Random access method and apparatus, and storage medium

Abstract

A random access method and apparatus, and a storage medium, which are used for expanding random access application scenarios. In the present application, a terminal apparatus receives first indication information, which is used for indicating a first uplink reference signal; and the terminal apparatus sends a preamble, which is used for initiating random access and is associated with the first uplink reference signal. The solution can be provided for the access of a terminal apparatus to a network apparatus having limited capabilities, so as to expand the application range of the random access process. For example, for a first network apparatus which does not have a downlink transmission capability or is not configured with information related to downlink transmission, the terminal apparatus can also access the first network apparatus on the basis of a first uplink reference signal by means of the solution provided by the present application.

Description

A random access method, device and storage medium

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on November 23, 2023, with application number 202311589233.5 and application name "A Random Access Method, Device and Storage Medium", the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of communication technology, and in particular to a random access method, device, and storage medium. Background Art

[0004] In a wireless communication system, in order to establish a connection with a network device, the terminal device needs to first initiate a random access process to the network device. The terminal device can establish a connection with the cell, obtain uplink synchronization or beam failure recovery through the random access process.

[0005] At present, in the protocols of the fourth-generation mobile communication system Long Term Evolution (LTE) and the fifth-generation mobile communication system New Radio (NR), terminal devices generally use a four-step random access (4-step physical random access channel, 4-step RACH) process for random access. The four-step random access process includes: the terminal device initiates a random access request to the network device (the request includes a preamble), the network device sends a random access response message to the terminal device, the terminal device initiates uplink data to the network device, and the network device sends contention resolution information to the terminal device. In order to support random access requests in low-latency scenarios, a two-step random access (2-step RACH) process is proposed. In the two-step random access process, the terminal device initiates a random access request to the network device, the request includes a preamble and uplink data; the network device sends a response message to the terminal in response to the random access request.

[0006] Whether it is a four-step random access process or a two-step random access process, before the random access process begins, the network device needs to first specify a downlink reference signal for the terminal device, and the downlink reference signal is associated with the random access process. The network device needs to send the downlink reference signal, the terminal device receives the downlink reference signal, and the signaling transmission between the terminal device and the network device in the random access process needs to refer to the downlink reference signal. For example, messages such as random access requests sent by the terminal device to the network device need to be associated with the spatial relationship of the specified downlink reference signal. For example, the path loss reference signal in the random access process also needs to be set to the specified downlink reference signal.

[0007] From the above content, it can be seen that the application scope of the current random access process is relatively limited. For example, the network device must send a downlink reference signal, the preamble sent by the terminal device is associated with the downlink reference signal, and the terminal device accesses the network device through a random access process based on the downlink reference signal. For network devices that do not send downlink reference signals (such as network devices that do not have the ability to send downlink signals or network devices that are not configured with relevant parameters for downlink transmission, etc.), the terminal device cannot use the above-mentioned random access process to access such network devices. It can be seen that how to broaden the application scenarios of random access has become a technical problem that needs to be solved urgently. Summary of the Invention

[0008] The present application provides a random access method, device and storage medium for enabling a terminal device to associate a preamble code with an uplink reference signal, and then for a network device that does not send a downlink reference signal (such as a network device that does not have downlink transmission capability, or a network device that is not configured with downlink transmission-related information, etc.), the terminal device can also access such a network device, thereby broadening the application scenarios of random access.

[0009] In a first aspect, the present application provides a random access method, which is executed by a terminal device, which may be a terminal equipment or a chip inside the terminal equipment.

[0010] In the present application, a terminal device receives first indication information. For example, the terminal device may receive first indication information from a second network device. The first indication information is used to instruct the terminal device to send a preamble code for a first uplink reference signal, and the preamble code is used to initiate random access. The preamble code is associated with the first uplink reference signal.

[0011] Since the terminal device can send a preamble based on the first uplink reference signal and then randomly access the first network device, this solution can provide a solution for the terminal device to access a network device with limited capabilities, thereby broadening the scope of application of the random access process.

[0012] In one possible implementation, the first network device does not have downlink transmission capabilities or the first network device is not configured with information related to downlink transmission. In one possible implementation, the information related to downlink transmission may include at least one of: information related to downlink reference signals, information related to downlink control channel transmission, information related to downlink data channel transmission, information related to downlink frame structure, information related to downlink time slots, or information related to downlink bandwidth. Information related to not configuring downlink reference signals may be replaced by not configuring downlink reference signals. Information related to not configuring downlink control channel transmission may be replaced by not configuring downlink control channel transmission. Information related to not configuring downlink data channel transmission may be replaced by not configuring downlink data channel transmission. Information related to not configuring downlink frame structure may be replaced by not configuring parameters related to downlink frame structure. Information related to not configuring downlink time slots may be replaced by not configuring parameters related to downlink time slots. Information related to not configuring downlink bandwidth may be replaced by not configuring downlink bandwidth.

[0013] In this case, by applying the solution provided in this application, the terminal device can still access such a network device through a random access process.

[0014] In another possible implementation, the first network device has uplink transmission capabilities; and / or the first network device configures information related to uplink transmission. In this implementation, the first network device does not have downlink transmission capabilities or the first network device does not configure information related to downlink transmission. In another possible implementation, it can also be described as follows: the first network device only has uplink transmission capabilities, and / or the first network device only configures information related to uplink transmission. Information related to uplink transmission may include at least one of: uplink reference signal information, uplink control channel transmission information, uplink data channel transmission information, uplink frame structure information, uplink time slot information, or uplink bandwidth information. Configuring information related to uplink reference signals may be replaced by configuring uplink reference signals. Configuring information related to uplink control channel transmission may be replaced by configuring uplink control channel transmission. Configuring information related to uplink data channel transmission may be replaced by configuring uplink data channel transmission. Configuring information related to uplink frame structure may be replaced by configuring parameters related to uplink frame structure. Configuring information related to uplink time slots may be replaced by configuring parameters related to uplink time slots. Configuring information related to uplink bandwidth may be replaced by configuring uplink bandwidth. In this way, the terminal device can send information, such as a preamble, to the first network device.

[0015] In one possible implementation, the preamble code may be carried in a physical random access channel (PRACH). The preamble code may be associated with the first uplink reference signal, which may be understood as some parameters in the preamble code transmission process may refer to the first uplink reference signal. For example, the spatial relationship (or beam) of the transmitted preamble code may refer to the spatial relationship (or beam) of the first uplink reference signal, or the spatial relationship (or beam) of the preamble code may be associated with the spatial relationship (or beam) of the first uplink reference signal. For another example, the path loss reference signal associated with the transmitted preamble code is the first uplink reference signal. Alternatively, it may be understood that the path loss of the transmitted preamble code may refer to (or be regarded as) the path loss of the first uplink reference signal.

[0016] There are multiple options for the information that carries the first indication information, such as being carried in downlink control information (DCI), or a media access control control element (MAC CE), or being carried in a radio resource control (RRC) message, which can make the solution more flexible and more compatible with existing solutions. For example, the first indication information can be carried in the DCI in a physical downlink control channel (PDCCH) order. The English word "MAC CE" in the embodiment of the present application can also be replaced by a medium access control control element (MAC CE).

[0017] In one possible implementation, the terminal device sends a preamble to the first network device. The first indication information comes from the second network device, and the first network device is different from the second network device. The terminal device can receive some relevant information, such as the first indication information, from the second network device, and then send a preamble to the first network device to access the first network device. This solution can provide a solution for the terminal device to access a network device with limited capabilities, thereby broadening the scope of application of the random access process. For example, the first network device does not have downlink transmission capability or the first network device is not configured with downlink transmission-related information. Based on the solution provided in this application, the terminal device can also receive some relevant information from the second network device, and then achieve the effect of accessing the first network device.

[0018] The solution provided in the present application is applicable to a variety of scenarios. In different scenarios, the forms of the first network device and the second network device are various. For example, the cell associated with the first network device is a non-service cell, or the first network device is a cell with a physical cell identifier (PCI) different from that of the service cell, and the cell associated with the second network device is a service cell. For another example, the first network device and the second network device can be different transmission reception points (TRPs) in the same cell. For another example, the cells associated with the first network device and the second network device can be different service cells (or different component carriers (CCs)). It can be seen that the solution provided in the present application is applicable to a variety of scenarios, thereby expanding the scope of application of the present application.

[0019] In one possible implementation, the terminal device may also receive a second indication message. For example, the terminal device receives a second indication message from a second network device. The second indication message is used to indicate at least one of the following: the first network device to which the terminal device initiates random access does not have downlink transmission capability; the signal type referenced by the random access initiated by the terminal device is an uplink reference signal; or, the first network device to which the terminal device initiates random access is not configured with information related to downlink transmission. In this way, the terminal device can determine, based on the received second indication message, that the random access to be initiated this time is associated with an uplink reference signal, and does not need to be associated with a downlink reference signal. In this way, the solution can be compatible with a random access process that requires association with a downlink reference signal, and the terminal device can distinguish whether the random access process uses an uplink reference signal or a downlink reference signal.

[0020] In one possible implementation, the terminal device may further receive (e.g., may receive from a second network device) information indicating the first network device. For example, the terminal device receives information from the second network device indicating the first network device. The information indicating the first network device is used to indicate the first network device. The first network device is the network device that initiates random access by the terminal device. The information indicating the first network device may include, for example, identification information of a cell associated with the first network device or index information of a CC of the first network device. For example, when the cells associated with the first network device and the second network device are different serving cells: the information indicating the first network device includes identification information of the serving cell associated with the first network device.

[0021] In this way, the terminal device can determine the first network device to be accessed this time. On the other hand, the terminal device can determine based on the pre-configured information that the first network device does not have the downlink transmission capability or the first network device is not configured with information related to downlink transmission. In this case, the terminal device can determine based on the information used to indicate the first network device that the random access to be initiated this time is associated with the uplink reference signal, and does not need to be associated with the downlink reference signal. In this way, the scheme can be compatible with the random access process that requires the association of the downlink reference signal, and the terminal device can distinguish whether the random access process uses the uplink reference signal or the downlink reference signal. On the other hand, when applying this embodiment, the terminal device can receive the above-mentioned second indication information. The terminal device may also not receive the above-mentioned second indication information, which can save signaling overhead.

[0022] Before sending a preamble, the terminal device needs to determine the preamble. There are various ways to determine the preamble. For example, the terminal device receives information indicating the preamble and determines the preamble based on the information indicating the preamble. For example, the terminal device receives information indicating the preamble from the second network device.

[0023] For another example, the terminal device may configure some association relationships in advance, and these association relationships may include the association relationship between one or more uplink reference signals and one or more preamble codes. One uplink reference signal may be associated with one or more preamble codes, and one or more preamble codes may be associated with one uplink reference signal. These association relationships may include a first association relationship, and the first association relationship indicates the association relationship between the first uplink reference signal and the preamble code. The terminal device may search for these association relationships based on the first uplink reference signal, and then find the preamble code associated with the first uplink reference signal based on the first association relationship. In this way, the terminal device does not need to receive information for indicating the preamble code, thereby saving signaling overhead.

[0024] Before sending a preamble, the terminal device must determine a random access opportunity. The terminal device sends the preamble at the random access opportunity. There are various ways to determine the random access opportunity. For example, the terminal device may receive mask information from a random access channel and determine the random access opportunity based on the mask information. For example, the terminal device may receive mask information from a random access channel of a second network device.

[0025] For another example, the terminal device may configure some association relationships in advance, and these association relationships may include the association relationship between one or more uplink reference signals and one or more random access opportunities. One uplink reference signal may be associated with one or more random access opportunities, and one or more random access opportunities may be associated with one uplink reference signal. These association relationships may include a second association relationship, and the second association relationship indicates the association relationship between the first uplink reference signal and the random access opportunity. The terminal device can search for these association relationships based on the first uplink reference signal, and then find the random access opportunity associated with the first uplink reference signal based on the second association relationship. In this way, the terminal device does not need to receive information for indicating the preamble code, thereby saving signaling overhead.

[0026] In a possible implementation, the first indication information includes: a resource identifier and / or a resource set identifier of the first uplink reference signal. In this way, the terminal device can determine the first uplink reference signal according to the first indication information.

[0027] In another possible implementation, the second network device may send a first threshold and a measurement result of at least one uplink reference signal, and the measurement result of the first uplink reference signal belongs to the measurement result of the at least one uplink reference signal. In this way, the terminal device may select an uplink reference signal whose indicated signal strength is greater than the first threshold from the measurement result of at least one uplink reference signal. For example, the first indication information includes the first threshold and the measurement result of the first uplink reference signal, and the signal strength indicated by the measurement result of the first uplink reference signal is greater than or equal to the first threshold. In this way, the terminal device can select the first uplink reference signal to provide assistance for the random access process. In this example, the second network device may not send the first threshold, for example, the first indication information includes the measurement result of the first uplink reference signal, but does not include the first threshold. The protocol may specify the first threshold, or the terminal device may preconfigure the first threshold.

[0028] For another example, the second network device may send a measurement result of at least one uplink reference signal, and the measurement result of the first uplink reference signal belongs to the measurement result of the at least one uplink reference signal. For example, the first indication information includes the measurement result of the first uplink reference signal. The uplink reference signals associated with these measurement results indicated by the second network device can all be used for random access, and the terminal device can arbitrarily select a measurement result (e.g., an uplink reference signal) from the measurement result of the at least one uplink reference signal, and the uplink reference signal associated with the measurement result is used for random access.

[0029] In one possible implementation, the terminal device may determine the uplink reference signal associated with an uplink reference signal based on a measurement result of the measurement result. For example, the first indication information also includes a resource index of the uplink reference signal associated with the measurement result (such as a resource identifier and / or resource set identifier of the uplink reference signal), and then the terminal device determines the uplink reference signal based on the resource index of the uplink reference signal.

[0030] In another possible implementation, the first indication information may not include a resource index of an uplink reference signal (such as a resource identifier and / or a resource set identifier of the uplink reference signal), so that the terminal device can infer an uplink reference signal associated with a measurement result based on some other information. For example, the terminal device sends three uplink reference signals, the first indication information includes the measurement results associated with the three uplink reference signals, and the order of the three measurement results in the message carrying the first indication information is consistent with the order of the three uplink reference signals sent by the terminal device, so that the terminal device can infer the uplink reference signal associated with the measurement result based on the order of the measurement results included in the first indication information.

[0031] In one possible implementation, the terminal device sends a preamble code based on the downlink timing of the third network device, the first network device initiated by the terminal device for random access is different from the third network device, the third network device is the same as or different from the second network device, and the second network device is the device that sends the first indication information.

[0032] This solution provides a solution for terminal devices to access network devices with limited capabilities, thereby broadening the scope of application of the random access process. For example, if a first network device lacks downlink transmission capabilities or is not configured with downlink transmission-related information, the terminal device cannot send a preamble based on the downlink timing of the first network device. Based on this solution, the terminal device can send a preamble based on the downlink timing of a third network device, thereby achieving access to the first network device.

[0033] In one possible implementation, the terminal device receives information for indicating a third network device. For example, the terminal device receives information for indicating a third network device from a second network device. The information for indicating the third network device may be sent by the second network device or another network device. The information for indicating the third network device and the first indication information may be carried in the same signaling, or may be carried in multiple signalings respectively. In another possible implementation, the terminal device determines the third network device based on the content defined by the protocol. For example, the CC of the third network device may be specified by the protocol to be a primary component carrier (PCC), or the protocol may specify other CCs. For another example, the cell associated with the third network device may be specified by the protocol to be a serving cell, or the protocol may specify other cells.

[0034] In one possible implementation, the terminal device may search for PDCCH in a public search space associated with a third network device or a fourth network device. The terminal device may also receive a random access response based on the first beam. The fourth network device may be different from the third network device, and the fourth network device may also be configured by the second network device. In the embodiment of the present application, an example is given of a terminal device searching for PDCCH in a public search space associated with a third network device. This solution may provide a solution for a terminal device to access a network device with limited capabilities, thereby broadening the scope of application of the random access procedure. For example, the first network device does not have downlink transmission capability or is not configured with downlink transmission-related information, and the terminal device cannot search for PDCCH in the public search space associated with the first network device. Based on this solution, the terminal device can search for PDCCH in the public search space associated with the third network device, thereby providing technical support for successfully receiving a random access response.

[0035] In one possible implementation, the terminal device receives a random access response, which is received through a first beam, and the first beam includes a beam associated with a unified transmission configuration indicator (TCI) state of a third network device or a beam associated with first indication information. In this implementation, the terminal device can receive a random access response after successfully searching for the PDCCH. This solution can provide a solution for the terminal device to access a network device with limited capabilities, thereby broadening the scope of application of the random access process. For example, the first network device does not have downlink transmission capability or is not configured with downlink transmission-related information, and the terminal device cannot receive a random access response based on the beam of the downlink reference signal of the first network device. Based on this solution, the terminal device can receive a random access response based on the first beam, thereby achieving the effect of accessing the first network device.

[0036] In one possible implementation, a terminal device sends first information. The first information includes identification information of the terminal device. The first information may be message (msg) 3 in four-step random access. The first information satisfies at least one of the following conditions: the first information is associated with a first uplink reference signal; or the first information is sent based on downlink timing of a third network device.

[0037] This solution can provide a solution for terminal devices to access network devices with limited capabilities, thereby broadening the scope of application of the random access process. For example, if the first network device does not have downlink transmission capabilities or is not configured with downlink transmission-related information, the terminal device cannot send the first information based on the downlink reference signal of the first network device. Based on this solution, the terminal device can send the first information based on the first uplink reference signal and / or the downlink timing of the third network device, thereby achieving the effect of accessing the first network device.

[0038] In one possible implementation, after the terminal device sends the first information, the terminal device receives the PDCCH based on the second beam, and the second beam includes a beam associated with the unified TCI state of the third network device, a beam associated with the first information, or a beam associated with the first indication information. PDCCH can be regarded as information in msg4 in four-step random access, that is, msg4 can include the PDCCH. In another possible implementation, msg4 also includes a subsequent physical downlink shared channel (physical downlink sharing channel, PDSCH). In another possible implementation, it can be considered that msg4 includes PDSCH but does not include PDCCH.

[0039] This solution can provide a solution for terminal devices to access network devices with limited capabilities, thereby broadening the scope of application of the random access process. For example, if the first network device does not have downlink transmission capabilities or is not configured with downlink transmission-related information, the terminal device cannot receive the PDCCH based on the beam of the downlink reference signal of the first network device. Based on this solution, the terminal device can receive a random access response based on a second beam, which can be a designated beam, or thereby achieve the effect of accessing the first network device.

[0040] In a second aspect, the present application provides a random access method, which is executed by a first network device, which may be a network device or a chip inside the network device.

[0041] In the present application, a first network device receives a preamble code. The preamble code is used to initiate random access and is associated with a first uplink reference signal.

[0042] This solution can provide a solution for terminal devices to access network devices with limited capabilities, thereby broadening the scope of application of the random access process. For example, if the first network device does not have downlink transmission capabilities or is not configured with downlink transmission-related information (the relevant content can be found in the relevant description of the first aspect above and will not be repeated here), based on the solution provided by this application, the first network device receives a preamble code, and the first network device sends second information to the second network device to trigger the second information to send a random access response, thereby allowing the terminal device to access the first network device based on the random access process.

[0043] In one possible implementation, the first network device sends second information to the second network device, where the second information indicates that the first network device has received a preamble. Thus, the second information can trigger the second network device to send a random access response. In some scenarios, the first network device may not send the second information. For example, if the first and second network devices are integrated into a single physical entity and form two CCs, in which case the second network device can send a random access response after the first network device receives the preamble, and the first network device does not need to send the second information.

[0044] In one possible implementation, a first network device receives first information. The first information includes identification information of the terminal device, and the first information satisfies at least one of the following: the first information is associated with a first uplink reference signal; or the first information is transmitted based on the downlink timing of a third network device. In one possible implementation, after the first network device receives the first information, the first network device transmits third information to the second network device, where the third information indicates that the first network device has received the first information.

[0045] This solution can provide a solution for terminal devices to access network devices with limited capabilities, thereby broadening the scope of application of the random access process. For example, if a first network device does not have downlink transmission capabilities or is not configured with downlink transmission-related information, based on the solution provided in this application, the first network device receives a preamble, and the first network device sends second information to a second network device to trigger the second information to send a random access response. Furthermore, the first network device receives the first information and triggers the second network device to send a PDCCH, thereby enabling the terminal device to access the first network device based on the four-step random access process.

[0046] The preamble is associated with the first uplink reference signal. For related solutions, please refer to the description of possible implementations in the first aspect above. For related introductions to the first network device and the second network device, please refer to the description of possible implementations in the first aspect above.

[0047] In a third aspect, the present application provides a random access method, which is executed by a second network device, which may be a network device or a chip inside the network device.

[0048] In the present application, the second network device sends first indication information, the first indication information is used to indicate a first uplink reference signal. The first uplink reference signal is used to associate with a preamble code for initiating random access. The second network device sends a random access response based on the second information.

[0049] This solution can provide a solution for a terminal device to access a network device with limited capabilities, thereby broadening the scope of application of the random access process. For example, the first network device does not have downlink transmission capabilities or is not configured with downlink transmission-related information (the relevant content can be found in the relevant description of the first aspect above, which will not be repeated here). Based on the solution provided by this application, the second network device sends a first indication information to associate the preamble sent by the terminal device with the first uplink reference signal, and then the first network device receives the preamble, and the first network device sends a second information to the second network device to trigger the second information to send a random access response, so that the terminal device accesses the first network device based on the random access process.

[0050] In one possible implementation, the second network device receives second information from the first network device, where the second information indicates that the first network device has received a preamble. Thus, the second information can trigger the second network device to send a random access response. In some scenarios, the first network device may not send the second information. For example, if the first network device and the second network device are integrated into a single physical entity, forming two CCs, in which case the second network device can send a random access response after the first network device receives the preamble, without the first network device needing to send the second information.

[0051] In one possible implementation, the second network device sends second indication information. The second indication information is used to indicate at least one of the following: the first network device to which the terminal device initiates random access does not have downlink transmission capabilities; the signal type referenced by the random access initiated by the terminal device is an uplink reference signal; or the first network device to which the terminal device initiates random access may not be configured with downlink transmission-related information. For related beneficial effects, please refer to the relevant description of the possible implementations of the first aspect above and will not be repeated here.

[0052] In one possible implementation, the second network device sends (e.g., to the terminal device) information indicating the first network device, and the information indicating the first network device is used to indicate the first network device. The first network device is the network device that the terminal device initiates random access, and the information indicating the first network device includes identification information of the cell associated with the first network device. For example, when the cells associated with the first network device and the second network device are different serving cells, the information indicating the first network device includes identification information of the serving cell associated with the first network device. For related beneficial effects, please refer to the relevant description of the possible implementation methods of the first aspect above, and will not be repeated here.

[0053] In one possible implementation, the second network device sends information indicating a preamble, and determines the preamble based on the information indicating a preamble. For related beneficial effects, reference may be made to the description of the possible implementation in the first aspect above, which will not be repeated here.

[0054] In one possible implementation, the second network device sends mask information of a random access channel, where the mask information of the random access channel indicates a random access timing of the preamble. For related beneficial effects, reference may be made to the description of the possible implementations in the first aspect above, which will not be repeated here.

[0055] In one possible implementation, the second network device transmits information for instructing a third network device. The third network device is configured to cause the terminal device to transmit a preamble based on the downlink timing of the third network device. The first network device from which the terminal device initiates random access is different from the third network device, the third network device is the same as or different from the second network device, and the second network device is the device that transmits the first indication information. For related beneficial effects, please refer to the description of possible implementations of the first aspect above and will not be elaborated upon.

[0056] In a possible implementation, the second network device sends information for instructing the third network device. For related beneficial effects, reference may be made to the description of the possible implementation in the first aspect above, which will not be repeated here.

[0057] In one possible implementation, the third network device is further configured to: cause the terminal device to search for a PDCCH in a common search space associated with the third network device, and receive a random access response based on a first beam, where the first beam includes a beam associated with a unified TCI state of the third network device or a beam associated with the first indication information. For related beneficial effects, refer to the description of possible implementations in the first aspect above and are not further elaborated upon.

[0058] In one possible implementation, the second network device receives third information, where the third information indicates that the first network device has received first information, where the first information includes identification information of the terminal device. The second network device transmits a PDCCH based on a second beam, where the second beam includes a beam associated with a unified TCI state of the third network device, a beam associated with the first information, or a beam associated with the first indication information. For related beneficial effects, please refer to the description of possible implementations of the first aspect above and will not be repeated here.

[0059] The preamble is associated with the first uplink reference signal. For related solutions, refer to the description of possible implementations in the first aspect above and are not repeated here. For the introduction of the first network device and the second network device, refer to the description of possible implementations in the first aspect above and are not repeated here. For the introduction of the first indication information, refer to the description of possible implementations in the first aspect above and are not repeated here.

[0060] In a fourth aspect, a communication device is provided, which may be the aforementioned terminal device, the first network device, or the second network device. The communication device may include a communication unit and a processing unit to perform any of the above-mentioned first to third aspects, or to perform any possible implementation of the first to third aspects. The communication unit is used to perform functions related to sending and receiving. The communication unit may be referred to as a transceiver unit. Optionally, the communication unit includes a receiving unit and a sending unit. In one design, the communication device is a communication chip, the processing unit may be one or more processors or processor cores, and the communication unit may be an input / output circuit, an input / output interface, or an antenna port of the communication chip.

[0061] In another design, the communication unit may be a transmitter and a receiver, or the communication unit may be a transmitter and a receiver.

[0062] Optionally, the communication device further includes modules that can be used to execute any one of the first to third aspects above, or execute any possible implementation of the first to third aspects.

[0063] In a fifth aspect, a communication device is provided, which may be the aforementioned terminal device, the first network device, or the second network device. The communication device may include a processor and a memory to perform any of the above-mentioned aspects 1 to 3, or any possible implementation of the above-mentioned aspects 1 to 3. Optionally, it further includes a transceiver, the memory is used to store a computer program or instruction, and the processor is used to call and execute the computer program or instruction from the memory. When the processor executes the computer program or instruction in the memory, the communication device performs any of the above-mentioned aspects 1 to 3, or any possible implementation of the above-mentioned aspects 1 to 3.

[0064] Optionally, there are one or more processors and one or more memories.

[0065] Optionally, the memory may be integrated with the processor, or the memory may be provided separately from the processor.

[0066] Optionally, the transceiver may include a transmitter (transmitter) and a receiver (receiver).

[0067] In a sixth aspect, a communication device is provided, which may be the aforementioned terminal device, the first network device, or the second network device. The communication device may include a processor to execute any of the aforementioned aspects from the first to the third aspect, or any possible implementation of the aspects from the first to the third aspect. For example, the processor executes any of the aforementioned aspects from the first to the third aspect, or any possible implementation of the aspects from the first to the third aspect, through a logic circuit or by executing a computer program or instruction in a memory. The processor is coupled to the memory. Optionally, the communication device also includes a memory. Optionally, the communication device also includes a communication interface, and the processor is coupled to the communication interface.

[0068] In one implementation, when the communication device is a terminal device, a first network device, or a second network device, the communication interface may be a transceiver or an input / output interface. Alternatively, the transceiver may be a transceiver circuit. Alternatively, the input / output interface may be an input / output circuit.

[0069] In another implementation, when the communication device is a chip or a chip system, the communication interface may be an input / output interface, an interface circuit, an output circuit, an input circuit, a pin, or related circuits on the chip or chip system. The processor may also be embodied as a processing circuit or a logic circuit.

[0070] In a seventh aspect, a system is provided, which includes the above-mentioned terminal device.

[0071] In a possible implementation, the system may further include a first network device and / or a second network device.

[0072] In an eighth aspect, a computer program product is provided, which includes: a computer program (also referred to as code, or instructions), which, when executed, enables a computer to execute any one of the above-mentioned first to third aspects, or any possible implementation of the first to third aspects.

[0073] In the ninth aspect, a computer-readable storage medium is provided, which stores a computer program (also referred to as code, or instructions). When the computer program is run on a computer, the computer executes any one of the above-mentioned first to third aspects, or executes any possible implementation of the first to third aspects.

[0074] In a tenth aspect, a processing device is provided, comprising: an interface circuit and a processing circuit. The interface circuit may include an input circuit and an output circuit. The processing circuit is configured to receive signals via the input circuit and transmit signals via the output circuit, thereby implementing any of the first to third aspects above, or any possible implementation of the first to third aspects.

[0075] In a specific implementation, the processing device may be a chip, the input circuit may be an input pin, the output circuit may be an output pin, and the processing circuit may be a transistor, a gate circuit, a trigger, or various logic circuits. The input signal received by the input circuit may be, for example, but not limited to, received and input by a receiver, and the signal output by the output circuit may be, for example, but not limited to, output to and transmitted by a transmitter. The input circuit and the output circuit may be the same circuit, which functions as an input circuit and an output circuit at different times. This application does not limit the specific implementation of the processor and various circuits.

[0076] In one implementation, when the communication device is a terminal device, a first network device, or a second network device, the interface circuit may be a radio frequency processing chip in the terminal device, the first network device, or the second network device, and the processing circuit may be a baseband processing chip in the terminal device, the first network device, or the second network device.

[0077] In another implementation, the communication device may be a component of a terminal device, the first network device, or the second network device, such as an integrated circuit product such as a system-on-chip (SoC) or a communication chip. The interface circuit may be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip or chip system. The processing circuit may be a logic circuit on the chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] FIG1 is a schematic diagram of a communication system architecture;

[0079] FIG2 is a schematic diagram of a possible flow chart of a random access method provided in an embodiment of the present application;

[0080] FIG3 is a possible flowchart of another random access method provided in an embodiment of the present application;

[0081] FIG4 is a possible flowchart of another random access method provided in an embodiment of the present application;

[0082] FIG5 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0083] FIG6 is another schematic diagram of the structure of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0084] Before introducing the present application, some of the terms used in the embodiments of the present application are briefly explained to facilitate understanding by those skilled in the art.

[0085] (1) Reference signal.

[0086] The reference signals in the embodiments of the present application include uplink reference signals and downlink reference signals. An uplink reference signal refers to a signal sent by a terminal device, such as a signal sent by a terminal device to a network device via an uplink. A downlink reference signal refers to a signal sent by a network device, such as a signal sent by a network device to a terminal device via a downlink.

[0087] In the embodiment of the present application, the reference signal may include (or be) a channel state information reference signal (CSI) reference signal (RS), a synchronization signal block (SSB), a synchronization signal / physical broadcast channel block (SS / PBCH block), a demodulation reference signal (DMRS), or a tracking reference signal (TRS), a phase tracking reference signal (PTRS) or a cell reference signal (CRS). The downlink reference signal may include (or be) at least one of these reference signals. In the embodiment of the present application, the SSB and the SS / PBCH block may be replaced with each other.

[0088] The uplink reference signal may include (or be) a sounding reference signal (SRS), etc.

[0089] (2) Resources.

[0090] The resources in the embodiments of the present application may include, for example, at least one of time domain resources or frequency domain resources.

[0091] Time domain resources may include at least one of a radio frame, a subframe, a time slot, a mini slot, or an orthogonal frequency division multiplexing (OFDM) symbol. A radio frame may include multiple subframes, a subframe may include one or more time slots, and a time slot may include at least one symbol. Alternatively, a radio frame may include multiple time slots, and a time slot may include at least one symbol. It should be noted that in the embodiments of the present application, an OFDM symbol may also be referred to as a symbol.

[0092] Frequency domain resources may include at least one of a resource element (RE), a resource block (RB), a channel, a subchannel, a carrier, or a bandwidth part (BWP). In this embodiment of the present application, a channel may be equivalently replaced by a resource block set (RB set), and the frequency domain bandwidth of an RB set may be 20 megahertz (MHz).

[0093] (3) Beam.

[0094] The embodiment of the beam in the new radio (NR) protocol can be a spatial domain filter, or a spatial filter, or a spatial domain parameter, a spatial parameter, a spatial domain setting, a spatial setting, or quasi-colocation (QCL) information, QCL assumption, QCL indication, etc. The beam can be indicated by a transmission configuration indicator state (TCI-state) parameter, or by a spatial relationship parameter. The TCI-state in the embodiment of the present application can also be recorded as TCI state. TCI is the English abbreviation for transmission configuration indicator (TCI).

[0095] Therefore, in this application, beam can be replaced by spatial filter, spatial filter, spatial parameter, spatial parameter, spatial setting, spatial setting, QCL information, QCL assumption, QCL indication, TCI-state (downlink TCI-state, uplink TCI-state), spatial relationship, etc. The above terms are also equivalent to each other. Beam can also be replaced by other terms representing beams, which are not limited in this application.

[0096] A beam used to transmit a signal may be referred to as a transmission beam (Tx beam), or may be referred to as a spatial domain transmission filter, a spatial transmission filter, a spatial domain transmission parameter or a spatial transmission parameter, a spatial domain transmission setting or a spatial transmission setting. A downlink transmit beam may be indicated by a TCI-state. In the present application, any two of the transmit beam, downlink beam, channel status information reference signal (CSI-RS), TCI-state, downlink (DL) / joint transmission configuration indication state (joint TCI state), synchronization signal-broadcast channel measurement resource block (SSB), synchronization signal block (SSB), or tracking reference signal (TRS) may be replaced with each other. In the embodiment of the present application, the downlink / joint configuration transmission indication information may also be recorded as DL or joint TCI state, or as DL / joint TCI state.

[0097] The beam used to receive signals can be called a reception beam (Rx beam), and can also be called a spatial domain reception filter, a spatial reception filter, a spatial domain reception parameter, or a spatial reception parameter, a spatial domain reception setting, or a spatial reception setting. The uplink transmit beam can be indicated by a spatial relationship, an uplink TCI-state, or an SRS resource (indicating the transmit beam using the SRS). Therefore, the uplink beam can also be replaced by an SRS resource.

[0098] In this application, any two of the receive beam, uplink beam, uplink transmission configuration indication state (UL TCI state) (where UL is the abbreviation for uplink (UL)), DL or joint TCI state, sounding reference signal (SRS), CSI-RS, SSB, or TRS can be replaced with each other.

[0099] The transmit beam may refer to the distribution of signal strength in different directions in space after the signal is transmitted by the antenna, and the receive beam may refer to the distribution of signal strength in different directions in space of the wireless signal received from the antenna.

[0100] Furthermore, the beam can be a wide beam, a narrow beam, or other types of beams. The beam forming technology can be beamforming technology or other technologies. The beamforming technology can specifically be digital beamforming technology, analog beamforming technology, or hybrid digital / analog beamforming technology.

[0101] Beams are generally associated with resources. For example, during beam measurement, network equipment uses different resources to measure different beams. The terminal device then provides feedback on the measured resource quality, allowing the network equipment to determine the quality of the associated beam. During data transmission, beam information is also indicated by its associated resources. For example, the network equipment uses the TCI field in the downlink control information (DCI) to indicate physical downlink shared channel (PDSCH) beam information to the terminal device.

[0102] Optionally, multiple beams with the same or similar communication characteristics can be considered a single beam. A beam can include one or more antenna ports for transmitting data channels, control channels, and sounding signals. The one or more antenna ports forming a beam can also be considered an antenna port set.

[0103] In the embodiments of the present application, unless otherwise specified, a beam refers to a transmission beam of a network device. In beam measurement, each beam of a network device is associated with a resource, so the resource index can be used to uniquely identify the beam associated with the resource.

[0104] (4)TCI-state (used to indicate the downlink beam).

[0105] Network devices can generate different beams pointing in different transmission directions. During downlink data transmission, when a network device uses a specific beam to send data to a terminal device, it must inform the terminal device of the transmit beam information it uses. This allows the terminal device to use the receive beam associated with that transmit beam to receive the data sent by the network device.

[0106] In the 3GPP R15 / R16 protocol, the network device uses the TCI field in the DCI to indicate to the terminal device the relevant information of the transmission beam it adopts. Specifically, the TCI field size is 3 bits, which can specifically represent 8 different field values ​​(codepoints). Each value of the TCI field is associated with a TCI-state index, and the TCI-state index can uniquely identify a TCI-state. The TCI-state in the embodiment of the present application can also be written as TCI state. TCI-state includes several parameters, and the relevant information of the transmission beam can be determined by these parameters. TCI-state is configured by the network device to each terminal device, and the structure of TCI-state is shown in Figure 1. Each TCI-state includes its own index TCI-state identifier, and two QCL information (QCL information, QCL-Info). Each QCL-Info includes a cell field and a bandwidth (bandwidth part, bwp) identifier, which respectively indicate which bandwidth of which cell the TCI-state is applied to, that is, different cells or different bandwidths of the same cell can be configured with different QCL-Info. QCL-Info also includes a reference signal, which is used to indicate which reference signal resource constitutes the QCL relationship.

[0107] In the R15 / R16 protocols, the word "beam" generally does not appear directly; it is usually replaced by other terms. For example, in data transmission and channel measurement, beams are associated with reference signal resources, with one beam associated with one reference signal resource. Therefore, when we say which reference signal resource forms a QCL relationship, we are actually referring to which beam forms a QCL relationship. A QCL relationship means that two reference signal resources (or two antenna ports, where antenna ports and reference signal resources are also associated one-to-one) have certain identical spatial parameters. Which spatial parameters are identical depends on the type of the QCL-Info, i.e., another field of the QCL-Info, qcl-Type. qcl-Type can have four values ​​{typeA, typeB, typeC, typeD}. Taking typeD as an example, typeD indicates that the two reference signal resources have the same spatial reception parameter information, i.e., the two beams have the same receive beam. At most one of the two QCL-Info included in the TCI-state can be TypeD.

[0108] (5) Spatial relation (used to indicate uplink beam).

[0109] In the current protocol, the transmit beam for uplink transmission is indicated by spatial relationships, which functions similarly to TCI-state, and is used to inform the terminal device which transmit beam to use for uplink transmission.

[0110] The spatial relationship also needs to be configured through radio resource control (RRC) signaling first. RRC signaling may include the identity (ID) of the spatial relationship, cell ID, target reference signal resource, path loss measurement reference signal, power control parameters, etc. Among them, the target reference signal resource (which may be one of SRS / SSB / CSI-RS) is used to indicate the associated uplink beam. If the uplink transmission adopts spatial relationship #1, and the spatial relationship #1 includes a target reference signal resource #2, it means that the transmission beam used for the uplink transmission is the transmission / reception beam of the target reference signal. For example, when the target reference signal resource is the uplink resource SRS, it means that the transmission beam used for the uplink transmission is the transmission beam of the SRS (the transmission beam of the SRS is known). For another example, the target reference signal resource is a downlink resource such as SSB / CSI-RS, which means that the transmission beam used for the uplink transmission is the reception beam of the SSB / CSI-RS (the reception beam of the SSB / CSI-RS is known).

[0111] The network device can configure multiple spatial relationships for the terminal device. Then one of them is activated for associated data transmission through the media access control control element (MAC CE). Uplink transmission includes the physical uplink control channel (PUCCH), SRS, physical uplink shared channel (PUSCH), etc., all of which require associated spatial relationships. The spatial relationship of PUCCH is indicated by MAC CE signaling. The spatial relationship of SRS is also indicated by MAC CE signaling. When PUSCH is transmitted, it will be associated with a specific SRS and use the spatial relationship of the SRS for transmission.

[0112] (6)TCI.

[0113] TCI, also known as TCI state (can be written as TCI-state or TCI state in English). In uplink and downlink transmission, the correct beam needs to be used between the network device and the terminal device to achieve correct transmission. In downlink transmission, the network device needs to indicate to the terminal device the downlink transmission beam it uses. The terminal device can determine the appropriate receiving beam based on the downlink transmission beam, and the receiving beam is used to receive information from the network device. In uplink transmission, the network device also needs to indicate to the terminal device which uplink transmission beam the terminal device uses to send information to the network device. The network device can determine the uplink transmission beam with better signal quality for the terminal device. Both the uplink transmission beam and the downlink transmission beam can be indicated by the corresponding TCI state. Specifically, the downlink transmission beam can be indicated by the downlink TCI state, and the uplink transmission beam can be indicated by the uplink TCI state.

[0114] In the 3GPP protocol, the network device can indicate the TCI state to the terminal device through the TCI field in the downlink control information (DCI). The size of the TCI field is 3 bits and can be specifically expressed as 8 different field values ​​(codepoints). Each field value of the TCI field can be associated with an index of a TCI state. The index of the TCI state can uniquely identify a TCI state, and the TCI state can be a downlink TCI state or an uplink TCI state. Each field value of the TCI field can also be associated with two TCI state indexes, and the two TCI state indexes can uniquely identify two TCI states, and the two TCI states can include a downlink TCI state and an uplink TCI state.

[0115] The downlink TCI state includes several parameters that allow the terminal device to determine the relevant information of the downlink transmit beam and thus determine the appropriate receive beam to receive information from the network device. The TCI state is configured by the network device for each terminal device. The structure of the downlink TCI state is as follows:

[0116] Each TCI state includes its own index (TCI-state ID) and two quasi-colocation information (QCL-info). Each QCL-info includes a reference signal resource, which is used to indicate that the downlink transmission of the TCI state should use the same downlink timing, frequency offset or receiving beam as the reference signal resource. It is specifically determined by the type of the QCL-info. The QCL type can have four values ​​{typeA, typeB, typeC, typeD}. When the QCL type is typeA, typeB and typeC, the downlink transmission should be carried out using the same downlink timing and frequency offset as the reference signal resource. When the QCL type is typeD, the downlink transmission should be carried out using the same receiving beam as the reference signal resource. Of the two QCL-infos mentioned above, one is of typeD and the other is of typeA or typeB or typeC. The terminal device can determine which receiving beam to use to receive the corresponding downlink transmission through the QCL-info of typeD. The specific execution steps are as follows:

[0117] The network device indicates a downlink TCI state to the terminal device through DCI. The terminal device determines that the type of the downlink TCI state is the reference signal resource in the QCL information of typeD. The terminal device uses the receiving beam of the reference signal resource as the receiving beam used for downlink transmission. It should be noted that the receiving beam of the reference signal resource is obtained by the terminal device in advance through the beam management process. Through the beam management process, the terminal device can determine which receiving beam is best to receive the reference signal resource, and use the receiving beam as the receiving beam of the reference signal resource.

[0118] The uplink TCI state includes a reference signal resource, which is used to indicate that the uplink transmission using this TCI state should use the same uplink transmit beam as the reference signal resource. The terminal device can determine which transmit beam to use for uplink transmission through this reference signal resource. In the uplink TCI state, the reference signal resource is not included in the QCL-info, and the QCL type is not distinguished, because there is no need to refer to the uplink timing and frequency offset information, only the uplink transmit beam. The structure of the uplink TCI state is shown below:

[0119] For example, the network device indicates a certain uplink TCI state to the terminal device through DCI. The terminal device determines the reference signal resource in the uplink TCI state. The terminal device uses the transmit beam of the reference signal resource as the transmit beam used by the terminal device for uplink transmission. It should be noted that the transmit beam of the reference signal resource is obtained in advance by the terminal device through the beam management process.

[0120] The following describes the configuration, activation and indication of TCI status.

[0121] TCI-state configuration: The network device configures multiple TCI-states to the terminal device through RRC signaling. These TCI-states all include a QCL-Info of type D. The network device can also configure TCI-states that do not include QCL-info of type D. However, these TCI-states are not used to indicate data transmission beams and are not further explained here.

[0122] TCI-state activation: After a network device is configured with multiple TCI-states, it must activate eight of them through a MAC CE. These eight TCI-states correspond one-to-one to the eight values ​​of the TCI field in the DCI. That is, the MAC CE determines which TCI-states correspond to the eight values ​​of the TCI field in the DCI.

[0123] TCI state indication: The network device indicates a specific TCI-state through the TCI field in the DCI. For example, the value of the TCI field in the DCI sent by the network device to the terminal device is 000, indicating that the data transmission beam adopts the TCI state corresponding to 000. The reference signal contained in the QCL-Info of type D in this TCI state is the channel state information-reference signal (CSI-RS) with an index of #1, indicating that the beam used for data transmission is the same as the receiving beam corresponding to the CSI-RS with an index of #1. The receiving beam corresponding to the CSI-RS with an index of #1 can be determined through the beam measurement process and is known to the terminal device. Therefore, through the specific value of the TCI field, the terminal device can determine the beam corresponding to the data transmission beam, and thus adopt the corresponding beam to send or receive data.

[0124] In this article, the three descriptions of TCI state, TCI-state and TCI state can be used interchangeably.

[0125] TCI mode: includes joint mode and separate mode. The joint mode means that the uplink transmission and downlink transmission between the TRP (i.e., the network device) and the terminal device use the same beam or TCI state. The separate mode means that the uplink transmission between the TRP and the terminal device and the downlink transmission between the TRP and the terminal device use different beams or TCI states. In this application, the network device can be a TRP or a device containing one or more TRPs. In the joint mode, the TCI state can be called a joint TCI state (JointTCI-State), and the joint TCI state can be used for uplink and downlink transmission. In the separate mode, the TCI state used for downlink transmission can be called a downlink TCI state (dl-TCI-State), and the TCI state used for uplink transmission can be called an uplink TCI state (ul-TCI-State).

[0126] In this application, TCI can be translated as transmission configuration indicator or transmission configuration number. The English translation of transmission configuration indicator is transmission configuration indicator or transmission configuration indication.

[0127] Figure 1 exemplarily shows an architectural diagram of a communication system 1000 applicable to an embodiment of the present application. As shown in Figure 1, Figure 1 is a schematic diagram of the architecture of the communication system 1000 applicable to an embodiment of the present application. As shown in Figure 1, the communication system includes a radio access network (RAN) 100 and a core network 200. Optionally, the communication system 1000 may also include the Internet 300. The RAN 100 includes at least one RAN node (such as 110a and 110b in Figure 1, collectively referred to as 110), and may also include at least one terminal (such as 120a-120j in Figure 1, collectively referred to as 120). The RAN 100 may also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in Figure 1). The terminal 120 is connected to the RAN node 110 via a wireless method, and the RAN node 110 is connected to the core network 200 via a wireless or wired method. The core network devices in the core network 200 and the RAN nodes 110 in the RAN 100 may be independent and distinct physical devices, or they may be a single physical device that integrates the logical functions of the core network devices and the logical functions of the RAN nodes. Terminals and RAN nodes may be connected to each other via wired or wireless means.

[0128] RAN100 may be an evolved universal terrestrial radio access (E-UTRA) system, a NR system, or a future radio access system defined in the 3rd Generation Partnership Project (3GPP). RAN100 may also include two or more of the aforementioned different radio access systems. RAN100 may also be an open RAN (O-RAN).

[0129] The network equipment involved in the embodiments of the present application may be a RAN node. A RAN node, also known as a radio access network device, a RAN entity or an access node, is used to help a terminal access a communication system wirelessly. In one application scenario, a RAN node may be a base station, an evolved NodeB (eNodeB), a TRP, a next generation NodeB (gNB) in a fifth generation (5G) mobile communication system, a next generation base station in a sixth generation (6G) mobile communication system, or a base station in a future mobile communication system. A RAN node may be a macro base station (such as 110a in FIG1 ), a micro base station or an indoor station (such as 110b in FIG1 ), or a relay node or a donor node.

[0130] In another application scenario, multiple RAN nodes can collaborate to help terminals achieve wireless access, with different RAN nodes implementing portions of the base station's functions. For example, a RAN node can be a centralized unit (CU), a distributed unit (DU), or a radio unit (RU). The CU implements the base station's radio resource control protocol and packet data convergence protocol (PDCP) functions, as well as the service data adaptation protocol (SDAP) functions. The DU implements the base station's radio link control layer and medium access control (MAC) layer functions, as well as some or all of the physical layer functions. For detailed descriptions of each of the above protocol layers, please refer to the relevant 3GPP technical specifications. The RU can be used to implement the transmission and reception of radio frequency signals. The CU and DU can be two independent RAN nodes, or they can be integrated into the same RAN node, such as in a baseband unit (BBU). The RU can be included in radio frequency equipment, such as a remote radio unit (RRU) or an active antenna unit (AAU). The CU can be further divided into two types of RAN nodes: the CU-control plane and the CU-user plane. In the embodiment of the present application, the MAC can also be replaced by the media access control (MAC).

[0131] In different systems, RAN nodes may have different names. For example, in an O-RAN system, CU may be called an open CU (open CU, O-CU), DU may be called an open DU (open DU, O-DU), and RU may be called an open RU (open RU, O-RU). The centralized unit control plane (central unit control panel, CU-CP) may also be called an open centralized unit control plane (open CU-CP, O-CU-CP), and the centralized unit user plane (central unit user panel, CU-UP) may also be called an open centralized unit user plane (open CU-UP, O-CU-UP). The RAN node in the embodiments of the present application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module. For example, the RAN node may be a server loaded with the corresponding software module. The embodiments of the present application do not limit the specific technology and specific device form adopted by the RAN node. For the convenience of description, the following description takes a base station as an example of a RAN node.

[0132] A terminal is a device with wireless transceiver capabilities that can send signals to a base station or receive signals from a base station. A terminal may also be referred to as a terminal device, user equipment (UE), mobile station, mobile terminal, etc. Terminals can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, etc. A terminal can be a mobile phone, tablet computer, computer with wireless transceiver capabilities, wearable device, vehicle, airplane, ship, robot, robotic arm, smart home device, etc. The embodiments of this application do not limit the specific technology and specific device form adopted by the terminal.

[0133] Base stations and terminals can be fixed or mobile. They can be deployed on land, indoors or outdoors, handheld or vehicle-mounted; on water; or on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of base stations and terminals.

[0134] The roles of base stations and terminals can be relative. For example, the helicopter or drone 120i in Figure 1 can be configured as a mobile base station. To terminals 120j accessing the wireless access network 100 via 120i, terminal 120i is a base station. However, to base station 110a, 120i is a terminal, meaning that communication between 110a and 120i occurs via a wireless air interface protocol. Of course, communication between 110a and 120i can also occur via a base station-to-base station interface protocol. In this case, 120i is also a base station relative to 110a. Therefore, base stations and terminals can be collectively referred to as communication devices. 110a and 110b in Figure 1 can be referred to as communication devices with base station functionality, while 120a-120j in Figure 1 can be referred to as communication devices with terminal functionality.

[0135] Communication between base stations and terminals, between base stations, and between terminals can be carried out through authorized spectrum, unauthorized spectrum, or both. Communication can be carried out through spectrum below 6 gigahertz (GHz), spectrum above 6 GHz, or spectrum below 6 GHz and spectrum above 6 GHz. The embodiments of the present application do not limit the spectrum resources used for wireless communication.

[0136] In the embodiments of the present application, the functions of the base station may also be performed by a module (such as a chip) in the base station, or by a control subsystem that includes the base station functions. The control subsystem that includes the base station functions here may be a control center in the above-mentioned application scenarios such as smart grid, industrial control, smart transportation, and smart city. The functions of the terminal may also be performed by a module (such as a chip or modem) in the terminal, or by a device that includes the terminal functions.

[0137] In this application, a base station sends downlink signals or downlink information to a terminal, and the downlink information is carried on a downlink channel; the terminal sends uplink signals or uplink information to the base station, and the uplink information is carried on an uplink channel. In order to communicate with the base station, the terminal needs to establish a wireless connection with the cell controlled by the base station. The cell with which the terminal has established a wireless connection is called the serving cell of the terminal. When the terminal communicates with the serving cell, it will also be subject to interference from signals in neighboring cells.

[0138] The communication between the access network device and the terminal device may follow a certain protocol layer structure. Exemplarily, the protocol layer structure may include a control plane protocol layer structure and a user plane protocol layer structure. For example, the control plane protocol layer structure may include at least one of the following: a radio resource control (RRC) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, a media access control (MAC) layer, or a physical (PHY) layer. For example, the user plane protocol layer structure may include at least one of the following: a service data adaptation protocol (SDAP) layer, a PDCP layer, an RLC layer, a MAC layer, or a physical layer.

[0139] The access network equipment may include a central unit (CU) and a distributed unit (DU). This design may be referred to as CU and DU separation. Multiple DUs may be centrally controlled by one CU. As an example, the interface between the CU and the DU is referred to as the F1 interface. Among them, the control plane (CP) interface may be F1-C, and the user plane (UP) interface may be F1-U. The embodiments of the present application do not limit the specific names of the interfaces. The CU and the DU may be divided according to the protocol layers of the wireless network: for example, the functions of the PDCP layer and the protocol layers above (such as the RRC layer and the SDAP layer, etc.) are set in the CU, and the functions of the protocol layers below the PDCP layer (such as the RLC layer, the MAC layer and the PHY layer, etc.) are set in the DU; for another example, the functions of the protocol layers above the PDCP layer are set in the CU, and the functions of the protocol layers below the PDCP layer are set in the DU, without limitation.

[0140] The above division of the processing functions of CU and DU according to the protocol layer is only an example, and they can also be divided in other ways. For example, the CU or DU can be divided into functions with more protocol layers, and the CU or DU can be divided into partial processing functions with protocol layers. For example, some functions of the RLC layer and the functions of the protocol layers above the RLC layer are set in the CU, and the remaining functions of the RLC layer and the functions of the protocol layers below the RLC layer are set in the DU. For another example, the functions of the CU or DU can be divided according to the service type or other system requirements, such as division by delay, and the functions whose processing time needs to meet the delay requirements are set in the DU, and the functions that do not need to meet the delay requirements are set in the CU.

[0141] Optionally, the CU may have one or more functions of the core network.

[0142] Optionally, the radio unit (RU) of the DU can be remotely located. The RU has radio frequency functions. Exemplarily, the DU and RU can be divided at the PHY layer. For example, the DU can implement high-layer functions in the PHY layer, and the RU can implement low-layer functions in the PHY layer. When used for transmission, the functions of the PHY layer may include at least one of the following: adding cyclic redundancy check (CRC) bits, channel coding, rate matching, scrambling, modulation, layer mapping, precoding, resource mapping, physical antenna mapping, or radio frequency transmission functions. When used for reception, the functions of the PHY layer may include at least one of the following: CRC check, channel decoding, rate matching, descrambling, demodulation, layer demapping, channel detection, resource demapping, physical antenna demapping, or radio frequency reception functions. The high-layer functions in the PHY layer may include a portion of the functions of the PHY layer, which is closer to the MAC layer; the low-layer functions in the PHY layer may include another portion of the functions of the PHY layer, such as a portion closer to the radio frequency functions. For example, the high-level functions in the PHY layer may include adding CRC bits, channel coding, rate matching, scrambling, modulation, and layer mapping, and the low-level functions in the PHY layer may include precoding, resource mapping, physical antenna mapping, and radio frequency transmission functions; or, the high-level functions in the PHY layer may include adding CRC bits, channel coding, rate matching, scrambling, modulation, layer mapping, and precoding, and the low-level functions in the PHY layer may include resource mapping, physical antenna mapping, and radio frequency transmission functions. For example, the high-level functions in the PHY layer may include CRC checking, channel decoding, rate matching, decoding, demodulation, and layer matching, and the low-level functions in the PHY layer may include channel detection, resource demapping, physical antenna demapping, and radio frequency reception functions; or, the high-level functions in the PHY layer may include CRC checking, channel decoding, rate matching, decoding, demodulation, layer matching, and channel detection, and the low-level functions in the PHY layer may include resource demapping, physical antenna demapping, and radio frequency reception functions.

[0143] Optionally, the functions of the CU can be further divided, and the control plane and the user plane can be separated and implemented through different entities. The separated entities are the control plane CU entity (i.e., CU-CP entity) and the user plane CU entity (i.e., CU-UP entity). The CU-CP entity and the CU-UP entity can be connected to the DU respectively. In the embodiment of the present application, the entity can be understood as a module or a unit, and its existence can be a hardware structure, a software module, or a hardware structure plus a software module, without limitation.

[0144] Optionally, any one of the above-mentioned CU, CU-CP, CU-UP, DU and RU can be a software module, a hardware structure, or a software module plus a hardware structure, without limitation. The existence forms of different entities can be the same or different. For example, CU, CU-CP, CU-UP and DU are software modules, and RU is a hardware structure. For the sake of brevity, all possible combinations are no longer listed here. These modules and their execution methods are also within the scope of protection of the embodiments of the present application. For example, when the method of the embodiment of the present application is executed by an access network device, it can be specifically executed by at least one of CU, CU-CP, CU-UP or DU.

[0145] Based on the embodiment shown in FIG1 , FIG2 exemplarily shows a possible flow chart of a random access method provided in an embodiment of the present application. The terminal device in FIG2 may be the terminal device shown in FIG1 or a chip inside the terminal device, and the first network device and / or the second network device in FIG2 may be the network device (such as a RAN node, such as a CU or DU) or a chip in a network device (such as a chip in a RAN node, such as a chip in a CU or DU) in FIG1 .

[0146] As shown in Figure 2, the method includes step 201 and step 202. The following is an introduction with reference to Figure 2.

[0147] Step 201: The second network device sends first indication information.

[0148] Correspondingly, the terminal device receives the first indication information.

[0149] The first indication information is used to indicate the first uplink reference signal. The first indication information may, for example, include at least one of a resource identifier of the first uplink reference signal, a resource set identifier of the first uplink reference signal, or a measurement result of the first uplink reference signal. In a possible implementation, the first indication information may be used to indicate a joint / uplink transmission configuration indication state (UL TCI state). The joint / uplink transmission configuration indication state (UL TCI state) in the embodiment of the present application may also be recorded as joint or UL TCI state, or as joint / UL TCI state. Optionally, the terminal device sends a preamble (or sends a random access (random access channel, RACH)) beam with reference to the joint / UL TCI state. For related solutions, please refer to the subsequent description and will not elaborate on it here.

[0150] The first indication information may be carried in DCI.

[0151] Step 202: The terminal device sends a preamble.

[0152] Correspondingly, the first network device receives the preamble.

[0153] The terminal device may initiate random access to the first network device. The first network device is different from the second network device.

[0154] In one possible implementation, the first network device does not have downlink transmission capabilities; and / or the first network device is not configured with information related to downlink transmission. In one possible implementation, the information related to downlink transmission may include at least one of: information related to downlink reference signals, information related to downlink control channel transmission, information related to downlink data channel transmission, information related to downlink frame structure, information related to downlink time slots, or information related to downlink bandwidth. Information related to not configuring downlink reference signals may be replaced by not configuring downlink reference signals. Information related to not configuring downlink control channel transmission may be replaced by not configuring downlink control channel transmission. Information related to not configuring downlink data channel transmission may be replaced by not configuring downlink data channel transmission. Information related to not configuring downlink frame structure may be replaced by not configuring parameters related to downlink frame structure. Information related to not configuring downlink time slots may be replaced by not configuring parameters related to downlink time slots. Information related to not configuring downlink bandwidth may be replaced by not configuring downlink bandwidth.

[0155] In another possible implementation, the first network device has uplink transmission capabilities and / or is configured with uplink transmission-related parameters. The uplink transmission-related parameters may include at least one of an uplink reference signal, uplink control channel transmission, uplink data channel transmission, parameters related to an uplink frame structure, parameters related to an uplink time slot, or an uplink bandwidth.

[0156] The preamble can be associated with the first uplink reference signal, which can be understood as some parameters in the preamble transmission process can refer to the first uplink reference signal. For example, the spatial relationship (or beam) for transmitting the preamble can refer to the spatial relationship (or beam) of the first uplink reference signal, or the spatial relationship (or beam) of the preamble is associated with the spatial relationship (or beam) of the first uplink reference signal. For another example, the path loss reference signal associated with the preamble is the first uplink reference signal. Alternatively, it can be understood that the path loss of the preamble can refer to (or be regarded as) the path loss of the first uplink reference signal.

[0157] In another possible implementation, the terminal device may send a preamble code based on the first uplink reference signal indicated by the first indication information, or send a preamble code based on the joint / UL TCI state indicated by the first indication information, that is, the beam of the preamble code may refer to the beam of the first uplink reference signal indicated in the DCI1_0, or refer to the joint / UL TCI state indicated in the DCI1_0.

[0158] In this embodiment, because the first network device does not have downlink transmission capabilities or is not configured with downlink transmission-related information, the terminal device cannot access the first network device based on the current random access process. However, in the solution provided in the embodiment of the present application, the terminal device can send a preamble code based on the first uplink reference signal and then randomly access the first network device. This solution provides a solution for terminal devices to access network devices with limited capabilities, thereby broadening the scope of application of the random access process.

[0159] The solution provided in the embodiments of the present application is applicable to a variety of random access scenarios. The following is an illustrative introduction of possible flow charts of random access methods in two scenarios, respectively, with Figures 3 and 4 exemplifying the above. In Figure 3, non-contention-free random access (CFRA) is used as an example for introduction, and in Figure 4, contention-based random access (CBRA) is used as an example for introduction. The contents of the terminal device, the first network device, and the second network device involved in Figures 3 and 4 can be found in the relevant introduction of Figure 2 above, and will not be repeated here. The third network device in Figure 2 can be the network device in Figure 1 (such as a RAN node, such as a CU or DU) or a chip in a network device (such as a chip in a RAN node, such as a chip in a CU or DU).

[0160] The following is described in conjunction with Figure 3 . The embodiment shown in Figure 3 includes steps 301, 302, 303, and 304. In a possible implementation, the embodiment shown in Figure 3 also includes steps 305 and 306.

[0161] Step 301: The second network device sends configuration information.

[0162] The configuration information may include one or more of information A1, information A2, information A3, information A4, information A5, information A6, information A7, information A8, or information A9. The content included in the configuration information may be transmitted via a single signaling message or via multiple signaling messages, which is not limited in the embodiments of the present application. In one possible implementation, the configuration information may be carried in radio resource control (RRC) signaling.

[0163] Information A1 is used to indicate information of an uplink reference signal.

[0164] The second network device may be configured with one or more uplink reference signals, and the first uplink reference signal in the embodiment of the present application may be one or more of the one or more uplink reference signals. The information used to indicate the uplink reference signal includes: a resource identifier and / or a resource set identifier of the uplink reference signal. For example, the information used to indicate the uplink reference signal may include a resource identifier and / or a resource set identifier of the first uplink reference signal. In the embodiment of the present application, the resource identifier and / or resource set identifier of the first uplink reference signal may also be replaced with a resource index of the first uplink reference signal.

[0165] Information A2 is used to indicate the information of the preamble code.

[0166] The second network device may be configured with one or more preambles. A preamble may be written as "preamble" in English, or may have other names, such as pilot. The information indicating the preamble may be used to indicate an index of the preamble or pilot.

[0167] In an embodiment of the present application, the preamble may be associated with the first uplink reference signal. In this case, when the terminal device transmits the preamble, the spatial relationship of the preamble may be associated with the first uplink reference signal. Alternatively, it can be understood that the terminal device transmits the preamble with reference to the beam of the first uplink reference signal.

[0168] Information A3 is used to indicate the random access occasion.

[0169] The second network device may configure one or more random access opportunities. The random access opportunity may also be a RACH transmission opportunity (occasion) and / or a PRACH transmission opportunity (occasion). The information used to indicate the random access opportunity may include random access channel mask information, and the random access channel mask information is used to indicate the random access opportunity. The random access channel mask information may include, for example, an index of the random access channel mask.

[0170] Information A4: information about time-frequency resources.

[0171] The information of the time-frequency resources in the embodiment of the present application can be used to indicate the time-frequency resources. The time-frequency resources are used to initiate random access, and the time-frequency resources can be used to transmit signaling in the random access process.

[0172] The information about time-frequency resources may include information about time domain resources and / or information about frequency domain resources. The information about time domain resources may include at least one of a frame number, a subframe number, a starting symbol of a random access opportunity, a PRACH time slot, or the number of random access opportunities in the time domain (e.g., the number of PRACH transmission opportunities in a time slot), which may be configured using a higher-layer parameter (e.g., the parameter prach-ConfigurationIndex). The information about frequency domain resources may include at least one of a frequency domain starting point for transmitting a RACH and the number of random access opportunities in the frequency domain (e.g., the number of PRACH transmission opportunities in the frequency domain).

[0173] Information A5, indicating the association relationship between any multiple items of uplink reference signal, preamble and random access opportunity.

[0174] In the embodiment of the present application, there may be an association relationship between the various parameters configured by the second network device, and the association relationship between the various parameters may be expressed in a table or text form. The second network device may configure (for example, by indicating through some instructions) the association relationship between the uplink reference signal, the preamble, and the random access opportunity.

[0175] In the embodiment of the present application, one random access opportunity may be associated with (or associated with) one uplink reference signal; or one random access opportunity may be associated with multiple uplink reference signals; or multiple random access opportunities may be associated with one uplink reference signal. Similarly, in the embodiment of the present application, one preamble may be associated with (or associated with) one uplink reference signal; or one preamble may be associated with multiple uplink reference signals; or multiple preambles may be associated with (or associated with) one uplink reference signal.

[0176] Information A6, random access resources.

[0177] In an embodiment of the present application, the second network device may also indicate the association relationship between the configured parameters (such as any multiple items of the uplink reference signal, the preamble, and the random access opportunity) in an implicit manner. For example, the second network device sets the parameters with an associated relationship together, for example, the parameters with an associated relationship may be set in a parameter set. In a possible example, the name of the parameter set may be called a random access resource, for example, it may be recorded as CFRA-SRS-resource, and it may also be understood as: the parameters with an associated relationship are set in the same CFRA-SRS-resource.

[0178] The second network device may configure one or more random access resources for the terminal device, and one random access resource may be associated with one resource identifier. For example, the resource identifier may be recorded as CFRA-SRS-resource ID, where ID is the abbreviation of identity.

[0179] One (or each) random access resource (such as CFRA-SRS-resource) may include one or more of information for indicating an uplink reference signal (such as first indication information), information for indicating a preamble, or information for indicating a random access opportunity. The parameters indicated by the information belonging to the same random access resource (such as CFRA-SRS-resource) (at least two of the uplink reference signal, preamble, and random access opportunity) are associated with each other. In this solution, the second network device implicitly indicates the association between the various parameters (part or all of the uplink reference signal, preamble, or random access opportunity), that is, the terminal device believes that the various parameters belonging to the same random access resource have an association relationship, so the second network device no longer needs to separately indicate the association through additional information, thereby saving signaling overhead.

[0180] In the embodiment of the present application, the uplink reference signals in the two random access resources may be different or the same, the preambles in the two random access resources may be the same or different, and the random access timings in the two random access resources may be the same or different. For example, CFRA-SRS-resource#1 includes preamble#1, uplink reference signal#1, and random access timing#1, and CFRA-SRS-resource#2 includes preamble#2, uplink reference signal#2, and random access timing#2. The terminal considers that preamble#1, uplink reference signal#1, and random access timing#1 are associated, and preamble#2, uplink reference signal#2, and random access timing#2 are associated. Preamble#1 and preamble#2 may be the same or different. Uplink reference signal#1 and uplink reference signal#2 may be the same or different. Random access timing#1 and random access timing#2 may be the same or different.

[0181] CFRA-SRS-resource may also include part of the uplink reference signal, the preamble, and part of the parameters in the random access opportunity, and the CFRA-SRS-resource may have an association relationship with the parameters not included. For example, a CFRA-SRS-resource includes information for indicating the preamble and information for indicating the uplink reference signal (such as the first indication information), and may not include information for indicating the random access opportunity. The CFRA-SRS-resource may be associated with one or more random access opportunities. A random access opportunity may be associated (or associated) with one random access resource (such as CFRA-SRS-resource); or one random access opportunity may be associated with multiple random access resources (such as CFRA-SRS-resource); or multiple random access opportunities may be associated with one random access resource (such as CFRA-SRS-resource).

[0182] For another example, a CFRA-SRS-resource includes information for indicating a random access opportunity and information for indicating an uplink reference signal (such as first indication information), but may not include information for indicating a preamble. The CFRA-SRS-resource may be associated with one or more pieces of information for indicating preambles. A preamble may be associated with (or associated with) one random access resource (such as a CFRA-SRS-resource); or one preamble may be associated with multiple random access resources (such as a CFRA-SRS-resource); or multiple preambles may be associated with one random access resource (such as a CFRA-SRS-resource).

[0183] Information A7, quantity information.

[0184] The quantity information may include at least one of the following: the number of random access opportunities associated with an uplink reference signal; the number of uplink reference signals associated with a random access opportunity; the number of preambles associated with an uplink reference signal; or the number of uplink reference signals associated with a preamble. The quantity information may also include at least one of the number of uplink reference signals, the number of random access opportunities, or the number of preambles.

[0185] The first network device can know the beam index of the uplink reference signal used by the terminal device (such as the beam index of the uplink reference signal with the best signal quality) based on the time-frequency domain position of the random access opportunity where the received preamble is located, and the information used to indicate the preamble (such as the index of the preamble). The second network device can configure the relationship between the number of uplink reference signals, the number of random access opportunities and the number of preambles through a parameter (the name of the parameter can be defined by itself, such as the parameter name SRS-perRACH-OccasionAndCB-PreamblesPerSRS). For example, the second network device can associate and map the three to different random access opportunities according to a specific mapping rule. This operation also implicitly indicates the association between the number of uplink reference signals, the number of random access opportunities and the number of preambles.

[0186] Information A8 is used to indicate information of the third network device.

[0187] The third network device may be used to guide the terminal device to transmit information in a random access process, for example, the terminal device may send a preamble based on the downlink timing of the third network device.

[0188] In this embodiment of the present application, the information used to indicate the third network device may include indication information of a cell associated with the third network device and / or indication information of a CC associated with the third network device. In this embodiment of the present application, the identification information of the cell (or CC) of the third network device may also be referred to as identification information of a reference cell (or reference CC). The third network device is a network device with downlink transmission capability.

[0189] Information A9, root sequence index of the preamble code.

[0190] The preamble may be generated by cyclic shifting a root sequence (such as a ZC root sequence). The second network device configures the root sequence of the preamble for the terminal device, and the terminal device may generate one or more preambles according to the root sequence.

[0191] Step 302: The second network device sends fourth information to the terminal device.

[0192] Correspondingly, the terminal device receives the fourth information. The fourth information is used to trigger the terminal device to initiate random access.

[0193] In step 302, the fourth information may be carried in signaling for triggering the terminal device to initiate random access. The signaling may be, for example, DCI format 1_0 or other DCI formats, carried in a PDCCH order, and the PDCCH order may be used to trigger CFRA.

[0194] In the embodiment of the present application, the second network device may further transmit one or more of the following information B1, information B2, information B3, information B4, information B5, information B6, or information B7. The information transmitted by the second network device (one or more of information B1, information B2, information B3, information B4, information B5, information B6, or information B7) may be carried in one or more signaling messages. For example, all or part of the information transmitted by the second network device (one or more of information B1, information B2, information B3, information B4, information B5, information B6, or information B7) may be carried in a PDCCH order.

[0195] Information B1, first indication information.

[0196] The first indication information may be used to indicate a first uplink reference signal. For example, the first indication information may include an identifier and / or a resource set identifier of the first uplink reference signal. For example, if the first uplink reference signal is an SRS, the indication information of the first uplink reference signal may be a resource index of the SRS (e.g., a resource identifier and / or a resource set identifier of the SRS).

[0197] The first uplink reference signal may be an uplink reference signal among a plurality of uplink reference signals configured by the second network device. For related content, please refer to the aforementioned information A1 and will not be described in detail.

[0198] Information B2 is used to indicate the information of the preamble code.

[0199] The information for indicating the preamble is used to indicate the preamble used by the terminal to initiate random access. The information for indicating the preamble may be an index of the preamble.

[0200] The preamble code may be a preamble code among a plurality of preamble codes configured by the second network device. The content of the information B2 may refer to the content of the aforementioned information A2 and will not be described in detail.

[0201] Information B3 is used to indicate the random access opportunity.

[0202] The random access opportunity may refer to an opportunity when the terminal device receives a preamble at a certain specific position on the time-frequency resource. The network device (such as the first network device) may receive the preamble at this opportunity. The information used to indicate the random access opportunity may be a PRACH mask index.

[0203] The random access opportunity may be a random access opportunity among a plurality of random access opportunities configured by the second network device. For the content of the information B3 , reference may be made to the content of the aforementioned information A3 , which will not be described in detail.

[0204] Information B4: identifier of the first random access resource.

[0205] When the terminal device receives the identifier of the first random access resource, it can be considered that this random access needs to be performed based on one or more of the uplink reference signal, preamble, or random access opportunity in the first random access resource. Therefore, the identifier of the first random access resource can also be regarded as (or replaced by): one or more of: first indication information (information B1), information for indicating the preamble (information B2), or information for indicating the random access opportunity (information B3).

[0206] For example, when the terminal device determines that the random access resource used for random access is CFRA-SRS-resource#1, the terminal device refers to the spatial relationship (or beam) of the uplink reference signal indicated by the information used to indicate the uplink reference signal in the CFRA-SRS-resource#1, and sends a preamble code at the random access timing indicated by the information used to indicate the random access timing in the CFRA-SRS-resource#1.

[0207] In another possible implementation, for the parameters in the two random access resources, the terminal device may not identify whether the parameters in the two random access resources are associated, or the terminal device believes that there is no association between the two random access resources. For example, when the terminal device determines to enable the parameters of CFRA-SRS-resource#1, it will look for the preamble code and the uplink reference signal to which the preamble code is referenced from CFRA-SRS-resource#1, and also look for the random access opportunity in the CFRA-SRS-resource#1. However, when the terminal device determines to enable the parameters of CFRA-SRS-resource#1, it will not look for the uplink reference signal associated with the preamble code in CFRA-SRS-resource#1 from other resources (such as CFRA-SRS-resource#2). It can also be understood that the terminal device believes that the preamble code in CFRA-SRS-resource#1 is not associated with the uplink reference signal in CFRA-SRS-resource#2.

[0208] The first random access resource may be one of a plurality of random access resources, such as one of a plurality of random access resources configured for the second network device. The content of information B4 may refer to the content of information A6 above, and will not be described in detail.

[0209] Information B5: Second instruction information.

[0210] The second indication information is used to indicate at least one of the following: the first network device on which the terminal device initiates random access does not have downlink transmission capability; the signal type referenced by the random access initiated by the terminal device is an uplink reference signal; or the first network device on which the terminal device initiates random access is not configured with information related to downlink transmission. In this way, the terminal device can determine, based on the second indication information, that the reference signal that needs to be referenced in the process of initiating random access is an uplink reference signal, not a downlink reference signal. In another possible implementation, when the information configured by the second network device includes both an uplink reference signal and a downlink reference signal, the terminal device can identify which reference signal is used to initiate random access.

[0211] In the embodiment of the present application, the second network device may or may not send the second indication information. When the second network device does not send the second indication information, the terminal device may identify that an uplink reference signal is required to initiate random access through this other method.

[0212] For example, the message received by the terminal device (such as PDCCH order) only includes an uplink reference signal but does not include a downlink reference signal. The terminal device then determines that the uplink reference signal is required to initiate random access this time.

[0213] For another example, if the message received by the terminal device (e.g., a PDCCH order) includes identification information of a cell associated with the first network device, the terminal device determines that the network device initiating the random access is the first network device. The terminal device may also determine, based on other information (e.g., pre-configuration), that the first network device does not have downlink transmission capabilities or is not configured with downlink transmission-related information, and then determine that the random access requires the use of an uplink reference signal.

[0214] Information B6: information indicating the first network device.

[0215] The first network device is the network device to which the terminal device initiates random access. In this way, the terminal device can identify the network device to which random access needs to be initiated based on the identification information of the cell associated with the first network device.

[0216] The information used to indicate the first network device may include, for example: identification information of a cell associated with the first network device, index information of a CC associated with the first network device, and the like.

[0217] On the other hand, the terminal device can pre-configure some parameters of each cell in advance. For example, the terminal device can pre-configure the first network device to have no downlink transmission capability or no downlink transmission-related information. In this way, the terminal device can determine that the reference signal that needs to be referenced in the process of initiating random access is an uplink reference signal, not a downlink reference signal. In this embodiment, since the terminal device can determine that the reference signal that needs to be referenced in the process of initiating random access is an uplink reference signal in combination with the identification information of the cell associated with the first network device, in this embodiment, the second network device does not need to configure the above-mentioned second indication information (i.e., information B5).

[0218] Information B7 is used to indicate information of the third network device.

[0219] The second network device can be configured with multiple third network devices, and the third network device in the information B7 can be a network device among the multiple third network devices. The content of the information B7 can refer to the content of the aforementioned information A8 and will not be repeated here.

[0220] There are many application scenarios for the embodiments of the present application. The following describes several scenarios by way of example through Implementation C1, Implementation C2, and Implementation C3. Implementation C1 uses the inter-cell multiple transmission reception point (inter-cell mTRP) scenario as an example. Implementation C2 uses the intra-cell multiple transmission reception point (intra-cell mTRP) scenario as an example. Implementation C3 uses the carrier aggregation (CA) scenario as an example.

[0221] Implementation method C1, inter-cell mTRP scenario.

[0222] In implementation C1, the cell associated with the first network device is a non-serving cell or the first network device is a cell with a PCI different from that of the serving cell, and the cell associated with the second network device is a serving cell. The non-serving cell in the embodiment of the present application may also be replaced with a cell with a PCI different from that of the serving cell. The serving cell in this implementation may also be replaced with a cell associated with the second network device, and the non-serving cell may also be replaced with a cell associated with the first network device.

[0223] In this implementation C1, the serving cell and the non-serving cell are associated with different physical cell identifiers (PCIs). For the sake of distinction, the PCI of the non-serving cell can be referred to as an additional PCI. The second network device can send a signaling (such as MAC CE TCI state) to the terminal device. If the TCI-state activated by the signaling includes additionalPCI, it indicates that the terminal device is operating in the inter-cell mTRP scenario.

[0224] In implementation C1, cells that only have uplink receiving capability (i.e., do not have downlink transmission capability) or are not configured with downlink transmission-related information (or all) (or cells understood as indicated by additional PCI) are referred to as first cells. A serving cell, a cell with downlink receiving capability, or configured with downlink transmission-related information (or a cell understood as indicated by the PCI of a serving cell) can be referred to as a second cell. In this implementation, the first cell can also be replaced by a cell associated with the first network device, and the second cell can also be replaced by a cell associated with the second network device. In one possible implementation, the embodiment of the present application can be stipulated (or restricted) by a protocol: the serving cell has downlink transmission capability; and / or the serving cell is configured with downlink transmission-related information.

[0225] In implementation C1, the second network device may send signaling (e.g., a PDCCH order) to the terminal device through the second cell (the second cell may also be understood as a cell associated with the second network device, or the second cell may be referred to as the cell of the second network device). The signaling (e.g., a PDCCH order) is used to trigger the terminal device to initiate random access (e.g., CFRA) to the first cell (or the first network device). One or more of the above-mentioned information B1, information B2, information B3, information B4, information B5, or information B6 sent by the second network device to the terminal device may be carried in one signaling (e.g., a PDCCH order) or multiple signalings.

[0226] For example, the DCI1_0 carried by the PDCCH order includes the first indication information, and the beam for the terminal device to send the preamble (or send the RACH) refers to the beam of the first uplink reference signal, or refers to the beam of the first uplink reference signal indicated by the first indication information, or refers to the joint / UL TCI state indicated by the first indication information. Optionally, DCI1_0 is scrambled by a cell-radio network temporary identifier (C-RNTI), and the frequency domain resource assignment field of the DCI1_0 is all 1s.

[0227] There are multiple possible implementations for carrying the first indication information, which are described below using Implementation C1.1 and Implementation C1.2 as examples. For example, the first indication information may be located in a newly added field of the signaling (e.g., DCI1_0) (Implementation C1.1). Another example is the first indication information being located in an existing field of the signaling (e.g., DCI1_0) (Implementation C1.2), such as a field originally used to carry downlink reference signal information.

[0228] In implementation C1.1, the first indication information is located in a newly added field of the signaling (eg, DCI1_0).

[0229] For example, a new field is added to DCI1_0, which is used to carry the first indication information.

[0230] In one possible implementation, DCI1_0 may include first indication information and information indicating a downlink reference signal (e.g., SS / PBCH indication information). DCI1_0 may be used to trigger random access (e.g., CFRA) of the first network device, or may be used to trigger random access (e.g., CFRA) of the second network device. In implementation C1.1, the information used to trigger random access of the first network device may be replaced by information used to trigger random access of the first cell, and the information used to trigger random access of the second network device may be replaced by information used to trigger random access of the second cell.

[0231] When DCI1_0 triggers random access of the first network device, the terminal device may not process the field carrying the downlink reference signal information (such as the SS / PBCH resource index) in DCI1_0, or may consider the field to be meaningless. The terminal device may send a preamble based on the uplink reference signal, that is, the beam of the preamble may refer to the beam of the uplink reference signal in DCI1_0.

[0232] In another possible implementation, the terminal device may send a preamble code based on the first uplink reference signal indicated by the first indication information, or send a preamble code based on the joint / UL TCI state indicated by the first indication information, that is, the beam of the preamble code may refer to the beam of the first uplink reference signal indicated in the DCI1_0, or refer to the joint / UL TCI state indicated in the DCI1_0.

[0233] When DCI1_0 triggers random access of the second network device, the terminal device may not process the field in DCI1_0 that carries the first indication information (such as the SRS resource index) or consider the field to be meaningless. The terminal device may send a preamble based on the downlink reference signal, that is, the beam of the preamble may refer to the beam of the downlink reference signal in DCI1_0.

[0234] In one possible implementation, DCI1_0 may further include information indicating whether the DCI1_0 triggers random access for the first network device or the second network device. The information indicating whether the DCI1_0 triggers random access for the first network device or the second network device may include identification information of a cell associated with the network device (e.g., an identification of a cell associated with the second network device or an identification of a cell associated with the first network device) (see Example 1 below). Alternatively, whether the DCI1_0 triggers random access for the first network device or the second network device may be indicated by second indication information (see Example 2 below). The following two examples illustrate these two aspects.

[0235] Example 1: When DCI1_0 includes the cell identification information associated with the first network device (such as additionalPCI), it can be considered that the DCI1_0 indicates the cell associated with the first network device (such as a non-service cell), and the terminal device processes the field carrying the first indication information in DCI1_0, and does not process the field carrying the information for indicating the downlink reference signal in DCI1_0, and the preamble sent is associated with the first uplink reference signal (or the signaling transmission in the random access process refers to the first uplink reference signal). When DCI1_0 includes the cell identification information associated with the second network device (such as the PCI of the serving cell), it can be considered that the DCI1_0 indicates the cell associated with the second network device (such as the serving cell), and the terminal device processes the field carrying the information for indicating the downlink reference signal in DCI1_0, and does not process the field carrying the first indication information in DCI1_0, and the preamble sent is associated with the downlink reference signal (or the signaling transmission in the random access process refers to the downlink reference signal).

[0236] In a second example, DCI1_0 may include a field whose value indicates whether DCI1_0 triggers random access for the first or second network device. For example, a value of "1" indicates triggering the first network device; a value of "0" indicates triggering the second network device. A value of "1" indicates that DCI1_0 includes the second indication information, while a value of "0" indicates that DCI1_0 does not include the second indication information.

[0237] When DCI1_0 includes the above-mentioned second indication information, the terminal device processes the field carrying the first indication information in DCI1_0, does not process the field carrying the information for indicating the downlink reference signal in DCI1_0, and the preamble sent is associated with the first uplink reference signal (or the signaling transmission in the random access process refers to the first uplink reference signal). When DCI1_0 does not include the above-mentioned second indication information, the terminal device processes the field carrying the information for indicating the downlink reference signal in DCI1_0, does not process the field carrying the first indication information in DCI1_0, and the preamble sent is associated with the downlink reference signal (or the signaling transmission in the random access process refers to the downlink reference signal). The second indication information can be carried in a new field or an existing field (such as a reserved field) of DCI1_0.

[0238] For example, DCI1_0 includes a field with a length of 1. When the field is "1", it can be considered that the DCI1_0 indicates the cell associated with the first network device (for example, a non-service cell) (the bit value "1" on this bit can be regarded as the second indication information), and the terminal device determines that the DCI1_0 triggers the first network device. Therefore, the terminal device processes the field of the indication information of the uplink reference signal (such as the first uplink reference signal) carried in DCI1_0, and does not process the field in DCI1_0 that carries the information used to indicate the downlink reference signal. The preamble code sent by the terminal device is associated with the first uplink reference signal (or the signaling transmission in the random access process refers to the first uplink reference signal). When this field is "0", it can be considered that the DCI1_0 indicates the cell associated with the second network device (for example, the serving cell) (at this time, it can be considered that the DCI1_0 does not include the second indication information), then the terminal device processes the field in DCI1_0 that carries the information for indicating the downlink reference signal, and does not process the field in DCI1_0 that carries the indication information of the uplink reference signal (such as the first uplink reference signal). The preamble code sent by the terminal device is associated with the downlink reference signal (or the signaling transmission in the random access process refers to the downlink reference signal).

[0239] In implementation C1.2, the first indication information is located in an existing field of signaling (eg, DCI1_0).

[0240] In implementation C1.2, the first indication information is located in an existing field of signaling (e.g., DCI1_0). This field may originally be a reserved field of DCI1_0 or a field used to carry a downlink reference signal. The name of this field may or may not be changed later, and this embodiment of the application does not limit this.

[0241] For example, the first indication information and the information for indicating the downlink reference signal multiplex the same field in DCI1_0. When DCI1_0 triggers random access of the first network device, the field carries the first indication information; when DCI1_0 triggers random access of the second network device, the field carries information for indicating the downlink reference signal. In this embodiment, the terminal device can determine whether the random access of the first network device or the second network device needs to be triggered based on whether the signaling carries an uplink reference signal or information for indicating a downlink reference signal. In this embodiment, the second network device does not need to indicate the network device it triggers through additional signaling, and the signaling can only carry one type of reference signal (uplink or downlink), so this solution can save signaling overhead.

[0242] In one possible implementation, the length of the field used to carry the indication information of the uplink reference signal (such as the first uplink reference signal) depends on N SSB The maximum number of SSBs that can be configured for network devices, N SRS The maximum number of SRSs can be configured for network devices. Indicates rounding up, and max(a, b) means taking the maximum value from a and b.

[0243] For example, the first indication information and the information for indicating the downlink reference signal multiplex the same field in DCI1_0, for example, referred to as the first field. When DCI1_0 triggers random access of the first network device, the first field carries the first indication information; when DCI1_0 triggers random access of the second network device, the first field carries information for indicating the downlink reference signal. In this embodiment, the terminal device can determine whether the first field carries the first indication information or the information for indicating the downlink reference signal according to whether the random access of the first network device or the second network device is triggered by the signaling. In this embodiment, the second network device does not need to indicate the network device it triggers through additional signaling, and the signaling can only carry one type of reference signal (uplink or downlink), so this solution can save signaling overhead.

[0244] In a possible implementation manner, the first indication information is used to indicate an uplink reference signal, and the length of the first field depends on N SSB The maximum number of SSBs that can be configured for network devices, N SRS The maximum number of SRSs can be configured for network devices. Indicates rounding up, and max(a, b) means taking the maximum value from a and b.

[0245] In one possible implementation, the first indication information is used to indicate the joint / UL TCI state. The length of the first field depends on N SSB The maximum number of SSBs that can be configured for network devices, N TCI The maximum number of joint / UL TCI states can be configured for network devices. Indicates rounding up, and max(a, b) means taking the maximum value from a and b.

[0246] In implementation C1.2, DCI1_0 may include information indicating whether the DCI1_0 triggers random access for the first network device or the second network device. This information may also be understood as indicating whether the DCI1_0 carries information indicating an uplink reference signal (e.g., first indication information) or information indicating a downlink reference signal. It is understood that when DCI1_0 triggers the first network device, DCI1_0 carries information indicating an uplink reference signal (e.g., first indication information). When DCI1_0 triggers the second network device, DCI1_0 carries information indicating a downlink reference signal. The information indicating whether the DCI1_0 triggers random access for the first network device or the second network device may include identification information of a cell associated with the network device (e.g., an identification of a cell associated with the second network device or an identification of a cell associated with the first network device). Alternatively, whether the DCI1_0 triggers random access for the first network device or the second network device may be indicated by whether the signaling includes the second indication information. For related content, please refer to the relevant descriptions of Example 1 and Example 2 in the aforementioned implementation C1.1, which will not be repeated here.

[0247] In one possible implementation, in implementation C1.2, DCI1_0 may include information indicating whether the DCI1_0 triggers random access for the first network device or the second network device. This information may also be understood as indicating whether the first field in DCI1_0 carries information indicating an uplink reference signal (e.g., first indication information) or a downlink reference signal. This information may also be understood as indicating whether the first field in DCI1_0 carries information indicating a joint / UL TCI state or a downlink reference signal. It is understood that when DCI1_0 triggers the first network device, the first field in DCI1_0 carries information indicating an uplink reference signal or a joint / UL TCI state (e.g., first indication information). When DCI1_0 triggers the second network device, the first field in DCI1_0 carries information indicating a downlink reference signal. The information indicating whether DCI1_0 triggers random access for the first network device or the second network device may include identification information of a cell associated with the network device (e.g., an identification of a cell associated with the second network device or an identification of a cell associated with the first network device). Alternatively, whether the DCI1_0 triggers random access of the first network device or the second network device can be indicated by whether the signaling includes second indication information. For related content, please refer to the description of Example 1 and Example 2 in the above implementation C1.1, which will not be repeated here.

[0248] Implementation method C2, intra-cell mTRP scenario.

[0249] In this implementation C2, the terminal device operates in an intra-cell mTRP scenario, in which a cell may have multiple TRPs. This implementation is introduced by taking the first network device and the second network device as different TRPs in the same cell as an example. Implementation C2 can be configured as a single DCI mTRP scenario, that is, only the control resource set pool index (CORESETpoolindex) 0 is configured, or the CORESETpoolindex is not configured. When the TCI field indicated by each TCI code point (TCI Codepoint) (or DCI) activated by the second network device through MAC CE is associated with a pair of TCI-states, and the TCI-state does not contain additionalPCI, it can be considered that the terminal device operates in an intra-cell mTRP scenario. In this scenario, the second network device sends a PDCCH order to the terminal device, and the terminal device may not be able to perceive the two TRPs. The terminal device believes that the PDCCH order is sent from the serving cell.

[0250] In this scenario, there are multiple possible implementations for carrying the first indication information. For example, the first indication information may be located in a newly added field or an existing field of the signaling (e.g., DCI1_0 in the PDCCH order). For related details, see the relevant description in Implementation C1 and will not be repeated here. In this implementation, the second network device may send the second indication information. For related solutions, see the relevant description in Implementation C1 and will not be repeated here.

[0251] Implementation method C3, CA scenario.

[0252] In the CA scenario, multiple component carriers (CCs) can be aggregated, and each CC can be regarded as a service cell. In this implementation, the cells associated with the first network device and the second network device can be used as different service cells for illustration. In implementation C3, the first network device and the second network device can also be said to belong to two CCs respectively. For example, the first network device is a secondary component carrier (SCC), and the second network device is a PCC. In the embodiment of the present application, the cell of the PCC (the cell of the second network device) can be called a primary cell (Pcell), and the cell of the SCC (the cell of the first network device) can be called a secondary cell (Scell). The first network device and the second network device belong to the same device or different devices.

[0253] For example, DCI1_0 carried by a PDCCH order includes a field that carries information indicating the first network device (e.g., identification information of the cell associated with the first network device or index information of the CC associated with the first network device). This field is used to indicate which cell or CC the PDCCH order triggers random access (e.g., CFRA). In this example, because the cells associated with the first network device and the second network device are different serving cells, the information indicating the first network device can be identification information of the serving cell associated with the first network device. The information indicating the first network device can be a newly added field in the signaling, or an existing field.

[0254] In this scenario, there are multiple possible implementations for carrying the first indication information. For example, the first indication information may be located in a newly added field or an existing field of the signaling (e.g., DCI1_0 in the PDCCH order). For related details, see the relevant description in Implementation C1 and will not be repeated here. In this implementation, the second network device may send the second indication information. For related solutions, see the relevant description in Implementation C1 and will not be repeated here.

[0255] Step 303: The terminal device determines parameters of the random access procedure.

[0256] The parameters of the random access procedure may include, for example, an uplink reference signal and a preamble, and may also include a random access opportunity.

[0257] The terminal device may determine the first uplink reference signal according to the first indication information. There are multiple schemes for the terminal device to determine other parameters of the random access procedure. Several possible examples are described below through implementation D1 and implementation D2.

[0258] In implementation mode D1, a terminal device receives information indicating parameters of a random access procedure, and determines the parameters of the random access procedure according to the information indicating parameters of the random access procedure.

[0259] The parameters of the random access procedure may be, for example, a preamble and / or a random access opportunity. The information indicating the parameters of the random access procedure may include, for example, information indicating the preamble and / or information indicating the random access opportunity. When the parameter of the random access procedure is the random access opportunity, the information indicating the parameters of the random access procedure may be replaced with information about a random access channel mask. The information about the random access channel mask is used to indicate the random access opportunity.

[0260] In this example, there may be multiple parameters for the same type of random access process, for example, the second network device may indicate multiple preambles and / or multiple random access opportunities. In this case, the terminal device can obtain the association relationship between the uplink reference signal and the parameters of the random access process (such as the preamble and / or random access opportunity, etc.) (such as the association relationship involved in the above information A5), and the second network device can indicate the association relationship in an explicit or implicit manner. The terminal device then determines the parameters of the random access process associated with the first uplink reference signal (such as the preamble and / or random access opportunity, etc.) based on the association relationship.

[0261] In implementation mode D2, the terminal device determines the parameters of the random access procedure based on the association relationship and the first uplink reference signal, and the association relationship indicates the association between the first uplink reference signal and the parameters of the random access procedure. In example two, the terminal device can pre-acquire some association relationships, which are the association relationships between the uplink reference signal and the parameters of one or more random access procedures. Afterwards, the terminal device can find out the parameters of the random access procedure associated with the first uplink signal (such as the preamble and / or random access timing, etc.) from these association relationships. These association relationships can be in the form of a mapping table or text. For examples of the association relationship between the uplink reference signal and the parameters of the random access procedure (such as the preamble and / or random access timing, etc.), please refer to the aforementioned related description and will not be repeated here. This solution can reduce the signaling overhead caused by the parameters indicating the random access procedure, thereby saving resources.

[0262] For example, the association relationship configured by the terminal device may include an association relationship between one or more uplink reference signals and one or more preamble codes, an uplink reference signal may be associated with one or more preamble codes, and one or more preamble codes may be associated with an uplink reference signal. These association relationships may include a first association relationship, and the first association relationship indicates the association relationship between the first uplink reference signal and the preamble code. The terminal device can search for these association relationships based on the first uplink reference signal, and then find the preamble code associated with the first uplink reference signal based on the first association relationship. In this way, the terminal device does not need to receive information for indicating the preamble code, thereby saving signaling overhead. In one possible implementation, a first uplink reference signal can be associated with a preamble code, so that the terminal device can uniquely determine a preamble code.

[0263] To give another example, the association relationship configured by the terminal device may include an association relationship between one or more uplink reference signals and one or more random access opportunities, one uplink reference signal may be associated with one or more random access opportunities, and one or more random access opportunities may be associated with one uplink reference signal. These association relationships may include a second association relationship, and the second association relationship indicates the association relationship between the first uplink reference signal and the random access opportunity. The terminal device can search for these association relationships based on the first uplink reference signal, and then find the random access opportunity associated with the first uplink reference signal based on the second association relationship. In this way, the terminal device does not need to receive information for indicating the preamble code, thereby saving signaling overhead. In one possible implementation, a first uplink reference signal can be associated with a random access opportunity, so that the terminal device can determine a unique random access opportunity.

[0264] The implementation methods provided in the above-mentioned implementation methods D1 and D2 can be used separately or in combination. For example, some parameters of the random access process are determined by the scheme provided in Example 1, and some parameters of the random access process are determined by the scheme provided in Example 2. For example, the terminal device determines the random access timing based on the mask information of the received random access channel. For another example, the terminal device determines the preamble code based on the first association relationship and the first uplink reference signal. In this example, the second network device can send the mask information of the random access channel, but may not send information for indicating the preamble code.

[0265] Step 304: The terminal device sends a preamble.

[0266] Correspondingly, the first network device receives the preamble.

[0267] In step 304, after the terminal device determines the first uplink reference signal, the spatial relationship of the terminal device sending the preamble code can refer to the spatial relationship of the first uplink reference signal. The terminal device can also determine the preamble code and determine the associated random access radio network temporary identifier (RA-RANTI), and send the preamble code on the PRACH resource (for example, at the random access opportunity).

[0268] In another possible implementation, the terminal device may send a preamble code based on the first uplink reference signal indicated by the first indication information, or send a preamble code based on the joint / UL TCI state indicated by the first indication information, that is, the beam of the preamble code may refer to the beam of the first uplink reference signal indicated in the DCI1_0, or refer to the joint / UL TCI state indicated in the DCI1_0.

[0269] Because the first network device is unable to send a downlink reference signal, the terminal device is unable to send a preamble based on the downlink timing of the first network device. Based on this situation, an embodiment of the present application provides a possible solution in which the terminal device determines a third network device and sends a preamble based on the downlink timing of the third network device. The third network device is different from the first network device.

[0270] The third network device may be the second network device, or may be a network device different from the second network device. For example, if the third network device is the second network device, in this case, the terminal device may send a preamble based on the downlink timing of the second network device. For example, the terminal device sends a preamble based on the downlink timing of the PDCCH order received from the second network device and then advances the uplink timing offset. The timing advance (TA) during the transmission of the preamble is 0. The uplink timing offset may be defined by a network configuration (such as the second network device) or a protocol.

[0271] In an embodiment of the present application, the terminal device can determine the third network device in a variety of ways. For example, the second network device sends information for indicating the third network device, and the terminal device determines the third network device based on the received information for indicating the third network device. For another example, the information for indicating the third network device can be sent by a network device other than the second network device. For another example, the third network device can also be defined by a protocol, or pre-configured, or agreed upon. For example, the protocol stipulates that the third network device is a PCC or a reference CC configured by the network device, or the protocol stipulates that the cell associated with the third network device is a serving cell or a reference cell configured by the network device.

[0272] When the terminal device operates in an intra-cell or inter-cell mTRP scenario, the terminal device can send a preamble code in advance of an uplink timing offset based on the downlink timing of the serving cell (the third network device is the serving cell), and the TA is 0. When the terminal device operates in a multi-CC scenario, the network device can configure a reference CC or a reference cell (a CC or cell associated with a third network device). The reference CC (CC associated with the third network device) can be any CC in CA, and the reference cell (cell associated with the third network device) can be an Scell, PCell, or a primary secondary cell (PScell). The terminal device sends a preamble code in advance of an uplink timing offset based on the downlink timing of the reference CC or reference cell (CC or cell associated with the third network device), and the TA is 0. The uplink timing offset can be defined by the network configuration (such as the second network device) or the protocol.

[0273] The content of step 304 can refer to the content of the aforementioned step 202 and will not be repeated here.

[0274] Step 305: The first network device sends second information.

[0275] Correspondingly, the second network device receives the second information, where the second information is used to indicate that the first network device has received the preamble.

[0276] Since the first network device cannot send a random access response, the first network device sends second information to the second network device to inform the first network device that the preamble is received and the second network device can send a random access response to the terminal.

[0277] Step 305 is an optional step and may not be performed. For example, if the first network device and the second network device are integrated into a single physical entity and the first network device and the second network device are two CCs, in this case, after the first network device receives the preamble, the second network device can send a random access response. The first network device does not need to send the second information, and the second network device can know that the first network device has received the preamble (for example, the first network device and the second network device may share a processing unit).

[0278] Step 306: The second network device sends a random access response.

[0279] Correspondingly, the terminal device receives the random access response.

[0280] In step 306, the terminal device may search for PDCCH in the common search space associated with the third network device or the fourth network device. The terminal device may also receive a random access response based on the first beam. The fourth network device may be different from the third network device, and the fourth network device may also be configured by the second network device. In the embodiment of the present application, an example is given in which the terminal device searches for PDCCH in the common search space associated with the third network device. The random access response in the embodiment of the present application may include a PDCCH random access response (RAR) and / or a PDSCH RAR. The PDCCH random access response is used to schedule the PDSCH RAR.

[0281] The first beam may be a beam associated with a joint TCI state of the third network device. The first beam may be a beam associated with a unified TCI state of the third network device. The unified TCI state may be a unified TCI state in English. The unified TCI state may also be a downlink unified TCI state. Alternatively, the first beam may be a beam associated with the first indication information.

[0282] In the example of Figure 3 , for example, if the first indication information is carried in a PDCCH order, the terminal device may receive the random access response with reference to the beam of the PDCCH order (i.e., the receive beam associated with the first indication information). This means that the reference signal of the random access response received by the terminal may satisfy a QCL relationship with the DMRS of the PDCCH order.

[0283] For example, after sending the preamble, the terminal device will search for PDCCH in the common search space (such as type 1 PDCCH common search space) of the CC or cell of the configured third network device within the RAR time window (RAR window) to obtain DCI 1_0 on the PDCCH, and rely on the information of DCI 1_0 to receive the random access response scrambled by the associated random access cell radio network temporary identifier (Random Access-radio network temporary identifier, RA-RNTI). It can be understood that when the terminal device initiates random access to the cell or CC of the first network device, the random access response and the type 1 PDCCH common search space of the CC or cell of the third network device meet the quasi-co-location relationship. Type 1 PDCCH common search space can be written in English as Type1-PDCCH common search space.

[0284] In one possible example, when the terminal device operates in a multi-CC scenario and a unified TCI (unified TCI) mode, the terminal device may receive a random access response based on the unified TCI state of a configured or protocol-specified reference CC (i.e., the CC of the third network device). Alternatively, the terminal device may receive a random access response based on the unified TCI state of a CC in a PDCCH order received from the second network device.

[0285] The random access response may include: the random access preamble in step 304, the terminal device's uplink TA (11 bits, coarse adjustment), and a backoff parameter (which can be written as backoff in English and is used to indicate the time to delay re-access after resending the preamble). If the terminal device does not receive the random access response within the RAR time window, the random access process is considered to have failed.

[0286] In the embodiment shown in Figure 3, because the first network device does not have downlink transmission capabilities or is not configured with downlink transmission-related information, the terminal device cannot access the first network device based on the current random access process. However, in the solution provided in the embodiment of the present application, the terminal device can send a preamble code based on the first uplink reference signal and then randomly access the first network device. This solution provides a solution for terminal devices accessing network devices with limited capabilities, thereby broadening the scope of application of the random access process.

[0287] On the other hand, because the first network device cannot send a downlink reference signal, the terminal device cannot receive a random access response based on the downlink reference signal from the first network device. However, in the embodiment of the present application, a third network device is configured, and the terminal device can receive a random access response based on information of the third network device (such as a beam associated with the unified TCI state of the third network device), thereby improving the success rate of the terminal device receiving the random access response and, in turn, improving the success rate of random access.

[0288] The following is described in conjunction with Figure 4, which uses CBRA as an example. The embodiment shown in Figure 4 includes steps 401, 402, 403, and 404. In one possible implementation, the embodiment shown in Figure 4 also includes steps 405, 406, 407, and 408.

[0289] Step 401: The second network device sends configuration information.

[0290] The configuration information in the embodiment shown in Figure 4 may include one or more of information E1, information A2, information A3, information A4, information A5, information A6, or information A7. The content included in the configuration information may be transmitted through a single signaling or through multiple signalings, which is not limited in the embodiment of the present application. In one possible implementation, the configuration information may be carried in radio resource control (RRC) signaling. The relevant contents of information A2, information A3, information A4, information A5, information A6, and information A7 can be found in the above description and will not be repeated here.

[0291] Information E1, first indication information.

[0292] In the embodiment shown in Figure 4 , the terminal device may transmit at least one uplink reference signal, the first uplink reference signal belonging to the at least one uplink reference signal, and the second network device may measure some or all of the received at least one uplink reference signal to obtain a measurement result of the at least one uplink reference signal. The specific content of the first indication information is described in Examples E1.1 and E1.2 below.

[0293] In Example E1.1, the first indication information may include a measurement result of at least one uplink reference signal. The measurement result of the first uplink reference signal is a measurement result among the measurement results of the at least one uplink reference signal.

[0294] In Example E1.1, the terminal device may determine, based on the measurement result of the first uplink reference signal, that the random access procedure needs to use the first uplink reference signal (for example, the preamble needs to be associated with the first uplink reference signal). In the embodiment of the present application, the measurement result of the uplink reference signal may include, for example, reference signal receiving power (RSRP).

[0295] For example, the terminal device can select a measurement result from the measurement results of the at least one uplink reference signal (for example, it can select the one indicating the strongest or second strongest signal strength), and associate the uplink reference signal associated with the measurement result (for example, the first uplink reference signal) with the preamble code.

[0296] For another example, the terminal device may obtain a first threshold. In this example, the first threshold may not be carried in the first indication information. The first threshold may be defined by a protocol, or pre-agreed or pre-configured. The terminal device may select a measurement result indicating that the signal strength of the measurement result is greater than the first threshold, and associate an uplink reference signal associated with the measurement result (such as the first uplink reference signal) with the preamble.

[0297] Example E1.2: The first indication information may include a measurement result of at least one uplink reference signal and a first threshold.

[0298] In Example E1.2, the measurement result of the uplink reference signal and the first threshold may be sent via one or more signaling messages. The signal strength indicated by the measurement result of the first uplink reference signal is greater than or equal to the first threshold. The terminal device may search for a measurement result having a signal strength greater than the first threshold from the measurement results of at least one uplink reference signal, such as a measurement result associated with the first uplink reference signal, and then the terminal device may perform random access based on the first uplink reference signal, such as by associating a preamble with the first uplink reference signal.

[0299] In Example E1.1 and / or Example E1.2, the terminal device may determine, based on a measurement result of an uplink reference signal, an uplink reference signal associated with the measurement result. For example, the first indication information also includes a resource index of the uplink reference signal associated with the measurement result (e.g., a resource identifier and / or a resource set identifier of the uplink reference signal), and then the terminal device determines the uplink reference signal based on the resource index of the uplink reference signal.

[0300] In Example E1.1 and / or Example E1.2, in another possible implementation, the first indication information may not include a resource index of an uplink reference signal (such as a resource identifier and / or a resource set identifier of the uplink reference signal), so that the terminal device can infer an uplink reference signal associated with a measurement result based on some other information. For example, the terminal device sends three uplink reference signals, the first indication information includes measurement results associated with the three uplink reference signals, and the order of the three measurement results in the message carrying the first indication information is consistent with the order of the three uplink reference signals sent by the terminal device, so that the terminal device can infer an uplink reference signal associated with a measurement result based on the order of the measurement results included in the first indication information.

[0301] The embodiment provided in FIG4 may also be used in combination with the embodiment provided in FIG3 . For example, in the embodiment provided in FIG4 , the above-mentioned information E1 first indication information may also include the resource identifier and resource set identifier of the first uplink reference signal. In the embodiment provided in FIG3 , the configuration information sent by the second network device may also include the measurement result of at least one uplink reference signal. Or in the embodiment provided in FIG3 , the configuration information sent by the second network device may also include the measurement result of at least one uplink reference signal and the first threshold value. In the embodiment provided in FIG3 , the first indication information may also include the measurement result of at least one uplink reference signal (for relevant content, please refer to the above example E1.1), or the first indication information includes the measurement result of at least one uplink reference signal and the first threshold value (for relevant content, please refer to the above example E1.2).

[0302] Step 402: The terminal device determines parameters of the random access procedure according to the configuration information.

[0303] The parameters of the random access procedure may include, for example, an uplink reference signal and a preamble, and may also include a random access opportunity.

[0304] The terminal device can determine the uplink reference signal used in the random access process, that is, the first uplink reference signal, based on the first indication information (such as the measurement result of the first uplink reference signal, and further such as the measurement result of the first uplink reference signal and the first threshold).

[0305] For example, the second network device may send a first threshold and a measurement result of at least one uplink reference signal, and the measurement result of the first uplink reference signal belongs to the measurement result of the at least one uplink reference signal. In this way, the terminal device may select an uplink reference signal whose indicated signal strength is greater than the first threshold from the measurement result of at least one uplink reference signal. For example, the first indication information includes the first threshold and the measurement result of the first uplink reference signal, and the signal strength indicated by the measurement result of the first uplink reference signal is greater than or equal to the first threshold. In this way, the terminal device can select the first uplink reference signal to provide assistance for the random access process. In this example, the second network device may not send the first threshold, for example, the first indication information includes the measurement result of the first uplink reference signal, but does not include the first threshold. The protocol may specify the first threshold, or the terminal device may preconfigure the first threshold.

[0306] For another example, the second network device may send a measurement result of at least one uplink reference signal, and the measurement result of the first uplink reference signal belongs to the measurement result of the at least one uplink reference signal. For example, the first indication information includes the measurement result of the first uplink reference signal. The uplink reference signals associated with these measurement results indicated by the second network device can all be used for random access, and the terminal device can arbitrarily select a measurement result from the measurement results of the at least one uplink reference signal (for example, the first uplink reference signal is selected), and the uplink reference signal associated with the measurement result is used for random access.

[0307] There are various schemes for a terminal device to determine parameters of other random access procedures. For example, the terminal device receives information indicating parameters of the random access procedure (such as the information carried in the configuration information in step 401), and determines the parameters of the random access procedure based on the information indicating the parameters of the random access procedure. For another example, the terminal device determines the parameters of the random access procedure based on the association relationship and the first uplink reference signal. For related content, please refer to the description of the aforementioned Implementation Methods D1 and D2, which will not be repeated here.

[0308] Step 403: The terminal device sends a preamble.

[0309] Correspondingly, the first network device receives the preamble.

[0310] The information carrying the preamble code may also be referred to as message 1 (message1, msg1).

[0311] In step 403, because the first network device is unable to transmit a downlink reference signal, the terminal device is unable to transmit a preamble based on the downlink timing of the first network device. Based on this situation, an embodiment of the present application provides a possible solution in which the terminal device determines a third network device, which is configured to transmit a preamble based on the downlink timing of the third network device. The terminal device transmits a preamble based on the downlink timing of the third network device. The third network device is different from the first network device.

[0312] The content of step 403 can refer to the content of the aforementioned step 304 and will not be repeated here.

[0313] In step 404 , the first network device sends second information.

[0314] Correspondingly, the second network device receives the second information.

[0315] The content of step 404 can refer to the content of the aforementioned step 305 and will not be repeated here.

[0316] Step 405: The second network device sends a random access response.

[0317] Correspondingly, the terminal device receives the random access response.

[0318] In the embodiment of FIG. 4 , the information carrying the random access response may be referred to as message 2 (message2, msg2).

[0319] The random access response may include: the random access preamble in step 403 (the preamble in msg1), the uplink TA of the terminal device (11 bits, coarse adjustment), the backoff parameter (written as backoff in English, used to indicate the time when re-sending the preamble should delay re-access), the PUSCH uplink scheduling information allocated for the transmission of msg3 (the uplink scheduling information may include uplink (UL) authorization (grant) information, such as whether to frequency hop, modulation and coding rate, access resources or access time, etc.), temporary cell radio network temporary identifier (TC-RNTI) (this parameter can be used for subsequent msg3 scrambling). If the terminal device does not receive a random access response within the RAR time window, it is considered that the random access process has failed.

[0320] The terminal device may search for the PDCCH in the common search space associated with the third network device. The terminal device may also receive a random access response based on the first beam. The content of step 405 may refer to the content of the aforementioned step 306 and will not be repeated here.

[0321] Step 406: The terminal device sends the first information.

[0322] Correspondingly, the first network device receives the first information.

[0323] The first message includes identification information of the terminal device. The identification information of the terminal device will be used for subsequent conflict resolution. The message carrying the identification information of the terminal device may also be referred to as message 3 (message3, msg3).

[0324] The first information can be associated with the first uplink reference signal, which can be understood as some parameters in the process of sending the first information can refer to the first uplink reference signal. For example, the spatial relationship (or beam) of the first information can refer to the spatial relationship (or beam) of the first uplink reference signal, or the spatial relationship (or beam) of the first information is associated with the spatial relationship (or beam) of the first uplink reference signal. For another example, the path loss reference signal associated with the first information is the first uplink reference signal. Alternatively, it can be understood that the path loss of the first information can refer to (or be regarded as) the path loss of the first uplink reference signal.

[0325] In another possible implementation, if the UL / joint transmission configuration indication state (TCI state) indicated by the first indication information is associated with a path loss (PL) offset, the path loss compensation of the PRACH can be added with the PL offset.

[0326] For example, the PRACH transmit power is:

[0327] P PRACH,b,f,c (i) = min{P CMAX,f,c (i),P PRACH,target,f,c +PL b,f,c +PL offset}[dBm]……Formula (1)

[0328] In formula (1), PL offset The PL offset associated with the UL / joint TCI state indicated by the first indication information;

[0329] P CMAX,f,c (i) represents the maximum transmit power of the UE at time i on carrier f in serving cell c;

[0330] P PRACH,target,f,c The target PRACH receive power for activating UL BWP b in serving cell c carrier f is configured via the RRC parameter preambleReceivedTargetPower.

[0331] PLb,f,c Activate UL BWP b for UE in serving cell c carrier f. Activate the downlink path loss value based on the DL RS associated with the PRACH, obtained by RSRP measurement and cell reference signal transmit power, where the cell reference signal transmit power is set by parameter referenceSignalPower.

[0332] Because the first network device is unable to transmit a downlink reference signal, the terminal device is unable to transmit the first information based on the downlink timing of the first network device. Based on this situation, an embodiment of the present application provides a possible solution in which the terminal device identifies a third network device and transmits the first information based on the downlink timing of the third network device. For details about the third network device, please refer to the relevant description in Figure 3 and will not be repeated here.

[0333] In one possible implementation, the uplink transmission timing of the first information transmitted by the terminal device may include (or be): the sum of the downlink timing of the third network device, the TA, and an uplink timing offset. The TA may be indicated in the random access response, and the TA may be non-zero; or the TA may be 0. The uplink timing offset may be defined by a network configuration (e.g., the second network device) or a protocol.

[0334] When the terminal device operates in an intra-cell or inter-cell mTRP scenario, the terminal device can advance the downlink timing of the serving cell (the third network device is the serving cell) by TA plus an uplink timing offset to send the first information. When the terminal device operates in a multi-CC scenario, the network device can configure or reference the cell (CC or cell associated with the third network device), and the terminal device sends the first information based on the downlink timing of the CC or cell associated with the third network device by TA plus an uplink timing offset. The uplink timing offset can be defined by the network configuration (such as the second network device) or the protocol. The reference CC (CC associated with the third network device) can be any CC in CA, and the reference cell (cell associated with the third network device) can be an Scell, PCell or primary secondary cell (PScell).

[0335] In step 407 , the first network device sends third information.

[0336] Correspondingly, the second network device receives the third information, where the third information indicates that the first network device has received the first information.

[0337] Since the first network device cannot send the PDCCH, the first network device sends third information to the second network device to trigger the second network device to send the PDCCH.

[0338] Step 407 is an optional step and may not be performed. For example, if the first network device and the second network device are integrated into a single physical entity and the first network device and the second network device are two CCs, the first network device does not need to send the third information, and the second network device can know that the first network device has received the first information (for example, the first network device and the second network device may share a processing unit).

[0339] Step 408: The second network device sends a PDCCH.

[0340] Correspondingly, the terminal device receives the PDCCH.

[0341] In the embodiment of FIG. 4 , information carrying the PDCCH may belong to msg4. The PDCCH may be considered as information in msg4 during four-step random access, i.e., msg4 may include the PDCCH. In another possible implementation, msg4 may also include a subsequent PDSCH. In another possible implementation, msg4 may be considered to include the PDSCH but not the PDCCH.

[0342] The terminal device may also receive the PDCCH based on the second beam.

[0343] The second beam may be a beam associated with a joint TCI state of the third network device. The second beam may be a beam associated with a unified TCI state of the third network device. The unified TCI state can be written as a unified TCI-state in English. The unified TCI state can also be a downlink unified TCI state. Alternatively, the second beam includes a beam associated with the first information. Alternatively, the second beam is a beam associated with the first indication information, such as a beam associated with configuration information.

[0344] In one possible example, when the terminal device operates in a multi-CC scenario, the terminal device may receive the PDCCH based on the downlink unified TCI state of the reference CC (i.e., the CC of the third network device or the cell associated with the third network device) configured or specified by the protocol; or, the terminal device may receive the PDCCH based on the joint TCI state of the reference CC (i.e., the CC of the third network device or the cell associated with the third network device) configured or specified by the protocol. When the terminal device operates in an intra-cell or inter-cell mTRP scenario, the terminal device uses the beam with the downlink unified TCI state of the serving cell (i.e., the cell of the third network device) to receive the PDCCH.

[0345] In step 306, after the terminal device sends the first message (msg3), a timer may be started, such as the timer named mac-ContentionResolutionTimer, and the timer may be restarted when the first message (msg3) is retransmitted using a hybrid automatic repeat request (HARQ). The terminal device will continue to monitor the PDCCH until the timer times out or stops. If the terminal device monitors the PDCCH and the terminal device carries the C-RNTI MAC control element when sending the first message (msg3), then in the following two cases (case one or case two below), the terminal device considers that the conflict resolution is successful (that is, the terminal device successfully accesses), at which time the terminal device will stop the timer and discard the TC-RNTI.

[0346] In case 1, the random access process is triggered by the MAC sublayer, and the PDCCH received by the terminal device is scrambled by the C-RNTI carried by the first message (msg3), and an uplink grant (UL Grant) is allocated to the newly transmitted data.

[0347] In case 2, the random access process is triggered by the PDCCH order, and the PDCCH received by the terminal device is scrambled by the C-RNTI carried in the first message (msg3).

[0348] If the timer expires, the terminal device discards the TC-RNTI and considers the contention resolution to have failed.

[0349] In this embodiment, because the first network device does not have downlink transmission capabilities or is not configured with downlink transmission-related information, the terminal device cannot access the first network device based on the current random access process. However, in the solution provided in the embodiment of the present application, the terminal device can send a preamble code based on the first uplink reference signal and then randomly access the first network device. This solution provides a solution for terminal devices to access network devices with limited capabilities, thereby broadening the scope of application of the random access process.

[0350] On the other hand, because the first network device cannot send a downlink reference signal, the terminal device cannot receive a random access response based on the downlink reference signal from the first network device. However, in the embodiment of the present application, a third network device is configured, and the terminal device can receive a random access response based on information of the third network device (such as a beam associated with the unified TCI state of the third network device), thereby improving the success rate of the terminal device receiving the random access response and, in turn, improving the success rate of random access.

[0351] On the other hand, in the embodiment provided in FIG4 , the terminal device can transmit the first information (msg3) based on the first uplink reference signal and can also receive the PDCCH based on the second beam. Therefore, this solution can apply the four-step random access process to network devices that cannot transmit downlink reference signals. This solution provides a solution for terminal devices to access network devices with limited capabilities, thereby broadening the scope of application of the random access process.

[0352] It is understood that in order to implement the functions in the above embodiments, the first device, the second device, and the positioning management device may include hardware structures and / or software modules that perform the corresponding functions. Those skilled in the art should readily appreciate that, in combination with the units and method steps of the various examples described in the embodiments disclosed in this application, this application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in hardware or in a manner driven by computer software depends on the specific application scenario and design constraints of the technical solution.

[0353] Figures 5 and 6 are schematic diagrams of the structures of possible communication devices provided in embodiments of the present application. These communication devices can be used to implement the functions of the terminal or base station in the above-mentioned method embodiments, thereby also achieving the beneficial effects of the above-mentioned method embodiments. In the embodiments of the present application, the communication device can be a terminal device as shown in Figure 1, or a network device (such as a RAN node) as shown in Figure 1, or a chip system applied to the terminal device or network device as shown in Figure 1.

[0354] As shown in Figure 5, communication device 1300 includes a processing unit 1310 and a transceiver unit 1320. Communication device 1300 is used to implement the functions of the terminal device, the first network device, or the second network device in the method embodiments shown in Figures 2, 3, or 4. Transceiver unit 1320 may also be referred to as a communication unit. Transceiver unit 1320 may include a transmitting unit and a receiving unit.

[0355] When the communication device 1300 is used to implement the functions of the terminal device in the method embodiment shown in FIG2 , the transceiver unit 1320 may perform steps 201 and 202 described above. When the communication device 1300 is used to implement the functions of the terminal device in the method embodiment shown in FIG3 , the processing unit 1310 may perform step 303 described above, and the transceiver unit 1320 may perform steps 301, 302, 304, and 306 described above. When the communication device 1300 is used to implement the functions of the terminal device in the method embodiment shown in FIG4 , the processing unit 1310 may perform step 402 described above, and the transceiver unit 1320 may perform steps 401, 403, 405, 406, and 408 described above.

[0356] In one possible implementation, the receiving unit may be used to receive the fourth information, and the sending unit or the receiving unit may also be used to transmit the first signal. In another possible implementation, the receiving unit may also be used to receive the first information, and the sending unit may also be used to send the second information.

[0357] When the communication device 1300 is used to implement the functions of the terminal device in the method embodiment shown in Figure 2, Figure 3 or Figure 4, in one possible implementation, the receiving unit is used to receive the first indication information, and the sending unit is used to send the preamble code.

[0358] When the communication device 1300 is used to implement the function of the terminal device in the method embodiment shown in FIG. 2 , FIG. 3 or FIG. 4 , in one possible implementation, the sending unit is used to send a preamble code to the first network device.

[0359] When the communication device 1300 is used to implement the functions of the terminal device in the method embodiment shown in FIG. 2 , FIG. 3 or FIG. 4 , in a possible implementation manner, the receiving unit is used to receive the second indication information.

[0360] When the communication device 1300 is used to implement the function of the terminal device in the method embodiment shown in FIG. 2 , FIG. 3 or FIG. 4 , in a possible implementation manner, the receiving unit is used to receive information indicating the first network device.

[0361] When the communication device 1300 is used to implement the functions of the terminal device in the method embodiment shown in FIG. 2 , FIG. 3 or FIG. 4 , in one possible implementation, the receiving unit is used to receive information indicating a preamble code.

[0362] When the communication device 1300 is used to implement the functions of the terminal device in the method embodiment shown in Figure 2, Figure 3 or Figure 4, in one possible implementation, the processing unit 1310 is used to determine the preamble code according to the first association relationship and the first uplink reference signal.

[0363] When the communication device 1300 is used to implement the functions of the terminal device in the method embodiment shown in Figure 2, Figure 3 or Figure 4, in one possible implementation, the receiving unit is used to receive mask information of the random access channel and determine the random access timing according to the mask information of the random access channel.

[0364] When the communication device 1300 is used to implement the functions of the terminal device in the method embodiment shown in Figure 2, Figure 3, or Figure 4, in one possible implementation, the processing unit 1310 is configured to determine a random access timing based on the second association relationship and the first uplink reference signal, where the second association relationship indicates that the first uplink reference signal is associated with the random access timing. The sending unit is configured to send a preamble code at the random access timing.

[0365] When the communication device 1300 is used to implement the function of the terminal device in the method embodiment shown in Figure 2, Figure 3 or Figure 4, in one possible implementation, the sending unit is used to send a preamble code based on the downlink timing of the third network device, the first network device in which the terminal device initiates random access is different from the third network device, the third network device is the same as or different from the second network device, and the second network device is the device that sends the first indication information.

[0366] When the communication device 1300 is used to implement the functions of the terminal device in the method embodiment shown in FIG. 2 , FIG. 3 or FIG. 4 , in a possible implementation manner, the receiving unit is used to receive information indicating the third network device.

[0367] When the communication device 1300 is used to implement the functions of the terminal device in the method embodiment shown in FIG. 2 , FIG. 3 or FIG. 4 , in one possible implementation, the processing unit 1310 is used to determine the third network device based on the content defined by the protocol.

[0368] When the communication device 1300 is used to implement the functions of the terminal device in the method embodiments shown in Figure 2, Figure 3 or Figure 4, in one possible implementation, the processing unit 1310 is used to search for PDCCH in the common search space associated with the third network device, and the receiving unit is used to receive a random access response based on the first beam.

[0369] When the communication device 1300 is used to implement the function of the terminal device in the method embodiment shown in FIG. 2 , FIG. 3 or FIG. 4 , in a possible implementation manner, the sending unit is used to send the first information.

[0370] When the communication device 1300 is used to implement the functions of the terminal device in the method embodiment shown in Figure 2, Figure 3 or Figure 4, in one possible implementation, the receiving unit is used to receive the PDCCH based on the second beam.

[0371] When the communication device 1300 is used to implement the functions of the first network device in the method embodiment shown in FIG2 , the transceiver unit 1320 may perform the above step 202. When the communication device 1300 is used to implement the functions of the first network device in the method embodiment shown in FIG3 , the transceiver unit 1320 may perform the above steps 304 and 305. When the communication device 1300 is used to implement the functions of the first network device in the method embodiment shown in FIG4 , the transceiver unit 1320 may perform the above steps 403, 404, 406, and 407.

[0372] When the communication device 1300 is used to implement the function of the first network device in the method embodiment shown in Figure 2, Figure 3 or Figure 4, in one possible implementation, the receiving unit is used to receive the preamble code, and the sending unit is used to send the second information to the second network device.

[0373] When the communication device 1300 is used to implement the function of the first network device in the method embodiment shown in FIG. 2 , FIG. 3 or FIG. 4 , in a possible implementation manner, the receiving unit is used to receive the first information.

[0374] When the communication device 1300 is used to implement the function of the first network device in the method embodiment shown in FIG. 2 , FIG. 3 or FIG. 4 , in a possible implementation manner, the sending unit is used to send the third information to the second network device.

[0375] When the communication device 1300 is used to implement the functions of the second network device in the method embodiment shown in FIG2 , the transceiver unit 1320 may perform the above step 201. When the communication device 1300 is used to implement the functions of the first network device in the method embodiment shown in FIG3 , the transceiver unit 1320 may perform the above steps 301, 302, 305, and 306. When the communication device 1300 is used to implement the functions of the first network device in the method embodiment shown in FIG4 , the transceiver unit 1320 may perform the above steps 401, 404, 405, 407, and 408.

[0376] When the communication device 1300 is used to implement the function of the second network device in the method embodiment shown in Figure 2, Figure 3 or Figure 4, in one possible implementation, the sending unit is used to send the first indication information, the receiving unit is used to receive the second information from the first network device, and the sending unit is used to send the random access response based on the second information.

[0377] When the communication device 1300 is used to implement the function of the second network device in the method embodiment shown in FIG. 2 , FIG. 3 or FIG. 4 , in a possible implementation manner, the sending unit is used to send the second indication information.

[0378] When the communication device 1300 is used to implement the function of the second network device in the method embodiment shown in FIG. 2 , FIG. 3 or FIG. 4 , in a possible implementation manner, the sending unit is used to send information for indicating the first network device.

[0379] When the communication device 1300 is used to implement the function of the second network device in the method embodiment shown in FIG. 2 , FIG. 3 or FIG. 4 , in a possible implementation manner, the sending unit is used to send information indicating a preamble.

[0380] When the communication device 1300 is used to implement the function of the second network device in the method embodiment shown in FIG. 2 , FIG. 3 or FIG. 4 , in a possible implementation manner, the sending unit is used to send mask information of the random access channel.

[0381] When the communication device 1300 is used to implement the function of the second network device in the method embodiment shown in FIG. 2 , FIG. 3 or FIG. 4 , in a possible implementation manner, the sending unit is used to send information for indicating the third network device.

[0382] When the communication device 1300 is used to implement the function of the second network device in the method embodiment shown in FIG. 2 , FIG. 3 or FIG. 4 , in a possible implementation manner, the sending unit is used to send information for indicating the third network device.

[0383] When the communication device 1300 is used to implement the function of the second network device in the method embodiment shown in Figure 2, Figure 3 or Figure 4, in one possible implementation, the receiving unit is used to receive the third information, and the sending unit is used to send the PDCCH based on the second beam.

[0384] For a more detailed description of the processing unit 1310 and the transceiver unit 1320 , reference may be made to the relevant descriptions in the method embodiments shown in FIG. 2 , FIG. 3 or FIG. 4 .

[0385] As shown in Figure 6, the communication device 1400 includes a processor 1410 and an interface circuit 1420. The processor 1410 and the interface circuit 1420 are coupled to each other. It is understandable that the interface circuit 1420 can be a transceiver or an input-output interface. The transceiver includes a transmitter and a receiver. The transmitter can be used to send information, the receiver can be used to receive information, and other functions can be implemented by the processor. The input-output interface is used to input and / or output information. Output can be understood as sending, and input can be understood as receiving. Other functions can be implemented by the processor. Optionally, the communication device 1400 may also include a memory 1430 for storing instructions executed by the processor 1410 or storing input data required by the processor 1410 to execute instructions or storing data generated after the processor 1410 executes instructions.

[0386] When the communication device 1400 is used to implement the method shown in FIG. 2 , FIG. 3 or FIG. 4 , the processor 1410 is used to implement the functions of the processing unit 1310 , and the interface circuit 1420 is used to implement the functions of the transceiver unit 1320 .

[0387] When the above-mentioned communication device is a chip applied to a terminal, the terminal chip implements the functions of the terminal device in the above-mentioned method embodiment. When the terminal chip receives information from the base station, it can be understood that the information is first received by other modules in the terminal (such as a radio frequency module or antenna) and then sent to the terminal chip by these modules. When the terminal chip sends information to the base station, it can be understood that the information is first sent to other modules in the terminal (such as a radio frequency module or antenna) and then sent to the base station by these modules.

[0388] When the above-mentioned communication device is a chip applied to a base station, the base station chip implements the functions of the network device in the above-mentioned method embodiment. When the base station chip receives information from the terminal, it can be understood that the information is first received by other modules in the base station (such as a radio frequency module or antenna) and then sent to the base station chip by these modules. When the base station chip sends information to the terminal, it can be understood that the information is sent to other modules in the base station (such as a radio frequency module or antenna) and then sent to the terminal by these modules.

[0389] In this application, when entity A sends information to entity B, it can be done directly from A to B or indirectly through another entity. Similarly, when entity B receives information from entity A, it can be done directly from entity B or indirectly through another entity. Entities A and B herein can be RAN nodes or terminals, or modules within a RAN node or terminal. The sending and receiving of information can be information exchange between a RAN node and a terminal, for example, between a base station and a terminal; the sending and receiving of information can also be information exchange between two RAN nodes, for example, between a CU and a DU; the sending and receiving of information can also be information exchange between different modules within a device, for example, between a terminal chip and other modules in the terminal, or between a base station chip and other modules within the base station.

[0390] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0391] The method steps in the embodiments of the present application can be implemented in hardware or in software instructions that can be executed by a processor. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, mobile hard disks, compact disc read-only memory (CD-ROM) or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. The storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a base station or a terminal. The processor and the storage medium can also be present in a base station or a terminal as discrete components.

[0392] In the above embodiments, all or part of the embodiments may be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. A computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, all or part of the processes or functions of the embodiments of the present application are performed. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, or other programmable device. The computer program or instructions may be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions may be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media, such as floppy disks, hard disks, or magnetic tapes; optical media, such as digital video disks; or semiconductor media, such as solid-state drives. The computer-readable storage medium may be a volatile or nonvolatile storage medium, or may include both volatile and nonvolatile types of storage media.

[0393] In the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0394] In this application, "at least one" means one or more, and "more" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. In the text description of this application, the character " / " generally indicates that the previous and next associated objects are in an "or" relationship; in the formula of this application, the character " / " indicates that the previous and next associated objects are in a "division" relationship. "Including at least one of A, B or C" can mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B and C.

[0395] It is understood that the various numbers involved in the embodiments of this application (such as the numerical numbers "first" and "second", and the letter numbers "A1, A2", "B1, B2", "C1, C2", etc.) are only for the convenience of description and are not intended to limit the scope of the embodiments of this application. The order of the sequence numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic.

Claims

1. A random access method, characterized in that: The method is applicable to a terminal device, and the method comprises: receiving first indication information, where the first indication information is used to indicate a first uplink reference signal; A preamble is sent, where the preamble is used to initiate random access, and the preamble is associated with the first uplink reference signal.

2. The method according to claim 1, characterized in that The sending of the preamble code comprises: sending the preamble to the first network device; The first indication information comes from a second network device, and the first network device is different from the second network device.

3. The method according to claim 2, characterized in that: The cell associated with the first network device is a non-serving cell, and the cell associated with the second network device is a serving cell; or, The first network device and the second network device are different transmission reception points TRP in the same cell; or, The cells associated with the first network device and the second network device are different serving cells.

4. The method according to any one of claims 2 to 3, characterized in that: The first network device satisfies at least one of the following: The first network device does not have downlink transmission capability; or, The first network device is not configured with information related to downlink transmission, and the information related to downlink transmission includes at least one of information related to downlink reference signals, information related to downlink control channel transmission, information related to downlink data channel transmission, information related to downlink frame structure, information related to downlink time slots, or information related to downlink bandwidth.

5. The method according to any one of claims 1 to 4, characterized in that: The method further comprises: Receive second indication information, where the second indication information is used to indicate at least one of the following: The first network device initiating random access by the terminal device does not have downlink transmission capability; The type of signal referenced by the random access initiated by the terminal device is an uplink reference signal; or, The first network device to which the terminal device initiates random access is not configured with information related to downlink transmission, and the information related to downlink transmission includes at least one of information related to downlink reference signals, information related to downlink control channel transmission, information related to downlink data channel transmission, information related to downlink frame structure, information related to downlink time slots, or information related to downlink bandwidth.

6. The method according to any one of claims 1 to 5, characterized in that: The method further comprises: Information indicating a first network device is received, where the first network device is a network device for initiating random access by the terminal device.

7. The method according to any one of claims 1 to 6, characterized in that: Before sending the preamble, the method further includes: receiving information indicating the preamble, and determining the preamble according to the information indicating the preamble; or, The preamble is determined according to a first association relationship and the first uplink reference signal, where the first association relationship indicates that the first uplink reference signal is associated with the preamble.

8. The method according to any one of claims 1 to 7, characterized in that: The method further comprises: receiving mask information of a random access channel, and determining a random access opportunity according to the mask information of the random access channel; or, Determine a random access opportunity according to the second association relationship and the first uplink reference signal, where the second association relationship indicates that the first uplink reference signal is associated with the random access opportunity; The sending of the preamble code comprises: A preamble is sent at the random access opportunity.

9. The method according to any one of claims 1 to 8, characterized in that: The sending of the preamble code comprises: The preamble code is sent based on the downlink timing of the third network device, the first network device initiating random access by the terminal device is different from the third network device, the third network device is the same as or different from the second network device, and the second network device is the network device that sends the first indication information.

10. The method according to any one of claims 1 to 9, characterized in that: After sending the preamble, the method further includes: Searching for a physical downlink control channel PDCCH in a common search space associated with the third network device; A random access response is received according to the searched PDCCH, the random access response is received through a first beam, the first beam is a beam associated with a unified transmission configuration indication TCI state of the third network device or a beam associated with the first indication information, the first network device from which the terminal device initiates random access is different from the third network device, the third network device is the same as or different from the second network device, and the second network device is the network device that sends the first indication information.

11. The method according to claim 10, characterized in that The method further comprises: Sending first information, wherein the first information includes identification information of the terminal device; The first information satisfies at least one of the following conditions: the first information is associated with the first uplink reference signal; or the first information is sent based on the downlink timing of the third network device; The first network device for the terminal device to initiate random access is different from the third network device, the third network device is the same as or different from the second network device, and the second network device is the network device that sends the first indication information.

12. The method according to claim 11, characterized in that After sending the first information, the method further includes: PDCCH is received based on the second beam, where the second beam is a beam associated with the unified TCI state of the third network device, a beam associated with the first information, or a beam associated with the first indication information.

13. The method according to any one of claims 9 to 12, characterized in that: The method further comprises: receiving information indicating the third network device; or, The third network device is determined based on the content of the protocol definition.

14. The method according to any one of claims 1 to 13, characterized in that: The first indication information includes: a resource identifier and / or a resource set identifier of the first uplink reference signal.

15. The method according to any one of claims 1 to 14, characterized in that: The first indication information includes: a measurement result of the first uplink reference signal; or, A first threshold and a measurement result of the first uplink reference signal.

16. The method according to any one of claims 1 to 15, characterized in that: The path loss reference signal associated with the preamble code is the first uplink reference signal.

17. The method according to any one of claims 1 to 16, characterized in that: The first indication information is carried in downlink control information DCI or radio resource control RRC message.

18. A random access method, characterized in that: The method comprises: The first network device receives a preamble, where the preamble is used to initiate random access, and the preamble is associated with a first uplink reference signal; The second network device sends a random access response based on the preamble received by the first network device.

19. The method according to claim 18, characterized in that After the first network device receives the preamble, before the second network device sends a random access response based on the preamble received by the first network device, the method further includes: The first network device sends second information to the second network device, where the second information is used to indicate that the first network device has received the preamble; The second network device receives the second information.

20. The method according to claim 18 or 19, characterized in that The method further comprises: The first network device receives first information, the first information includes identification information of the terminal device, and the first information satisfies at least one of the following: the first information is associated with the first uplink reference signal; or the first information is sent based on the downlink timing of the third network device.

21. A communication device, characterized in that: Comprising means for executing the method as claimed in any one of claims 1 to 20.

22. A communication device, characterized in that: The device comprises a processor, wherein the processor implements the method according to any one of claims 1 to 20 through a logic circuit or executing a computer program or instruction.

23. A computer-readable storage medium, characterized in that: The storage medium stores a computer program or an instruction, and when the computer program or the instruction is executed by the communication device, the method according to any one of claims 1 to 20 is implemented.

24. A computer program product, characterized in that The computer program product stores a computer program, wherein the computer program includes program instructions, and when the program instructions are executed by a computer, the computer is caused to perform the method according to any one of claims 1 to 20.

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