of the first message is determined to be 6 or 8.

[0134] In the above description, the terminal device first selects at least one SSB from a plurality of SSBs, and then determines the number of transmission beams and transmissions for the first message. In addition, the terminal device may further first determine the number of transmissions for the first message, then select at least one SSB from a plurality of SSBs according to the number of transmissions for the first message, and then determine the number of transmission beams according to the number of at least one SSB.

[0135] In possible implementations, the terminal device detects the RSRP of multiple received SSBs. If the maximum RSRP of multiple SSBs falls within a pre-configured interval, the pre-configured interval corresponds to a pre-configured number of PRACH transmissions. Thus, the terminal device may determine the pre-configured number of PRACH transmissions as the number of transmissions of the first message. After determining the number of transmissions of the first message, the terminal device may determine that the number of at least one SSB is equal to the number of transmissions of the first message; that is, the terminal device may select at least one SSB whose number is equal to the number of transmissions of the first message from multiple SSBs. After determining the number of at least one SSB, the terminal device may determine the number of transmission beams according to the number of at least one SSB. The specific process for determining the number of transmission beams according to the number of at least one SSB has been described above and is not described again in detail herein.

[0136] S706: The terminal device determines the transmission power for each transmission of the first message.

[0137] The terminal device needs to transmit the first message with a specific transmission power. The transmission power is related to the RSRP of at least one SSB and the RSRP of each SBB. For PRACH associated with different SSBs, including mapped ROs, the terminal device may use a different transmission power for each transmission of the first message. The formula for PRACH power control is as follows: P PRACH =min{P max ,P PRACH , target +PL}

[0138] Here, P max This represents the maximum power that can be output by a terminal device in each time slot on the serving cell carrier, and depends on the type of terminal device, and is usually considered to be 23 dBm. PRACH,targetrepresents the preamble sequence target parameter, which is controlled by the open-loop power and can be determined by the high-level parameter "PREAMBLE_RECEIVED_TARGET_POWER", where PL represents the path loss.

[0139] P PRACH,target The formula for calculating this is as follows: P PRACH,target =preambleReceivedTargetPower+DELTA_PREAMBLE +(PREAMBLE_POWER_RAMPING_COUNTER-1) ×PREAMBLE_POWER_RAMPING_STEP Here, preambleReceivedTargetPower represents the target received power of the preamble sequence and can be obtained from the "preambleReceivedTargetPower" parameter of the SIB-1 message.

[0140] DELTA_PREAMBLE represents the power offset and can be determined by converting the PRACH configuration index to the preamble format and then using a pre-configured correspondence between the preamble format and the PRACH configuration index. The PRACH configuration index can be obtained from the SIB-1 message. For example, when the preamble format is "0", the corresponding power offset is 0dB; when the preamble format is "1", the corresponding power offset is -3dB; when the preamble format is "2", the corresponding power offset is -6dB; and when the preamble format is "3", the corresponding power offset is 0dB.

[0141] PREAMBLE_POWER_RAMPING_COUNTER represents the number of transmissions in the preamble sequence, with an initial value of 1, which increases by 1 each time the preamble sequence is retransmitted. PREAMBLE_POWER_RAMPING_STEP represents the transmission step size of the preamble sequence and can be obtained from the "powerRampingStep" parameter.

[0142] The formula for calculating PL is as follows: PL=referenceSignalPower-HigherlayerfilteredRSRP Here, referenceSignalPower represents the reference signal power, which can be determined by the "ss-PBCH-BlockPower" and "powerControlOffsetSS" parameters in SSB, or by the channel state information reference signal (CSI-RS) associated with PRACH, and HigherlayerfilteredRSRP represents the RSRP measured when PRACH is transmitted.

[0143] In addition, network devices may configure a transmission power offset in a quasi-static or pre-configured manner to sequentially increase the transmission power when the first message is transmitted multiple times, thereby improving the probability of successful transmission of the first message.

[0144] S707: A terminal device transmits the first message multiple times based on the number of transmission beams, the number of transmissions of the first message, and the transmission power for each transmission of the first message. Correspondingly, a network device may receive the first message multiple times.

[0145] Consider an example where a first message is transmitted once based on a first transmission beam among multiple transmission beams. The terminal device uses the first transmission beam with the transmission power for this transmission of the first message and transmits the first message at the location of the time-frequency resources for this transmission of the first message.

[0146] The random access method provided in the embodiments of this application has been described above with reference to Figures 4 to 8, and the apparatus provided in the embodiments of this application for carrying out the above method is described below. As shown in Figure 9, Figure 9 is a schematic diagram of the random access apparatus provided in one embodiment of this application. The random access apparatus may be a terminal device in the embodiments of this application, or a chip or chip system in a terminal device.

[0147] As shown in Figure 9, the random access device 900 may be used in a communication device, circuit, hardware component, or chip. The random access device 900 includes a processing unit 901 and a transceiver unit 902. The processing unit 901 is configured to support the random access device 900 when performing steps of information processing. The transceiver unit 902 is configured to support the random access device 900 when performing steps of transmitting data and receiving data. The transceiver unit 902 may be an input / output interface, pins, circuit, etc. In embodiments of this application, the processing unit may also be referred to as a processing module, and the transceiver unit may also be referred to as a transceiver module.

[0148] Specifically, the processing unit 901 is configured to determine when a trigger condition is met, and the transceiver unit 902 is configured to transmit a first message that is accessed randomly based on multiple transmission beams. The trigger condition includes at least one of the following: the network device allows the terminal device to perform multiple PRACH transmissions based on multiple transmission beams; the service type of the terminal device is a pre-configured service type; and the maximum RSRP of multiple SSBs detected by the terminal device is less than a first threshold.

[0149] In possible embodiments, the random access device 900 may further include a storage unit 903. The processing unit 901 is connected to the storage unit 903 via a communication line. The storage unit 903 may include one or more memories, which may be components of one or more devices or circuits configured to store programs or data. The storage unit 903 may exist independently and be connected to the processing unit 901 of the calibration device via a communication line. The storage unit 903 may further be integrated with the processing unit 901.

[0150] The storage unit 903 may store computer-executable instructions for the method in a terminal device in order to cause the processing unit 901 to execute the method of the embodiment described above. The storage unit 903 may be a register, a cache, random access memory (RAM), etc. The storage unit 903 may be a read-only memory (ROM) or another type of static storage device capable of storing static information and instructions, and the storage unit 903 may be independent of the processing unit 901.

[0151] Figure 10 is a schematic diagram of the hardware structure of another terminal device provided in one embodiment of the present application. As shown in Figure 10, the terminal device includes a processor 1001, a communication line 1004, and at least one communication interface (for example, communication interface 1003 in Figure 10 is used as an example for illustrative purposes).

[0152] The processor 1001 may be a central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to control the execution of the program of the solution of this application.

[0153] The communication line 1004 may include a circuit configured to transmit information between the aforementioned components.

[0154] The communication interface 1003 communicates with another device or a communication network such as Ethernet or wireless local area networks (WLAN) using any transceiver-type device.

[0155] In some cases, the terminal device may further include memory 1002.

[0156] Memory 1002 may be ROM, another type of static storage device capable of storing static information and instructions, RAM, or another type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), or compact disc read-only memory (CD-ROM), or another compact disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital versatile optical discs, and Blu-ray discs), magnetic disk storage media, or another magnetic storage device, or any other medium that can be used to hold or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited to these. Memory may exist independently or may be connected to the processor via a communication line 1004. Memory may also be integrated with the processor.

[0157] Memory 1002 is configured to store computer-executable instructions for performing the solution of the present application, and the computer-executable instructions are controlled by processor 1001 for execution. Processor 1001 is configured to execute the computer-executable instructions stored in memory 1002 to perform the method provided in the embodiments of the present application.

[0158] In some cases, the computer executable instructions of the embodiments of this application may also be referred to as application code. This is not specifically limited to the embodiments of this application.

[0159] In one embodiment, the processor 1001 may include one or more CPUs, for example, CPU0 and CPU1 in Figure 10.

[0160] In one embodiment, among specific implementations, the terminal device may include a plurality of processors, for example, processors 1001 and 1005 in Figure 10. Each such processor may be a single-CPU or a multi-CPU. In this specification, a processor may refer to one or more devices, circuits, and / or processing cores configured to process data (e.g., computer program instructions).

[0161] A computer program product includes one or more computer instructions. When computer program instructions are loaded and executed in a computer, all or part of the processes or functions according to embodiments of this application are generated. The computer may be a general-purpose computer, a dedicated computer, a computer network, or another programmable device. Computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wired means (e.g., coaxial cable, optical fiber, or digital subscriber line (DSL)) or wireless means (e.g., infrared, radio waves, or microwaves). The computer-readable storage medium may be any available medium that can be stored by a computer, or a data storage device such as a server or data center that includes one or more available media. For example, available media may include magnetic media (e.g., floppy disks, hard disks, or magnetic tapes), optical media (e.g., digital versatile discs (DVDs)), and semiconductor media (e.g., solid state disks (SSDs)).

[0162] The random access method provided in the embodiments of this application may be applied to a terminal device having communication capabilities. For specific device configurations of the terminal device, please refer to the relevant descriptions above. Further details are not provided herein.

[0163] One embodiment of this application provides a terminal device. The terminal device includes a processor and memory. The memory stores computer executable instructions, and the processor executes the computer executable instructions stored in the memory, enabling the terminal device to perform the aforementioned method.

[0164] One embodiment of this application provides a chip, which includes a processor, configured to invoke a computer program in memory to execute the technical solution of the aforementioned embodiment. Their implementation principles and technical effects are the same as those of the aforementioned related embodiment and will not be described in detail again here.

[0165] One embodiment of this application further provides a computer-readable storage medium. The computer-readable storage medium stores a computer program. When executed by a processor, the computer program performs the method described above. The method described in the above embodiment may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. If implemented by software, the function may be stored in the computer-readable medium or used as one or more instructions or codes transmitted in the computer-readable medium. The computer-readable medium may include a computer storage medium and a communication medium, and may further include any medium on which a computer program can be transmitted from one place to another. The storage medium may be any target medium accessible to a computer.

[0166] In possible implementations, computer-readable media may include RAM, ROM, compact disc read-only memory (CD-ROM), or other optical disc memory, magnetic disc memory, or other magnetic storage device, or any other medium that holds or stores the necessary program code in the form of instructions or data structures and can be accessed by a computer. Furthermore, any connection is appropriately referred to as computer-readable media. For example, if software is transmitted from a website, server, or another remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technology (such as infrared, radio waves, and microwaves), then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technology (such as infrared, radio waves, and microwaves) are included in the definition of media. As used herein, magnetic disks and optical disks include compact discs (CDs), laserdiscs, optical disks, digital versatile discs (DVDs), floppy disks, and Blu-ray discs. Magnetic disks generally reproduce data magnetically, while optical disks reproduce data optically using a laser. The aforementioned combinations should also be included within the scope of computer-readable media.

[0167] One embodiment of this application provides a computer program product, which, when executed, causes a computer to perform the method described above.

[0168] Embodiments of this application are described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of this application. It should be understood that computer program instructions can implement each process and / or block of a flowchart and / or block diagram, as well as combinations of processes and / or blocks of a flowchart and / or block diagram. These computer program instructions may be provided to a processing unit of a general-purpose computer, a dedicated computer, an embedded processor, or any other programmable device to generate a machine, and as a result, instructions executed by the processing unit of the computer or any other programmable data processing device generate a machine to implement a particular function in one or more processes of a flowchart and / or one or more blocks of a block diagram.

[0169] The purpose, technical solution, and beneficial effects of this application are described in more detail in the specific implementation described above. It should be understood that the foregoing description is merely a specific implementation of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, or improvements made based on the technical solution of this application shall fall within the scope of protection of this application. [Explanation of Symbols]

[0170] 100, 502 terminal devices 110 processors 120 External memory interface 121 Internal Memory 130 USB Interfaces 140 Charging Management Module 141 Power Management Module 142 batteries 150 Mobile Communication Modules 160 Wireless Communication Modules 170 Audio Modules 170A speaker 170B receiver 170C Microphone 170D headset jack 180 Sensor Modules 180A pressure sensor 180B Gyroscope Sensor 180°C Barometric Pressure Sensor 180D Magnetic Sensor 180E Accelerometer 180F Distance Sensor 180G Optical Proximity Sensor 180H Fingerprint Sensor 180J Temperature Sensor 180K touch sensor 180L Ambient Light Sensor 180M Bone Conduction Sensor 190 keys 191 Motor 192 Indicators 193 Camera 194 Display screen 195 Subscriber Identification Module (SIM) Card Interface r1, r2 Downlink coverage range r3 Uplink coverage range 500 Communication Systems 501 Network Device 900 Random Access Devices 901 Processing Unit 902 Transceiver Unit 903 Memory Unit 1001, 1005 processors 1002 memory 1003 Communication Interface 1004 Communication line

Claims

1. A random access method applicable to terminal devices, The step of determining whether the trigger condition is met, The process includes the step of transmitting a first message that is accessed randomly based on multiple transmission beams, The trigger conditions are as follows: A method comprising at least one of the following: a network device allows the terminal device to perform multiple physical random access channel (PRACH) transmissions based on multiple transmission beams; the service type of the terminal device is a pre-configured service type; and the maximum value of multiple synchronization signals and reference signal received power (RSRP) of PBCH blocks (SSBs) detected by the terminal device is less than a first threshold.

2. The method according to claim 1, further comprising the step of receiving first instruction information used to indicate whether the network device permits the terminal device to perform a plurality of PRACH transmissions based on a plurality of transmission beams.

3. The method according to claim 2, wherein the first instruction information is placed in a system information block (SIB) message.

4. The steps further include determining the number of transmission beams, the number of transmissions of the first message, and the transmission power for each transmission of the first message. The step of transmitting a first message that is accessed randomly based on multiple transmission beams, The method according to any one of claims 1 to 3, comprising the step of transmitting the first message once based on a first transmission beam among the plurality of transmission beams, with the transmission power for this transmission of the first message, in a random access opportunity for this transmission of the first message, wherein the first transmission beam is any one of the plurality of transmission beams.

5. The steps include receiving the aforementioned multiple SSBs, The further step includes selecting at least one SSB from the plurality of SSBs, The method according to claim 4, wherein the number of transmission beams is equal to the number of at least one SSB, and the number of transmissions of the first message is equal to the number of at least one SSB.

6. The method according to claim 5, wherein the RSRP of each SSB of the at least one SSB is greater than a second threshold.

7. The method according to claim 6, wherein the direction of the downlink transmission beam associated with the at least one SSB is different.

8. The method according to any one of claims 5 to 7, wherein in a single PRACH transmission cycle, each of the SSBs among the plurality of SSBs is mapped to a random access opportunity in all frequency domains within the same time period.

9. A random access device comprising a module configured to perform the method described in any one of claims 1 to 8.

10. A random access device comprising a processor and memory, The memory is configured to store computer programs, A random access device, wherein the processor is configured to call and execute the computer program to cause the random access device to perform the method according to any one of claims 1 to 8.

11. A computer-readable storage medium configured to store a computer program, wherein the computer program, when executed on a computer, causes the computer to perform the method described in any one of claims 1 to 8.

12. A computer program product comprising a computer program, wherein the computer program, when executed on a computer, causes the computer to perform the method described in any one of claims 1 to 8.

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