Random access method and apparatus, device, and storage medium

Abstract

A random access method and apparatus, a device, and a storage medium, relating to the technical field of communications. The method comprises: when initiating random access on a first cell, a terminal device uses at least one spatial domain filter to send a first random access message (810); and a network device sends a second random access message, the second random access message carrying first information, the first information being used for determining a first spatial domain filter, and the first spatial domain filter being a spatial domain filter to be used by the terminal device to perform uplink transmission on the first cell (820). In the above method, the network device can determine, on the basis of at least one received first random access message, a first spatial domain filter having a better transmission condition, thereby ensuring the reliability of subsequent uplink transmission by the terminal device using the first spatial domain filter.

Description

Random access methods, devices, equipment and storage media Technical Field

[0001] This application relates to the field of communication technology, and in particular to a random access method, apparatus, device, and storage medium. Background Technology

[0002] Carrier aggregation (CA) enables NR (New Radio) systems to support greater bandwidth by jointly scheduling and using resources on multiple member carriers.

[0003] For CA scenarios, considering the impact of service transmission requirements on network equipment power consumption, uplink and downlink cells / carriers can be decoupled. For example, when the downlink service load of the network equipment is low while the uplink service load is high, multiple cells / carriers can be allowed to provide uplink services, while only a few cells / carriers provide downlink services, thereby reducing the energy consumption of network equipment.

[0004] Further research is needed on how terminal devices should perform random access in the aforementioned carrier aggregation scenarios. Summary of the Invention

[0005] This application provides a random access method, apparatus, device, and storage medium. The technical solutions provided by this application are as follows:

[0006] According to one aspect of the embodiments of this application, a random access method is provided, the method being executed by a terminal device, the method comprising:

[0007] During the process of initiating random access on the first cell, at least one spatial filter is used to send the first random access message;

[0008] The terminal receives a second random access message, which carries first information. The first information is used to determine a first spatial filter, which is the spatial filter used by the terminal device for uplink transmission in the first cell.

[0009] According to one aspect of the embodiments of this application, a random access method is provided, the method being executed by a network device, the method comprising:

[0010] During the process of receiving terminal equipment initiating random access in the first cell, the first random access message is sent using at least one spatial filter.

[0011] A second random access message is sent to the terminal device. The second random access message carries first information, which is used to determine a first spatial filter. The first spatial filter is the spatial filter used by the terminal device for uplink transmission in the first cell.

[0012] According to one aspect of the embodiments of this application, a random access device is provided, the device comprising: a transmitting module and a receiving module;

[0013] The sending module is used to send a first random access message using at least one spatial filter during the process of initiating random access on the first cell.

[0014] The receiving module is used to receive a second random access message, the second random access message carrying first information, the first information being used to determine a first spatial filter, the first spatial filter being the spatial filter used by the terminal device for uplink transmission in the first cell.

[0015] According to one aspect of the embodiments of this application, a random access device is provided, the device comprising: a receiving module and a transmitting module;

[0016] The receiving module is used to receive the first random access message sent by the terminal device using at least one spatial filter during the process of initiating random access in the first cell.

[0017] The sending module is used to send a second random access message to the terminal device. The second random access message carries first information, which is used to determine a first spatial filter. The first spatial filter is the spatial filter used by the terminal device for uplink transmission in the first cell.

[0018] According to one aspect of the embodiments of this application, a communication device is provided, the communication device including a processor and a memory, the memory storing a computer program, and the processor executing the computer program to implement the above-described random access method.

[0019] According to one aspect of the embodiments of this application, a computer-readable storage medium is provided, the storage medium storing a computer program for execution by a processor to implement the above-described random access method.

[0020] According to one aspect of the embodiments of this application, a chip is provided, the chip including programmable logic circuits and / or program instructions, which, when the chip is running, are used to implement the above-described random access method.

[0021] According to one aspect of the embodiments of this application, a computer program product is provided, the computer program product including computer instructions stored in a computer-readable storage medium, and a processor reading from the computer-readable storage medium and executing the computer instructions to implement the above-described random access method.

[0022] The technical solutions provided in this application embodiment may have the following beneficial effects:

[0023] The terminal device transmits the first random access message using at least one spatial filter, meaning it uses at least one beam to transmit the first random access message. Each beam corresponds to a specific direction, avoiding the limited uplink coverage problem caused by omnidirectional transmission of the first random access message in related technologies, thereby improving the reliability of the first random access message transmission. Simultaneously, the network device can determine the first spatial filter with optimal transmission conditions based on the received at least one first random access message, such as determining the spatial filter corresponding to the first random access message with the strongest signal reception as the first spatial filter, thus ensuring the reliability of subsequent uplink transmission by the terminal device using this first spatial filter. Attached Figure Description

[0024] Figure 1 is a schematic diagram of a network architecture provided in one embodiment of this application;

[0025] Figure 2 is a schematic diagram of a contention-based random access method provided in an embodiment of this application;

[0026] Figure 3 is a schematic diagram of a non-contention-based random access method provided in an embodiment of this application;

[0027] Figure 4 is a schematic diagram of a two-step random access method provided in an embodiment of this application;

[0028] Figure 5 is a schematic diagram of a two-step random access method falling back to a four-step random access method according to an embodiment of this application;

[0029] Figure 6 is a schematic diagram of carrier aggregation technology provided in another embodiment of this application;

[0030] Figure 7 is a schematic diagram of carrier aggregation technology provided in an embodiment of this application;

[0031] Figure 8 is a flowchart of a random access method provided in an embodiment of this application;

[0032] Figure 9 is a flowchart of a random access method provided in another embodiment of this application;

[0033] Figure 10 is a flowchart of a random access method provided in another embodiment of this application;

[0034] Figure 11 is a flowchart of a random access method provided in another embodiment of this application;

[0035] Figure 12 is a block diagram of a random access device provided in an embodiment of this application;

[0036] Figure 13 is a block diagram of a random access device provided in another embodiment of this application;

[0037] Figure 14 is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0039] The network architecture and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0040] The technical solutions of this application embodiment can be applied to various communication systems, such as: Global System for Mobile communication (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, Advanced Long Term Evolution (LTE-A) system, New Radio System, evolution system of NR system, LTE-based access to unlicensed spectrum (LTE-U) system, NR-based access to unlicensed spectrum (NR-U) system, Non-Terrestrial Networks (NTN) system, Universal Mobile Telecommunication System (UMTS), Wireless Local Area Networks (WLAN), and Wireless Fidelity (WF). Fidelity (WiFi), 5th-Generation (5G) systems, B5G (Beyond 5G) systems, 6th-Generation (6G) systems, or other communication systems.

[0041] Traditional communication systems typically support a limited number of connections and are easy to implement. However, with the development of communication technology, mobile communication systems will not only support traditional communication but also, for example, device-to-device (D2D) communication, machine-to-machine (M2M) communication, machine-type communication (MTC), vehicle-to-vehicle (V2V) communication, or vehicle-to-everything (V2X) communication. The embodiments of this application can also be applied to these communication systems.

[0042] The communication system in this application embodiment can be applied to carrier aggregation scenarios, dual connectivity (DC) scenarios, and standalone (SA) network deployment scenarios.

[0043] The communication system in this application embodiment can be applied to unlicensed spectrum, wherein unlicensed spectrum can also be considered as shared spectrum; or, the communication system in this application embodiment can also be applied to licensed spectrum, wherein licensed spectrum can also be considered as non-shared spectrum.

[0044] The embodiments of this application can be applied to both non-terrestrial networks (NTN) and terrestrial networks (TN). NTN typically uses satellite communication to provide communication services to terrestrial users. Currently, NTN systems include NR-NTN and IoT-NTN systems, and other NTN systems may be included in the future.

[0045] Please refer to Figure 1, which shows a schematic diagram of a network architecture 100 provided in one embodiment of this application. The network architecture 100 may include: a terminal device 10, an access network device 20, and a core network element 30.

[0046] Terminal device 10 can refer to UE (User Equipment), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, wireless communication device, user agent, or user equipment. In some embodiments, terminal device 10 can also be a cellular phone, cordless phone, SIP (Session Initiation Protocol) phone, WLL (Wireless Local Loop) station, PDA (Personal Digital Assistant), handheld device with wireless communication capabilities, computing device or other processing device connected to a wireless modem, vehicle-mounted device, wearable device, terminal device in 5GS (5th Generation System), or terminal device in the future evolved PLMN (Public Land Mobile Network), etc., and this application embodiment is not limited thereto. For ease of description, the devices mentioned above are collectively referred to as terminal devices. The number of terminal devices 10 is usually multiple, and one or more terminal devices 10 can be distributed within the cell managed by each access network device 20. Terminal equipment can also be simply referred to as terminal or UE, the meaning of which can be understood by those skilled in the art.

[0047] Access network device 20 is a device deployed in an access network to provide wireless communication functionality to terminal device 10. Access network device 20 may include various forms of macro base stations, micro base stations, relay stations, access points, etc. In systems employing different wireless access technologies, the name of the device with access network device functionality may differ; for example, in a 5G NR system, it is called gNodeB or gNB. As communication technologies evolve, the name "access network device" may change. For ease of description, in this embodiment, the aforementioned devices providing wireless communication functionality to terminal device 10 are collectively referred to as access network devices. In some embodiments, a communication relationship can be established between terminal device 10 and core network element 30 through access network device 20. For example, in an LTE (Long Term Evolution) system, access network device 20 may be one or more eNodeBs in an EUTRAN (Evolved Universal Terrestrial Radio Access Network) or EUTRAN; in a 5G NR system, access network device 20 may be one or more gNBs in a RAN (Radio Access Network). In the embodiments of this application, unless otherwise specified, the term "network device" refers to access network device 20, such as a base station.

[0048] Core network element 30 is a network element deployed in the core network. Its main functions are to provide user connectivity, manage users, and bear services, serving as an interface to external networks. For example, core network elements in a 5G NR system may include AMF (Access and Mobility Management Function) entities, UPF (User Plane Function) entities, and SMF (Session Management Function) entities.

[0049] In some embodiments, the access network device 20 and the core network element 30 communicate with each other via some air interface technology, such as the NG interface in a 5G NR system. The access network device 20 and the terminal device 10 communicate with each other via some air interface technology, such as the Uu interface.

[0050] The "5G NR system" in this application embodiment can also be referred to as a 5G system or an NR system, but those skilled in the art will understand its meaning. The technical solutions described in this application embodiment can be applied to LTE systems, 5G NR systems, and subsequent evolution systems of 5G NR systems (such as B5G (Beyond 5G, a fifth-generation mobile communication technology) systems, 6G systems (6th Generation System, a sixth-generation mobile communication system)), and other communication systems such as NB-IoT (Narrow Band Internet of Things) systems. This application does not limit these applications.

[0051] In this embodiment, the network device can provide services to a cell. The terminal device communicates with the network device through the transmission resources (e.g., frequency domain resources, or spectrum resources) on the carrier used by the cell. The cell can be the cell corresponding to the network device (e.g., a base station). The cell can belong to a macro base station or to a base station corresponding to a small cell. The small cell can include: metro cell, micro cell, pico cell, femto cell, etc. These small cells have the characteristics of small coverage area and low transmission power, and are suitable for providing high-speed data transmission services.

[0052] Before introducing the technical solution of this application, some related technical knowledge involved in this application will be introduced and explained. The following related technologies are optional solutions and can be arbitrarily combined with the technical solutions of the embodiments of this application, all of which fall within the protection scope of the embodiments of this application. The embodiments of this application include at least some of the following contents.

[0053] Currently, with people's pursuit of speed, latency, high-speed mobility, and energy efficiency, as well as the diversity and complexity of business in future life, the 3GPP (3rd Generation Partnership Project) international standards organization has begun to develop 5G. The main application scenarios of 5G are: enhanced mobile broadband (eMBB), ultra-reliable and low-latency communications (URLLC), and massive machine-type communications (mMTC).

[0054] eMBB still aims to provide users with multimedia content, services, and data, and its demand is growing rapidly. On the other hand, because eMBB may be deployed in different scenarios, such as indoors, urban areas, and rural areas, its capabilities and needs vary considerably. Therefore, generalizations cannot be made; a detailed analysis based on the specific deployment scenario is necessary. Typical applications of URLLC include industrial automation, power automation, remote medical operations (surgery), and traffic safety assurance. Typical characteristics of mMTC include high connection density, small data volume, latency-insensitive services, low module cost, and long module lifespan.

[0055] NR can also be deployed independently. In 5G network environments, to reduce air interface signaling and quickly restore wireless connections and data services, a new RRC (Radio Resource Control) state is defined, namely the RRC_INACTIVE state (inactive state). This state is different from the RRC_IDLE state (idle state) and the RRC_CONNECTED state (connected state).

[0056] RRC_IDLE state: Mobility is based on UE-based cell selection and reselection. Paging is initiated by the CN (Core Network), and the paging area is configured by the CN. There is no UE AS (Access Stratum) context or RRC connection on the base station side.

[0057] RRC_CONNECTED state: An RRC connection exists, and the base station and UE share a UE AS context. The network side knows the UE's location at the cell level. Mobility is network-controlled. Unicast data can be transmitted between the UE and the base station.

[0058] RRC_INACTIVE state: Mobility is based on UE cell selection reselection, there is a connection between CN and NR, the UE AS context exists on a certain base station, paging is triggered by RAN (Radio Access Network), the RAN-based paging area is managed by RAN, and the network side knows the UE's location at the RAN-based paging area level.

[0059] 1. NR Random Access Procedure

[0060] The random access process is mainly triggered by the following events:

[0061] 1. Establishing a radio connection during initial UE access: The UE transitions from the RRC (Radio Resource Control)_IDLE state (idle state) to the RRC_CONNECTED state (connected state);

[0062] 2. RRC connection reconstruction process: to enable the UE to rebuild the radio connection after the radio link fails;

[0063] 3. Handover: The UE needs to establish uplink synchronization with the new cell;

[0064] 4. In the RRC_CONNECTED state, DL (DownLink) data arrives, and UL is out of sync at this time;

[0065] 5. In the RRC_CONNECTED state, UL (UpLink) data arrives. At this time, the UL is out of sync or there is no PUCCH (Physical Uplink Control Channel) resource for sending SR.

[0066] 6. SR failed;

[0067] 7. Synchronization reconfiguration request from RRC;

[0068] 8. The UE transitions from the RRC_INACTIVE state to the RRC_CONNECTED state;

[0069] 9. Establish time calibration during the SCell addition process;

[0070] 10. Request other SIs;

[0071] 11. Beam failure recovery.

[0072] In NR, two main random access methods are supported: contention-based random access and contention-free random access. These two methods are applicable to different scenarios. In contention-based random access, the RACH (Random Access Channel) is a resource pool available to the terminal device, and different terminal devices can use the same resources, leading to resource contention. In contention-free random access, specific resources are reserved and allocated to a specific terminal device at a given time.

[0073] Figure 2 illustrates a contention-based random access method, characterized by code resource sharing and a four-step access process, including access request, access response, connection request, and contention resolution (also known as conflict resolution). This process comprises steps Step 1 through Step 4. It is important to note that the interaction messages in each step of the contention-based random access method are referred to as Msg1 through Msg4.

[0074] Step 1: Access Request (Msg1)

[0075] The terminal device selects a PRACH (Physical Random Access Channel) resource (including time-frequency resources and code domain resources) and transmits the selected preamble on the selected PRACH time-frequency resource. Based on the preamble, the network device can estimate the uplink timing and the grant size required for the terminal device to transmit Msg3.

[0076] Step 2: Access Response (Msg2)

[0077] After receiving the preamble from the terminal device, the network device sends a RAR (Random Access Response) to the terminal device. After sending Msg1, the terminal device opens a RAR window and monitors the PDCCH (Physical Downlink Control Channel) scrambled with RA-RNTI (Random Access-Radio Network Temporary Identifier).

[0078] The RA-RNTI is calculated as follows: RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id

[0079] Wherein, s_id is the index of the first OFDM (Orthogonal Frequency Division Multiplexing) symbol of the PRACH timing (0≤s_id≤14), t_id is the index of the first slot of the PRACH timing in the system frame (0≤t_id≤80), f_id is the index of the PRACH timing in the frequency domain (0≤f_id≤8), and ul_carrier_id is the UL (Uplink) carrier used for random access preamble transmission (0 indicates NUL (Normal Uplink) carrier, and 1 indicates SUL (Supplementary Uplink) carrier).

[0080] As can be seen from the calculation formula of RA-RNTI above, RA-RNTI is related to the PRACH time and frequency resources used by the terminal device to send Msg1.

[0081] After the terminal device successfully receives the RA-RNTI scrambled PDCCH, it can obtain the PDSCH (Physical Downlink Shared Channel) scheduled by the PDCCH, which contains the RAR. The RAR specifically contains the following information:

[0082] The RAR subheader contains a BI (Backoff Indicator), which indicates the backoff time for retransmitting Msg1.

[0083] RAPID (Random Access Preamble ID) in RAR: the preamble index received in the network response;

[0084] The payload in the RAR contains a TAG, which is used to adjust the uplink timing;

[0085] The UL grant (uplink grant) in the RAR message indicates the uplink resources used to schedule Msg3. Because the terminal device has not yet established an RRC connection with the network device or performed uplink synchronization, it cannot request uplink grants from the network device for uplink transmission via a Scheduling Request. Instead, it must include uplink grant information in the RAR message to allow the terminal device to send the first uplink message, Msg3, which is the RRC Setup Request. The UL-Grant field indicates the resources used for uplink transmission. The UL-Grant field is 20 bits long, and Msg3 is actually sent using these resources.

[0086] The Temporary C-RNTI in RAR, or TC-RNTI (Temporary Cell-RNTI, Temporary Cell-Radio Network Temporary Identifier), is used to scramble Msg4's PDCCH.

[0087] If the terminal device receives a PDCCH scrambled with RAR-RNTI, and the RAR contains the preamble index it sent, then the terminal considers it to have successfully received the random access response.

[0088] For non-contention-based random access, the random access process ends after the terminal successfully receives Msg2. For contention-based random access, after the terminal device successfully receives Msg2, it still needs to transmit Msg3 and receive Msg4.

[0089] Step 3: Connection Request (Msg3)

[0090] Msg3 is primarily used to inform network devices what event triggered the RACH procedure. For example, if it's an initial access random procedure, Msg3 will carry the UE ID and establishment cause; if it's an RRC reconstruction, it will carry the connected UE identifier and establishment cause. Additionally, the ID carried in Msg3 allows contention to be resolved in Step 4.

[0091] Step 4: Competition Resolution (Msg4)

[0092] Msg4 has two functions: first, it is used for contention resolution, and second, it is used to transmit RRC configuration messages to the terminal device.

[0093] There are two ways to resolve contention: Method 1: If the terminal device carries a C-RNTI in Msg3, then Msg4 is scheduled using a PDCCH scrambled with the C-RNTI. Method 2: If the terminal device does not carry a C-RNTI in Msg3, such as during initial access, then Msg4 is scheduled using a PDCCH scrambled with the TC-RNTI. Conflict resolution is achieved by the terminal device receiving the PDSCH carrying Msg4 and matching the CCCH (Common Control Channel) SDU (Service Data Unit) in the PDSCH with the contention resolution ID in its own Msg3.

[0094] Figure 3 illustrates a non-contention-based random access method, characterized by exclusive code resources and a three-step access process: preamble allocation, access request, and access response. This process includes the following steps: Step 0 to Step 2. It's important to note that the interaction messages in each step of this non-contention-based random access method are referred to as Msg0 to Msg2, respectively.

[0095] Step 0: Leader assignment (Msg0)

[0096] Network devices assign random access preambles to terminal devices and send them using RRC messages or DCI (Downlink Control Information).

[0097] Step 1: Access Request (Msg1)

[0098] Step 2: Access Response (Msg2)

[0099] For explanations of Msg1 and Msg2, please refer to the above text; they will not be repeated here.

[0100] As can be seen from the above random access process, the main purpose of random access is for the terminal device to achieve uplink synchronization with the cell. During the random access process, the network device can know the time when the terminal device sends the preamble based on the RACH time-frequency resources used by the preamble received from the terminal device. Therefore, it determines the initial TA (Timing Advance) of the terminal device based on the transmission and reception times of the preamble, and informs the terminal through the RAR.

[0101] To reduce UE access latency and signaling overhead, NR introduces a two-step random access procedure. The MsgA step in this procedure includes a preamble transmitted on the PRACH and payload information transmitted on the PUSCH (Physical Uplink Shared Channel). After MsgA transmission, the terminal device listens for network responses within a configured window, as shown in Figure 4. If it receives a successful contention resolution indication from the network, the terminal device terminates the random access process. As shown in Figure 5, if a fallback indication is received in MsgB, the terminal device executes Msg3 transmission and listens for the contention resolution result. If contention resolution fails after Msg3 transmission, the terminal continues with MsgA transmission.

[0102] 2. NR Beam Management

[0103] A key feature of NR cells is their support for multiple beams. Before communication between the network device and the UE, the network device needs to know the UE's beam to set the appropriate beam direction during subsequent data transmission. Since the PRACH in the random access procedure is the first message sent by the UE to the network device, and for the transmission of Msg2, the network device needs to know the UE's beam information. Therefore, the function of reporting the UE's beam is naturally carried by the PRACH. Because the preamble is a sequence signal and cannot explicitly carry information, but can implicitly carry beam information using the time-frequency resources occupied by the preamble or different preamble codeword sequences, the NR system needs to establish a mapping relationship between the SSB and the PRACH Occasion.

[0104] Before a UE initiates anytime access, it measures and evaluates the signal quality of the cell and the signal strength of each SSB within the cell. When initiating a PRACH, the UE sends a preamble on the PRACH Occasion corresponding to the SSB with the strongest or relatively strong signal. If the network device successfully receives the preamble, it obtains the UE's downlink beam information based on the PRACH Occasion containing the preamble, and then uses this beam information for subsequent communication, such as Msg2, Msg4, etc.

[0105] In addition to pairing downlink transmit and receive beams, the random access procedure can also perform coarse pairing of uplink transmit and receive beams. That is, when the UE transmits the preamble, it determines the transmission direction by selecting the SSB receive direction, and the network determines the approximate reception direction based on the corresponding SSB transmission direction when receiving the preamble. To quickly complete the coarse pairing between uplink transmit and receive beams, the corresponding uplink transmit and receive beams may be relatively wide. Therefore, the resulting beam pairing achieves good performance, but not optimal results. To further improve performance, for connected UEs, fine-tuning can be performed on the network's uplink receive beam and the terminal's uplink transmit beam based on the coarse pairing, using a finer beam to further improve transmission performance.

[0106] 3. Carrier aggregation technology

[0107] To provide higher data transmission rates and improve user experience, 5G NR further increases system bandwidth compared to 4G. In 5G NR, for frequency bands below 6 GHz, the maximum bandwidth supported by a single carrier is 100 MHz; for frequency bands above 6 GHz, the maximum bandwidth supported by a single carrier is 400 MHz.

[0108] Similar to LTE systems, 5G NR also supports carrier aggregation technology. Carrier aggregation, by jointly scheduling and utilizing resources on multiple component carriers (CCs), enables the NR system to support greater bandwidth, thereby achieving higher peak system rates. Based on the continuity of the aggregated carriers in the spectrum, it can be divided into continuous carrier aggregation (as shown in sub-Figure A of Figure 6) and discontinuous carrier aggregation (as shown in sub-Figure B of Figure 6); based on whether the aggregated carriers are in the same band, it can be divided into intra-band carrier aggregation (as shown in sub-Figure A of Figure 6) and inter-band carrier aggregation (as shown in sub-Figure B of Figure 6).

[0109] The PCC (Primary Cell Component) is called the primary carrier. Within a Cell Group, there is one and only one PCC. The PCC provides RRC signaling connectivity, NAS (Non-Access Stratum) functions, security, etc. The SCC (Secondary Cell Component) is called the secondary carrier, providing additional radio resources. The PCC and SCC are collectively referred to as the serving cell. The PCC corresponds to the primary serving cell (PCell), and the SCC corresponds to the secondary serving cell (SCell). As shown in Figure 7, the MCG (Master Cell Group) refers to the primary cell group, and the SCG (Secondary Cell Group) refers to the secondary cell group. For terminal devices supporting CA features, in addition to having one PCell, the network RRC can also configure one or more SCells for the terminal device. The SCG also includes the PSCell (Primary Secondary Cell). The standard also stipulates that aggregated carriers belong to the same base station. All aggregated carriers use the same C-RNTI, and the base station ensures that the C-RNTI does not conflict in each carrier's cell. Since it supports both asymmetric and symmetric carrier aggregation, it requires that the aggregated carriers must have downlink, but uplink is not required.

[0110] A SCell has two states: active and inactive. Only when a SCell is active can a terminal send and receive data on that SCell.

[0111] In the NR protocol, for CA scenarios, uplink and downlink cells appear in pairs and are activated / deactivated simultaneously. However, base station energy consumption mainly occurs in the downlink transmission module. When the downlink service load of the base station is low while the uplink service load is high, multiple pairs of uplink and downlink cells need to be activated simultaneously to meet data transmission requirements, leading to an unnecessary surge in downlink power consumption. Furthermore, since user equipment transmit power is typically much lower than that of the base station, the uplink coverage range is usually significantly smaller than the downlink coverage range, requiring dedicated deployment of some sites to address uplink coverage limitations. In traditional network architectures with strong uplink and downlink site binding, small cells originally designed for uplink coverage enhancement must also provide downlink services, resulting in unnecessary downlink power consumption, and overlapping downlink coverage can cause severe downlink interference. Therefore, it is currently proposed that 6G should consider the impact of service and coverage requirements on base station power consumption, allowing uplink and downlink cell / carrier decoupling, allowing multiple sites to provide uplink services while only a few sites provide downlink services, and supporting independent uplink cells / carriers to reduce network energy consumption. For uplink independent cells, since the base station does not send downlink reference signals in the cell, if the UE sends Msg1 / MsgA in an omnidirectional manner during initial access, it will obviously affect uplink coverage. Therefore, how to effectively manage the uplink beam of the UE in this type of cell and determine the uplink beam of the UE as early as possible is a problem that needs to be studied.

[0112] Please refer to Figure 8, which shows a flowchart of a random access method provided in an embodiment of this application. This method can be applied to the network architecture shown in Figure 1. The method may include at least one of the following steps (810-820):

[0113] Step 810: During the process of initiating random access in the first cell, the terminal device sends a first random access message using at least one spatial filter.

[0114] Accordingly, the network device receives the first random access message sent by the terminal device.

[0115] In some embodiments, the first cell is a cell that supports uplink carriers but does not support downlink carriers. That is, the first cell supports the terminal device sending uplink signals to the network device, but does not support the network device sending downlink signals to the terminal device. The above method, when the downlink traffic load of the network device is low while the uplink traffic load is high, by configuring the first cell to only support uplink carriers and not downlink carriers, allows the first cell to meet uplink data transmission requirements while effectively reducing network power consumption.

[0116] A spatial filter is a signal processing technique used to control the radiation direction of an antenna array, causing the signal to radiate strongly in a specific direction and weakly or even without radiation in other directions. A beam refers to the high-intensity radiation region formed by the antenna array in a specific direction after adjustment by a spatial filter. In other words, there can be a one-to-one correspondence between spatial filters and beams; one spatial filter corresponds to one beam, and different spatial filters correspond to different beams. Therefore, the concepts of spatial filter and beam can be used interchangeably. In some embodiments, one beam corresponds to a specific radiation direction, and different beams can correspond to different radiation directions, which are also called beam directions.

[0117] In step 810 above, the terminal device uses at least one spatial filter to send the first random access message, that is, the terminal device uses at least one beam to send the first random access message. The beam and the first random access message can have a one-to-one correspondence; one beam corresponds to one first random access message, and different beams correspond to different first random access messages. In other words, one beam direction corresponds to one first random access message, and different beam directions correspond to different first random access messages, but the content of the first random access messages sent in different beam directions is the same. That is, the different first random messages mentioned in this application are used to indicate that the spatial filter / beam / time-frequency resources transmitting each first random message are different, and each first random access message contains the same content. The terminal device can attempt to send the first random access message in multiple different beam directions to detect which beam direction has the strongest signal strength.

[0118] It is understood that in the above method, the terminal device transmits the first random access message in at least one beam direction. This at least one beam direction is a partial direction within the omnidirectional range. In other words, the terminal device transmits the first random access message in a specific direction, avoiding the signal dispersion and short signal coverage distance problems caused by omnidirectional transmission in related technologies. This improves the efficiency and reliability of the first random access message transmission. The aforementioned specific direction refers to the beam direction corresponding to at least one spatial filter. The omnidirectional transmission method means that when the terminal device transmits the first random access message, the transmitted signal propagates uniformly in all directions, rather than being concentrated in a specific direction.

[0119] Step 820: The network device sends a second random access message to the terminal device. The second random access message carries first information, which is used to determine the first spatial filter. The first spatial filter is the spatial filter used by the terminal device for uplink transmission in the first cell.

[0120] Accordingly, the terminal device receives the second random access message sent by the network device.

[0121] In some embodiments, the network device receives at least one first random access message sent by a terminal device, wherein different first random access messages are sent using different spatial filters; determines the signal reception strength of each first random access message; and determines a first spatial filter based on the signal reception strength of each first random access message. For example, the spatial filter corresponding to the first random access message with the highest signal reception strength is determined as the first spatial filter.

[0122] In some embodiments, when a terminal device sends a first random access message using a spatial filter, the network device determines that spatial filter as the first spatial filter. When the terminal device sends the first random access message using at least two spatial filters respectively, the network device can select one of the at least two spatial filters as the first spatial filter. For example, the network device can select the spatial filter with the strongest received signal strength from the at least two spatial filters as the first spatial filter. This method allows the network device to flexibly determine the first spatial filter, such as determining the spatial filter corresponding to the first random access message with the strongest received signal strength as the first spatial filter. This first spatial filter is the spatial filter used by the terminal device for uplink transmission in the first cell, thereby ensuring the reliability of subsequent uplink transmissions by the terminal device.

[0123] In some embodiments, the first random access message is Msg1 and the second random access message is Msg2; or, the first random access message is MsgA and the second random access message is MsgB.

[0124] In some embodiments, when the random access method is a contention-based random access method (as shown in Figure 2), or when the random access method is a non-contention-based random access method (as shown in Figure 3), the first random access message is Msg1, and the second random access message is Msg2. In some embodiments, when the random access method is a two-step random access method (as shown in Figures 4 and 5), the first random access message is MsgA, and the second random access message is MsgB. The above method can adapt to different random access methods, and can flexibly determine whether the first random access message is Msg1 or MsgA, and whether the second random access message is Msg2 or MsgB, depending on the different random access methods.

[0125] In some embodiments, after receiving the second random access message, the terminal device uses a first spatial filter on the first cell to send a first uplink channel or signal, the first uplink channel or signal including at least one of the following: a third random access message, PUSCH, and PUCCH.

[0126] In some embodiments, the first uplink channel or signal is a third random access message, which is Msg3. In some embodiments, when the random access method is a contention-based random access method, as shown in FIG2, the second random access message is Msg2. After receiving Msg2, the terminal device uses a first spatial filter on the first cell and sends Msg3. In some embodiments, when the random access method is a two-step random access method, as shown in FIG5, the terminal device sends MsgA to the network device. If the terminal device receives a backoff indication in MsgB, the terminal device uses a first spatial filter on the first cell and sends Msg3. In the above method, the terminal device can use a first spatial filter to send the third random access message Msg3, ensuring the smooth progress of subsequent random access procedures.

[0127] In some embodiments, the first uplink channel or signal is PUSCH or PUCCH. In some embodiments, when the random access method is a contention-free random access method, as shown in FIG3, the terminal device sends Msg1 to the network device. If the terminal device receives a random access response in Msg2, after receiving Msg2, the terminal device uses a first spatial filter on the first cell to send PUSCH or PUCCH, wherein PUSCH is used to carry uplink data information and PUCCH is used to carry uplink control information. In some embodiments, when the random access method is a two-step random access method, as shown in FIG4, the terminal device sends MsgA to the network device. If the terminal device receives a collision resolution success indication in MsgB, the terminal device uses a first spatial filter on the first cell to send PUSCH or PUCCH, wherein PUSCH is used to carry uplink data information and PUCCH is used to carry uplink control information. With the above method, when the random access process is determined to be complete, the terminal device can use a first spatial filter to send PUSCH and / or PUCCH to achieve reliable uplink data transmission.

[0128] In summary, the technical solution provided in this application involves a terminal device transmitting a first random access message using at least one spatial filter, i.e., using at least one beam. Each beam corresponds to a specific direction, avoiding the limited uplink coverage problem caused by omnidirectional transmission of the first random access message in related technologies, thereby improving the reliability of the first random access message transmission. Simultaneously, the network device can determine a first spatial filter with optimal transmission conditions based on the received at least one first random access message, such as determining the spatial filter corresponding to the first random access message with the strongest signal reception as the first spatial filter, thus ensuring the reliability of subsequent uplink transmission using this first spatial filter by the terminal device.

[0129] The following three specific embodiments illustrate examples of how to determine the specific implementation of the first spatial filter. The scope of this application is not limited thereto.

[0130] Example 1

[0131] As shown in Figure 9, step 1: The network device sends first configuration information to the terminal device. The first configuration information is used to determine at least one of the following: the number of times N the terminal device repeatedly sends the first random access message, and the association between N first random access messages and N ROs, where N is an integer greater than 1. Accordingly, the terminal device receives the first configuration information sent by the network device.

[0132] RO (RACH Occasion) is the time-frequency resource used to carry the random access preamble (also known as PRACH). For example, if contention-based / non-contention-based random access is supported, RO is the time-frequency resource used to carry the Msg1 PRACH. For example, if two-step random access is supported, RO is the time-frequency resource used to carry the MsgA PRACH.

[0133] The number of times, N, the terminal device repeatedly sends the first random access message (RQMS) refers to the number of times the terminal device needs to repeatedly send the RQMS when initiating a random access procedure. When N is small, the terminal device needs to send fewer RQMS messages, consuming less RO resources. However, a smaller number of retransmissions means that the success rate of each transmission has a greater impact on the random access procedure. If channel conditions are poor or there is significant interference, the RQMS may not be correctly received by the network device, thus reducing the random access success rate. When N is larger, the more retransmissions increase the probability that the RQMS will be successfully received by the network device, especially under poor channel conditions or interference. Multiple transmissions can improve the transmission success rate of the RQMS. However, because more transmissions are required, the total time of the random access procedure increases, and more RO resources are consumed. The network device can reasonably configure the value of N according to specific channel conditions, load conditions, and system requirements to achieve the optimal balance between RO resource utilization and random access success rate. Optionally, when channel conditions are poor or system load is high, the network device can appropriately increase the value of N to improve the random access success rate; when channel conditions are good and system load is low, the value of N can be decreased to improve RO resource utilization efficiency. In some embodiments, the number of times N that the terminal device repeatedly sends the first random access message can be configured, pre-configured, or predefined by the standard by the network device, or depend on the implementation of the terminal device, and this application does not limit this.

[0134] The association between the first random access message and the ROs refers to which specific ROs should be used to carry the first random access message when the terminal device sends it. It can be understood that there can be a one-to-one correspondence between the first random access message and the ROs, meaning one first random access message corresponds to one RO, and different first random access messages correspond to different ROs. That is, one first random access message is sent on one RO, and different first random access messages are sent on different ROs. The content of the first random access message sent by each RO is the same, but the time-frequency resources (i.e., RO resources) occupied by different ROs are different. For example, assuming N is 4, the first random access messages include first random access message 0, first random access message 1, first random access message 2, and first random access message 3; the ROs can include RO 0, RO 1, RO 2, and RO 3. Specifically, first random access message 0 can correspond to RO 0, first random access message 1 can correspond to RO 1, first random access message 2 can correspond to RO 2, and first random access message 3 can correspond to RO 3. The time-frequency resources occupied by RO 0, RO 1, RO 2, and RO 3 are different, and the contents of the four first random access messages (first random access message 0, first random access message 1, first random access message 2, and first random access message 3) are the same. In some embodiments, the correspondence between the first random access message and the RO can be configured, pre-configured, or predefined by the standard by the network device, or may depend on the implementation of the terminal device; this application does not limit this.

[0135] The above method enables the network device to dynamically determine the number of times N the terminal device repeatedly sends the first random access message and / or the association between N first random access messages and N ROs based on the real-time network status, thereby ensuring the reliability of the subsequent random access process of the terminal device.

[0136] In some embodiments, the aforementioned first configuration information can be carried in system messages or terminal-specific signaling. System messages are broadcast, specifically, the network device can broadcast the first configuration information within the first cell. When a terminal device in the first cell has a random access requirement, it can send a first random access message on the corresponding RO based on the received first configuration information. Terminal-specific signaling is sent to a specific terminal device, ensuring accurate transmission of the first configuration information. Furthermore, this accurate transmission method allows the network device to provide customized first configuration information for each terminal device, ensuring the relevance of the first configuration information. For example, different terminal devices may be located in different positions within the network. Specifically, when a terminal device is located in an area close to the network device with strong signal coverage, due to good signal transmission conditions, it can successfully access the network without repeatedly sending the first random access message too many times. In this case, the number of times N is configured to repeatedly send the first random access message can be a small value to save RO resource usage. When a terminal device is located in an edge area far from the network device, resulting in weak signal, the number of times N is configured to repeatedly send the first random access message can be a larger value to increase the chance of successful access for the terminal device.

[0137] Step 2: The terminal device repeatedly transmits the first random access message N times on N consecutive ROs using different spatial filters. Correspondingly, the network device receives the first random access message sent by the terminal device.

[0138] N consecutive ROs refer to N ROs occupying adjacent time-domain resources. Time-domain resources refer to transmission resources that are divided and managed in time, and can be time slots, symbols, frames, subframes, etc., which are not limited in this application. For example, N ROs can occupy N consecutive time slots, where one RO occupies one time slot.

[0139] In the above method, the N consecutive ROs are adjacent in time, meaning the terminal device can continuously send the first random access message on the N ROs without using other ROs intermittently. By continuously sending the first random access message N times, the time interval between each first random access message is reduced, thereby reducing the transmission time required to send the N first random access messages.

[0140] In some embodiments, the terminal device sends a first random access message once using a spatial filter during a random access event. For example, according to the above example, the spatial filter may include spatial filter 0, spatial filter 1, spatial filter 2, and spatial filter 3. Then, the terminal device can send the first random access message 0 using spatial filter 0 on RO 0; the terminal device can send the first random access message 1 using spatial filter 1 on RO 1; the terminal device can send the first random access message 2 using spatial filter 2 on RO 2; and the terminal device can send the first random access message 3 using spatial filter 3 on RO 3. Wherein, RO 0, RO 1, and RO 2 can be three consecutive ROs.

[0141] The above method, by repeatedly sending the first random access message, can improve the success rate of the network device receiving the first random access message. It also facilitates the subsequent determination of the first spatial filter by the network device based on the received multiple first random access messages.

[0142] In some embodiments, after sending a first random access message, the terminal device listens for a second random access message on a second cell, which is different from the first cell.

[0143] In some embodiments, the first cell supports uplink carriers but does not support downlink carriers, and the second cell is a cell that supports downlink carriers. The second cell can be either a cell that supports uplink carriers or a cell that does not support uplink carriers; this application does not limit this. The above method, by monitoring the second random access message on the second cell, can be adapted to scenarios where the first cell only supports uplink carriers.

[0144] In some embodiments, the first cell supports both uplink and downlink carriers, and the second cell is a cell that supports downlink carriers. The second cell can be a cell that supports uplink carriers or a cell that does not support uplink carriers; this application does not limit this. The above method, by listening to the second random access message on the second cell, can distribute the network load across different cells, avoiding overload of the first cell.

[0145] In some embodiments, the second cell is the primary cell of the terminal device, or the second cell is a cell associated with the first cell. In some embodiments, the terminal device includes multiple serving cells, among which one may be a primary cell, and the other serving cells may be secondary cells. Wherein, the second cell is the primary cell of the terminal device, and the first cell may be a secondary cell of the terminal device.

[0146] In some embodiments, the association between the second cell and the first cell may be configured by the network device, pre-configured, predefined by the standard, or depend on the implementation of the terminal device; this application does not limit this. For example, the second cell may be a cell with overlapping coverage area with the first cell.

[0147] In some embodiments, listening to a second random access message on a second cell includes: using a second spatial filter on the second cell to listen to the second random access message. The second spatial filter is a spatial filter used by the terminal device for downlink reception in the second cell. The second spatial filter is a receive beam design used to concentrate the received signal energy in a specific direction, thereby enhancing the signal from the second cell while suppressing interference from other directions, which helps to ensure stable reception of the second random access message.

[0148] In some embodiments, when the terminal device is listening for the second random access message, it generates a dedicated receive beam using a second spatial filter. This receive beam is generated based on the signal characteristics and expected direction of arrival of the second cell, ensuring accurate capture of the second random access message emitted by the second cell.

[0149] Step 3: The network device sends a second random access message to the terminal device. The second random access message carries first information, which is used to determine the first spatial filter. The first spatial filter is the spatial filter used by the terminal device for uplink transmission in the first cell.

[0150] In some embodiments, the network device determines a spatial filter as a first spatial filter from N different spatial filters based on the signal reception strength corresponding to each of the N received first random access messages. In some embodiments, the network device determines the maximum signal strength among the signal reception strengths corresponding to each of the N first random access messages; and uses the spatial filter corresponding to the maximum signal strength as the first spatial filter.

[0151] In some embodiments, the first information includes: identification information of the first spatial filter, or identification information of the RO corresponding to the first spatial filter.

[0152] The identification information of a spatial filter refers to the unique identifier assigned to a spatial filter in a communication system, used to distinguish different spatial filters. There can be a one-to-one correspondence between a spatial filter and its identification information; one spatial filter corresponds to one identification information, and different spatial filters correspond to different identification information.

[0153] For example, if the first random access messages 0 to N-1 are transmitted on RO 0 to RO N-1 respectively using spatial filters 0 to N-1. Assuming that the signal reception strength of the first random access message 0 is the highest among the first random access messages 0 to N-1, then the first information is the identification information of spatial filter 0, and the first information is used to directly determine spatial filter 0 as the first spatial filter.

[0154] The identification information of an RO refers to a unique identifier assigned to an RO in a communication system, used to distinguish different ROs. There can be a one-to-one correspondence between ROs and their identification information; one RO corresponds to one identification information, and different ROs correspond to different identification information. For example, based on the above example, assuming that among the first random access messages 0 to N-1, the signal reception strength of the first random access message 0 is the highest, then the first information is the identification information of RO 0. This first information is used to indirectly determine the spatial filter 0 corresponding to RO 0 as the first spatial filter.

[0155] In the above method, the first information can be the identification information of the first spatial filter to directly determine the first spatial filter. Alternatively, the first information can be the identification information of an originating region (RO), which can be used to identify the spatial filter corresponding to the RO's identification information as the first spatial filter, thus indirectly determining the first spatial filter.

[0156] Step 4: After receiving the second random access message, the terminal device uses a first spatial filter on the first cell to transmit a first uplink channel or signal. The first uplink channel or signal includes at least one of the following: a third random access message, PUSCH, or PUCCH. For detailed information, please refer to the corresponding content above.

[0157] Example 2

[0158] As shown in Figure 10, in step 1, during the process of the terminal device initiating random access on the first cell, the terminal device sends the first random access message using at least one spatial filter, which is pre-configured by the network device.

[0159] In some embodiments, the network device may send system messages or terminal-specific signaling to the terminal device. These system messages or terminal-specific signaling are used to pre-configure at least one spatial filter. Because the at least one spatial filter is pre-configured by the network device, the terminal device can directly and quickly send a first random access message based on the pre-configured at least one spatial filter.

[0160] In some embodiments, at least one spatial filter includes: spatial filters used and / or candidate spatial filters for uplink transmissions of the terminal device in at least one other serving cell besides the first cell.

[0161] Spatial filters used for uplink transmission in other serving cells refer to the spatial filters actually used by the terminal device during uplink transmission in serving cells other than the first cell. Candidate spatial filters refer to spatial filters that the terminal device may use during uplink transmission in serving cells other than the first cell but have not yet actually used.

[0162] The above method allows the terminal device to directly use these verified and effective spatial filters during random access when at least one spatial filter is used for uplink transmission in other serving cells, thereby improving the success rate of random access and reducing random access latency. When at least one spatial filter is a candidate spatial filter, the terminal device can quickly switch to the candidate filter when access to other serving cells fails, ensuring the reliability of random access.

[0163] In some embodiments, sending a first random access message using at least one spatial filter includes: (1) sending a first random access message using a spatial filter when the network device is pre-configured with a spatial filter; or (2) sending a first random access message using a spatial filter selected from the multiple spatial filters when the network device is pre-configured with multiple spatial filters; or (3) repeatedly sending the first random access message multiple times using different spatial filters on multiple consecutive ROs when the network device is pre-configured with multiple spatial filters.

[0164] (1) In some embodiments, a spatial filter is used to send the first random access message on a RO. Since only the first random access message is sent, the RO resource utilization rate can be reduced.

[0165] (2) In some embodiments, when the network device is pre-configured with multiple spatial filters, a spatial filter is randomly selected from the multiple spatial filters to send a first random access message.

[0166] In some embodiments, when a network device pre-configures multiple spatial filters, each spatial filter corresponds to a priority level. The priority level indicates at least one of the following: the performance, reliability, and applicability of the spatial filter. The performance of the spatial filter refers to its ability and efficiency in transmitting signals under specific channel conditions. Specifically, this includes performance in terms of transmission rate, signal-to-noise ratio, bit error rate, and channel capacity. The reliability of the spatial filter refers to its ability to maintain stable signal transmission under different channel conditions and environments. Specifically, this includes performance in terms of anti-interference capability, signal stability, and transmission success rate. The applicability of the spatial filter refers to its adaptability and flexibility in different channel conditions and application scenarios. Specifically, this includes performance in terms of adaptability to different channel environments, coverage, and flexibility of use. A higher priority level indicates better performance, higher reliability, and wider applicability of the spatial filter; a lower priority level indicates worse performance, lower reliability, and narrower applicability. The terminal device selects one spatial filter from the multiple spatial filters according to its respective priority level and sends a first random access message. For example, the spatial filters used for uplink transmission in other serving cells can have a higher priority, while the candidate spatial filters can have a lower priority. For example, the terminal device selects the spatial filter with the highest priority (i.e., the spatial filter used for uplink transmission in other serving cells) to send the first random access message. The above method, which determines the spatial filter for sending the first random access message based on priority, improves the transmission reliability of the first random access message while reducing RO resource consumption.

[0167] (3) It is understood that this method is the same as the method in Embodiment 1 above. For details, please refer to the relevant content in Embodiment 1.

[0168] The above method allows the terminal device to flexibly select at least one spatial filter from the spatial filters pre-configured by the network device to send the first random access message, according to its needs.

[0169] In some embodiments, after sending a first random access message, the terminal device listens for a second random access message on a second cell, which is different from the first cell. In some embodiments, the second cell is a cell that supports downlink carriers.

[0170] In some embodiments, the second cell is the primary cell of the terminal device, or the second cell is a cell associated with the first cell.

[0171] In some embodiments, listening to the second random access message on the second cell includes: using a second spatial filter on the second cell to listen to the second random access message, wherein the second spatial filter is a spatial filter used by the terminal device for downlink reception in the second cell. For detailed information, please refer to the corresponding content in Embodiment 1.

[0172] Step 2: The network device sends a second random access message to the terminal device. The second random access message carries first information, which is used to determine the first spatial filter. The first spatial filter is the spatial filter used by the terminal device for uplink transmission in the first cell.

[0173] In some embodiments, when the terminal device uses a single spatial filter to send the first random access message, the first information is used to indicate that the spatial filter used by the terminal device to send the first random access message is identified as the first spatial filter. In some embodiments, when the terminal device uses multiple spatial filters to send the first random access message, the first information includes: identification information of the first spatial filter, or identification information of the RO corresponding to the first spatial filter. For detailed information, please refer to the corresponding content in Embodiment 1.

[0174] Step 3: After receiving the second random access message, the terminal device uses a first spatial filter on the first cell to transmit a first uplink channel or signal. The first uplink channel or signal includes at least one of the following: a third random access message, PUSCH, or PUCCH. For detailed information, please refer to the corresponding content above.

[0175] The following describes the specific implementation method of the terminal device switching from the first transmission mode (corresponding to the above embodiment 2) to the second transmission mode (corresponding to the above embodiment 1).

[0176] In some embodiments, when a first condition is met, the system switches from a first sending mode to a second sending mode; wherein, the first sending mode refers to a mode in which the terminal device sends a first random access message using a spatial filter pre-configured by the network device, and the second sending mode refers to a mode in which the terminal device repeatedly sends the first random access message N times on N consecutive ROs using different spatial filters, where N is an integer greater than 1.

[0177] Understandably, in the first transmission mode, at least one spatial filter is pre-configured, and under favorable channel conditions, the first transmission mode can provide stable and efficient random access. In the second transmission mode, the network device can dynamically determine the number of times N the terminal device repeatedly transmits the first random access message and / or the correlation between N first random access messages and N ROs based on the real-time network status. This allows the terminal device to increase the chance of successful random access and the reliability of subsequent uplink transmissions by trying different spatial filters multiple times.

[0178] The first condition refers to the condition that triggers the terminal device to switch from the first transmission mode to the second transmission mode. In some embodiments, the first condition includes: the number of random access attempts by the terminal device on the first cell reaches a first threshold, or the terminal device receives handover indication information, which indicates a switch from the first transmission mode to the second transmission mode. In some embodiments, the value of the first threshold may be configured by the network device, pre-configured, or predefined by the standard, or may depend on the implementation of the terminal device; this application does not limit this.

[0179] In some embodiments, the number of random access attempts by the terminal device in the first cell reaching a first threshold means that the number of random access attempts made by the terminal device in the first cell has reached a preset threshold. That is, if the terminal device fails to access the network after making the first threshold number of random access attempts in the first cell, it is determined that the terminal device switches from a first transmission mode to a second transmission mode. By setting the first threshold, the network device can promptly identify the random access attempts of the terminal device in the first cell and decide whether a mode switch is necessary, thereby improving the success rate of random access and the reliability of subsequent uplink transmissions.

[0180] In some embodiments, the network device sends a second configuration message to the terminal device. The second configuration information is used to determine whether to switch from a first transmission mode to a second transmission mode if the number of random access attempts reaches a first threshold. Accordingly, the terminal device receives the second configuration information sent by the network device.

[0181] In some embodiments, the network device sends a second configuration message to the terminal device. This second configuration information determines whether to trigger a random access failure if the number of random access attempts reaches a first threshold. Accordingly, the terminal device receives the second configuration information sent by the network device. In the above method, continuing to attempt random access after multiple failed attempts by the terminal device wastes transmission resources and terminal device energy. By triggering a random access failure, the network device can promptly stop invalid random access attempts, saving transmission resources and terminal device energy.

[0182] In some embodiments, a network device receives multiple first random access messages sent by a terminal device. When it is determined that the signal reception strength of all the multiple first random access messages does not exceed a second threshold, the network device sends handover indication information to the terminal device. In some embodiments, the value of the second threshold may be configured, pre-configured, or predefined by a standard, or may depend on the implementation of the terminal device; this application does not limit this. By setting a second threshold, the above method allows the network device to adjust the transmission mode of the first random access messages in a timely manner when the signal strength of the multiple first random access messages sent by the terminal device is weak, thereby improving the success rate of random access and the reliability of subsequent uplink transmission.

[0183] In some embodiments, the handover indication information is carried in the second random access message, or in the fourth random access message. The second random access message can be Msg2 or MsgB. When using a contention-based / non-contention-based random access method, the second random access message is Msg2. When using a two-step random access method, the second random access message is MsgB. This method allows the network device to adapt to different random access methods, flexibly selecting the appropriate second or fourth random access message to send the handover indication information.

[0184] In some embodiments, the specific way in which the terminal device switches from the first transmission mode to the second transmission mode can be implemented as shown in the following embodiment 3.

[0185] Example 3

[0186] As shown in Figure 11, in step 1, during the process of the terminal device initiating random access on the first cell, the terminal device sends the first random access message using at least one spatial filter, which is pre-configured by the network device.

[0187] Step 2: The network device sends a second configuration message to the terminal device. This second configuration information determines whether to switch from the first sending mode to the second sending mode, or to trigger a random access failure, if the number of random access attempts reaches a first threshold. Accordingly, the terminal device receives the second configuration information sent by the network device.

[0188] In some embodiments, step 2 above can also be replaced by: the network device sending a second random access message or a fourth random access message to the terminal device, the second random access message or the fourth random access message including handover indication information, the handover indication information being used to indicate a switch from the first transmission mode to the second transmission mode. For detailed information, please refer to the corresponding content above.

[0189] The above embodiments only describe the technical solution provided in this application from the perspective of the interaction between the terminal device and the network device. The steps described above, performed by the terminal device, can be implemented independently as a random access method on the terminal device side. Similarly, the steps described above, performed by the network device, can be implemented independently as a random access method on the network device side.

[0190] The following are embodiments of the apparatus described in this application, which can be used to execute the embodiments of the method described in this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method described in this application.

[0191] Please refer to Figure 12, which shows a block diagram of a random access device provided in an embodiment of this application. This device has the function of implementing the above-described random access method; the function can be implemented in hardware or by hardware executing corresponding software. This device can be the terminal device described above, or it can be installed within a terminal device. As shown in Figure 12, the device 1200 may include a transmitting module 1210 and a receiving module 1220.

[0192] The sending module 1210 is used to send a first random access message using at least one spatial filter during the process of initiating random access on the first cell.

[0193] The receiving module 1220 is used to receive a second random access message, the second random access message carrying first information, the first information being used to determine a first spatial filter, the first spatial filter being the spatial filter used by the terminal device for uplink transmission in the first cell.

[0194] In some embodiments, the sending module 1210 is used to repeatedly send the first random access message N times on N consecutive ROs using different spatial filters, where N is an integer greater than 1.

[0195] In some embodiments, the receiving module 1220 is further configured to receive first configuration information, the first configuration information being used to determine at least one of the following: the number of times N the terminal device repeatedly sends the first random access message, and the association between the N times the first random access message and the N ROs.

[0196] In some embodiments, the first information includes: the identification information of the first spatial filter, or the identification information of the RO corresponding to the first spatial filter.

[0197] In some embodiments, the at least one spatial filter is pre-configured by the network device.

[0198] In some embodiments, the at least one spatial filter includes: spatial filters used and / or candidate spatial filters by the terminal device for uplink transmission in at least one other serving cell besides the first cell.

[0199] In some embodiments, the sending module 1210 is configured to send the first random access message using a spatial filter when the network device is pre-configured with a spatial filter; or, when the network device is pre-configured with multiple spatial filters, to send the first random access message using a spatial filter selected from the multiple spatial filters; or, when the network device is pre-configured with multiple spatial filters, to repeatedly send the first random access message multiple times on multiple consecutive ROs using different spatial filters.

[0200] In some embodiments, when the terminal device uses a spatial filter to send the first random access message, the first information is used to indicate that the spatial filter used by the terminal device to send the first random access message is identified as the first spatial filter; or, when the terminal device uses multiple spatial filters to send the first random access message, the first information includes: the identification information of the first spatial filter, or the identification information of the RO corresponding to the first spatial filter.

[0201] In some embodiments, the receiving module 1220 is further configured to listen for the second random access message on a second cell, the second cell being different from the first cell.

[0202] In some embodiments, the second cell is a cell that supports downlink carriers.

[0203] In some embodiments, the second cell is the primary cell of the terminal device, or the second cell is a cell associated with the first cell.

[0204] In some embodiments, the receiving module 1220 is used to listen to the second random access message in the second cell using a second spatial filter, wherein the second spatial filter is a spatial filter used by the terminal device for downlink reception in the second cell.

[0205] In some embodiments, the sending module 1210 is further configured to switch from a first sending mode to a second sending mode when a first condition is met; wherein, the first sending mode refers to the mode in which the terminal device sends the first random access message using a spatial filter pre-configured by the network device, and the second sending mode refers to the mode in which the terminal device repeatedly sends the first random access message N times on N consecutive ROs using different spatial filters, where N is an integer greater than 1.

[0206] In some embodiments, the first condition includes: the number of random access attempts made by the terminal device in the first cell reaches a first threshold, or the terminal device receives handover indication information, the handover indication information being used to indicate a switch from the first transmission mode to the second transmission mode.

[0207] In some embodiments, the receiving module 1220 is further configured to receive second configuration information, the second configuration information being configured to determine, when the number of random access attempts reaches the first threshold, to switch from the first sending mode to the second sending mode, or to trigger a random access failure.

[0208] In some embodiments, the handover indication information is carried in the second random access message, or the handover indication information is carried in the fourth random access message.

[0209] In some embodiments, the transmitting module 1210 is further configured to use the first spatial filter on the first cell to transmit a first uplink channel or signal, the first uplink channel or signal including at least one of the following: a third random access message, PUSCH, and PUCCH.

[0210] In some embodiments, the first cell is a cell that supports uplink carriers but does not support downlink carriers.

[0211] In some embodiments, the first random access message is Msg1 and the second random access message is Msg2; or, the first random access message is MsgA and the second random access message is MsgB.

[0212] Please refer to Figure 13, which shows a block diagram of a random access device provided in another embodiment of this application. This device has the function of implementing the above-described random access method; this function can be implemented in hardware or by hardware executing corresponding software. This device can be a network device as described above, or it can be installed within a network device. As shown in Figure 13, the device 1300 may include a receiving module 1310 and a transmitting module 1320.

[0213] The receiving module 1310 is used to receive the first random access message sent by the terminal device using at least one spatial filter during the process of initiating random access in the first cell.

[0214] The sending module 1320 is used to send a second random access message to the terminal device. The second random access message carries first information, which is used to determine a first spatial filter. The first spatial filter is the spatial filter used by the terminal device for uplink transmission in the first cell.

[0215] In some embodiments, the receiving module 1310 is used to receive the first random access message N times repeatedly sent by the terminal device on N consecutive ROs using different spatial filters, where N is an integer greater than 1.

[0216] In some embodiments, the sending module 1320 is used to send first configuration information, the first configuration information being used to determine at least one of the following: the number of times N the terminal device repeatedly sends the first random access message, and the association between the N times the first random access message and the N ROs.

[0217] In some embodiments, the first information includes: the identification information of the first spatial filter, or the identification information of the RO corresponding to the first spatial filter.

[0218] In some embodiments, the at least one spatial filter is pre-configured by the network device.

[0219] In some embodiments, the at least one spatial filter includes: spatial filters used and / or candidate spatial filters by the terminal device for uplink transmission in at least one other serving cell besides the first cell.

[0220] In some embodiments, the receiving module 1310 is configured to receive the first random access message sent by the terminal device using the one spatial filter when the network device is pre-configured with a spatial filter; or, when the network device is pre-configured with multiple spatial filters, to receive the first random access message sent by the terminal device using one spatial filter selected from the multiple spatial filters; or, when the network device is pre-configured with multiple spatial filters, to receive multiple first random access messages repeatedly sent by the terminal device on multiple consecutive ROs using different spatial filters.

[0221] In some embodiments, when the terminal device uses a spatial filter to send the first random access message, the first information is used to indicate that the spatial filter used by the terminal device to send the first random access message is identified as the first spatial filter; or, when the terminal device uses multiple spatial filters to send the first random access message, the first information includes: the identification information of the first spatial filter, or the identification information of the RO corresponding to the first spatial filter.

[0222] In some embodiments, the sending module 1320 is used to send the second random access message to the terminal device on a second cell, the second cell being different from the first cell.

[0223] In some embodiments, the second cell is a cell that supports downlink carriers.

[0224] In some embodiments, the second cell is the primary cell of the terminal device, or the second cell is a cell associated with the first cell.

[0225] In some embodiments, the spatial filter used to listen to the second random access message on the second cell is a second spatial filter, which is the spatial filter used by the terminal device for downlink reception in the second cell.

[0226] In some embodiments, when a first condition is met, the sending mode of the first random access message is switched from a first sending mode to a second sending mode; wherein, the first sending mode refers to the mode in which the terminal device sends the first random access message using a spatial filter pre-configured by the network device, and the second sending mode refers to the mode in which the terminal device repeatedly sends the first random access message N times on N consecutive ROs using different spatial filters, where N is an integer greater than 1.

[0227] In some embodiments, the first condition includes: the number of random access attempts made by the terminal device in the first cell reaches a first threshold, or the terminal device receives handover indication information, the handover indication information being used to indicate a switch from the first transmission mode to the second transmission mode.

[0228] In some embodiments, the sending module 1320 is used to send second configuration information, the second configuration information being used to determine whether to switch from the first sending mode to the second sending mode or to trigger a random access failure when the number of random access attempts reaches the first threshold.

[0229] In some embodiments, the handover indication information is carried in the second random access message, or the handover indication information is carried in the fourth random access message.

[0230] In some embodiments, the receiving module 1310 is further configured to receive a first uplink channel or signal transmitted by the terminal device on the first cell using the first spatial filter, wherein the first uplink channel or signal includes at least one of the following: a third random access message, PUSCH, and PUCCH.

[0231] In some embodiments, the first cell is a cell that supports uplink carriers but does not support downlink carriers.

[0232] In some embodiments, the first random access message is Msg1 and the second random access message is Msg2; or, the first random access message is MsgA and the second random access message is MsgB.

[0233] It should be noted that the above embodiments only illustrate the division of the above functional modules when implementing the device. In actual applications, the above functions can be assigned to different functional modules according to actual needs, that is, the content structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0234] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here. For details not described in detail in the apparatus embodiments, please refer to the above method embodiments.

[0235] Please refer to Figure 14, which shows a schematic diagram of a communication device provided in one embodiment of this application. The communication device 1400 may include a processor 1401, a transceiver 1402, and a memory 1403. The transceiver 1402 is used to implement sending and / or receiving functions, such as implementing the functions of the sending module and / or receiving module described above. The processor can be used to implement other processing functions or control sending and / or receiving.

[0236] The processor 1401 includes one or more processing cores, and the processor 1401 executes various functional applications and information processing by running software programs and modules.

[0237] The transceiver 1402 may include a receiver and a transmitter, for example, the receiver and transmitter may be implemented as the same wireless communication component, which may include a wireless communication chip and a radio frequency antenna.

[0238] The memory 1403 can be connected to the processor 1401 and the transceiver 1402.

[0239] The memory 1403 can be used to store computer programs executed by the processor, and the processor 1401 is used to execute the computer program.

[0240] In some embodiments, when the communication device is a terminal device, the transceiver 1402 is used to send a first random access message and receive a second random access message using at least one spatial filter during the process of initiating random access on the first cell.

[0241] In some embodiments, when the communication device is a network device, the transceiver 1402 is used to receive a first random access message sent by the terminal device using at least one spatial filter during the process of the terminal device initiating random access in the first cell; and to send a second random access message to the terminal device.

[0242] For details not described in this embodiment, please refer to the embodiments above, which will not be repeated here.

[0243] Furthermore, the memory can be implemented by any type of volatile or non-volatile storage device or a combination thereof, including but not limited to: magnetic disks or optical disks, electrically erasable programmable read-only memory, erasable programmable read-only memory, statically accessible memory, read-only memory, magnetic memory, flash memory, and programmable read-only memory.

[0244] This application also provides a computer-readable storage medium storing a computer program for execution by a processor to implement the above-described on-demand access method. In some embodiments, the computer-readable storage medium may include ROM (Read-Only Memory), RAM (Random-Access Memory), SSD (Solid State Drives), or optical disc, etc. The random access memory may include ReRAM (Resistance Random Access Memory) and DRAM (Dynamic Random Access Memory).

[0245] This application also provides a chip, which includes programmable logic circuits and / or program instructions, and is used to implement the above-described random access method when the chip is running.

[0246] This application also provides a computer program product, which includes computer instructions stored in a computer-readable storage medium. A processor reads and executes the computer instructions from the computer-readable storage medium to implement the above-described random access method.

[0247] It should be understood that the term "instruction" mentioned in the embodiments of this application can be a direct instruction, an indirect instruction, or an indication of a relationship. For example, A instructing B can mean that A directly instructs B, such as B being able to obtain information through A; it can also mean that A indirectly instructs B, such as A instructing C, so B can obtain information through C; or it can mean that there is a relationship between A and B.

[0248] In the description of the embodiments of this application, the term "correspondence" may indicate that there is a direct or indirect correspondence between two things, or that there is an association between two things, or that there is a relationship of instruction and being instructed, configuration and being configured, etc.

[0249] In some embodiments of this application, "predefined" can be achieved by pre-storing corresponding codes, tables, or other means that can be used to indicate relevant information in the device (e.g., including terminal devices and network devices). This application does not limit the specific implementation method. For example, predefined can refer to what is defined in the protocol.

[0250] In some embodiments of this application, the term "protocol" may refer to standard protocols in the field of communications, such as LTE protocols, NR protocols, and related protocols applied in future communication systems. This application does not limit the scope of these protocols.

[0251] In this article, "multiple" refers to 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. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0252] In this article, "greater than or equal to" can mean greater than or equal to, and "less than or equal to" can mean less than or equal to.

[0253] Furthermore, the step numbers described herein are merely illustrative of one possible execution order between steps. In some other embodiments, the steps may not be executed in the order of their numbers, such as two steps with different numbers being executed simultaneously, or two steps with different numbers being executed in the reverse order of the illustration. This application does not limit this.

[0254] Those skilled in the art will recognize that the functions described in the embodiments of this application in one or more of the above examples can be implemented using hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transfer of a computer program from one place to another. Storage media can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0255] The above description is merely an exemplary embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A random access method, characterized in that, The method is executed by a terminal device, and the method includes: During the process of initiating random access on the first cell, at least one spatial filter is used to send the first random access message; The terminal receives a second random access message, which carries first information. The first information is used to determine a first spatial filter, which is the spatial filter used by the terminal device for uplink transmission in the first cell.

2. The method according to claim 1, characterized in that, The step of sending the first random access message using at least one spatial filter includes: At N consecutive random access times (RO), the first random access message is repeatedly sent N times using different spatial filters, where N is an integer greater than 1.

3. The method according to claim 2, characterized in that, The method further includes: Receive first configuration information, the first configuration information being used to determine at least one of the following: the number of times N the terminal device repeatedly sends the first random access message, and the association between the N times the first random access message and the N ROs.

4. The method according to claim 2 or 3, characterized in that, The first information includes: the identification information of the first spatial filter, or the identification information of the RO corresponding to the first spatial filter.

5. The method according to claim 1, characterized in that, The at least one spatial filter is pre-configured by the network device.

6. The method according to claim 5, characterized in that, The at least one spatial filter includes: spatial filters used and / or candidate spatial filters by the terminal device for uplink transmission in at least one other serving cell besides the first cell.

7. The method according to claim 5 or 6, characterized in that, The step of sending the first random access message using at least one spatial filter includes: If the network device is pre-configured with a spatial filter, the first random access message is sent using the spatial filter; or, When the network device is pre-configured with multiple spatial filters, the first random access message is sent using one of the multiple spatial filters; or... When the network device is pre-configured with multiple spatial filters, the first random access message is repeatedly sent multiple times on multiple consecutive ROs using different spatial filters.

8. The method according to any one of claims 5 to 7, characterized in that, When the terminal device uses a spatial filter to send the first random access message, the first information is used to indicate that the spatial filter used by the terminal device to send the first random access message is identified as the first spatial filter. or, When the terminal device sends the first random access message using multiple spatial filters, the first information includes: the identification information of the first spatial filter, or the identification information of the RO corresponding to the first spatial filter.

9. The method according to any one of claims 1 to 8, characterized in that, After sending the first random access message using at least one spatial filter, the method further includes: Listen for the second random access message on the second cell, which is different from the first cell.

10. The method according to claim 9, characterized in that, The second cell is a cell that supports downlink carrier.

11. The method according to claim 9 or 10, characterized in that, The second cell is the primary cell of the terminal device, or the second cell is a cell associated with the first cell.

12. The method according to any one of claims 9 to 11, characterized in that, The step of listening to the second random access message on the second cell includes: The second spatial filter is used to listen to the second random access message in the second cell. The second spatial filter is the spatial filter used by the terminal device for downlink reception in the second cell.

13. The method according to any one of claims 1 to 12, characterized in that, The method further includes: If the first condition is met, switch from the first transmission mode to the second transmission mode; Wherein, the first sending mode refers to the mode in which the terminal device sends the first random access message using a spatial filter pre-configured by the network device, and the second sending mode refers to the mode in which the terminal device repeatedly sends the first random access message N times on N consecutive ROs using different spatial filters, where N is an integer greater than 1.

14. The method according to claim 13, characterized in that, The first condition includes: the number of random access attempts made by the terminal device in the first cell reaches a first threshold, or the terminal device receives a handover indication information, the handover indication information being used to indicate a switch from the first transmission mode to the second transmission mode.

15. The method according to claim 14, characterized in that, The method further includes: Receive second configuration information, which is used to determine whether to switch from the first sending mode to the second sending mode or trigger a random access failure when the number of random access attempts reaches the first threshold.

16. The method according to claim 14, characterized in that, The handover indication information is carried in the second random access message, or the handover indication information is carried in the fourth random access message.

17. The method according to any one of claims 1 to 16, characterized in that, After receiving the second random access message, the method further includes: The first spatial filter is used on the first cell to transmit a first uplink channel or signal, the first uplink channel or signal including at least one of the following: a third random access message, a physical uplink shared channel (PUSCH), and a physical uplink control channel (PUCCH).

18. The method according to any one of claims 1 to 17, characterized in that, The first cell is a cell that supports uplink carriers but does not support downlink carriers.

19. The method according to any one of claims 1 to 18, characterized in that, The first random access message is Msg1, and the second random access message is Msg2; or, The first random access message is MsgA, and the second random access message is MsgB.

20. A random access method, characterized in that, The method is performed by a network device, and the method includes: During the process of receiving terminal equipment initiating random access in the first cell, the first random access message is sent using at least one spatial filter. A second random access message is sent to the terminal device. The second random access message carries first information, which is used to determine a first spatial filter. The first spatial filter is the spatial filter used by the terminal device for uplink transmission in the first cell.

21. The method according to claim 20, characterized in that, During the process of initiating random access in the first cell, the receiving terminal device sends a first random access message using at least one spatial filter, including: The terminal device receives the first random access message N times at N consecutive random access times (RO), using different spatial filters, where N is an integer greater than 1.

22. The method according to claim 21, characterized in that, The method further includes: Send first configuration information, which is used to determine at least one of the following: the number of times N the terminal device repeatedly sends the first random access message, and the association between the N times the first random access message and the N ROs.

23. The method according to claim 21 or 22, characterized in that, The first information includes: the identification information of the first spatial filter, or the identification information of the RO corresponding to the first spatial filter.

24. The method according to claim 20, characterized in that, The at least one spatial filter is pre-configured by the network device.

25. The method according to claim 24, characterized in that, The at least one spatial filter includes: spatial filters used and / or candidate spatial filters by the terminal device for uplink transmission in at least one other serving cell besides the first cell.

26. The method according to claim 24 or 25, characterized in that, During the process of initiating random access in the first cell, the receiving terminal device sends a first random access message using at least one spatial filter, including: If the network device is pre-configured with a spatial filter, the first random access message sent by the terminal device using the spatial filter is received; or, When the network device is pre-configured with multiple spatial filters, the first random access message sent by the terminal device using one of the multiple spatial filters is received; or, When the network device is pre-configured with multiple spatial filters, it receives multiple first random access messages repeatedly sent by the terminal device on multiple consecutive ROs using different spatial filters.

27. The method according to any one of claims 24 to 26, characterized in that, When the terminal device uses a spatial filter to send the first random access message, the first information is used to indicate that the spatial filter used by the terminal device to send the first random access message is identified as the first spatial filter. or, When the terminal device sends the first random access message using multiple spatial filters, the first information includes: the identification information of the first spatial filter, or the identification information of the RO corresponding to the first spatial filter.

28. The method according to any one of claims 20 to 27, characterized in that, Sending the second random access message to the terminal device includes: The second random access message is sent to the terminal device in a second cell, which is different from the first cell.

29. The method according to claim 28, characterized in that, The second cell is a cell that supports downlink carrier.

30. The method according to claim 28 or 29, characterized in that, The second cell is the primary cell of the terminal device, or the second cell is a cell associated with the first cell.

31. The method according to any one of claims 28 to 30, characterized in that, The spatial filter used to listen to the second random access message on the second cell is the second spatial filter, which is the spatial filter used by the terminal device for downlink reception in the second cell.

32. The method according to any one of claims 20 to 31, characterized in that, If the first condition is met, the sending mode of the first random access message is switched from the first sending mode to the second sending mode; Wherein, the first sending mode refers to the mode in which the terminal device sends the first random access message using a spatial filter pre-configured by the network device, and the second sending mode refers to the mode in which the terminal device repeatedly sends the first random access message N times on N consecutive ROs using different spatial filters, where N is an integer greater than 1.

33. The method according to claim 32, characterized in that, The first condition includes: the number of random access attempts made by the terminal device in the first cell reaches a first threshold, or the terminal device receives handover indication information, the handover indication information being used to indicate a switch from the first transmission mode to the second transmission mode.

34. The method according to claim 33, characterized in that, The method further includes: Send second configuration information, which is used to determine whether to switch from the first sending mode to the second sending mode or to trigger a random access failure if the number of random access attempts reaches the first threshold.

35. The method according to claim 33, characterized in that, The handover indication information is carried in the second random access message, or the handover indication information is carried in the fourth random access message.

36. The method according to any one of claims 20 to 35, characterized in that, After sending the second random access message to the terminal device, the method further includes: The terminal device receives a first uplink channel or signal transmitted in the first cell using the first spatial filter. The first uplink channel or signal includes at least one of the following: a third random access message, a physical uplink shared channel (PUSCH), and a physical uplink control channel (PUCCH).

37. The method according to any one of claims 20 to 36, characterized in that, The first cell is a cell that supports uplink carriers but does not support downlink carriers.

38. The method according to any one of claims 20 to 37, characterized in that, The first random access message is Msg1, and the second random access message is Msg2; or, The first random access message is MsgA, and the second random access message is MsgB.

39. A random access device, characterized in that, The device includes: a transmitting module and a receiving module; The sending module is used to send a first random access message using at least one spatial filter during the process of initiating random access on the first cell. The receiving module is used to receive a second random access message, the second random access message carrying first information, the first information being used to determine a first spatial filter, the first spatial filter being the spatial filter used by the terminal device for uplink transmission in the first cell.

40. A random access device, characterized in that, The device includes: a receiving module and a transmitting module; The receiving module is used to receive the first random access message sent by the terminal device using at least one spatial filter during the process of initiating random access in the first cell. The sending module is used to send a second random access message to the terminal device. The second random access message carries first information, which is used to determine a first spatial filter. The first spatial filter is the spatial filter used by the terminal device for uplink transmission in the first cell.

41. A communication device, characterized in that, The communication device includes a processor and a memory, the memory storing a computer program, the processor executing the computer program to implement the method as claimed in any one of claims 1 to 19, or to implement the method as claimed in any one of claims 20 to 38.

42. A computer-readable storage medium, characterized in that, The storage medium stores a computer program that is executed by a processor to implement the method as described in any one of claims 1 to 19, or to implement the method as described in any one of claims 20 to 38.

43. A chip, characterized in that, The chip includes programmable logic circuitry and / or program instructions, which, when the chip is running, are used to implement the method as described in any one of claims 1 to 19, or to implement the method as described in any one of claims 20 to 38.

44. A computer program product, characterized in that, The computer program product includes computer instructions stored in a computer-readable storage medium, which a processor reads from and executes to implement the method as claimed in any one of claims 1 to 19, or the method as claimed in any one of claims 20 to 38.

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