Communication method and communication apparatus

Abstract

The present application discloses a communication method and a communication apparatus. The present application can be applied to communication scenarios that support a random access procedure and a multi-node resource multiplexing scenarios. The method comprises: receiving a first message, the first message comprising a first random access preamble; performing downlink transmission, where downlink transmission resources do not comprise downlink resources in a first window or downlink resources in the first window and in a beam direction where the first message is located, the first window comprising k time units in the cell to which the first random access preamble belongs and used for sending a second message, the second message and the first message belonging to the same random access process, and k being an integer greater than 0. Since the resources for downlink transmission do not comprise downlink resources in the first window or downlink resources in the first window and in a beam direction where the first message is located, interference of the transmission of second message caused by downlink transmission can be prevented, thereby improving the success rate of random access.

Description

Communication method and communication device

[0001] This application claims priority to the Chinese patent application with application number 202311295552.5 filed with the State Intellectual Property Office of China on September 28, 2023, and priority to the Chinese patent application with the invention name “Communication Method and Communication Device”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communications, and in particular to a communication method and a communication device. Background Art

[0003] Random access is the process by which user equipment (UE) establishes a connection with a cell (or network) and achieves uplink synchronization. After random access is completed, data interoperability can be performed between the base station and the UE. The UE can perform three basic functions through random access: 1) achieve uplink synchronization with the base station (e.g., gNB) through timing advance (TA); 2) apply for uplink resources (UL_GRANT): used to send Msg3; 3) allocate a unique identifier to the UE: the cell radio network temporary identifier (C-RNTI). The purpose of random access is to establish an uplink synchronization relationship between the UE and the cell and request that the cell allocate dedicated resources to the UE so that the UE can transmit services.

[0004] Currently, existing technical solutions have the problem of low random access success rate. Therefore, it is necessary to study technical solutions to improve the random access success rate.

[0005] Summary of the Invention

[0006] The embodiments of the present application disclose a communication method and a communication device, in order to improve the success rate of random access.

[0007] In a first aspect, an embodiment of the present application provides a communication method, the method comprising: receiving a first message, the first message including a first random access preamble; performing downlink transmission, the downlink transmission resources not including downlink resources within a first window or downlink resources within the first window in the beam direction where the first message is located, the first window including k time units used by the cell to which the first random access preamble belongs to send a second message, the second message and the first message belonging to the same random access process, and k is an integer greater than 0.

[0008] The resources for the downlink transmission do not include the downlink resources within the first window or the downlink resources within the first window in the beam direction where the first message is located. This can be replaced by: the resources for the downlink transmission do not include all beam directions within the first window or the downlink resources in the beam direction where the first message is located. Downlink transmission is performed, and the resources for the downlink transmission do not include the downlink resources within the first window or the downlink resources within the first window in the beam direction where the first message is located. This can be replaced by: no downlink transmission is performed within the first window or no downlink transmission is performed within the first window in the beam direction where the first message is located. Optionally, the first window is used to monitor the physical downlink control channel (PDCCH) corresponding to the second message. For example, the terminal device that sends the first message monitors the PDCCH corresponding to the second message in the first window, and receives the second message. In this application, the time unit can be a time slot, a subframe, or other time length (for example, a time length defined by a future communication standard), which is not limited in this application. The subframe can be 1ms, and the time slot can be 1ms, 0.5ms, 0.25ms, 0.125ms, 0.0625, etc. The subframes and time slots in this application may conform to the definitions in one or more existing communication standards, and may also change with the subsequent evolution of communication standards.

[0009] In an embodiment of the present application, the first window includes k time units used by the cell to which the first random access preamble belongs to send the second message, and the resources for downlink transmission do not include the downlink resources within the first window or the downlink resources within the first window in the beam direction where the first message is located. This can avoid interference of the downlink transmission with the transmission of the second message, thereby improving the success rate of random access.

[0010] In a possible implementation manner, the method is applied to an entity corresponding to a first cell, and the first random access preamble does not belong to a random access preamble of the first cell.

[0011] In this implementation, the first random access preamble does not belong to the random access preamble of the first cell, indicating that downlink transmission by the entity corresponding to the first cell within the first window may interfere with the transmission of the second message. The resources for downlink transmission by the entity corresponding to the first cell do not include downlink resources within the first window or downlink resources within the first window in the beam direction of the first message, thereby avoiding interference with the transmission of the second message.

[0012] In a possible implementation manner, the method further includes: detecting the received first message using a logical root sequence that is not the first cell (ie, not the current cell).

[0013] In this implementation, by detecting the received message (or signal) using the logical root sequence of a non-cell, it can be known that a random access preamble belonging to another cell is received, thereby avoiding interference with the random access process of other cells.

[0014] In a possible implementation manner, the time domain position of the first window and the time domain position of the first message satisfy a predefined relationship.

[0015] In this implementation, the time domain position of the first window and the time domain position of the first message satisfy a predefined relationship, so that the first cell obtains the time domain position of the first window based on the predefined relationship and the time domain position of the first message, and then avoids interference with the transmission of the second message by not using the downlink resources within the first window or the downlink resources within the first window in the beam direction where the first message is located during downlink transmission.

[0016] In a possible implementation manner, the method further includes: obtaining the time domain position of the first window based on the predefined relationship and the time domain position of the first message.

[0017] In this implementation, the time domain position of the first window can be obtained without increasing signaling overhead, thereby avoiding interference with the transmission of the second message based on the first window.

[0018] In one possible implementation, the second message is a random access response (RAR) message or a contention resolution message, and the first time unit in the first window is offset from the time unit in which the first random access preamble is located or the time unit in which the last symbol of the first random access preamble is located by f time units, where f is a predefined integer greater than 0. The offset of the first time unit in the first window from the time unit in which the first random access preamble is located or the time unit in which the last symbol of the first random access preamble is located by f time units can be an example of the above-mentioned predefined relationship. Alternatively, the above-mentioned predefined relationship can include: the offset of the first time unit in the first window from the time unit in which the first random access preamble is located or the time unit in which the last symbol of the first random access preamble is located by f time units. In this application, the random access preamble can be referred to as Msg1, the random access response message can be referred to as Msg2, and the contention resolution message can be referred to as Msg4; alternatively, the random access preamble can be referred to as MsgA, and the random access response message can be referred to as MsgB.

[0019] In this implementation, the first time unit in the first window is predefined to be offset by f time units from the time unit where the first random access preamble is located or the time unit where the last symbol of the first random access preamble is located. In this way, the first cell can obtain the first time unit in the first window based on the time domain position of the first message and the predefined relationship, and then avoid interference with the transmission of the second message by not using the downlink resources in the first window or the downlink resources in the first window in the beam direction where the first message is located during downlink transmission.

[0020] In a possible implementation, the second message is a contention resolution message, the first time unit among the k time units is offset by h time units from the time unit where the random access response message is located or the time unit where the last symbol of the random access response message is located, the random access response message and the second message belong to the same random access process, and h is a predefined integer greater than 0. The first time unit among the k time units may be the first time unit used to send (or transmit) the second message. The above-mentioned predefined relationship may include: the first time unit among the k time units is offset by h time units from the time unit where the random access response message is located or the time unit where the last symbol of the random access response message is located. In other words, the offset of h time units from the time unit where the random access response message is located or the time unit where the last symbol of the random access response message is located is included in the above-mentioned predefined relationship.

[0021] In this implementation, the first time unit for sending the second message is predefined to be offset by h time units from the time unit where the random access response message is located or the time unit where the last symbol of the random access response message is located; in this way, the first cell can obtain the first time unit for sending the second message based on the time domain position of the random access response message and the predefined relationship, thereby avoiding interference with the transmission of the second message.

[0022] In a possible implementation, the first time unit used by the cell to which the first random access preamble belongs to send the random access response message is offset by g time units from the time unit in which the first random access preamble is located or the time unit in which the last symbol of the first random access preamble is located, where g is a predefined integer greater than 0. The above-mentioned predefined relationship may further include: the first time unit used by the cell to which the first random access preamble belongs to send the random access response message is offset by g time units from the time unit in which the first random access preamble is located or the time unit in which the last symbol of the first random access preamble is located. In other words, the first time unit used by the cell to which the first random access preamble belongs to send the random access response message is offset by g time units from the time unit in which the first random access preamble is located or the time unit in which the last symbol of the first random access preamble is located, which is included in the above-mentioned predefined relationship.

[0023] In this implementation, the first time unit for the cell to which the first random access preamble belongs to send a random access response message is predefined to be offset by g time units from the time unit where the first random access preamble is located or the time unit where the last symbol of the first random access preamble is located; in this way, the first cell can obtain the first time unit for the cell to send a random access response message based on the time domain position of the first random access preamble and the predefined relationship, thereby avoiding interference with the transmission of the second message.

[0024] In a possible implementation manner, the first window is a random access response window, and the second message is a random access response message.

[0025] In one possible implementation, the second message is a random access response message, and the first window further includes s time units used by the cell to which the first random access preamble belongs to send a contention resolution message, the contention resolution message and the first message belong to the same random access procedure, and s is an integer greater than 0. Optionally, the first window is also used to monitor the PDCCH corresponding to the contention resolution message. For example, the terminal device that sends the first message also monitors the PDCCH corresponding to the contention resolution message within the first window, and receives the contention resolution message.

[0026] In this implementation, the first window also includes s time units used by the cell to which the first random access preamble belongs to send the contention resolution message. Downlink transmission resources performed by the entity corresponding to the first cell do not include downlink resources within the first window or downlink resources within the first window in the beam direction of the first message. This can prevent downlink transmission performed by the first cell from interfering with the transmission of the second message and the contention resolution message, thereby improving the random access success rate.

[0027] In a possible implementation, the starting position of the first window is offset by t time units from the time unit in which the first random access preamble is located or the time unit in which the last symbol of the first random access preamble is located, where t is a predefined integer greater than 0, or the starting position of the first window is the first downlink time unit after the cell to which the first random access preamble belongs sends the first message. The starting position of the first window can be replaced by the first time unit in the first window.

[0028] In this implementation, the starting position of the first window is predefined to be offset by t time units from the time unit where the first random access preamble is located or the time unit where the last symbol of the first random access preamble is located, so that the first cell determines the starting position of the first window based on the time domain position of the first random access preamble and the predefined time offset relationship, thereby avoiding interference with the transmission of the second message.

[0029] In one possible implementation, the method is applied to a communication scenario including multiple network devices, where at least two of the multiple network devices are unable to directly exchange information. Exemplarily, each network device in the communication scenario is unable to directly exchange information. The inability to directly exchange information between two network devices may be due to the two network devices having no wired connection and no wireless or backhaul interfaces.

[0030] If two network devices cannot directly exchange information, then when there is an overlapping coverage area between the two network devices, the random access process initiated by the two network devices for the UE in the overlapping coverage area cannot be coordinated between cells to avoid interference. In this implementation, the resources used by the entity corresponding to the first cell (a network device) for downlink transmission do not include the downlink resources within the first window or the downlink resources within the first window in the beam direction where the first message is located. This can avoid interference with the transmission of the second message and does not require interaction with the entities corresponding to other cells, thus solving the problem that the entities corresponding to other cells cannot avoid interference through information exchange.

[0031] In one possible implementation, the method is applied to any of the following multi-node resource reuse scenarios: relay, wireless mesh, integrated access and backhaul (IAB), ad hoc networks, and communications scenarios involving mobile IABs and / or mobile base stations. A multi-node resource reuse scenario refers to a networking scenario in which multiple nodes reuse resources (or multiplex resources).

[0032] In this implementation, the entity corresponding to the first cell avoids interference with the transmission of the second message by not using downlink resources within the first window or downlink resources within the first window in the beam direction of the first message during downlink transmission. The entity corresponding to the first cell does not need to exchange information with entities corresponding to other cells (e.g., base stations) to implement interference coordination, which can save signaling overhead.

[0033] In a second aspect, an embodiment of the present application provides another communication method, the method comprising: receiving a first message, the first message including a first random access preamble; sending a second message within a first window, the second message and the first message belonging to the same random access procedure, the time domain position of the first window and the time domain position of the first message satisfying a predefined relationship, and the second message being a contention resolution message. Optionally, the first window is used to monitor a PDCCH corresponding to the second message.

[0034] In an embodiment of the present application, the time domain position of the first window and the time domain position of the first message satisfy a predefined relationship, so that the network device (such as a base station) that receives the first message can obtain the time domain position of the first window based on the time domain position of the first message and the predefined relationship, and then avoid interference with the transmission of the second message by not using the downlink resources in the first window or the downlink resources in the first window in the beam direction where the first message is located during downlink transmission.

[0035] In a possible implementation manner, the method further includes: sending a random access response message within the first window, where the random access response message and the first message belong to the same random access procedure.

[0036] In this implementation, a random access response message and a contention resolution message (i.e., the second message) are sent within the first window. In this way, after the network device (e.g., a base station) that receives the first message obtains the time domain position of the first window based on the time domain position of the first message and the predefined relationship, it can avoid interference with the transmission of the random access response message and the contention resolution message by not using the downlink resources within the first window or the downlink resources within the first window in the beam direction where the first message is located during downlink transmission.

[0037] In a third aspect, an embodiment of the present application provides another communication method, the method comprising: sending a first message, the first message including a first random access preamble; receiving a second message, the second message and the first message belonging to the same random access process, the second message being sent by the cell to which the first random access preamble belongs within a first window, the time domain position of the first window and the time domain position of the first message satisfy a predefined relationship, and the second message being a contention resolution message. Optionally, the first window is used to monitor a PDCCH corresponding to the second message.

[0038] In an embodiment of the present application, the time domain position of the first window and the time domain position of the first message satisfy a predefined relationship, so that the network device (such as a base station) that receives the first message can obtain the time domain position of the first window based on the time domain position of the first message and the predefined relationship, and then avoid interference with the transmission of the second message by not using the downlink resources in the first window or the downlink resources in the first window in the beam direction where the first message is located during downlink transmission.

[0039] In a possible implementation manner of the third aspect, the method further includes: receiving a random access response message, where the random access response message is sent by the cell to which the first random access preamble belongs within the first window, and the random access response message and the first message belong to the same random access process.

[0040] In this implementation, a random access response message and a contention resolution message sent by a cell to which a first random access preamble belongs within a first window are received. Because the random access response message and the contention resolution message are sent by the cell within the first window, a network device (e.g., a base station) that receives the first message can avoid interference with the transmission of the random access response message and the contention resolution message by not using downlink resources within the first window or downlink resources within the first window in the beam direction of the first message during downlink transmission after obtaining the time domain position of the first window based on the time domain position of the first message and the predefined relationship.

[0041] In a possible implementation of the second aspect or the third aspect, a first time unit in the first window is offset from a time unit in which the first random access preamble is located or a time unit in which the last symbol of the first random access preamble is located by f time units, where f is a predefined integer greater than 0, and k is an integer greater than 0. The predefined relationship may include: the first time unit in the first window is offset from a time unit in which the first random access preamble is located or a time unit in which the last symbol of the first random access preamble is located by f time units.

[0042] In this implementation, the first time unit in the first window is predefined to be offset by f time units from the time unit where the first random access preamble is located or the time unit where the last symbol of the first random access preamble is located, so that the network device receiving the first message can obtain the first time unit in the first window based on the time domain position of the first message and the predefined relationship, and then avoid interference with the transmission of the second message by not using the downlink resources in the first window or the downlink resources in the first window in the beam direction where the first message is located during downlink transmission.

[0043] In a possible implementation manner of the second aspect or the third aspect, the method is applied to a communication scenario including multiple network devices, and at least two of the multiple network devices cannot directly exchange information.

[0044] In this implementation, the time domain position of the first window and the time domain position of the first message satisfy a predefined relationship, so that the network device that receives the first message obtains the time domain position of the first window based on the time domain position of the first message and the predefined relationship, without the need to interact with the network devices corresponding to other cells, thereby solving the problem that entities corresponding to other cells cannot avoid interference through information interaction.

[0045] In a possible implementation of the second or third aspect, the method is applied to any of the following multi-node resource reuse scenarios: relay, wireless mesh network, IAB, ad hoc network, and communication scenario including mobile IAB and / or mobile base station.

[0046] In this implementation, the time domain position of the first window and the time domain position of the first message satisfy a predefined relationship, so that the network device that receives the first message obtains the time domain position of the first window based on the time domain position of the first message and the predefined relationship, and does not need to interact with the network devices corresponding to other cells, which can save signaling overhead.

[0047] In a fourth aspect, an embodiment of the present application provides another communication method, comprising: receiving a first message, the first message including a first random access preamble; and sending a random access response message and a contention resolution message within a first window, wherein the first message, the random access response message, and the contention resolution message belong to the same random access procedure, and a time domain position of the first window and a time domain position of the first message satisfy a predefined relationship. Sending the random access response message and the contention resolution message within the first window can be understood as limiting the sending of the random access response message and the contention resolution message to within the first window.

[0048] In an embodiment of the present application, the time domain position of the first window and the time domain position of the first message satisfy a predefined relationship, so that the network device (such as a base station) that receives the first message can obtain the time domain position of the first window based on the time domain position of the first message and the predefined relationship, and then avoid interference with the transmission of random access response messages and contention resolution messages by not using the downlink resources within the first window or the downlink resources within the first window in the beam direction where the first message is located during downlink transmission.

[0049] In a fifth aspect, an embodiment of the present application provides another communication method, which includes: sending a first message, the first message including a first random access preamble; receiving a random access response message and a contention resolution message within a first window, the first message, the random access response message, and the contention resolution message belong to the same random access process, and the time domain position of the first window and the time domain position of the first message satisfy a predefined relationship.

[0050] In an embodiment of the present application, the time domain position of the first window and the time domain position of the first message satisfy a predefined relationship, so that the network device (such as a base station) that receives the first message can obtain the time domain position of the first window based on the time domain position of the first message and the predefined relationship, and then avoid interference with the transmission of random access response messages and contention resolution messages by not using the downlink resources within the first window or the downlink resources within the first window in the beam direction where the first message is located during downlink transmission.

[0051] In a possible implementation manner of the fourth aspect or the fifth aspect, the starting position of the first window is offset by w time units from the time unit in which the first random access preamble is located or the time unit in which the last symbol of the first random access preamble is located, where w is a predefined integer greater than 0, or the starting position of the first window is the first time unit after the cell to which the first random access preamble belongs sends the first message. The predefined relationship may include: the starting position of the first window is offset by w time units from the time unit in which the first random access preamble is located or the time unit in which the last symbol of the first random access preamble is located, where w is a predefined integer greater than 0, or the starting position of the first window is the first time unit after the cell to which the first random access preamble belongs sends the first message.

[0052] In this implementation, the network device that receives the first message can obtain the starting position within the first window based on the time domain position of the first message and the predefined relationship.

[0053] In a sixth aspect, an embodiment of the present application provides another communication method, which includes: receiving a first message, wherein the first message includes a first random access preamble; sending a second message, wherein the second message and the first message belong to the same random access process, and the time domain position of the second message and the time domain position of the first message satisfy a predefined relationship.

[0054] In an embodiment of the present application, the time domain position of the second message and the time domain position of the first message satisfy a predefined relationship, so that the network device (such as a base station) that receives the first message can obtain the time domain position of the second message based on the time domain position of the first message and the predefined relationship, thereby avoiding interference with the transmission of the second message.

[0055] In one possible implementation, the second message is a random access response message; the method also includes: sending a contention resolution message, the contention resolution message and the first message belong to the same random access process, the time domain position of the contention resolution message and the time domain position of the first message satisfy a predefined relationship, or the time domain position of the contention resolution message and the time domain position of the second message satisfy a predefined relationship.

[0056] In this implementation, the time domain position of the contention resolution message satisfies a predefined relationship with the time domain position of the first message; a network device (e.g., a base station) that receives the first message can obtain the time domain position of the contention resolution message based on the time domain position of the first message and the predefined relationship, thereby avoiding interference with the transmission of the contention resolution message. The time domain position of the contention resolution message satisfies a predefined relationship with the time domain position of the second message; a network device (e.g., a base station) that receives the first message can obtain the time domain position of the contention resolution message based on the time domain position of the second message and the predefined relationship, thereby avoiding interference with the transmission of the contention resolution message.

[0057] In the seventh aspect, an embodiment of the present application provides another communication method, which includes: sending a first message, the first message including a first random access preamble; receiving a second message, the second message and the first message belonging to the same random access process, and the time domain position of the second message and the time domain position of the first message satisfy a predefined relationship.

[0058] In an embodiment of the present application, the time domain position of the second message and the time domain position of the first message satisfy a predefined relationship, so that the network device (such as a base station) that receives the first message can obtain the time domain position of the second message based on the time domain position of the first message and the predefined relationship, thereby avoiding interference with the transmission of the second message.

[0059] In one possible implementation, the second message is a random access response message; the method also includes: receiving a contention resolution message, the contention resolution message and the first message belong to the same random access process, the time domain position of the contention resolution message and the time domain position of the first message satisfy a predefined relationship, or the time domain position of the contention resolution message and the time domain position of the second message satisfy a predefined relationship.

[0060] In this implementation, the time domain position of the contention resolution message satisfies a predefined relationship with the time domain position of the first message; a network device (e.g., a base station) that receives the first message can obtain the time domain position of the contention resolution message based on the time domain position of the first message and the predefined relationship, thereby avoiding interference with the transmission of the contention resolution message. The time domain position of the contention resolution message satisfies a predefined relationship with the time domain position of the second message; a network device (e.g., a base station) that receives the first message can obtain the time domain position of the contention resolution message based on the time domain position of the second message and the predefined relationship, thereby avoiding interference with the transmission of the contention resolution message.

[0061] In a possible implementation manner of the fourth or fifth aspect, the time domain position of the second message and the time domain position of the first message satisfying a predefined relationship include: a first time unit for transmitting the second message and a time unit in which the first random access preamble is located or a time unit in which the last symbol of the first random access preamble is located are offset by y time units, where y is a predefined integer greater than 0. For example, y is a predefined integer greater than 0.

[0062] In an eighth aspect, an embodiment of the present application provides a communication device having the function of implementing the behavior in the method embodiment of the first aspect, the second aspect, the fourth aspect, or the sixth aspect. The communication device can be a network device, or it can be a component of a network device (such as a processor, a chip, or a chip system, etc.), or it can be a logic module or software that can implement all or part of the functions of the network device. The functions of the communication device can be implemented by hardware, or they can be implemented by hardware executing corresponding software, and the hardware or software includes one or more modules or units corresponding to the above functions.

[0063] In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is used to receive a first message, the first message including a first random access preamble; the processing module is used to parse the first message; the transceiver module is also used to perform downlink transmission, the downlink transmission resources do not include downlink resources within the first window or downlink resources within the first window in the beam direction where the first message is located, the first window includes k time units used by the cell to which the first random access preamble belongs to send a second message, the second message and the first message belong to the same random access process, and k is an integer greater than 0.

[0064] In a possible implementation, the processing module is further configured to detect the received first message using a logical root sequence that is not the first cell (ie, not the current cell).

[0065] In a possible implementation, the time domain position of the first window and the time domain position of the first message satisfy a predefined relationship; the processing module is further used to obtain the time domain position of the first window based on the predefined relationship and the time domain position of the first message.

[0066] In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is used to receive a first message, the first message including a first random access preamble; the processing module is used to parse the first message; the transceiver module is also used to send a second message within a first window, the second message and the first message belong to the same random access process, the time domain position of the first window and the time domain position of the first message satisfy a predefined relationship, and the second message is a contention resolution message.

[0067] In a possible implementation manner, the transceiver module is further configured to send a random access response message within the first window, where the random access response message and the first message belong to the same random access procedure.

[0068] In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is used to receive a first message, the first message including a first random access preamble; the processing module is used to generate a random access response message and a contention resolution message; the transceiver module is further used to send the random access response message and the contention resolution message within a first window, the first message, the random access response message, and the contention resolution message belong to the same random access process, and the time domain position of the first window and the time domain position of the first message satisfy a predefined relationship.

[0069] In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the transceiver module is used to receive a first message, the first message including a first random access preamble; the processing module is used to generate a second message; the transceiver module is also used to send the second message, the second message and the first message belong to the same random access process, and the time domain position of the second message and the time domain position of the first message satisfy a predefined relationship.

[0070] In one possible implementation, the second message is a random access response message; the transceiver module is further used to send a contention resolution message, the contention resolution message and the first message belong to the same random access process, the time domain position of the contention resolution message and the time domain position of the first message satisfy a predefined relationship, or the time domain position of the contention resolution message and the time domain position of the second message satisfy a predefined relationship.

[0071] Possible implementations of the communication device of the eighth aspect may refer to various possible implementations of the first aspect, the second aspect, the fourth aspect, or the sixth aspect.

[0072] For the technical effects brought about by various possible implementation methods of the eighth aspect, reference may be made to the introduction to the technical effects of various possible implementation methods of the first aspect, the second aspect, the fourth aspect, or the sixth aspect.

[0073] In a ninth aspect, an embodiment of the present application provides a communication device having the function of implementing the behavior in the method embodiment of the third aspect, the fifth aspect, or the seventh aspect. The communication device may be a terminal device, or a component of the terminal device (such as a processor, a chip, or a chip system), or a logic module or software that can implement all or part of the functions of the terminal device. The functions of the communication device may be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions. In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the processing module is configured to generate a first message; the transceiver module is configured to send the first message, the first message including a first random access preamble; and receive a second message, the second message belonging to the same random access process as the first message, the second message being sent by the cell to which the first random access preamble belongs within a first window, the time domain position of the first window and the time domain position of the first message satisfy a predefined relationship, and the second message is a contention resolution message.

[0074] In a possible implementation, the transceiver module is further configured to receive a random access response message, where the random access response message is sent by the cell to which the first random access preamble belongs within the first window, and the random access response message and the first message belong to the same random access process.

[0075] In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the processing module is used to generate a first message; the transceiver module is used to send the first message, the first message including a first random access preamble; a random access response message and a contention resolution message are received within a first window, the first message, the random access response message, and the contention resolution message belong to the same random access process, and the time domain position of the first window and the time domain position of the first message satisfy a predefined relationship.

[0076] In one possible implementation, the communication device includes a transceiver module and a processing module, wherein: the processing module is used to generate a first message; the transceiver module is used to send the first message, the first message including a first random access preamble; and receive a second message, the second message and the first message belong to the same random access process, and the time domain position of the second message and the time domain position of the first message satisfy a predefined relationship.

[0077] In one possible implementation, the second message is a random access response message; the transceiver module is further used to receive a contention resolution message, the contention resolution message and the first message belong to the same random access process, the time domain position of the contention resolution message and the time domain position of the first message satisfy a predefined relationship, or the time domain position of the contention resolution message and the time domain position of the second message satisfy a predefined relationship.

[0078] Possible implementations of the communication device of the ninth aspect may refer to various possible implementations of the third aspect, the fifth aspect, or the seventh aspect.

[0079] For the technical effects brought about by various possible implementation methods of the ninth aspect, reference may be made to the introduction to the technical effects of various possible implementation methods of the third aspect, the fifth aspect, or the seventh aspect.

[0080] In the tenth aspect, an embodiment of the present application provides another communication device, which includes one or more processors, and the one or more processors are used to process data and / or information so that the method in any one of the above-mentioned aspects from the first to the seventh aspect is implemented.

[0081] Optionally, the communication device further includes a memory storing a program or instruction. When the program or instruction is executed by the processor, the communication device performs the method described in any one of the first to seventh aspects. Exemplarily, the communication device may be a chip, the processor may be a processing circuit in the chip, and the memory may be a random access memory or cache in the chip.

[0082] In the embodiment of the present application, during the execution of the above method, the process of sending information (or signals) in the above method can be understood as the process of outputting information based on the instructions of the processor. When outputting information, the processor outputs the information to the transceiver so that it can be transmitted by the transceiver. After being output by the processor, the information may undergo other processing before reaching the transceiver. Similarly, when the processor receives input information, the transceiver receives the information and inputs it into the processor. Furthermore, after the transceiver receives the information, the information may undergo other processing before being input into the processor.

[0083] For operations such as sending and / or receiving involved in the processor, unless otherwise specified, or unless they conflict with their actual functions or internal logic in the relevant descriptions, they can be generally understood as instructions output based on the processor.

[0084] During implementation, the processor may be a processor specifically configured to execute these methods, or may be a processor that executes computer instructions in a memory to execute these methods, such as a general-purpose processor. For example, the processor may also be configured to execute a program stored in a memory. When the program is executed, the communication device performs the method described in the first aspect or any possible implementation of the first aspect.

[0085] In a possible implementation, the memory is located outside the communication device. In a possible implementation, the memory is located inside the communication device.

[0086] In a possible implementation, the processor and the memory may also be integrated into one device, that is, the processor and the memory may also be integrated together.

[0087] In a possible implementation, the communication device further includes a transceiver, and the transceiver is configured to receive signals or send signals.

[0088] In the eleventh aspect, the present application provides another communication device, which includes a processing circuit and an interface circuit, wherein the interface circuit is used to acquire a signal or output a signal; the processing circuit is used to execute the method shown in any one of the above-mentioned first to seventh aspects.

[0089] In the twelfth aspect, the present application provides a computer-readable storage medium, which stores a computer program, and the computer program includes program instructions, which, when executed, enable the computer to execute the method shown in any one of the above-mentioned first to seventh aspects.

[0090] In a thirteenth aspect, the present application provides a computer program product, which includes a computer program, and the computer program includes program instructions, which, when executed, enable the computer to execute the method shown in any one of the above-mentioned first to seventh aspects.

[0091] In the fourteenth aspect, the present application provides a chip comprising a communication interface and a processor; the communication interface is used for transmitting and receiving signals of the chip; the processor is used for executing computer program instructions so that a communication device comprising the chip executes a method as shown in any one of the above-mentioned first to seventh aspects.

[0092] In the fifteenth aspect, an embodiment of the present application provides a communication system, comprising a communication device for implementing the above-mentioned first aspect or any possible implementation of the first aspect, a communication device for implementing the above-mentioned second aspect or any possible implementation of the second aspect, and a communication device for implementing the above-mentioned third aspect or any possible implementation of the third aspect.

[0093] In a sixteenth aspect, an embodiment of the present application provides a communication system, comprising a communication device for implementing the fourth aspect or any possible implementation of the fourth aspect, and a communication device for implementing the fifth aspect or any possible implementation of the fifth aspect. Optionally, the communication system further comprises a communication device for implementing the first aspect or any possible implementation of the first aspect.

[0094] In a seventeenth aspect, an embodiment of the present application provides a communication system, comprising a communication device for implementing the sixth aspect or any possible implementation of the sixth aspect, and a communication device for implementing the seventh aspect or any possible implementation of the seventh aspect. Optionally, the communication system further comprises a communication device for implementing the first aspect or any possible implementation of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0095] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background technology, the drawings required for use in the embodiments of the present application or the background technology will be described below.

[0096] FIG1 is a schematic diagram of a contention-based random access process;

[0097] FIG2 is a schematic diagram of a non-contention-based random access process;

[0098] FIG3 is a schematic diagram of a multi-node resource reuse scenario provided by an embodiment of the present application;

[0099] FIG4A is a schematic diagram of the architecture of a communication system to which an embodiment of the present application may be applied;

[0100] FIG4B is a schematic diagram of the architecture of another communication system that can be applied in the embodiment of the present application;

[0101] FIG4C is a schematic diagram of a possible application framework in a communication system;

[0102] FIG5 is a flow chart of a communication method provided in an embodiment of the present application;

[0103] FIG6A is a schematic diagram of a time unit for transmitting Msg1, Msg2, and Msg4 according to an embodiment of the present application;

[0104] FIG6B is a schematic diagram of another time unit for transmitting Msg1, Msg2, and Msg4 provided in an embodiment of the present application;

[0105] FIG7A is an example of a comparison diagram of a first window determined by network device #1 and a first window determined by network device #2 provided in an embodiment of the present application;

[0106] FIG7B is an example of a comparison diagram of a second window determined by network device #1 and a second window determined by network device #2 provided in an embodiment of the present application;

[0107] FIG8 is a flow chart of another communication method provided in an embodiment of the present application;

[0108] FIG9 is a flow chart of another communication method provided in an embodiment of the present application;

[0109] FIG10 is a flow chart of another communication method provided in an embodiment of the present application;

[0110] FIG11 is an example of the time domain position of a first window and the time domain position of Msg1 provided in an embodiment of the present application;

[0111] FIG12 is another example of the time domain position of the first window and the time domain position of Msg1 provided in an embodiment of the present application;

[0112] FIG13 is a schematic structural diagram of a communication device 1300 provided in an embodiment of the present application;

[0113] FIG14 is a schematic structural diagram of another device 140 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0114] The terms "first" and "second" in the specification, claims and drawings of the present application are only used to distinguish different objects, rather than to describe a specific order. It will be understood that the various digital numbers involved in the embodiments of the present application are only for the convenience of description and are not used to limit the scope of the embodiments of the present application. The size of the sequence number of each of the above processes does not mean the order of execution, and the order of execution of each process should be determined by its function and inherent logic. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0115] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it refer to independent or alternative embodiments that are mutually exclusive of other embodiments. It will be understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0116] The terms used in the following embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and appended claims of the present application, the singular expressions "one", "a kind of", "said", "above", "the" and "this" are intended to also include plural expressions, unless there is a clear contrary indication in the context. It should also be understood that the term "and / or" used in the present application refers to and includes any or all possible combinations of one or more listed items. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The term "multiple" used in the present application refers to two or more. In the textual description of the present application, the character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0117] It is understood that in each embodiment of the present application, "A corresponds to B" means that there is a corresponding relationship between A and B, and B can be determined according to A. However, it should also be understood that determining (or generating) B according to (or based on) A does not mean that B is determined (or generated) only according to (or based on) A, and B can also be determined (or generated) according to (or based on) A and / or other information.

[0118] It should be understood that, in this application, indication includes direct indication (also known as explicit indication) and implicit indication. Direct indication of information A refers to including information A; implicit indication of information A refers to indicating information A through the correspondence between information A and information B and the direct indication of information B. The correspondence between information A and information B can be predefined, pre-stored, pre-burned, or pre-configured.

[0119] It should be understood that, in this application, information C is used to determine information D, which includes both information D being determined solely based on information C and information D being determined based on information C and other information. Furthermore, information C can also be used to determine information D indirectly, for example, where information D is determined based on information E, and information E is determined based on information C.

[0120] In addition, in each embodiment of the present application, "network element A sends information A to network element B" can be understood as the destination end of the information A or the intermediate network element in the transmission path between the destination end and the network element B, which may include directly or indirectly sending information to network element B. "Network element B receives information A from network element A" can be understood as the source end of the information A or the intermediate network element in the transmission path between the source end and the network element A, which may include directly or indirectly receiving information from network element A. The information may be processed as necessary between the source end and the destination end of the information transmission, such as format changes, but the destination end can understand the valid information from the source end. Similar expressions in this application can be understood similarly and will not be elaborated here.

[0121] To facilitate understanding of the solutions of the present application, the following first introduces the terms and technical solutions involved in the embodiments of the present application.

[0122] Random Access

[0123] Random access is the process by which user equipment (UE) establishes a connection with a cell (or network) and achieves uplink synchronization. It is also a necessary process for establishing a wireless link between the UE and the cell (e.g., 4G network, 5G network). After the UE completes random access, data can be interoperated between the base station and the UE. The UE can achieve the following three basic functions through random access:

[0124] 1) Acquire uplink synchronization with network equipment (e.g., gNB) through timing advance (TA). Once uplink synchronization is lost, that is, the UE fails to achieve uplink synchronization with the network equipment, the UE can only transmit signals in the physical random access channel (PRACH). Downlink synchronization between the UE and the network equipment is achieved through a special synchronization channel. Specifically, the network equipment broadcasts the downlink synchronization signal to each UE through the special synchronization channel, and the network equipment continuously broadcasts the downlink synchronization signal at a certain interval. If the UE uses this broadcast synchronization mechanism in the uplink, it will actually waste energy and cause a lot of interference to other UEs.

[0125] 2) UL_GRANT: includes uplink resources used by the UE to send Msg3, which is the message sent by the UE in the third step of the contention-based random access procedure.

[0126] 3) Assign a unique identifier to the UE: the cell radio network temporary identifier (C-RNTI). The purpose of random access is to establish uplink synchronization between the UE and the cell and request the cell to allocate dedicated resources to the UE, so that normal service transmission can be carried out.

[0127] Some examples of random access usage scenarios are as follows:

[0128] Scenario Example (Case) 1: Initial Radio Resource Control (RRC) Connection Establishment: When the UE transitions from the RRC-IDLE state to the RRC-CONNECTED state, the UE initiates random access, such as initial access.

[0129] Scenario Example 2: RRC Connection Reestablishment: When the radio link failure (RLF) between the UE and the cell fails and the UE needs to re-establish the RRC connection with the cell, the UE initiates random access.

[0130] Scenario Example 3: Cell Handover: When a UE performs cell handover, the UE initiates random access in the target cell (the cell to which the UE will be handed over).

[0131] Scenario Example 4: Downlink Data Arrival. When a UE is in a connected state and a network device (e.g., an eNodeB) has downlink data to transmit to the UE but detects that the UE is out of uplink synchronization, the network device controls the UE to initiate random access and transmit the corresponding ACK / NACK character in the uplink.

[0132] Scenario Example 5: Uplink Data Arrival. When a UE is in a connected state and has uplink data to transmit to a network device, but finds itself in an uplink out-of-sync state or no physical uplink control channel (PUCCH) resources are available for scheduling request (SR) transmission (UEs already in uplink synchronization are allowed to use the random access channel (RACH) to replace the SR function), the UE will initiate a random access.

[0133] There are two modes of random access procedure: contention based random access procedure (implies inherent collision risk) and non-contention based random access procedure.

[0134] Figure 1 is a schematic diagram of a contention-based random access process. The contention-based random access process shown in Figure 1 can be called a four-step random access process. As shown in Figure 1, the contention-based random access process is divided into the following four steps:

[0135] The first step (or step 1): The UE sends a random access preamble on the physical random access channel (PRACH). The base station obtains the random access preamble identifier (RAPID) and the downlink transmission beam (Tx Beam) by detecting the random access preamble, and estimates the transmission delay. The random access preamble can be called Msg1. The principle of the base station detecting the random access preamble is to use the logical root sequence of the cell to calculate the correlation peak of the random access preamble in the detection interval, and send the identifier (preamble ID) of the random access preamble to the UE through the RAR. If the preamble ID in the RAR received by the UE is consistent with the sent preamble ID, it is considered that Msg2 is received successfully; if not, it is considered that Msg2 reception failed, and the UE will re-initiate random access on the next PRACH after the RAR detection window.

[0136] Step 2 (or Step 2): The base station sends a random access response (RAR) (also called Msg2) on the physical downlink shared channel (PDSCH). The RAR carries the TA, RAPID, temporary cell radio network temporary identifier (TC-RNTI) corresponding to the transmission delay estimated in the first step, and the uplink grant (UL Grant) sent for Msg3 in step 3. UL is the abbreviation for uplink. The UE uses the TA to adjust the uplink timing. Msg2 is sent on the downlink transmission beam determined in the first step.

[0137] Step 3 (or step 3): The UE schedules to send Msg3 according to the uplink authorization in the RAR, and Msg3 carries the identification information of the UE.

[0138] Step 4: The base station sends a contention resolution message (also called Msg4) to the UE on the PDSCH. This resolves contention and collisions caused by multiple UEs attempting to access the same random access resource and the same random access preamble. Msg4 is sent on the downlink transmission beam determined in Step 1.

[0139] Figure 2 is a schematic diagram of a non-contention-based random access process. The non-contention-based random access process shown in Figure 1 can be called a two-step random access process. As shown in Figure 2, the non-contention-based random access process is divided into the following two steps:

[0140] In step A, the UE sends a random access preamble (also called MsgA) to the first network device.

[0141] In step A, the random access preamble and the content sent via the physical uplink shared channel (PUSCH) ("PUSCH payload") are generally referred to as MsgA. The "PUSCH payload" is generally considered to be similar to Msg3 ("Scheduled Transmission") in the four-step random access process. MsgA, or the "PUSCH payload," can carry RRC messages such as RRCSetupRequest, RRCResumeRequest, and RRCResumeRequest1.

[0142] In step B, after successfully receiving the random access preamble, the first network device returns a random access response message (also called MsgB) to the UE.

[0143] In step B, the random access response message is generally referred to as MsgB, which generally carries the content of the RAR message in the second step and the contention resolution message in the fourth step of the four-step random access process.

[0144] Non-contention-based random access uses dedicated random access resources and random access preambles, and there is no contention conflict, so the third and fourth steps are not required.

[0145] In a multi-node networking scenario, in order to improve the system spectrum efficiency, resources (including frequency resources) are usually reused between nodes. Hereinafter, a multi-node resource reuse scenario refers to a networking scenario of multi-node resource reuse (or resource reuse). Figure 3 is a schematic diagram of a multi-node resource reuse scenario provided by an embodiment of the present application. As shown in Figure 3, node 1 and node 2 reuse resources, that is, the resources used for the downlink transmission of node 1 and the downlink transmission of node 2 are the same. After node 3 in the coverage overlap area of ​​node 1 and node 2 initiates random access to node 1, the Msg2 / Msg4 sent by node 1 to node 3 will be interfered with by the downlink transmission of node 2. The interference will cause node 3 to fail to decode Msg2 / Msg4, thereby causing random access failure. Exemplarily, node 3 needs to join the self-organizing network associated with node 1, and node 3 initiates random access to node 1. Exemplarily, node 3 initiates random access to node 1 after RLF occurs. Exemplarily, node 3 initiates random access to node 1 when switching from the cell corresponding to node 2 to the cell corresponding to node 1. This application does not limit the triggering conditions for node 3 to initiate random access to node 1.

[0146] A node in this application can be a network device (e.g., a gNB), a terminal device, a node with some or all of the functions of a network device, or a node with wireless backhaul and / or wireless access functions (e.g., an IAB node). Referring to Figure 3, an example of a multi-node resource reuse scenario is as follows: Nodes 1, 2, and 3 all include gNBs and customer premises equipment (CPE). Customer premises equipment can also be referred to as customer terminal equipment (CPE). CPE refers to hardware physically located on the user side, such as servers, workstations, modems, hubs, bridges, switches, routers, and mobile terminals (MTs) in IAB nodes. In this application, a gNB is used as an example of a network device. When node 3 includes a gNB and a CPE, a random access initiated by node 3 to node 1 can be initiated by the CPE included in node 3 to node 1. Referring to Figure 3, another example of a multi-node resource reuse scenario is as follows: Nodes 1 and 2 all include gNBs and CPEs, and node 3 is a terminal device. Referring to Figure 3, another example of a multi-node resource reuse scenario is as follows: Nodes 1 and 2 are both gNBs, and Node 3 is a terminal device. Referring to Figure 3, another example of a multi-node resource reuse scenario is as follows: One of Nodes 1 and 2 is a gNB, the other of these two nodes includes a gNB and a CPE, and Node 3 is a terminal device.

[0147] In a multi-node resource reuse scenario, a terminal device initiates a random access process in an overlapping coverage area of ​​multiple nodes (such as a base station). Due to inter-node resource reuse, downlink interference may occur, causing the terminal device to fail to decode Msg2 or Msg4, thereby causing random access failure. Referring to Figure 3, the Msg2 / Msg4 sent by node 1 to node 3 will be interfered with by the downlink transmission of node 2. This interference will cause node 3 to fail to decode Msg2 / Msg4, thereby causing random access failure. In a multi-node resource reuse scenario, since the Msg2 / Msg4 sent by the network device to the terminal device will be interfered with by the downlink transmission of other network devices, the existing technical solutions have the problem of low random access success rate. Therefore, it is necessary to study technical solutions applicable to multi-node resource reuse scenarios, so as to improve the random access success rate. The present application provides a technical solution applicable to multi-node resource reuse scenarios, which can improve the random access success rate.

[0148] The technical solution provided by the present application is intended to reduce or avoid interference from downlink transmission of other network devices to Msg2 / Msg4 sent by a network device to a terminal device in a multi-node resource reuse scenario. For example, referring to Figure 3, the interference from downlink transmission of node 2 to Msg2 / Msg4 sent by node 1 to node 3 is reduced or avoided. An example of the technical solution provided by the present application is: in the process of node 1 sending a RAR message (Msg2) to node 3, node 2 does not perform downlink transmission (or downlink scheduling) or does not perform downlink transmission in the beam direction corresponding to the RAR message. The beam direction corresponding to the RAR message can be the beam direction of the random access preamble (Mg1) associated with the RAR message, that is, the beam direction of the random access preamble sent by the terminal device. In other words, an example of the technical solution provided by the present application is: referring to Figure 3, node 1 sends a RAR message to node 3, and the resources for node 2 to perform downlink transmission do not include: the downlink resources within the time window in which node 1 sends the RAR message (for example, the first window below), or, within the time window in which node 1 sends the RAR message, the downlink resources in the beam direction corresponding to the RAR message.

[0149] Based on the above ideas, a possible implementation method of the technical solution provided by the present application is as follows: predefine the relationship between the time domain position of Msg1 and the time domain position of the first window, or in other words, the time domain position of Msg1 and the time domain position of the first window satisfy the predefined relationship, and the first window includes the time unit used by the cell to which the Msg1 belongs to send Msg2 and / or Msg4 associated with the Msg1; the network device that receives the Msg1 (for example, node 2 in Figure 3) obtains the time domain position of the first window based on the time domain position of Msg1; the resources for downlink transmission by the network device do not include the downlink resources within the first window or the downlink resources in the beam direction of the Msg1 within the first window. The first window can be regarded as the time window for the cell to which Msg1 belongs to send Msg2 and / or Msg4. Since the resources for downlink transmission by the network device that receives the Msg1 do not include the downlink resources within the first window or the downlink resources in the beam direction of the Msg1 within the first window, the downlink transmission of the network device will not interfere with the transmission of Msg2 and / or Msg4 associated with the Msg1. In this possible implementation, the network device obtains the time domain position of the first window based on the time domain position of the received Msg1, and does not need to interact with the network device corresponding to the cell to which the Msg1 belongs. That is to say, in the technical solution provided by the present application, the network devices do not need to interact with each other through information to reduce or avoid interference caused to Msg2 / Msg4, which can save signaling overhead. The technical solution provided by the present application is applicable to multi-node resource reuse scenarios where network devices cannot directly interact with each other. In addition, the technical solution provided by the present application can also be applicable to multi-node resource reuse scenarios where network devices can directly interact with each other, which can reduce signaling overhead.

[0150] The following describes a communication system to which the technical solution provided by this application is applicable.

[0151] The technical solution provided in this application can be applied to various communication systems, such as: long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, world-wide interoperability for microwave access (WiMAX) communication system, fifth generation (5G) or new radio (NR) system, wireless local area network (WLAN) system, satellite communication system, future communication system, such as sixth generation (6G) mobile communication system, or a fusion system of multiple systems, etc., which supports random access procedures.

[0152] The technical solutions provided in the embodiments of the present application are also applicable to other communication systems that support random access procedures. The above-mentioned communication systems to which the technical solutions provided in the embodiments of the present application are applicable are merely examples. The communication systems to which the power control solution provided in the present application is applicable are not limited thereto. They are described here uniformly and will not be elaborated on below.

[0153] A first device in a communication system can send a signal to a second device or receive a signal from a third device. The signal may include information, signaling, or data, etc. The device may also be replaced by an entity, a network entity, a communication device, a communication module, a node, a communication node, etc. The present disclosure uses a network element as an example for description. The first device may be a network device or a terminal device, the second device may be a network device or a terminal device, and the third device may be a network device or a terminal device. For example, the communication system may include at least one terminal device and at least one network device. The network device may send a downlink signal to the terminal device, and / or the terminal device may send an uplink signal to the network device. It is understandable that the terminal device in the present disclosure may be replaced by the first device, and the network device may be replaced by the second device, and both perform the corresponding communication method in the present disclosure.

[0154] The technical solution provided in this application can be applied to any of the following scenarios: relay, wireless mesh network, integrated access & backhaul (IAB), mobile IAB, ad hoc network, mobile base station and other scenarios. The networking nodes in the above scenarios include nodes with all or part of the functions of a base station, or nodes with wireless backhaul function and wireless access function. For scenarios such as mobile base stations and mobile IAB, the cells are not fixed and static, there is no wired connection between base stations, and there are no wireless interfaces and backhaul interfaces. The base stations cannot directly exchange information. Then, the random access process initiated by the base station for the terminal device in the overlapping coverage area cannot be coordinated between cells to avoid interference. The technical solution provided in this application does not require direct information exchange between base stations, and is therefore applicable to scenarios such as mobile base stations and mobile IAB. For communication scenarios where there is a wired connection or wireless interface between at least two base stations, in order to reduce the overhead of information exchange between base stations, it is also possible not to transmit information between base stations to achieve interference coordination. The technical solution provided in this application is applied to communication scenarios where there is a wired connection or wireless interface between at least two base stations, which can save signaling overhead.

[0155] Figure 4A is a schematic diagram of the architecture of a communication system that can be used in an embodiment of the present application. As shown in Figure 4A, the communication system includes a network device 110, a network device 120, a terminal device 130, and a terminal device 140. The communication system that can be used in an embodiment of the present application includes one or more terminal devices, with terminal device 130 and terminal device 140 being used as examples of terminal devices in the communication system. Figure 4A is merely a schematic diagram, and the embodiment of the present application does not limit the number of network devices and terminal devices included in the communication system. Terminal device 130 can access network device 110 and communicate with network device 110. Terminal device 140 can access network device 120 and communicate with network device 120. Exemplarily, terminal device 130 is located in the overlapping coverage area of ​​network device 110 and network device 120.

[0156] Figure 4B is a schematic diagram of the architecture of another communication system that can be applied in an embodiment of the present application. As shown in Figure 4B, the communication system includes a network device 110, a terminal device 130, a terminal device 140, and multiple relay nodes (Figure 4B only shows relay nodes #1 to #7). The communication system that can be applied in an embodiment of the present application includes one or more terminal devices, with terminal device 130 and terminal device 140 as examples of terminal devices in the communication system. Figure 4B is only a schematic diagram, and the embodiment of the present application does not limit the number of network devices, terminal devices, and relay nodes included in the communication system. Terminal device 130 and terminal device 140 can access network device 110 through the relay node and communicate with network device 110. Exemplarily, the relay node is an IAB node or an AP, and terminal device 130 can be located in the overlapping coverage area of ​​relay node #1 and relay node #2.

[0157] In the embodiments of the present application, terminal equipment may also be referred to as user equipment (UE), access terminal, subscriber unit, user station, mobile station, mobile station (MS), remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device.

[0158] The terminal device may be a device that provides wireless communication functions, such as a handheld device or a vehicle-mounted device with a wireless connection function. At present, some examples of terminal devices are: mobile phones, cellular phones, smart phones, tablet computers, laptop computers, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to wireless modems, wearable devices, terminal devices in 5G networks or future evolved public land mobile communication networks (PLMNs). Terminal equipment in a land mobile network (PLMN), etc., is not limited to this in the embodiments of the present application.

[0159] By way of example and not limitation, in embodiments of the present application, the terminal device may also be a mobile termination (MT) in an IAB node. Referring to FIG4B , the relay node may be an IAB node. When the IAB node faces its parent node, it may be considered a terminal device, in which case the IAB node plays the role of the MT.

[0160] As an example and not a limitation, in the embodiment of the present application, the terminal device may also be a wearable device. Wearable devices may also be called wearable smart devices, which are a general term for wearable devices that are intelligently designed and developed using wearable technology for daily wear, such as glasses, gloves, watches, clothing, and shoes. A wearable device is a portable device that is worn directly on the body or integrated into the user's clothes or accessories. Wearable devices are not only hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are fully functional, large in size, and can achieve complete or partial functions without relying on smartphones, such as smart watches or smart glasses, as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0161] In the embodiments of the present application, the device for realizing the function of the terminal device can be a terminal device, or a device capable of supporting the terminal device to realize the function, such as a chip system, which can be installed in the terminal device or used in combination with the terminal device. In the embodiments of the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices. In the embodiments of the present application, only the terminal device is used as an example for description, and the embodiments of the present application are not limited to the solutions of the embodiments of the present application.

[0162] The network device in the embodiments of the present application may be a device for communicating with a terminal device, and may also be referred to as an access network device or a radio access network device. For example, the network device may be a base station. The network device in the embodiments of the present application may refer to a radio access network (RAN) node (or device) that connects a terminal device to a wireless network. The term "base station" may broadly cover the following names or be replaced with the following names, such as RAN node, NodeB, evolved NodeB (eNB), next generation NodeB (gNB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home evolved NodeB, or home NodeB, HNB), baseband unit (BBU), wireless relay node, wireless backhaul node, relay station, transmitting and receiving point (TRP), IAB node, transmitting point (TP), master station, auxiliary station, multi-standard radio (motor slide retainer, MSR) node, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CNU), etc. unit (CU), distributed unit (DU), radio unit (RU), positioning node, one or a group of (including multiple antenna panels) antenna panels of a base station in a 5G system, etc.

[0163] An IAB node integrates a mobile termination (MT) and a distributed unit (DU). An IAB node may include an MT, a DU, and a central unit (CU). A central unit may be referred to as a central unit or central unit. An IAB node may include one CU and one or more DUs. When an IAB node includes a CU, it is an IAB donor node. The CU in the IAB donor node accesses the core network through a next-generation application protocol (NG) interface. When an IAB node faces its parent node, it can be considered a terminal, in which case the IAB node plays the role of an MT. When an IAB node faces its child node (the child node may be a terminal or the MT of another IAB node), the IAB node can be considered a network device. An IAB node can establish a backhaul connection with at least one parent node of the IAB node through the MT portion. The DU portion of an IAB node can provide access services to the MT portion of a terminal or another IAB node.

[0164] The base station can be a macro base station, a micro base station, a relay node, a donor node or the like, or a combination thereof. The base station can also refer to a communication module, a modem or a chip used to be set in the aforementioned device or apparatus. The base station can also be a mobile switching center and a device that performs the base station function in device to device (D2D), vehicle to everything (V2X), and machine to machine (M2M) communications, a network side device in a 6G network, and a device that performs the base station function in future communication systems. The base station can support networks with the same or different access technologies. Optionally, the RAN node can also be a server, a wearable device, a vehicle or an on-board device, etc. For example, the access network device in the V2X technology can be a road side unit (RSU). The embodiments of the present application do not limit the specific technology and specific device form adopted by the network equipment.

[0165] Base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move based on the location of the mobile base station. In other examples, a helicopter or drone can be configured to act as a device that communicates with another base station.

[0166] In some deployments, the network devices mentioned in the embodiments of the present application may include a CU, a DU, or both a CU and a DU, or a control plane CU node (central unit-control plane (CU-CP)), a user plane CU node (central unit-user plane (CU-UP)), and a DU node. For example, the network devices may include a gNB-CU-CP, a gNB-CU-UP, and a gNB-DU.

[0167] In some deployments, multiple RAN nodes collaborate to assist terminals in achieving wireless access, with different RAN nodes implementing portions of base station functionality. For example, a RAN node can be a CU, DU, CU-CP, CU-UP, or RU. The CU and DU can be separate or included in the same network element, such as the BBU. The RU can be included in radio frequency equipment, such as the RRU, AAU, or RRH.

[0168] The RAN node may support one or more types of fronthaul interfaces, with different fronthaul interfaces corresponding to DUs and RUs with different functions. If the fronthaul interface between the DU and the RU is a common public radio interface (CPRI), the DU is configured to implement one or more baseband functions, and the RU is configured to implement one or more radio frequency functions. If the fronthaul interface between the DU and the RU is another type of interface, relative to the CPRI, some of the downlink and / or uplink baseband functions, such as precoding, digital beamforming (BF), or one or more of inverse fast Fourier transform (IFFT) / cyclic prefix (CP) for downlink, are moved from the DU to the RU for implementation; and for uplink, one or more of digital beamforming (BF), or fast Fourier transform (FFT) / cyclic prefix (CP) removal, are moved from the DU to the RU for implementation. In one possible implementation, the interface may be an enhanced common public radio interface (eCPRI). In the eCPRI architecture, the division between the DU and RU is different, corresponding to different types (Categories) of eCPRI, such as eCPRI Cat A, B, C, D, E, and F.

[0169] Taking eCPRI Cat A as an example, for downlink transmission, based on layer mapping, the DU is configured to implement layer mapping and one or more functions preceding it (i.e., one or more of coding, rate matching, scrambling, modulation, and layer mapping). Other functions after layer mapping (e.g., resource element (RE) mapping, digital beamforming (BF), or one or more of inverse fast Fourier transform (IFFT) / cyclic prefix (CP) addition) are moved to the RU for implementation. For uplink transmission, based on RE demapping, the DU is configured to implement demapping and one or more functions preceding it (i.e., one or more of decoding, rate matching, descrambling, demodulation, inverse discrete Fourier transform (IDFT), channel equalization, and RE demapping). Other functions after demapping (e.g., one or more of digital BF or fast Fourier transform (FFT) / CP removal) are moved to the RU for implementation. It is understandable that for the functional description of DU and RU corresponding to various types of eCPRI, reference can be made to the eCPRI protocol, which will not be described in detail here.

[0170] In one possible design, the processing unit for implementing baseband functions in the BBU is called a baseband high layer (BBH) unit, and the processing unit for implementing baseband functions in the RRU / AAU / RRH is called a baseband low layer (BBL) unit.

[0171] In different systems, CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in an open radio access network (ORAN) system, CU may also be referred to as O-CU (open CU), DU may also be referred to as O-DU, CU-CP may also be referred to as O-CU-CP, CU-UP may also be referred to as O-CU-UP, and RU may also be referred to as O-RU. Any of the CU (or CU-CP, CU-UP), DU and RU in this application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0172] In the embodiments of the present application, the device for implementing the functions of the network device can be a network device; it can also be a device that can support the network device to implement the functions, such as a chip system, a hardware circuit, a software module, or a hardware circuit and a software module. The device can be installed in the network device or used in conjunction with the network device. In the embodiments of the present application, only the device for implementing the functions of the network device is used as an example to illustrate, and does not constitute a limitation on the solutions of the embodiments of the present application.

[0173] The network device and / or terminal device can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on the water surface; it can also be deployed on aircraft, balloons and satellites in the air. The embodiments of this application do not limit the scenarios in which the network device and the terminal device are located. In addition, the terminal device and the network device can be hardware devices, or they can be software functions running on dedicated hardware, software functions running on general-purpose hardware, such as virtualization functions instantiated on a platform (e.g., a cloud platform), or entities including dedicated or general-purpose hardware devices and software functions. This application does not limit the specific forms of the terminal device and the network device.

[0174] It should be noted that the network architecture described in the embodiment of the present application is to more clearly illustrate the technical solutions of the embodiment of the present application, and does not constitute a limitation on the technical solutions provided in the embodiment of the present application. Those skilled in the art will appreciate that, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiment of the present application are equally applicable to similar technical problems. In the following embodiments, the technical solutions provided in the embodiment of the present application are described by taking the device for implementing the functions of the network device as a network device and the network device as a base station as an example.

[0175] Figure 4C is a schematic diagram of a possible application framework in a communication system. As shown in Figure 4C, the communication system includes: core network equipment, access network nodes, operation administration and maintenance (OAM) network elements, and terminal equipment. In this communication system, network elements are connected through interfaces (such as NG, Xn) or air interfaces. The access network node can be a separate RAN node, or it can include multiple RAN nodes, for example, including CU and DU. The CU and / or DU can also be set with one or more AI modules. Optionally, the CU can also be split into CU-CP and CU-UP. One or more AI models are set in the CU-CP and / or CU-UP.

[0176] It is understood that the present application does not specifically limit the specific structure of the execution subject of the method provided in the embodiment of the present application. As long as it is possible to communicate according to the method provided in the embodiment of the present application by running a program that records the code of the method provided in the embodiment of the present application. The method provided in the embodiment of the present application can be applied to communication between a terminal device and a network device. The following is an example of the interaction between a terminal device and a network device (taking a base station as an example) for explanation.

[0177] FIG5 is a flow chart of a communication method provided in an embodiment of the present application. As shown in FIG5 , the method includes:

[0178] 501. The terminal device sends a first message to the network device #1.

[0179] Correspondingly, network device #1 receives the first message from the terminal device, and network device #2 receives the first message from the terminal device. The dotted arrow in Figure 5 indicates that network device #2 receives the first message from the terminal device. Exemplarily, the terminal device may be located in the overlapping coverage area of ​​network device #1 and network device #2, and network device #1 and network device #2 reuse resources. The message sent by network device #1 to the terminal device (such as the second message below) may be interfered with by the downlink transmission of network device #2. Network device #2 can be an example of a network device (excluding network device #1) that receives the first message. If multiple network devices (including network device #2) receive the first message, the operations performed by the multiple network devices may be similar to the operations performed by network device #2 after receiving the first message. Figure 5 takes network device #2 as an example to describe the operations performed by the network device (excluding network device #1) that receives the first message after receiving the first message.

[0180] The first message may include a first random access preamble. The first message may be Msg1, MsgA, or other messages having a similar function to Msg1 / MsgA, such as a message sent by a terminal device in a random access process defined by a subsequent communication standard. The entity corresponding to the cell to which the first random access preamble belongs may be network device #1. In other words, the first random access preamble is included in a preamble sequence associated with the cell managed by network device #1. The first random access preamble does not belong to a random access preamble of the first cell supported by network device #2. In other words, the first random access preamble is not included in a preamble sequence associated with the cell managed by network device #2.

[0181] 502. Network device #1 sends a second message to the terminal device in the first window.

[0182] The second message may be a random access response message (i.e., Msg2), a contention resolution message (i.e., Msg4), MsgB, or a message having a similar function to Msg2. The second message and the first message belong to the same random access procedure. The first window includes k time units used by the cell to which the first random access preamble belongs to send the second message. The second message and the first message belong to the same random access procedure, where k is an integer greater than 0. Optionally, the first window is used to monitor the PDCCH corresponding to the second message. For example, the terminal device monitors the PDCCH corresponding to the second message within the first window and receives the second message. The length (or size) of the first window may be a predefined fixed value or a plurality of predefined optional values. The length of the first window used by network device #1 may be any one of the plurality of predefined optional values. For example, network device #1 determines the length of the first window based on channel quality. The length of the first window determined by network device #1 when the channel quality is poor (e.g., below a threshold value) is greater than the length of the first window determined when the channel quality is good (e.g., above a threshold value). Network device #1 may also determine the length of the first window in other ways, which is not limited in this application. For example, the first window includes v time units, where v is a predefined integer greater than 0, for example, v is 1. For another example, the first window is a RAR window, and the second message is Msg2. For another example, the first window includes multiple time units included in the RAR window and s time units for sending a contention resolution message, and the contention resolution message and the first message belong to the same random access process, and s is an integer greater than 0. The multiple time units in the first window may be continuous in time or discontinuous in time. For example, the first window includes a first sub-window and a second sub-window, and the time units in the first sub-window are time units used by network device #1 to transmit the second message, and the time units in the second sub-window are time units used by network device #1 to transmit the contention resolution message, and the time units in the first sub-window and the time units in the second sub-window are discontinuous in time. Among them, the RAR window refers to the window in which the terminal device receives the RAR. All or part of the time domain resources in the window are actually used by the network device to transmit the RAR or at least one of the PDCCHs of the RAR. The length of the window can be configured by the network device to the terminal device, such as 1, 2, 4, 8, 10, 20, 40, or 80 time slots. For details, please refer to the definition in the existing 3GPP protocol and will not be repeated here.

[0183] In one possible implementation, the time-domain position of the first window and the time-domain position of the first message satisfy a predefined relationship. Exemplarily, network device #1 may store or pre-configure the predefined relationship. After receiving the first message, network device #1 may obtain the time-domain position of the first window based on the time-domain position of the first message and the predefined relationship. After obtaining the time-domain position of the first window, network device #1 executes step 502.

[0184] In a possible implementation, the first window is a random access response window, and the second message is a random access response message.

[0185] In one possible implementation, the first window is a time window used by network device #1 to send a second message, and the first window may include one or more time units. The time domain position of the first window may be the time domain position of the above-mentioned second message. The time domain position of the second message (i.e., the time domain position of the first window) satisfies a predefined relationship with the time domain position of the first message. Exemplarily, the time domain position of the second message and the time domain position of the first message satisfying a predefined relationship may be: the first time unit used to transmit the second message (i.e., the first time unit used by network device #1 to transmit the second message) is offset by y time units from the time unit where the first random access preamble is located or the time unit where the last symbol of the first random access preamble is located, where y is a predefined integer greater than 0. 502 may be replaced by: network device #1 sends a second message to the terminal device. The second message is a random access response message or a contention resolution message.

[0186] 503. Network device #2 performs downlink transmission, and the resources of the downlink transmission do not include downlink resources within the first window or downlink resources within the first window in the beam direction where the first message is located.

[0187] The first window includes k time units used by the cell to which the first random access preamble belongs to send the second message. The second message and the above-mentioned first message belong to the same random access process. k is an integer greater than 0. For example, k is 1, 2, 3, 4, 5, 6, 8, etc. In the present application, a time unit can be one or more subframes, one or more time slots, one or more mini-time slots or other time lengths, which are not limited in this application. Step 503 can be replaced by: network device #2 does not perform downlink transmission within the first window or does not perform downlink transmission in the beam direction where the above-mentioned first message is located within the first window, and the first window includes k time units used by the cell to which the first random access preamble belongs to send the second message.

[0188] Figure 6A is a schematic diagram of a time unit for transmitting Msg1, Msg2, and Msg4 provided in an embodiment of the present application. In Figure 6A, each rectangular box represents a time unit, the terminal device sends Msg1 in the time unit indicated by arrow 601 (hereinafter referred to as time unit #1), the network device #1 sends Msg2 in the time unit indicated by arrow 602 (hereinafter referred to as time unit #2), and the network device #1 sends Msg4 in the time unit indicated by arrow 603 (hereinafter referred to as time unit #3). Exemplarily, the first window includes time unit #2 and / or time unit #3. Referring to Figure 6A, an example of step 503 is: network device #2 performs downlink transmission, and the resources of the above downlink transmission do not include downlink resources within time unit #2 (i.e., the first window) or downlink resources within time unit #2 in the beam direction where the first message is located. Referring to Figure 6A, another example of step 503 is: network device #2 performs downlink transmission, and the resources for the above downlink transmission do not include the downlink resources within time unit #3 (i.e., the first window) or the downlink resources within time unit #3 in the beam direction where the first message is located. Referring to Figure 6A, another example of step 503 is: network device #2 performs downlink transmission, and the resources for the above downlink transmission do not include the downlink resources within time unit #2 or the downlink resources within time unit #2 in the beam direction where the first message is located, as well as the downlink resources within time unit #3 or the downlink resources within time unit #3 in the beam direction where the first message is located. Figure 6A is only an example, and the embodiment of the present application does not limit the offset between time unit #1 and time unit #2, and the offset between time unit #2 and time unit #3. In addition, there is no limitation on whether each time unit in Figure 6A corresponds to uplink or downlink.

[0189] Figure 6B is a schematic diagram of another time unit for transmitting Msg1, Msg2, and Msg4 provided in an embodiment of the present application. In Figure 6B, each rectangular box represents a time unit, the terminal device sends Msg1 in the j1 time units indicated by arrow 604 (hereinafter referred to as time unit #4), the network device #1 sends Msg2 in the j2 time units indicated by arrow 605 (hereinafter referred to as time unit #5), and the network device #1 sends Msg4 in the j3 time units indicated by arrow 606 (hereinafter referred to as time unit #6). j1, j2, and j3 are all integers greater than 0, and at least one of j1, j2, and j3 is greater than 1. Exemplarily, the first window includes time unit #5 and / or time unit #6. Referring to Figure 6B, another example of step 503 is: network device #2 performs downlink transmission, and the resources of the above downlink transmission do not include the downlink resources within time unit #5 (i.e., the first window) or the downlink resources within time unit #5 in the beam direction where the first message is located. Referring to Figure 6B, another example of step 503 is: network device #2 performs downlink transmission, and the resources for the downlink transmission do not include the downlink resources within time unit #5 or the downlink resources within time unit #5 in the beam direction where the first message is located, and the downlink resources within time unit #6 or the downlink resources within time unit #6 in the beam direction where the first message is located. Figure 6B is only an example, and the embodiment of the present application does not limit the offset between the first time unit in time unit #4 and the first time unit in time unit #5, and the offset between the first time unit in time unit #5 and the first time unit in time unit #6. In addition, there is no limitation on whether each time unit in Figure 6B corresponds to uplink or downlink.

[0190] In one possible implementation, the time domain position of the first window and the time domain position of the first message satisfy a predefined relationship. Exemplarily, network device #2 may store the predefined relationship or be pre-configured with the predefined relationship. After receiving the first message, network device #2 may obtain the time domain position of the first window based on the time domain position of the first message and the predefined relationship. After obtaining the time domain position of the first window, network device #2 executes step 503. The first window obtained by network device #2 based on the time domain position of the first message and the predefined relationship may be consistent with the first window obtained by network device #1 based on the time domain position of the first message and the predefined relationship. Alternatively, the first window obtained by network device #2 based on the time domain position of the first message and the predefined relationship may include the first window obtained by network device #1 based on the time domain position of the first message and the predefined relationship.

[0191] In one possible implementation, after receiving the first message and before executing step 503, network device #2 performs the following operations: by detecting the received first message using the logical root sequence of a cell not managed by network device #2, it is determined that a random access preamble that does not belong to the current cell (i.e., the cell managed by network device #2) has been received. In other words, network device #2 detects the received first message using the logical root sequence of a cell not managed by network device #2, and determines that a random access preamble that does not belong to the current cell (i.e., the cell managed by network device #2) has been received. Exemplarily, network device #2 first detects the received first message using the logical root sequence of the current cell; after failing to successfully detect the random access preamble that belongs to the current cell, it detects the received first message using the logical root sequence of the cell managed by network device #1, and determines that a random access preamble that does not belong to the current cell (i.e., the cell managed by network device #2) has been received. Network device #2 may store the logical root sequence of the cell managed by network device #1. Network device #2 can obtain the logical root sequence of the cell managed by network device #1 by interacting with network device #1; it can also be obtained based on the physical cell identifier (PCI) of the cell managed by network device #1, for example, the logical root sequence supported by the cell managed by network device #1 is the product of the PCI of the cell managed by network device #1 and a predefined sequence; the logical root sequence of the cell managed by network device #1 can also be obtained in other ways. For example, cell #2 managed by network device #2 is adjacent to cell #1 managed by network device #1, that is, network device #2 and network device #1 are adjacent, network device #2 can store the logical root sequence of cell #1, and network device #1 can store the logical root sequence of cell #2. In this implementation, by detecting the received message (or signal) using the logical root sequence of a non-cell, it can be known that a random access preamble belonging to another cell is received, thereby avoiding interference with the random access process of other cells.

[0192] In an embodiment of the present application, the first window includes k time units used by the cell to which the first random access preamble belongs to send the second message, and the resources for downlink transmission by network device #2 do not include the downlink resources within the first window or the downlink resources within the first window in the beam direction where the first message is located. This can avoid interference of the downlink transmission with the transmission of the second message, thereby improving the success rate of random access.

[0193] The following describes possible implementations of the predefined relationship between the time domain position of the first window and the time domain position of the first message, and an example of network device #1 or network device #2 obtaining the first window based on the first message and the predefined relationship.

[0194] In one possible implementation, the predefined relationship may include a time offset between the first time unit of the first window and the time unit in which the first message (or the first random access preamble) is located, or the time unit in which the last symbol of the first message is located. For example, when the terminal device transmits the first message through one time unit, the predefined relationship includes the time offset between the first time unit in the first window and the time unit in which the first random access preamble is located; when the terminal device transmits the first message through multiple time units, the predefined relationship includes the time offset between the first time unit in the first window and the time unit in which the last symbol of the first random access preamble is located.

[0195] Example 1: The second message is a random access response message or a contention resolution message, and the predefined relationship is that the first time unit in the first window is offset from the time unit where the first random access preamble is located or the time unit where the last symbol of the first random access preamble is located by f time units, and f is a predefined integer greater than 0. The first window can be the time window used by network device #1 to transmit the second message. The time domain position of the first window and the time domain position of the first message satisfy the predefined relationship, which can be: the time domain position of the second message and the time domain position of the first message satisfy the predefined relationship. For example, the first time unit used by network device #1 to transmit the second message is offset from the time unit where the first random access preamble is located or the time unit where the last symbol of the first random access preamble is located by f time units. In this example, f is a predefined fixed value. For example, f is any one of 5, 6, 8, 9, 10, 12, 15, 20, 30, etc. The offset of the first time unit in the first window from the time unit in which the first random access preamble is located by f time units can be replaced by: the interval between the first time unit in the first window and the time unit in which the first random access preamble is located is (f-1) time units. In other words, the predefined relationship is to fix the interval between the first time unit in the first window and the time unit in which the random access preamble is located to (f-1) time units. An example of the predefined relationship of the offset of the first time unit in the first window from the time unit in which the first random access preamble is located by f time units is: the second message is Msg2, and the first time unit used to transmit Msg2 (i.e., the first time unit in the first window) is separated from the time unit in which the first random access preamble is located by 10 time units, i.e., f is 11. In this example, assuming that the time unit in which the first random access preamble is located is the e-th time unit, network device #1 or network device #2 can determine, based on the first message and the predefined relationship, that the first time unit in the first window is the (e+11)-th time unit, where e is an integer greater than 0. Another example of the predefined relationship being that the first time unit in the first window and the time unit where the first random access preamble is located are offset by f time units is: the second message is Msg4, and the first time unit used to transmit Msg4 (i.e., the first time unit in the first window) is 10 time units away from the time unit where the first random access preamble is located, i.e., f is 11.

[0196] Example 2: The second message is a random access response message or a contention resolution message, and the predefined relationship is that the first time unit in the first window is offset from the time unit in which the first random access preamble is located or the time unit in which the last symbol of the first random access preamble is located by f time units, where the value of f is in the range of f1≤f≤f2, i.e., f is greater than or equal to f1, f is less than or equal to f2, and f1 and f2 are integers greater than 0. In other words, the predefined relationship is that the first time unit in the first window is offset from the time unit in which the first random access preamble is located or the time unit in which the last symbol of the first random access preamble is located by f1 to f2 time units, i.e., the offset is at least f1 time units and at most f2 time units. In other words, the predefined relationship is that the interval between the first time unit in the first window and the time unit in which the first random access preamble is located or the time unit in which the last symbol of the first random access preamble is (f1-1) to (f2-1) time units, i.e., the interval is at least (f1-1) time units and at most (f2-1) time units. For example, f1 is 5 and f2 is 10. For another example, f1 is 10 and f2 is 20. An example in which the predefined relationship is that the first time unit in the first window and the time unit in which the first random access preamble is located are offset by f (f1≤f≤f2) time units is as follows: the second message is Msg2, and the interval between the first time unit for transmitting MSG2 (i.e., the first time unit in the first window) and the time unit in which the first random access preamble is located is not less than 10 time units and not more than 20 time units, i.e., f1 is 11 and f2 is 21. In this example, assuming that the time unit in which the first random access preamble is located is the e-th time unit, network device #1 or network device #2 can determine, based on the first message and the predefined relationship, that the first time unit in the first window is any one of the (e+11)th time unit to the (e+21)th time unit, where e is an integer greater than 0.

[0197] The first window determined by network device #2 may be different from the first window determined by network device #1. When network device #1 determines, based on the first message and the predefined relationship, that the first time unit in the first window is any one of a plurality of temporally consecutive time units, network device #1 may use any of the plurality of time units as the first time unit in the first window. When network device #2 determines, based on the first message and the predefined relationship, that the first time unit in the first window is any one of a plurality of temporally consecutive time units, network device #2 may use the first time unit in the plurality of time units as the first time unit in the first window, and determine the last time unit in the first window by using the last time unit in the plurality of time units as the first time unit in the first window. For example, network device #1 or network device #2 can determine, based on the first message and the predefined relationship, that the first time unit in the first window is any one of the (e+11)th time unit to the (e+21)th time unit, where the first window includes v time units; network device #1 uses the (e+13)th time unit as the first time unit in the first window, and the (e+12+v)th time unit as the last time unit in the first window; network device #2 uses the (e+11)th time unit as the first time unit in the first window, and the (e+20+v)th time unit as the last time unit in the first window. Figure 7A is an example of a comparative schematic diagram of a first window determined by network device #1 and a first window determined by network device #2, provided in an embodiment of the present application. Referring to Figure 7A, the first time unit in the first window is any one of the (e+11)th time unit to the (e+21)th time unit; 701 represents the first window determined by network device #1, the first time unit in the first window determined by network device #1 is the (e+13)th time unit, and the last time unit is the (e+12+v)th time unit; 702 represents the first window determined by network device #2, the first time unit in the first window determined by network device #2 is the (e+11)th time unit, and the last time unit is the (e+20+v)th time unit.

[0198] Example 3: The second message is a random access response message, and the above predefined relationship is that the first time unit in the first window is offset from the time unit where the first random access preamble is located or the time unit where the last symbol of the first random access preamble is located by g time units, g is a predefined integer greater than 0, or the value range of g is g1≤g≤g2, g1 and g2 are integers greater than 0. In this example, the time unit in the first window is the time unit used to transmit the random access response message, and the last time unit in the first window is the time unit where the random access response message is located or the time unit where the last symbol of the above random access response message is located. The second window includes o time units used by the cell to which the above first random access preamble belongs (i.e., the cell managed by network device #1) to send contention resolution messages, and o is an integer greater than 0. In Example 3, the second window can be the time window used by network device #1 to transmit contention resolution messages. The time domain position of the second window satisfies the predefined relationship with the time domain position of the first window. To distinguish the predefined relationship between the time domain position of the second window and the time domain position of the first window, and the predefined relationship between the time domain position of the first window and the time domain position of the first message, the predefined relationship between the time domain position of the second window and the time domain position of the first window is named predefined relationship #1 below. Exemplarily, predefined relationship #1 includes the first time unit in the second window being offset from the last time unit in the first window by h time units, where h is a predefined integer greater than 0, or the value range of h is h1≤h≤h2, with h1 and h2 being integers greater than 0. For example, the last time unit in the first window is the dth time unit, and the first time unit in the second window is the (d+h)th time unit, where d is an integer greater than 0. For another example, the last time unit in the first window is the dth time unit, and the first time unit in the second window is any one of the (d+h1)th time unit to the (d+h2)th time unit.

[0199] The second window determined by network device #1 may be different from the second window determined by network device #2. When network device #1 determines, based on the time domain position of the first window and predefined relationship #1, that the first time unit in the second window is any one of a plurality of temporally continuous time units, network device #1 may use any one of the plurality of time units as the first time unit in the second window. When network device #2 determines, based on the time domain position of the first window and predefined relationship #1, that the first time unit in the second window is any one of a plurality of temporally continuous time units, network device #2 may use the first time unit in the plurality of time units as the first time unit in the second window, and determine the last time unit in the second window by using the last time unit in the plurality of time units as the first time unit in the second window. For example, network device #1 and network device #2 can determine, based on the first message and the predefined relationship, that the first time unit in the first window is any one of the (e+11)th time unit to the (e+21)th time unit, and the first window includes v time units; network device #1 uses the (e+13)th time unit as the first time unit in the first window, and the (e+12+v)th time unit as the last time unit in the first window; network device #2 uses the (e+11)th time unit as the first time unit in the first window, and the (e+20+v)th time unit as the last time unit in the first window; network device #1 determines, based on the time domain position of the first window determined by it and the predefined relationship #1, that the first time unit in the second window is any one of the (e+12+v+h1)th time unit to the (e+12+v+h2)th time unit, and the second window includes v1 time units, where v1 is an integer greater than 0; network device #1 The (e+13+v+h1)th time unit is used as the first time unit in the second window, and the (e+13+v+h1+v1-1)th time unit is used as the last time unit in the second window; network device #2 determines that the first time unit in the second window is any one of the (e+10+v+h1)th time unit to the (e+20+v+h2)th time unit based on the time domain position of the first window determined by it and the predefined relationship #1; network device #2 uses the (e+10+v+h1)th time unit as the first time unit in the second window, and the (e+20+v+h2+v1-1)th time unit as the last time unit in the second window.

[0200] FIG7B is an example of a comparison diagram of a second window determined by network device #1 and a second window determined by network device #2 provided in an embodiment of the present application. Referring to FIG7B , the first time unit in the first window is any one of the (e+11)th time unit to the (e+21)th time unit; 701 represents the first window determined by network device #1, the first time unit in the first window determined by network device #1 is the (e+13)th time unit, and the last time unit is the (e+12+v)th time unit; 702 represents the first window determined by network device #2, the first time unit in the first window determined by network device #2 is the (e+11)th time unit, and the last time unit is the (e+21)th time unit. +20+v) time unit; 703 represents the second window determined by network device #1, the first time unit in the second window determined by network device #1 is the (e+13+v+h1)th time unit, and the last time unit is the (e+13+v+h1+v1-1)th time unit; 704 represents the second window determined by network device #2, the first time unit in the second window determined by network device #2 is the (e+10+v+h1)th time unit, and the last time unit is the (e+20+v+h2+v1-1)th time unit.

[0201] Example 4: The second message is a random access response message. The first window also includes s time units used by the cell to which the first random access preamble belongs to send a contention resolution message. The contention resolution message and the first message belong to the same random access procedure, and s is an integer greater than 0. The predefined relationship is that the starting position of the first window (i.e., the first time unit in the first window) is offset by t time units from the time unit in which the first random access preamble is located or the time unit in which the last symbol of the first random access preamble is located, where t is a predefined integer greater than 0, or the value range of t is t1≤t≤t2, and t1 and t2 are integers greater than 0. Alternatively, the starting position of the first window is the first downlink time unit after the cell to which the first random access preamble belongs sends the first message. The starting position of the first window may also be other downlink time units after the cell to which the first random access preamble belongs sends the first message, which is not limited in this application. In this example, network device #1 transmits Msg2 and Msg4 within the first window. In other words, the transmission of Msg2 and Msg4 is completed within the first window. To prevent network device #2 (corresponding to the interfering cell of the terminal device) from interfering with the random access process of the terminal device, network device #2 can determine, based on the first message and the predefined relationship, that network device #1 (corresponding to the target serving cell of the terminal device) will send Msg2 and Msg4 within the first window. After network device #2 detects the random access preamble sent by the terminal device and learns that the random access preamble is a random access preamble of a non-cell, it does not perform downlink transmission within the first window or does not perform downlink transmission in the beam direction of the first message within the first window; this can prevent network device #2 (corresponding to the interfering cell of the terminal device) from interfering with the random access process of the terminal device.

[0202] Network device #1 and network device #2 may determine the starting position of the first window based on the first message and the predefined relationship. The length of the first window may be a predefined fixed value or a plurality of predefined optional values. When the length of the first window is a predefined fixed value, the first windows determined by network device #1 and network device #2 based on the first message and the predefined relationship may be the same. When the length of the first window is a plurality of predefined optional values, the first windows determined by network device #1 and network device #2 based on the first message and the predefined relationship may be different. The first window determined by network device #2 based on the first message and the predefined relationship may include the first window determined by network device #1 based on the first message and the predefined relationship. For example, network device #1 determines that the first time unit in the first window is the i-th time unit based on the first message and the predefined relationship, and the length of the first window is a predefined plurality of optional values, the plurality of optional values ​​including optional value #1, optional value #2, ..., optional value #z, where i is an integer greater than 0; when network device #1 uses optional value #2 as the length of the first window, the last time unit in the first window is the (i-1+optional value #2)th time unit; network device #2 determines that the first time unit in the first window is the i-th time unit based on the first message and the predefined relationship; network device #2 determines that the last time unit in the first window is the (i-1+optional value #z)th time unit, where optional value #z is the largest of the plurality of optional values. That is, when the length of the first window is a plurality of optional values, the first window in which network device #2 does not perform downlink transmission is the first window with the longest length. In this way, when network device #1 (the target service cell supporting the terminal device) sends MSG2 and MSG4 to the terminal device, network device #2 will not interfere with the terminal device's reception of MSG2 and MSG4.

[0203] FIG8 is a flow chart of another communication method provided in an embodiment of the present application. The method flow in FIG8 is a possible implementation of the method described in FIG5. As shown in FIG8, the method includes:

[0204] 801. The terminal device sends a first message to the network device #1.

[0205] Accordingly, network device #1 receives the first message from the terminal device, and network device #2 receives the first message from the terminal device. The dotted arrow in Figure 8 indicates that network device #2 receives the first message from the terminal device. Step 801 can refer to step 501. The first message may include a first random access preamble, for example, the first message is Msg1.

[0206] 802. Network device #1 detects the received first message using the logical root sequence of the current cell, and determines that a random access preamble belonging to the current cell has been received.

[0207] The procedure for network device #1 to detect the received first message using the logical root sequence of the local cell may be replaced by the procedure for network device #1 to detect the received first message using the logical root sequence of the cell it manages. The local cell in step 802 refers to the cell managed by network device #1. Step 802 may be replaced by the procedure for network device #1 to detect a random access preamble belonging to the local cell using the logical root sequence of the local cell.

[0208] 803. Network device #1 obtains the time domain position of the first window based on the time domain position of the first message.

[0209] In one possible implementation, the time domain position of the first window satisfies a predefined relationship with the time domain position of the first message. An example of step 803 is as follows: network device #1 obtains the time domain position of the first window based on the time domain position of the first message and the predefined relationship.

[0210] In one possible implementation, the first window is the time window used by network device #1 to send the second message. The first window may include one or more time units. The time domain position of the first window is the time domain position of the second message. The time domain position of the second message (i.e., the time domain position of the first window) satisfies a predefined relationship with the time domain position of the first message. Step 803 may be replaced by: Network device #1 obtains the time domain position of the second message based on the time domain position of the first message.

[0211] 804. Network device #1 sends a second message to the terminal device in the first window.

[0212] Accordingly, the terminal device receives the second message from network device #1. Step 804 may refer to step 502. The second message may be a random access response message, ie, Msg2. The first window includes k time units used by the cell to which the first random access preamble belongs to send the second message.

[0213] 805. Network device #2 detects the received first message using a logical root sequence of a non-cell and determines that a random access preamble not belonging to the cell is received.

[0214] The order of step 805 and step 802 is not limited. In step 805, the logical root sequence of the non-cell may be the logical root sequence of the neighboring cell (including the cell managed by network device #1) of the cell managed by it, which is stored or configured by network device #2. Step 805 can be replaced by: network device #2 detects the random access preamble that does not belong to the cell using the logical root sequence of the non-cell. The cell in step 805 refers to the cell managed by network device #2. A possible implementation of step 805 is as follows: network device #2 first detects the received first message using the logical root sequence of the cell; after failing to successfully detect the random access preamble belonging to the cell, it detects the received first message using the logical root sequence of the non-cell (including the cell managed by network device #1), and determines that a random access preamble that does not belong to the cell (i.e., the cell managed by network device #2) is received.

[0215] 806. Network device #2 obtains the time domain position of the first window based on the time domain position of the first message.

[0216] In one possible implementation, the time domain position of the first window satisfies a predefined relationship with the time domain position of the first message. An example of step 806 is as follows: network device #2 obtains the time domain position of the first window based on the time domain position of the first message and the predefined relationship.

[0217] In one possible implementation, the first window is the time window used by network device #1 to send the second message. The first window may include one or more time units. The time domain position of the second message (i.e., the time domain position of the first window) satisfies a predefined relationship with the time domain position of the first message. Step 806 may be replaced by: Network device #2 obtains the time domain position of the second message based on the time domain position of the first message.

[0218] 807. Network device #2 performs downlink transmission, and the resources of the downlink transmission do not include downlink resources within the first window or downlink resources within the first window in the beam direction where the first message is located.

[0219] Step 807 may refer to step 503 .

[0220] 808. The terminal device sends Msg3 to network device #1.

[0221] Correspondingly, network device #1 receives Msg3 from the terminal device. Msg3 may carry identification information of the terminal device.

[0222] 809. Network device #1 obtains the time domain position of the second window based on the time domain position of the first message or the time domain position of the first window.

[0223] The second window includes o time units used by network device #1 to send Msg4, where o is an integer greater than 0. Step 809 may be an operation in which network device #1 obtains the time window used by network device #1 to send Msg4 based on the time domain position of the first message or the time domain position of the first window. The second window and the first window may be discontinuous in time, which can reduce the impact on the downlink transmission of network device #2. The order of step 809 and step 803 or step 804 is not limited. In one possible implementation, the method in Figure 8 does not include step 809, and step 803 is replaced by: network device #1 obtains the time domain position of the first window based on the time domain position of the first message, and obtains the time domain position of the second window based on the time domain position of the first message or the time domain position of the first window.

[0224] In one possible implementation, the time domain position of the second window and the time domain position of the first message satisfy predefined relationship #2; network device #1 obtains the time domain position of the second window based on the time domain position of the first message, which may be: network device #1 obtains the time domain position of the second window based on the time domain position of the first message and the above-mentioned predefined relationship #2. The second window is the time window used by network device #1 to send the contention resolution message. The time domain position of the second window may be the time domain position of the contention resolution message. Exemplarily, the above-mentioned predefined relationship #2 is that the first time unit in the second window (i.e., the first time unit used to transmit Msg4) is offset by c time units from the time unit in which the first random access preamble is located or the time unit in which the last symbol of the first random access preamble is located, and the value range of c is c1≤c≤c2, that is, c is greater than or equal to c1, c is less than or equal to c2, and c1 and c2 are integers greater than 0. For example, c1 is 5 and c2 is 10. For another example, c1 is 10 and c2 is 20. For another example, c1 is 20 and c2 is 30. An example of predefined relationship #2 being an offset of c (c1≤c≤c2) time units between the first time unit in the second window and the time unit containing the first random access preamble or the time unit containing the last symbol of the first random access preamble is: the interval between the first time unit in the second window and the time unit containing the first random access preamble is no less than 10 time units and no more than 20 time units, i.e., c1 is 11 and c2 is 21. In this example, assuming that the time unit containing the first random access preamble is the c3th time unit, network device #1 and network device #2 can determine, based on the first message and predefined relationship #2, that the first time unit in the second window is any one of the (c3+11)th time unit to the (c3+21)th time unit, where e is an integer greater than 0. Network device #1 can use any one of the (c3+11)th time unit to the (c3+21)th time unit as the first time unit in the second window. Network device #2 may use the (c3+11)th time unit as the first time unit in the second window.

[0225] In one possible implementation, the time domain position of the second window and the time domain position of the first window satisfy the above-mentioned predefined relationship #1; network device #1 obtains the time domain position of the second window based on the time domain position of the first window, which may be: network device #1 obtains the time domain position of the second window based on the time domain position of the first window and the above-mentioned predefined relationship #1, refer to the relevant description of Example 3 above. Exemplarily, the first window is a time window for network device #1 to transmit a random access response message, and the second window is a time window for network device #1 to transmit a contention resolution message; the time domain position of the second window and the time domain position of the first window satisfying the above-mentioned predefined relationship #1 may be: the time domain position of the contention resolution message and the time domain position of the random access response message satisfy the above-mentioned predefined relationship #1; network device #1 obtains the time domain position of the second window based on the time domain position of the first window, which may be: network device #1 obtains the time domain position of the contention resolution message based on the time domain position of the random access response message.

[0226] 810. Network device #1 sends Msg4 to the terminal device in the second window.

[0227] Correspondingly, the terminal device receives Msg4 from network device #1.

[0228] 811. Network device #2 obtains the time domain position of the second window based on the time domain position of the first message or the time domain position of the first window.

[0229] The implementation of step 811 is similar to that of step 809 and will not be repeated here.

[0230] 812. Network device #2 performs downlink transmission, and the resources of the downlink transmission do not include downlink resources within the second window or downlink resources within the second window in the beam direction where the first message is located.

[0231] The first window is a moment or a time range. The second window is a moment or a time range. Network device #1 sends the second message, Msg2, to the terminal device within the first window and Msg4 to the terminal device within the second window. In other words, network device #1 schedules the transmission of Msg2 and Msg4 to occur at a fixed moment or within a time range.

[0232] In the embodiment of the present application, network device #1 transmits Msg2 and Msg4 at a fixed time or within a time range. Network device #2 detects the random access preamble of a non-local cell using the logical root sequence of the non-local cell, and does not perform downlink transmission at the time or time range corresponding to Msg2 and Msg4, or does not perform downlink transmission in the beam direction where the random access preamble is located. This can avoid interference with the random access process of the terminal device and improve the success rate of random access.

[0233] FIG9 is a flow chart of another communication method provided in an embodiment of the present application. The method flow in FIG9 is a possible implementation of the method described in FIG5. As shown in FIG9, the method includes:

[0234] 901. The terminal device sends MsgA to network device #1.

[0235] Accordingly, network device #1 receives MsgA from the terminal device, and network device #2 receives MsgA from the terminal device. The dotted arrow in Figure 9 indicates that network device #2 receives MsgA from the terminal device. MsgA may include a first random access preamble. MsgA may be an example of the first message in Figure 5. Steps 901 to 907 may refer to steps 801 to 807 and are not repeated here.

[0236] 902. Network device #1 detects the received MsgA using the logical root sequence of the current cell, and determines that a random access preamble belonging to the current cell has been received.

[0237] 903. Network device #1 obtains the time domain position of the first window based on the time domain position of MsgA.

[0238] The first window includes k time units used by network device #1 to send MsgB. Step 903 may be an operation in which network device #1 determines the time window used to transmit MsgB. MsgB is an example of the second message in FIG5 .

[0239] 904. Network device #1 sends MsgB to the terminal device in the first window.

[0240] Correspondingly, the terminal device receives MsgB from network device #1.

[0241] 905. Network device #2 detects the received MsgA using the logical root sequence of the non-cell and determines that a random access preamble not belonging to the cell is received.

[0242] The order of step 905 and step 902 is not limited.

[0243] 906. Network device #2 obtains the time domain position of the first window based on the time domain position of MsgA.

[0244] 907. Network device #2 performs downlink transmission, and the resources of the downlink transmission do not include the downlink resources in the first window or the downlink resources in the first window in the beam direction where MsgA is located.

[0245] The first window is a moment or a time range. Network device #1 sends MsgB to the terminal device within the first window, indicating that network device #1 will transmit MsgB at a fixed moment or a time range.

[0246] In the embodiment of the present application, network device #1 transmits MsgB at a fixed time or within a time range. Network device #2 detects the random access preamble of a non-local cell using the logical root sequence of the non-local cell, and does not perform downlink transmission at the time or time range corresponding to MsgB, or does not perform downlink transmission in the beam direction of the random access preamble. This can avoid interference with the random access process of the terminal device and improve the success rate of random access.

[0247] FIG10 is a flow chart of another communication method provided in an embodiment of the present application. The method flow in FIG10 is a possible implementation of the method described in FIG5. As shown in FIG10, the method includes:

[0248] 1001. The terminal device sends Msg1 to network device #1.

[0249] Accordingly, network device #1 receives Msg1 from the terminal device, and network device #2 receives Msg1 from the terminal device. The dotted arrow in Figure 10 indicates that network device #2 receives Msg1 from the terminal device. Msg1 may include a first random access preamble. Msg1 may be an example of the first message in Figure 5. Step 1001 may be an example of step 501.

[0250] 1002. Network device #1 detects the received Msg1 using the logical root sequence of the current cell, and determines that a random access preamble belonging to the current cell has been received.

[0251] Step 1002 may refer to step 802 .

[0252] 1003. Network device #1 obtains the time domain position of the first window based on the time domain position of Msg1.

[0253] The first window includes k time units used by network device #1 to send Msg2 and s time units used to send Msg4. Exemplarily, the time units in the first window are continuous in time. The first window may include a RAR window.

[0254] The time domain position of the first window and the time domain position of Msg1 satisfy a predefined relationship. For the predefined relationship satisfied by the time domain position of the first window and the time domain position of Msg1, please refer to the description of the predefined relationship in Example 4 above, which will not be repeated here. Figure 11 is an example of the time domain position of the first window and the time domain position of Msg1 provided in an embodiment of the present application. As shown in Figure 11, the time unit indicated by arrow 1101 is the time unit where the first random access preamble (i.e., the preamble in Figure 10) is located, and the time unit indicated by arrow 1102 is the first time unit in the first window. The first time unit in the first window is offset from the time unit where the first random access preamble is located by t time units, that is, the first time unit in the first window and the time unit where the first random access preamble is located are separated by (t-1) time units, and t is a predefined integer greater than 0, for example, t is 3, 4, 5, 6, 10, etc. Figure 12 is another example of the time domain position of the first window and the time domain position of Msg1 provided in an embodiment of the present application. As shown in Figure 12, the time unit indicated by arrow 1201 is the time unit where the first random access preamble (i.e., the preamble in the figure) is located, the time unit indicated by arrow 1202 is the first downlink time unit after network device #1 sends Msg1, and the starting position of the first window is the first downlink time unit after network device #1 sends Msg1.

[0255] In the above example 4, the implementation manner in which network device #1 determines the first window based on the first message and the predefined relationship is described, which will not be repeated here.

[0256] 1004. Network device #1 sends Msg2 to the terminal device in the first window.

[0257] Correspondingly, the terminal device receives Msg2 from network device #1. Step 1004 may refer to step 502. The second message may be a random access response message, ie, Msg2.

[0258] 1105. Network device #2 detects the received Msg1 using the logical root sequence of the non-cell and determines that a random access preamble that does not belong to the cell is received.

[0259] Step 1105 may refer to step 805. The order of step 1105 and step 1102 is not limited.

[0260] 1006. Network device #2 obtains the time domain position of the first window based on the time domain position of Msg1.

[0261] In Example 4 above, the implementation method of determining the first window by network device #2 based on the first message and the predefined relationship is described, which will not be repeated here. Step 1006 may be an operation in which network device #2 obtains the time window used by network device #1 to transmit Msg1 and Msg2.

[0262] 1007. Network device #2 performs downlink transmission, and the resources of the downlink transmission do not include the downlink resources in the first window or the downlink resources in the first window in the beam direction where Msg1 is located.

[0263] There is no limitation on the order of step 1107 and step 1008. There is no limitation on the order of step 1107 and step 1004.

[0264] 1008. The terminal device sends Msg3 to network device #1.

[0265] Correspondingly, network device #1 receives Msg3 from the terminal device.

[0266] 1009. Network device #1 sends Msg4 to the terminal device in the first window.

[0267] Correspondingly, the terminal device receives Msg4 from network device #1.

[0268] In the embodiment of the present application, the first window is the time window used by network device #1 to transmit Msg1 and Msg2. After detecting a random access preamble of a non-local cell, network device #2 does not perform downlink transmission within the first window or does not perform downlink transmission in the beam direction of the random access preamble. This can avoid interference with the random access process of the terminal device and improve the success rate of random access.

[0269] The following describes the structure of a communication device that can implement the communication method provided in the embodiment of the present application in conjunction with the accompanying drawings. The following only briefly describes the communication device. For details on the implementation of the solution, please refer to the description of the method embodiment above, which will not be repeated below.

[0270] Figure 13 is a schematic diagram of the structure of a communication device 1300 provided in an embodiment of the present application. This communication device 1300 can implement the functions or steps implemented by the terminal device in each of the aforementioned method embodiments, the functions or steps implemented by network device #1 in each of the aforementioned method embodiments, or the functions or steps implemented by network device #2 in each of the aforementioned method embodiments. The communication device may include a processing module 1310 and a transceiver module 1320. In one possible implementation, the device may also include a storage unit that can be used to store instructions (code or programs) and / or data. The processing module 1310 and the transceiver module 1320 may be coupled to the storage unit. For example, the processing module 1310 may read the instructions (code or programs) and / or data in the storage unit to implement the corresponding method. The aforementioned units may be independently configured or partially or fully integrated. For example, the transceiver module 1320 may include a transmitting module and a receiving module. The transmitting module may be a transmitter, and the receiving module may be a receiver. The entity corresponding to the transceiver module 1320 may be a transceiver circuit, such as a transceiver or a communication interface.

[0271] In some possible implementations, the communication device 1300 can implement the behaviors and functions of the terminal device in the above-described method embodiments. For example, the communication device 1300 can be a terminal device, or a component (such as a chip or circuit) used in the terminal device. The transceiver module 1320 can be used to perform all receiving or sending operations performed by the terminal device in the embodiments of Figures 5, 8, 9, and 10. The processing module 1310 can be used to perform all operations performed by the terminal device in the embodiments of Figures 5, 8, 9, and 10 except for the receiving and sending operations.

[0272] In some possible implementations, communication device 1300 can implement the corresponding behaviors and functions of network device #1 in the above-described method embodiments. For example, communication device 1300 can be network device #1, or a component (e.g., a chip or circuit) used in network device #1. Transceiver module 1320 can, for example, be used to perform all receiving or transmitting operations performed by network device #1 in the embodiments of Figures 5, 8, 9, and 10. Processing module 1310 can, for example, be used to perform all operations performed by network device #1 in the embodiments of Figures 5, 8, 9, and 10 except for the transmitting and receiving operations.

[0273] In some possible implementations, communication device 1300 can implement the corresponding behaviors and functions of network device #2 in the above-described method embodiments. For example, communication device 1300 can be network device #2, or a component (e.g., a chip or circuit) used in network device #2. Transceiver module 1320 can, for example, be used to perform all receiving or transmitting operations performed by network device #2 in the embodiments of Figures 5, 8, 9, and 10. Processing module 1310 can, for example, be used to perform all operations performed by network device #2 in the embodiments of Figures 5, 8, 9, and 10 except for the transmitting and receiving operations.

[0274] Figure 14 is a schematic diagram of the structure of another apparatus 140 provided in an embodiment of the present application. The apparatus in Figure 14 can be the aforementioned terminal device or a chip used in the aforementioned terminal device, or can be the aforementioned network device #1 or a chip used in the aforementioned network device #1, or can be the aforementioned network device #2 or a chip used in the aforementioned network device #2. As shown in Figure 14, apparatus 140 includes a processing circuit 1410 and a transceiver circuit 1420.

[0275] In some embodiments of the present application, the processing circuit 1410 and the transceiver circuit 1420 may be configured to execute functions or operations performed by a terminal device. The transceiver circuit 1420 may be configured to, for example, execute all receiving or transmitting operations performed by the terminal device in the embodiments of Figures 5, 8, 9, and 10. The processing circuit 1410 may be configured to, for example, execute all operations performed by the terminal device in the embodiments of Figures 5, 8, 9, and 10 except for the transceiver operations.

[0276] In some embodiments of the present application, processing circuit 1410 and transceiver circuit 1420 may be configured to execute functions or operations performed by network device #1. Transceiver circuit 1420, for example, may be configured to execute all receiving or transmitting operations performed by network device #1 in the embodiments of Figures 5, 8, 9, and 10. Processing circuit 1410, for example, may be configured to execute all operations performed by network device #1 in the embodiments of Figures 5, 8, 9, and 10 except for the transmitting and receiving operations.

[0277] In some embodiments of the present application, processing circuit 1410 and transceiver circuit 1420 may be configured to execute functions or operations performed by network device #2. Transceiver circuit 1420, for example, may be configured to execute all receiving or transmitting operations performed by network device #2 in the embodiments of Figures 5, 8, 9, and 10. Processing circuit 1410, for example, may be configured to execute all operations performed by network device #2 in the embodiments of Figures 5, 8, 9, and 10 except for the transmitting and receiving operations.

[0278] In one possible implementation, the transceiver circuit 1420 includes at least one transceiver, and the processing circuit 1410 includes at least one processor, or a circuit in at least one processor for processing or control.

[0279] The transceiver is used to communicate with other devices / apparatuses via a transmission medium. The processor uses the transceiver to send and receive data and / or signaling, and is used to implement the method in the above-mentioned method embodiment. The processor can implement the functions of the processing module 1310, and the transceiver can implement the functions of the transceiver module 1320. Optionally, the transceiver may include a radio frequency circuit and an antenna, and the radio frequency circuit is mainly used for converting baseband signals into radio frequency signals and processing radio frequency signals. The antenna is mainly used for sending and receiving radio frequency signals in the form of electromagnetic waves. Input and output devices, such as touch screens, display screens, keyboards, etc. are mainly used to receive data input by users and output data to users.

[0280] Optionally, device 140 may further include at least one memory for storing program instructions and / or data. The memory is coupled to the processor. Coupling in the embodiments of the present application is an indirect coupling or communication connection between devices, units, or modules, which may be electrical, mechanical, or other forms, and is used for information exchange between devices, units, or modules. The processor may operate in conjunction with the memory. The processor may execute program instructions stored in the memory. At least one of the at least one memory may be included in the processor.

[0281] The processor can read software programs in the memory, interpret and execute the instructions of the software programs, and process the data of the software programs. When data needs to be transmitted wirelessly, the processor performs baseband processing on the data to be transmitted and outputs the baseband signal to the radio frequency circuit. The radio frequency circuit performs radio frequency processing on the baseband signal and then transmits the radio frequency signal to the outside in the form of electromagnetic waves via the antenna. When data is sent to device 140, the radio frequency circuit receives the radio frequency signal via the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor. The processor converts the baseband signal into data and processes the data.

[0282] In another implementation, the RF circuit and antenna may be arranged independently of the processor performing baseband processing. For example, in a distributed scenario, the RF circuit and antenna may be arranged remotely from the device 140 .

[0283] The specific connection medium between the above-mentioned transceiver, processor and memory is not limited in the embodiments of the present application.

[0284] In the embodiments of the present application, the processor may be one of the following devices: a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, or all or part of the circuits used for processing functions in the aforementioned devices, which may implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present application. A general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the method disclosed in conjunction with the embodiments of the present application may be directly embodied as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0285] In one possible implementation, the processing circuit 1410 includes at least one logic circuit, and the transceiver circuit 1420 includes at least one interface. The processing module 1310 in Figure 13 can be implemented using a logic circuit, and the transceiver module 1320 in Figure 13 can be implemented using an interface. The logic circuit can be a chip, a processing circuit, an integrated circuit, or a system on chip (SoC) chip, and the interface can be a communication interface, an input / output interface, etc. In the embodiment of the present application, the logic circuit and the interface can also be coupled to each other. The embodiment of the present application does not limit the specific connection method of the logic circuit and the interface.

[0286] The present application also provides a computer-readable storage medium, in which a computer program or instruction is stored. When the computer program or instruction is executed on a computer, the computer executes the method of the above embodiment.

[0287] The present application also provides a computer program product, which includes instructions or a computer program. When the instructions or the computer program are run on a computer, the method in the above embodiment is executed.

[0288] The present application also provides a communication system, including the above-mentioned network device #1, the above-mentioned network device #2 and the above-mentioned terminal device.

[0289] The present application also provides a chip, which includes: a communication interface and a processor; the communication interface is used for sending and receiving signals of the above-mentioned chip; the processor is used to execute computer program instructions so that the communication device including the above-mentioned chip executes the method in the above-mentioned embodiment.

[0290] 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. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are performed in whole or in part. 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 medium may be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; an optical medium, such as a digital video disk; or a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or nonvolatile storage medium, or may include both volatile and nonvolatile types of storage media.

[0291] 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.

Claims

1. A communication method, characterized in that: include: receiving a first message, the first message comprising a first random access preamble; Perform downlink transmission, the downlink transmission resources do not include downlink resources within the first window or downlink resources within the first window in the beam direction where the first message is located, the first window includes k time units used by the cell to which the first random access preamble belongs to send a second message, the second message and the first message belong to the same random access process, and k is an integer greater than 0.

2. The method according to claim 1, characterized in that The method is applied to an entity corresponding to a first cell, and the first random access preamble does not belong to a random access preamble of the first cell.

3. The method according to claim 1 or 2, characterized in that: The time domain position of the first window and the time domain position of the first message satisfy a predefined relationship.

4. The method according to claim 3, characterized in that The method further comprises: Based on the predefined relationship and the time domain position of the first message, the time domain position of the first window is obtained.

5. The method according to claim 3 or 4, characterized in that: The second message is a random access response message or a contention resolution message, and the first time unit in the first window is offset by f time units from the time unit where the first random access preamble is located or the time unit where the last symbol of the first random access preamble is located, where f is a predefined integer greater than 0.

6. The method according to claim 1 or 2, characterized in that: The second message is a contention resolution message, the first time unit among the k time units is offset by h time units from the time unit where the random access response message is located or the time unit where the last symbol of the random access response message is located, the random access response message and the second message belong to the same random access process, and h is a predefined integer greater than 0.

7. The method according to claim 6, characterized in that The first time unit in which the cell to which the first random access preamble belongs sends the random access response message is offset by g time units from the time unit in which the first random access preamble is located or the time unit in which the last symbol of the first random access preamble is located, where g is a predefined integer greater than 0.

8. The method according to claim 1 or 2, characterized in that: The first window is a random access response window, and the second message is a random access response message.

9. The method according to claim 1 or 2, characterized in that: The second message is a random access response message, and the first window also includes s time units used by the cell to which the first random access preamble belongs to send a contention resolution message, the contention resolution message and the first message belong to the same random access process, and s is an integer greater than 0.

10. The method according to claim 9, characterized in that The starting position of the first window is offset by t time units from the time unit where the first random access preamble is located or the time unit where the last symbol of the first random access preamble is located, where t is a predefined integer greater than 0, or the starting position of the first window is the first downlink time unit after the cell to which the first random access preamble belongs sends the first message.

11. The method according to any one of claims 1 to 9, characterized in that: The method further includes detecting the received first message using a logical root sequence other than the first cell.

12. The method according to any one of claims 1 to 11, characterized in that: The method is applied to a communication scenario including a plurality of network devices, and at least two of the plurality of network devices cannot directly exchange information.

13. The method according to any one of claims 1 to 12, characterized in that: The method is applied to any of the following multi-node resource reuse scenarios: relay, wireless mesh network, integrated access and backhaul IAB, ad hoc network, and communication scenario including mobile IAB and / or mobile base station.

14. A communication method, characterized in that: include: receiving a first message, the first message comprising a first random access preamble; A second message is sent within a first window, wherein the second message and the first message belong to the same random access process, a time domain position of the first window and a time domain position of the first message satisfy a predefined relationship, and the second message is a contention resolution message.

15. The method according to claim 14, characterized in that The method further comprises: A random access response message is sent within the first window, where the random access response message and the first message belong to the same random access process.

16. The method according to claim 14 or 15, characterized in that The first time unit in the first window is offset from the time unit where the first random access preamble is located or the time unit where the last symbol of the first random access preamble is located by f time units, where f is a predefined integer greater than 0.

17. The method according to any one of claims 14 to 16, characterized in that The method is applied to a communication scenario including a plurality of network devices, and at least two of the plurality of network devices cannot directly exchange information.

18. The method according to any one of claims 14 to 17, characterized in that The method is applied to any of the following multi-node resource reuse scenarios: relay, wireless mesh network, integrated access and backhaul IAB, ad hoc network, and communication scenario including mobile IAB and / or mobile base station.

19. A communication method, characterized in that: include: Sending a first message, wherein the first message includes a first random access preamble; A second message is received, where the second message and the first message belong to the same random access process, the second message is sent by the cell to which the first random access preamble belongs within a first window, the time domain position of the first window and the time domain position of the first message satisfy a predefined relationship, and the second message is a contention resolution message.

20. The method according to claim 19, characterized in that The method further comprises: A random access response message is received, where the random access response message is sent by the cell to which the first random access preamble belongs within the first window, and the random access response message and the first message belong to the same random access process.

21. The method according to claim 19 or 20, characterized in that The first time unit in the first window is offset from the time unit where the first random access preamble is located or the time unit where the last symbol of the first random access preamble is located by f time units, where f is a predefined integer greater than 0.

22. The method according to any one of claims 19 to 21, characterized in that The method is applied to a communication scenario including a plurality of network devices, and at least two of the plurality of network devices cannot directly exchange information.

23. The method according to any one of claims 19 to 21, characterized in that The method is applied to any of the following multi-node resource reuse scenarios: relay, wireless mesh network, integrated access and backhaul IAB, ad hoc network, and communication scenario including mobile IAB and / or mobile base station.

24. A communication method, characterized in that: include: receiving a first message, the first message comprising a first random access preamble; A second message is sent, where the second message and the first message belong to the same random access process, and the time domain position of the second message satisfies a predefined relationship with the time domain position of the first message. The first time unit used to transmit the second message is offset by y time units from the time unit where the first random access preamble is located or the time unit where the last symbol of the first random access preamble is located, where y is a predefined integer greater than 0.

25. The method according to claim 24, characterized in that The second message is a random access response message; the method also includes: sending a contention resolution message, the contention resolution message and the first message belong to the same random access process, the time domain position of the contention resolution message and the time domain position of the first message satisfy a predefined relationship, or the time domain position of the contention resolution message and the time domain position of the second message satisfy a predefined relationship.

26. A communication method, characterized in that: include: Sending a first message, wherein the first message includes a first random access preamble; Receive a second message, where the second message and the first message belong to the same random access process, the time domain position of the second message and the time domain position of the first message satisfy a predefined relationship, and the first time unit for transmitting the second message is offset by y time units from the time unit where the first random access preamble is located or the time unit where the last symbol of the first random access preamble is located, where y is a predefined integer greater than 0.

27. The method according to claim 26, characterized in that The second message is a random access response message; the method also includes: receiving a contention resolution message, the contention resolution message and the first message belong to the same random access process, the time domain position of the contention resolution message and the time domain position of the first message satisfy a predefined relationship, or the time domain position of the contention resolution message and the time domain position of the second message satisfy a predefined relationship.

28. A communication method, characterized in that: include: receiving a first message, the first message comprising a first random access preamble; A random access response message and a contention resolution message are sent within a first window, wherein the first message, the random access response message, and the contention resolution message belong to the same random access process, and a time domain position of the first window and a time domain position of the first message satisfy a predefined relationship.

29. The method according to claim 28, characterized in that The starting position of the first window is offset by w time units from the time unit where the first random access preamble is located or the time unit where the last symbol of the first random access preamble is located, where w is a predefined integer greater than 0, or the starting position of the first window is the first time unit after the cell to which the first random access preamble belongs sends the first message.

30. A communication method, characterized in that: include: Sending a first message, wherein the first message includes a first random access preamble; A random access response message and a contention resolution message are received within a first window, wherein the first message, the random access response message, and the contention resolution message belong to the same random access process, and a time domain position of the first window and a time domain position of the first message satisfy a predefined relationship.

31. The method according to claim 30, characterized in that The starting position of the first window is offset by w time units from the time unit where the first random access preamble is located or the time unit where the last symbol of the first random access preamble is located, where w is a predefined integer greater than 0, or the starting position of the first window is the first time unit after the cell to which the first random access preamble belongs sends the first message.

32. A communication device, characterized in that: Comprising means for implementing the method of any one of claims 1 to 13 or any one of claims 14 to 18 or any one of claims 19 to 23 or any one of claims 24 to 25 or any one of claims 26 to 27 or any one of claims 28 to 29 or any one of claims 30 to 31.

33. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, wherein the computer program includes program instructions, and when the program instructions are executed, the computer is enabled to perform the method according to any one of claims 1 to 31.

34. A computer program product, characterized in that The computer program product comprises a computer program, the computer program comprising program instructions, which, when executed, cause a computer to perform the method according to any one of claims 1 to 31 .

35. A chip, characterized in that: It comprises a communication interface and a processor; the communication interface is used for sending and receiving signals of the chip; the processor is used for executing computer program instructions so that the communication device including the chip executes the method described in any one of claims 1 to 31.

36. A communication device, characterized in that: The device comprises a processor coupled to a memory, the memory being used to store a computer program or instructions, and the processor being used to execute the computer program or instructions in the memory, so that the communication device executes the method according to any one of claims 1 to 31.

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