Random access method and communication apparatus

Abstract

The present application provides a random access method and a communication apparatus, capable of avoiding use of a GNSS capability of a terminal apparatus for random access, and therefore, in the case of random access of a terminal apparatus having no GNSS capability, the success rate of random access can be improved. The random access method and the communication apparatus can be applied to a communication system. The method comprises: a terminal apparatus receives first indication information from a network device, wherein the first indication information is used for indicating a first correspondence between a first service area of the network device and at least one first timing advance, and the first service area is a service area where the terminal apparatus is located. In this way, the terminal apparatus can send a first message to the network device on the basis of the at least one first timing advance so as to perform random access.

Description

Random access method and communication device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on September 5, 2023, with application number 202311142426.6 and application name “Random Access Method and Communication Device”, the entire contents of which are incorporated by reference into this application. Technical Field

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

[0003] In a non-terrestrial network (NTN), a network device can indicate the position of a reference point to a terminal device, and the network device can also indicate the ephemeris information of a satellite to the terminal device. The terminal device determines its own position based on the global navigation satellite system (GNSS) capability, and determines the time advance in combination with its own position and the position of the reference point. In the process of random access by the terminal device, the terminal device can send a message to the network device according to the time advance, thereby performing random access. However, when the terminal device does not have GNSS capability, or when the terminal device cannot determine the time advance in combination with its own position, the success rate of random access will be reduced. Therefore, a method to solve this problem is urgently needed.

[0004] Summary of the Invention

[0005] The embodiments of the present application provide a random access method and a communication device, which can improve the random access success rate when a terminal device without GNSS capability randomly accesses, or when the terminal device cannot determine the timing advance based on its own position.

[0006] To achieve the above objectives, this application adopts the following technical solutions:

[0007] In the first aspect, a random access method is provided. Optionally, the execution subject of the method may be a terminal device, or a device in the terminal device (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can realize all or part of the functions of the terminal device. The following description is given using a terminal device as an example. The random access method includes: the terminal device receives first indication information from a network device. The first indication information is used to indicate a first correspondence between a first service area of ​​the network device and at least one first time advance. The first service area is the service area where the terminal device is located. The terminal device sends message one to the network device based on at least one first time advance. Message one is used for random access.

[0008] Based on the random access method provided in the first aspect, the terminal device can obtain at least one first time advance within the first service area where the terminal device is located from the network equipment, and send message one based on the at least one first time advance, thereby realizing time pre-compensation of message one, so that on the network equipment side, the message one sent by the terminal device can be aligned with the message one sent by other terminal devices. In this way, in the case of random access by a terminal device without GNSS capability, the success rate of random access can be improved.

[0009] In one possible design, at least one first timing advance is associated with at least one distance. The at least one distance is the distance between at least one first location within the first service area and the network device. This allows the at least one first timing advance to be matched with the network device and at least one first location within the first service area, further improving the random access success rate.

[0010] Optionally, one of the at least one first location may be: a location farthest from the network device in the first service area, or a location closest to the network device in the first service area, or a central location of the first service area.

[0011] In one possible design, the first indication information may also be used to indicate a second correspondence between different global satellite navigation system (GNSS) capabilities and the cyclic prefix (CP) length of the random access preamble. Message one includes a random access preamble, and the CP length of the random access preamble in message one is determined based on the GNSS capability of the terminal device and the second correspondence. In this way, the length of the cyclic prefix of the random access preamble used for the terminal device can be matched with the GNSS capability of the terminal device, thereby further improving the success rate of the terminal device's random access to the network device based on at least one first time advance indicated by the network device when the terminal device does not have GNSS capability.

[0012] Optionally, in the second corresponding relationship, the CP length of the random access preamble corresponding to the device without GNSS capability is greater than the CP length of the random access preamble corresponding to the device with GNSS capability. In this way, the CP length of the random access preamble used by the terminal device without GNSS capability can be longer than the CP length of the random access preamble used by the terminal device with GNSS capability. Therefore, when the first service area is large, the random access preambles of the terminal devices in the first service area can still be aligned on the network device side, thereby improving the success rate of random access.

[0013] In one possible design, the method provided in the first aspect may further include: the terminal device receiving a second message from the network device. Message two indicates the time-frequency resources for carrying message three. The terminal device sends a third message to the network device based on the time-frequency resources indicated by message two. Message three includes identification information of the terminal device. The terminal device receives a fourth message from the network device. Message four indicates that contention resolution has been successfully completed for the terminal device. In this manner, the random access procedure is completed.

[0014] Optionally, the first indication information can also be used to indicate the correspondence between different GNSS capabilities and the time-frequency resource set for random access. Message two includes second indication information, and the second indication information is used to indicate the time-frequency resources carrying message three. The time-frequency resources carrying message three are the time-frequency resources in the time-frequency resource set for random access corresponding to the GNSS capability of the terminal device. In this way, the correspondence between different GNSS capabilities and the time-frequency resource set for random access can be indicated by the first indication information, and the time-frequency resources for carrying message three can be determined from the time-frequency resource set for random access corresponding to no GNSS capability.

[0015] Optionally, the terminal device receiving the second message from the network device may include: the terminal device receiving the second message from the network device after the first moment. The time length between the end moment of sending the first message by the terminal device and the first moment is the first time length. The first time length is twice the first time advance. In other words, after sending the first message, the terminal device may wait for twice the first time advance before opening the monitoring window to monitor the second message. In this way, the time for monitoring the second message can be reduced, thereby reducing the power consumption of the terminal device.

[0016] Optionally, the terminal device receiving message four from the network device may include: the terminal device receiving message four from the network device after a second moment. The time length between the end moment of sending message three by the terminal device and the second moment is the second time length. The second time length is twice the first time advance. In other words, after sending message three, the terminal device may wait for twice the first time advance before opening the monitoring window to monitor message four. In this way, the time for monitoring message four can be reduced, thereby reducing power consumption of the terminal device.

[0017] In one possible design, the terminal device is a terminal device without GNSS capability, and the network device is a satellite.

[0018] In a second aspect, a random access method is provided. Optionally, the execution subject of the method may be a network device, or a device in the network device (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can implement all or part of the network device functions. The random access method includes: the network device sends a first indication message to the terminal device. The first indication information is used to indicate a first correspondence between a first service area of ​​the network device and at least one first time advance. The first service area is the service area where the terminal device is located. The network device receives message one from the terminal device. The message one is sent by the terminal device according to at least one first time advance, and the message one is used for random access.

[0019] Based on the random access method provided in the second aspect, the network device can configure at least one first time advance corresponding to the first service area where the terminal device is located for the terminal device, so that the terminal device can send message one based on the at least one first time advance to achieve time pre-compensation of message one, so that message one can be aligned with message one of other terminal devices on the network device side, thereby improving the success rate of random access.

[0020] In one possible design, at least one first timing advance is associated with at least one distance. The at least one distance is the distance between at least one first location within the first service area and the network device. This allows the at least one first timing advance to be matched with the network device and at least one first location within the first service area, further improving the random access success rate.

[0021] Optionally, one of the at least one first location may be: a location farthest from the network device in the first service area, or a location closest to the network device in the first service area, or a central location of the first service area.

[0022] In one possible design, the first indication information may also be used to indicate a second correspondence between different global satellite navigation system (GNSS) capabilities and the cyclic prefix (CP) length of the random access preamble. The CP length of the random access preamble in message one is determined based on the GNSS capability of the terminal device and the second correspondence. In this way, the length of the cyclic prefix of the random access preamble used for the terminal device can be matched with the GNSS capability of the terminal device. Thus, when the terminal device does not have GNSS capability, the success rate of the terminal device's random access to the network device can be further improved based on the first time advance indicated by the network device.

[0023] Optionally, in the second corresponding relationship, the CP length of the random access preamble corresponding to the device without GNSS capability is greater than the CP length of the random access preamble corresponding to the device with GNSS capability. In this way, the CP length of the random access preamble used by the terminal device without GNSS capability can be longer than the CP length of the random access preamble used by the terminal device with GNSS capability. Therefore, when the first service area is large, the random access preambles of the terminal devices in the first service area can still be aligned on the network device side, thereby improving the success rate of random access.

[0024] In one possible design, the network device receiving a first message from a terminal device may include: the network device receiving the first message from the terminal device within a first time period. The length of the first time period is related to the random access preamble carried by the first message. In this manner, the length of time the network device receives the first message can be matched to the cyclic shift value of the random access preamble, thereby matching the length of time the message is received to the range of the first service area. This improves a detection success rate for the first message and, in turn, improves a random access success rate.

[0025] Optionally, the length of the first time period is positively correlated with a cyclic shift value of a preamble sequence of a random access preamble code carried by message 1. In this way, as the range of the first service area increases, message 1 can be received over a longer period of time, thereby improving a detection success rate of message 1 and further improving a random access success rate.

[0026] In one possible design, the method provided in the second aspect may further include: the network device sending a second message to the terminal device. Message two indicates the time-frequency resources carrying message three. The network device receives message three from the terminal device on the time-frequency resources. Message three includes identification information of the terminal device. The network device sends a fourth message to the terminal device. Message four indicates to the terminal device that contention resolution has been successful. In this manner, the random access procedure is completed.

[0027] Optionally, the first indication information can also be used to indicate the correspondence between different GNSS capabilities and the time-frequency resource set for random access. Message two includes second indication information, and the second indication information is used to indicate the time-frequency resources carrying message three. The time-frequency resources carrying message three are the time-frequency resources in the time-frequency resource set for random access corresponding to the GNSS capability of the terminal device. In this way, the correspondence between different GNSS capabilities and the time-frequency resource set for random access can be indicated by the first indication information, and the time-frequency resources for carrying message three can be determined from the time-frequency resource set for random access corresponding to no GNSS capability.

[0028] In one possible design, the terminal device is a terminal device without GNSS capability, and the network device is a satellite.

[0029] In addition, the technical effects of the random access method described in the second aspect can refer to the technical effects of the random access method described in the first aspect, and will not be repeated here.

[0030] In a third aspect, a communication device is provided, which is configured to execute the random access method described in any one of the implementations of the first aspect or the second aspect.

[0031] In the present application, the communication device described in the third aspect can be the terminal device described in the first aspect or the network device described in the second aspect, or a chip (system) or other parts or components that can be set in the terminal device or network device, or a device that includes the terminal device or network device.

[0032] It should be understood that the communication device described in the third aspect includes a module, unit, or means corresponding to the random access method described in any one of the first or second aspects above. The module, unit, or means can be implemented by hardware, software, or hardware executing the corresponding software implementation. The hardware or software includes one or more modules or units for performing the functions involved in the random access method.

[0033] In a fourth aspect, a communication device is provided, including a processor configured to execute the random access method described in any possible implementation of the first aspect or the second aspect.

[0034] In one possible design solution, the communication device described in the fourth aspect may further include a transceiver. The transceiver may be a transceiver circuit or an interface circuit. The transceiver may be used for the communication device described in the fourth aspect to communicate with other communication devices.

[0035] In one possible design, the communication device described in the fourth aspect may further include a memory. The memory may be integrated with the processor or provided separately. The memory may be used to store computer programs and / or data involved in the random access method described in either the first aspect or the second aspect.

[0036] In the present application, the communication device described in the fourth aspect can be the terminal device described in the first aspect or the network device described in the second aspect, or a chip (system) or other parts or components that can be set in the terminal device or network device, or a device that includes the terminal device or network device.

[0037] In a fifth aspect, a communication device is provided. The communication device includes: a processor coupled to a memory, the processor being configured to execute a computer program stored in the memory, so that the communication device performs the random access method described in any possible implementation of the first aspect or the second aspect.

[0038] In one possible design solution, the communication device described in the fifth aspect may further include a transceiver. The transceiver may be a transceiver circuit or an interface circuit. The transceiver may be used for the communication device described in the fifth aspect to communicate with other communication devices.

[0039] In the present application, the communication device described in the fifth aspect can be the terminal device described in the first aspect or the network device described in the second aspect, or a chip (system) or other parts or components that can be set in the terminal device or network device, or a device that includes the terminal device or network device.

[0040] In the sixth aspect, a communication device is provided, comprising: a processor and a memory; the memory is used to store a computer program, and when the processor executes the computer program, the communication device executes the random access method described in any one of the implementation methods of the first aspect or the second aspect.

[0041] In one possible design solution, the communication device described in the sixth aspect may further include a transceiver. The transceiver may be a transceiver circuit or an interface circuit. The transceiver may be used for the communication device described in the sixth aspect to communicate with other communication devices.

[0042] In the present application, the communication device described in the sixth aspect can be the terminal device described in the first aspect or the network device described in the second aspect, or a chip (system) or other parts or components that can be set in the terminal device or network device, or a device that includes the terminal device or network device.

[0043] In the seventh aspect, a communication device is provided, comprising: a processor; the processor is used to couple with a memory, and after reading a computer program in the memory, execute the random access method as described in any one of the implementation methods of the first aspect or the second aspect according to the computer program.

[0044] In one possible design solution, the communication device described in the seventh aspect may further include a transceiver. The transceiver may be a transceiver circuit or an interface circuit. The transceiver may be used for the communication device described in the seventh aspect to communicate with other communication devices.

[0045] In the present application, the communication device described in the seventh aspect can be the terminal device described in the first aspect or the network device described in the second aspect, or a chip (system) or other parts or components that can be set in the terminal device or network device, or a device that includes the terminal device or network device.

[0046] In an eighth aspect, a processor is provided, wherein the processor is configured to execute the random access method described in any possible implementation manner of the first aspect or the second aspect.

[0047] In a ninth aspect, a communication system is provided, which includes one or more terminal devices and one or more network devices.

[0048] In the tenth aspect, a computer-readable storage medium is provided, comprising: a computer program or instructions; when the computer program or instructions are run on a computer, the computer executes the random access method described in any possible implementation of the first aspect or the second aspect.

[0049] In the eleventh aspect, a computer program product is provided, comprising a computer program or instructions, which, when executed on a computer, enables the computer to execute the random access method described in any possible implementation of the first aspect or the second aspect.

[0050] In addition, the technical effects of the communication devices described in the third to eleventh aspects above can refer to the technical effects of the random access methods described in the first or second aspects above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] FIG1 is a schematic diagram of the initial access process provided in an embodiment of the present application;

[0052] FIG2 is a schematic diagram of a random access process in a terrestrial network according to an embodiment of the present application;

[0053] FIG3 is a schematic diagram of a random access process in a non-terrestrial network according to an embodiment of the present application;

[0054] FIG4 is a schematic diagram of the architecture of a communication system provided in an embodiment of the present application;

[0055] FIG5 is a schematic diagram of a flow chart of a random access method provided in an embodiment of the present application;

[0056] FIG6 is a schematic diagram of a flow chart of another random access method provided in an embodiment of the present application;

[0057] FIG7 is a schematic diagram of a flow chart of another random access method provided in an embodiment of the present application;

[0058] FIG8 is a schematic diagram of a flow chart of another random access method provided in an embodiment of the present application;

[0059] FIG9 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0060] FIG10 is a schematic diagram of the structure of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0061] The following first introduces the technical terms and related technologies involved in the embodiments of this application.

[0062] 1. Timing advance (TA) refers to a parameter used in mobile communication systems to coordinate time slot synchronization between network devices, such as access network equipment, and terminal devices. This parameter ensures that the terminal device sends or receives data at the correct time to maintain communication reliability. For example, if a terminal device sends an uplink signal to a network device and expects the uplink signal to arrive at the network device at time T1, and the transmission delay between the terminal device and the network device is TA1, the terminal device can send the uplink signal at time T1 - TA1.

[0063] 2. Non-terrestrial networks (NTNs) can provide services to terminal devices via satellites or unmanned aerial systems (UASs), including high altitude platform stations (HAPSs). Network equipment in non-terrestrial networks has a wider coverage area than that of network equipment in terrestrial networks. For example, if a satellite is used as a network equipment in a non-terrestrial network, the higher the satellite's orbit, the greater the coverage area.

[0064] Satellite orbits can be divided into low-Earth orbit (LEO), medium-Earth orbit (MEO), and geostationary Earth orbit (GEO) based on their altitude. The orbital altitude of LEO is between 300 kilometers (km) and 2000 km. The orbital altitude of MEO is between 7000 km and 25000 km, and the orbital altitude of GEO is 35786 km. The relative position of satellites operating in GEO and the Earth is not affected by the Earth's rotation. Non-geosynchronous orbits (NGSO) include low-Earth orbits with altitudes of approximately 300 km to 1500 km and medium-Earth orbits with altitudes of approximately 7000 km to 25000 km. The corresponding relationship between the orbital altitudes and beam sizes of satellites in different orbits is shown in Table 1 below.

[0065] Table 1

[0066] In a cellular network, a terminal device can access the network through an initial access process. The process of initial access by a terminal device is shown in FIG1 . The initial access process includes:

[0067] S101: The terminal device searches for a cell and selects a cell.

[0068] Regarding the implementation of S101, reference may be made to the principles of cell search and cell selection in the prior art, which will not be described in detail here.

[0069] S102: The terminal device randomly accesses the selected cell.

[0070] After a terminal device selects a cell and resides in the selected cell, it initiates a random access procedure in the cell. Through the random access procedure, the terminal device can achieve uplink synchronization with the cell and obtain the uplink transmission timing advance. In addition, when establishing the initial radio link, that is, when the terminal device switches from idle to active state, it can obtain a user identity, such as the cell radio network temporary identifier (C-RNTI), through the random access procedure.

[0071] For the implementation principle of S102, reference may be made to the random access process provided in FIG. 2 below.

[0072] S103: A radio resource control (RRC) link is established between the terminal device and the first network equipment.

[0073] Regarding the implementation principle of S103, reference may be made to the principle of establishing an RRC connection in the prior art, which will not be repeated here.

[0074] S104: The terminal device establishes an initial context.

[0075] The terminal device may interact with the first network device and the second network device to establish an initial context. The second network device may include a core network element, or a device that implements the functions of a core network element.

[0076] The implementation principle of S104 may refer to the principle of establishing an initial context in the prior art, and will not be described in detail here.

[0077] S105: The terminal device establishes a protocol data unit (PDU) session connection.

[0078] Regarding the implementation principle of S105, reference may be made to the principle of establishing a PDU session connection in the prior art, which will not be described in detail here.

[0079] In a communication system based on a terrestrial network, the first network device may be a wireless access network device. In this case, the process of random access by the terminal device is shown in FIG2 . The random access process shown in FIG2 includes:

[0080] S201: The terminal device sends a message 1 to the first network device. Correspondingly, the first network device receives the message 1 from the terminal device.

[0081] Message 1 carries a random access (RA) preamble, which can be used to estimate the uplink time difference between the terminal device and the first network device. Alternatively, the random access preamble can be used by the terminal device to access the first network device. Message 1 can also be referred to as message 1 (Msg1), or the first message.

[0082] After sending the first message, the terminal device may start a first timer, and the timing duration of the first timer may be timing duration #1. For example, timing duration #1 may be the duration of the ra-ResponseWindow.

[0083] S202: The first network device sends a second message to the terminal apparatus. Correspondingly, the terminal apparatus receives the second message from the first network device.

[0084] The second message includes an uplink time difference from the terminal device to the first network device, and the uplink time difference is determined by the first network device according to the received random access preamble code.

[0085] Message 2 may be carried on the physical downlink shared channel (PDSCH). It is understood that the same PDSCH may carry the RARs corresponding to multiple terminal devices. Message 2 may also be referred to as a random access response (RAR), message 2 (Msg2), or a second message.

[0086] After receiving the first message, the terminal device may monitor and receive the second message from the network device within the timing duration #1 after starting the first timer.

[0087] After receiving the second message from the first network device, the terminal device can turn off the first timer, or in other words, stop the first timer, thereby reducing the monitoring time of the terminal device and thus reducing the overhead.

[0088] S203: The terminal device sends a third message to the first network device according to the second message. Correspondingly, the first network device receives the third message from the terminal device.

[0089] Message three may also be referred to as message 3 (Msg3) or the third message.

[0090] It is understandable that the terminal device may start a second timer after sending the third completion message, and the timing duration of the second timer may be timing duration #2. For example, timing duration #2 may be the duration of ra-ContentionResolutionTimer.

[0091] After receiving the third message, the first network device may execute the following S204.

[0092] S204: The first network device sends a message 4 to the terminal apparatus. Correspondingly, the terminal apparatus receives the message 4 from the first network device.

[0093] It is understandable that the terminal device can monitor and receive message four from the first network device within the timing duration #2 after the second timer is started.

[0094] After receiving the message 4 from the first network device, the terminal device can turn off the second timer, or in other words, stop the second timer. In this way, the monitoring time of the terminal device can be reduced, thereby reducing overhead.

[0095] After receiving the message 4, the terminal device determines that the random access is successful. At this time, data can be transmitted between the terminal device and the first network device.

[0096] Message four may also be referred to as message 4 (Msg4), or the fourth message, or a contention resolution message.

[0097] In the process provided in FIG. 2 , in the process of random access by a terminal, uplink time-frequency resources in the same cell are orthogonal, and therefore, uplink transmissions of different terminals in the same cell will not interfere with each other.

[0098] In order to maintain this uplink orthogonality, under a given parameter set (Numerology), such as the subcarrier spacing type, the uplink subframe boundaries in the same cell are required to be (approximately) aligned on the first network device side. In other words, the time misalignment of the received signal should fall within the cyclic prefix (CP). In order to ensure the time alignment of the received signal on the first network device, the new radio (NR) standard introduces the TA mechanism. TA is used for uplink transmission of the terminal device, which means that the subframe in which the terminal device sends uplink data must be advanced by a certain time compared to the corresponding uplink subframe. The specific advance amount is calculated by the gNodeB based on the RA preamble (random access preamble) sent by the UE, and then notified to the terminal device through the timing advance command (TAC). The terminal device adjusts the sending time of the uplink signal according to the received TA to achieve uplink synchronization between the terminal device and the gNodeB.

[0099] In a communication system based on a non-terrestrial network, such as a satellite communication system, the first network device is far away from the ground coverage area and has a large delay. On the other hand, the coverage range of the first network device is much larger than the coverage range of the first network device in the terrestrial network. The cyclic prefix of the existing random access preamble code cannot meet the alignment requirements, which will cause the terminal device to fail random access.

[0100] In order to solve the problem of random access of terminal devices in non-terrestrial networks, the terminal devices may perform time pre-compensation when sending random access preambles.

[0101] The following takes a communication system of a non-terrestrial network as an example to illustrate the process of random access of a terminal device in a non-terrestrial network. As shown in Figure 3, the communication system of the non-terrestrial network includes a terminal device and a first network device, wherein the first network device can be a device with a wireless access device function, such as a satellite, or an unmanned aerial vehicle. The terminal device is communicatively connected to the first network device, and the first network device is communicatively connected to the second network device through a ground gateway. The second network device may include a core network element, or a device that implements the function of a core network element. In the communication system shown in Figure 3, the process of random access of the terminal device is shown in Figure 3. The random access process includes:

[0102] S301: A first network device sends information #1 to a terminal device. Correspondingly, the terminal device receives the information #1 from the first network device.

[0103] Information #1 is used to indicate the location of the reference point of the link between the terminal device and the ground gateway.

[0104] In one possible design scheme, the position of the reference point can be the position of the satellite. In this case, the position of the reference point can be determined based on the satellite's ephemeris information. The satellite's ephemeris information includes one or more of the following: the satellite's semi-major axis (semi-major axis)), eccentricity (Eccentricity (eccentricity)), inclination angle (Inclination angle at reference time (inclination)), longitude of ascending node of orbit plane (right ascension of the ascending node)), argument of perigee (argument of periapsis)), mean anomaly at reference time (true anomaly and a reference point in time)), and reference time (Ephemeris reference time (the epoch)). It is understandable that the position of the reference point can also be a position on the feeder link or the service link, which will not be repeated here.

[0105] It is understandable that information #1 can be carried in a broadcast message.

[0106] S302: The terminal device determines a timing advance based on information #1 and the location of the terminal device.

[0107] The terminal device determines the position of the satellite based on the satellite's ephemeris information in information #1, and determines its own position based on its own GNSS. The terminal device determines the timing advance based on the satellite's position and its own position.

[0108] Regarding the implementation principle of the terminal device determining the timing advance amount based on the satellite position and its own position, reference can be made to existing technologies and will not be repeated here.

[0109] S303: The terminal device sends a message 1 to the first network device according to the timing advance. Correspondingly, the first network device receives the message 1 from the terminal device.

[0110] For the implementation principle of message 1, please refer to the relevant introduction of S201, which will not be repeated here.

[0111] S304: The first network device sends a second message to the terminal apparatus. Correspondingly, the terminal apparatus receives the second message from the first network device.

[0112] For the implementation principle of message 2, please refer to the relevant introduction of message 2 in S202 above. For the implementation principle of S304, please refer to the relevant introduction of S202 above, which will not be repeated here.

[0113] S305: The terminal device sends a third message to the first network device. Correspondingly, the first network device receives the third message from the terminal device.

[0114] For the implementation principle of message three, please refer to the relevant introduction in S203.

[0115] For the implementation principle of message 2, please refer to the relevant introduction of message 2 in S203 above. For the implementation principle of S305, please refer to the relevant introduction of S203 above, which will not be repeated here.

[0116] S306: The first network device sends a message 4 to the terminal apparatus. Correspondingly, the terminal apparatus receives the message 4 from the first network device.

[0117] For the implementation principle of message 4, please refer to the relevant introduction in S204. For the implementation principle of S306, please refer to the relevant introduction in S204, which will not be repeated here.

[0118] However, in non-terrestrial networks, if a terminal device lacks GNSS capabilities, it cannot obtain its own position. Therefore, it cannot accurately calculate the specific timing advance based on the distance from the first network device, such as a satellite, and thus cannot implement timing advance pre-compensation. Due to the large distance difference between the terminal device and the first network device, the message will have a significant delay upon arrival at the first network device, preventing alignment within the preset time window, which can lead to random access failure.

[0119] The technical solution in this application will be described below with reference to the accompanying drawings.

[0120] The technical solution of the present application can be applied to non-terrestrial network (NTN) systems such as satellite communication systems, high altitude platform station (HAPS) communications, and drones, for example, integrated communication and navigation (IcaN) systems, global navigation satellite systems (GNSS) and ultra-dense low-orbit satellite communication systems. Satellite communication systems can be integrated with traditional mobile communication systems. For example, the mobile communication system can be a fourth-generation (4G) communication system (for example, a long-term evolution (LTE) system), a worldwide interoperability for microwave access (WiMAX) communication system, a fifth-generation (5G) communication system (for example, a new radio (NR) system), and future mobile communication systems, such as a sixth-generation (6G) mobile communication system.

[0121] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as wireless fidelity (WiFi) systems, vehicle-to-everything (V2X) communication systems, device-to-device (D2D) communication systems, Internet of Vehicles communication systems, 4th generation (4G) mobile communication systems, such as long term evolution (LTE) systems, world-wide interoperability for microwave access (WiMAX) communication systems, 5th generation (5G) mobile communication systems, such as new radio (NR) systems, and future communication systems, such as 6th generation (6G) mobile communication systems.

[0122] This application will present various aspects, embodiments, or features in the context of systems that may include multiple devices, components, modules, etc. It should be understood and appreciated that each system may include additional devices, components, modules, etc., and / or may not include all of the devices, components, modules, etc. discussed in conjunction with the figures. Furthermore, combinations of these aspects may also be used.

[0123] Additionally, in the embodiments of this application, words such as "exemplarily" and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as an "exemplary" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of the word "exemplary" is intended to present concepts in a concrete manner.

[0124] The terms "first", "second" etc. in the specification and claims of the present application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprise" and "have" and any of their variations are intended to cover non-exclusive inclusions, for example, the process, method, system, product or equipment comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or that are inherent to these processes, methods, products or equipment.

[0125] In the embodiments of the present application, "at least one" refers to one or more, and "more" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c; a and b; a and c; b and c; or a, b, and c. Among them, a, b, and c can be single or multiple.

[0126] In the embodiments of the present application, sometimes a subscript such as W1 may be mistakenly written as a non-subscript form such as W1. When the difference is not emphasized, the meanings to be expressed are the same.

[0127] The network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Ordinary technicians in this field will know that with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0128] To facilitate understanding of the embodiments of the present application, a communication system applicable to the embodiments of the present application is first described in detail using the communication system shown in Figure 4 as an example. For example, Figure 4 is a schematic diagram of the architecture of a communication system applicable to the random access method provided in the embodiments of the present application.

[0129] As shown in FIG. 4 , the communication system includes a network device 401 and terminal devices (terminal devices 402 a to 402 c ).

[0130] Information exchange can be performed between the network device 401 and the terminal devices (terminal devices 402a to 402c).

[0131] It is understandable that the communication system shown in Figure 4 may further include a ground gateway 403. Information exchange can be performed between the network device 401 and the ground gateway 403.

[0132] The network device is located on the network side of the communication system and has wireless transceiver functions or is a chip or chip system that can be installed in the device. The network device includes, but is not limited to, an access point (AP) in a wireless fidelity (WiFi) system, such as a home gateway, a router, a server, a switch, a bridge, etc., an evolved Node B (eNB), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., home evolved NodeB, or home Node B, HNB), a baseband unit (BBU), a wireless relay node, a wireless backhaul node, a transmission and reception point (TRP or transmission point, TP), etc. It can also be 5G, such as a gNB in ​​a new radio (NR) system, or a transmission point (TRP or TP), one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or a network node constituting a gNB or a transmission point, such as a baseband unit (BBU) or a distributed unit (DBU). unit (DU), road side unit (RSU) with base station function, etc.

[0133] The above-mentioned ground gateway is a terminal that accesses the above-mentioned communication system and has a wireless transceiver function or a chip or chip system that can be set at the terminal. The terminal device can also be called an access terminal, a user unit, a user station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent or a user device. The terminal device in the embodiment of the present application can be a mobile phone, a tablet computer, a computer with a wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical care, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, a vehicle-mounted terminal, an RSU with terminal function, etc. The terminal device of the present application can also be a vehicle-mounted module, vehicle-mounted module, vehicle-mounted component, vehicle-mounted chip or vehicle-mounted unit built into the vehicle as one or more components or units. The vehicle can implement the random access method provided by the present application through the built-in vehicle-mounted module, vehicle-mounted module, vehicle-mounted component, vehicle-mounted chip or vehicle-mounted unit.

[0134] It should be noted that the random access method provided in the embodiment of the present application can be applied between the terminal device and the network device shown in Figure 4. The specific implementation can refer to the following method embodiment, which will not be repeated here.

[0135] It should be noted that the solutions in the embodiments of the present application can also be applied to other communication systems, and the corresponding names can also be replaced by the names of corresponding functions in other communication systems.

[0136] It should be understood that FIG4 is only a simplified schematic diagram for ease of understanding, and the communication system may also include other network devices and / or other terminal devices, which are not shown in FIG4 .

[0137] Based on the communication system shown in FIG. 4 , an embodiment of the present application provides a random access method. In this random access method, a network device may indicate to a terminal device, via first indication information, the TA corresponding to the first service area in which the terminal device is located. After obtaining the TA, the terminal device may send a message 1 to the network device based on the TA. Thus, when a terminal device without GNSS capabilities randomly accesses, the time difference in the arrival of the message 1 at the network device between different terminal devices within the first service area can be reduced, thereby improving the success rate of random access.

[0138] The random access method provided in the embodiment of the present application will be described in detail below with reference to FIG. 5 to FIG. 8 .

[0139] For example, Figure 5 is a flowchart of a random access method provided in an embodiment of the present application. The random access method can be applied to the communication between the terminal device and the network device shown in Figure 4.

[0140] As shown in FIG5 , the random access method includes the following steps:

[0141] S501: The network device sends first indication information to the terminal apparatus. Correspondingly, the terminal apparatus receives the first indication information from the network device.

[0142] The first indication information is used to indicate a first correspondence between a first service area of ​​the network device and at least one first timing advance. The first service area is a service area where the terminal device is located.

[0143] In one possible design, at least one first timing advance is associated with at least one distance, where the at least one distance is a distance between at least one first location within the first service area and the network device.

[0144] Optionally, the first indication information may include at least one distance. In this case, the first indication information may indicate at least one first timing advance by indicating at least one distance.

[0145] Alternatively, optionally, the first indication information may include at least one first position. In this case, the first indication information may indicate the first timing advance by indicating at least one first position.

[0146] In this case, the terminal device may determine the first timing advance based on each of the at least one first location and the location of the network device. The location of the network device may be determined by the terminal device based on operational information of the network device. For example, if the network device is a satellite, the operational information may be ephemeris information. For details about ephemeris information, please refer to the relevant description in S301 and will not be repeated here.

[0147] Alternatively, the first indication information may optionally include at least one parameter corresponding to the at least one first timing advance. That is, the first indication information may indicate the first timing advance using the at least one parameter corresponding to the at least one first timing advance. It is understood that the at least one parameter may be related to the at least one distance.

[0148] Optionally, one of the at least one first locations may be: the location farthest from the network device in the first service area, the location closest to the network device in the first service area, or the center of the first service area. The at least one first timing advance may include one first timing advance, or multiple first timing advances. The at least one distance may include one distance or multiple distances. Each timing advance in the at least one first timing advance may be determined based on one or two distances of the at least one distance. The distances used to determine different first timing advances are different.

[0149] For example, each first timing advance in the at least one first timing advance may be a round-trip delay between the first position corresponding to the first timing advance and the reference point.

[0150] For ease of understanding, the following description is provided in conjunction with Figure 4. Assume that the first service area is as shown in Figure 4. The location farthest from the network device in the first service area is location P1, the location closest to the network device in the first service area is location P2, and the center location of the first service area is location P3. Therefore, one of the at least one first locations can be a location between location P1 and location P3. For example, if one of the at least one first locations is location P1, then the first timing advance can include the round-trip delay between location P1 and the reference point.

[0151] For another example, the at least one first position may include position P1 and position P2, then the at least one first timing advance may include the round-trip delay between position P1 and the reference point, and the round-trip delay between position P2 and the reference point.

[0152] Here, one of the at least one first position is only used as an example. In actual implementation, the first position of the at least one position can be any other possible position in the first service area, which will not be repeated here.

[0153] It should be understood that the number of the at least one first position and the number of the at least one distance may be the same. In addition, when the number of the at least one first position is multiple, each position in the at least one first position is different.

[0154] It is understood that the first indication information may indicate at least one first timing advance corresponding to each of the multiple service areas of the network device. The first service area may be one of the multiple service areas. Assuming that each service area corresponds to a first timing advance, the service areas and the first timing advances are as shown in Table 2. Assuming that the multiple service areas of the network device include service areas 1 to n, the first timing advances corresponding to service areas 1 to n are timing advance 1 to first timing advance n, respectively.

[0155] Table 2

[0156] It should be understood that each of the multiple service areas of the network device corresponds to a beam or a cell. In other words, each of the multiple service areas of the network device is a beam or the coverage area of ​​a cell. It can also be said that in the first indication information, each of the multiple service areas of the network device can be represented by an identifier of the beam or an identifier of the synchronization signal and physical broadcast channel block (SSB). Therefore, the terminal device can determine the first service area based on the first correspondence indicated by the first indication information and the beam or cell carrying the first indication information. Among them, the terminal device can determine the beam or cell carrying the first indication information through a broadcast message, such as a system information block (SIB). In other words, the identifier of the beam carrying the first indication information or the identifier of the cell can be carried in the broadcast message.

[0157] It is understandable that the center position of the first service area can also be the center position of the beam or cell corresponding to the first service area. In some possible designs, the center position of the first service area can be the geometric center position of the first service area.

[0158] In this way, at least one first timing advance can be matched with the network device and at least one first location in the first service area, further improving the success rate of random access.

[0159] Optionally, the first indication information may also be used to indicate a second correspondence between different GNSS capabilities and the CP length of the random access preamble code.

[0160] In the embodiment of the present application, different GNSS capabilities refer to the GNSS capability states of different terminal devices, which may include GNSS capability and no GNSS capability. Among them, GNSS capability means that the terminal device has GNSS capability, and no GNSS capability means that the terminal device does not have GNSS capability. Among them, the second corresponding relationship is shown in Table 3 below. The CP length of the random access preamble corresponding to the GNSS capability is the first CP length, and the CP length of the random access preamble corresponding to the no GNSS capability is the second CP length. In the second corresponding relationship, the CP length of the random access preamble corresponding to the no GNSS capability is greater than the CP length of the random access preamble corresponding to the GNSS capability, that is, the first CP length is less than or equal to the second CP length. The CP length corresponding to the GNSS capability is the CP length of the random access preamble used for random access by the terminal device with GNSS capability. The CP length corresponding to the no GNSS capability is the CP length of the random access preamble used for random access by the terminal device without GNSS capability.

[0161] Table 3

[0162] In this way, the CP length of the random access preamble code used by the terminal device without GNSS capability can be longer than the CP length of the random access preamble code used by the terminal device with GNSS capability. Therefore, when the first service area is large, the random access preamble codes of the terminal devices in the first service area can still be aligned on the network equipment side, thereby improving the success rate of random access.

[0163] It is understood that in the embodiments of the present application, a terminal device with GNSS capability refers to a device or module that includes the terminal device, such as a terminal device with GNSS capability. A terminal device without GNSS capability refers to a device or module that includes the terminal device, such as a terminal device without GNSS capability. The GNSS capability of a terminal device refers to a device or module that includes the terminal device, such as the GNSS capability of the terminal device.

[0164] Optionally, the first indication information may also be used to indicate the correspondence between the GNSS capability of the terminal device and the time-frequency resource set used for random access.

[0165] Optionally, the first indication information may also be used to indicate a correspondence between the GNSS capability of the terminal device and a set of time-frequency resources used for random access, ie, a third correspondence.

[0166] Among them, the correspondence between GNSS capability and the time-frequency resource set for random access includes: the correspondence between terminal devices with GNSS capability and the time-frequency resource set for random access, and the correspondence between terminal devices without GNSS capability and the time-frequency resource set for random access. For example, in the third correspondence, GNSS capability corresponds to the first time-frequency resource set, and non-GNSS capability corresponds to the second time-frequency resource set. For the third correspondence, please refer to Table 4 below. The time-frequency resource set corresponding to GNSS capability is the time-frequency resource set used for random access by terminal devices with GNSS capability. The time-frequency resource set corresponding to non-GNSS capability is the time-frequency resource set of the random access preamble code used for random access by terminal devices without GNSS capability.

[0167] Table 4

[0168] Optionally, the time domain position of the time-frequency resource set for random access corresponding to the terminal device with GNSS capability is located before the time domain position of the time-frequency resource set for random access corresponding to the terminal device without GNSS capability. In this way, the service efficiency of the entire communication system can be improved.

[0169] In one possible design, the terminal device is a terminal device without GNSS capability, and the network device is a satellite or a drone.

[0170] It should be understood that the first indication information can be carried in RRC signaling.

[0171] S502: The terminal device sends a message 1 to the network device according to at least one first timing advance. Correspondingly, the network device receives the message 1 from the terminal device.

[0172] Message 1 is used for random access and should be understood to include a random access preamble.

[0173] The random access preamble may be configured by a network device for the terminal device. For example, the network device may carry the identifier of the random access preamble in a broadcast message, such as a master information block (MIB) or SIB, and in dedicated signaling, such as RRC signaling.

[0174] The random access preamble is described below in combination with different situations.

[0175] In a possible design scheme, when the first indication information is also used to indicate the second corresponding relationship, the CP length of the random access preamble code in message one is determined according to the GNSS capability of the terminal device and the second corresponding relationship.

[0176] For example, using the first CP length and the second CP length as an example, if the terminal device corresponding to the terminal device has GNSS capability, then the CP length of the random access preamble in message 1 is the first CP length. If the terminal device corresponding to the terminal device does not have GNSS capability, then the CP length of the random access preamble in message 1 is the second CP length.

[0177] In this way, the CP length of the random access preamble code used for the terminal device can be matched with the GNSS capability of the terminal device, so that when the terminal device has no GNSS capability, the success rate of the terminal device's random access to the network device can be further improved based on at least one first time advance indicated by the network device.

[0178] The CP length of the random access preamble is related to the cell or beam radius corresponding to the first service area. For example, if the beam radius corresponding to the first service area is 500km, the elevation angle of the farthest point between the first service area and the network device is 10°, and the transmission delay per 1km is 6.7 microseconds (us), then the CP length of the random access preamble is T CP The following relationship must be satisfied: CP =(D02-D01)*6.7us. Wherein, D01 is the fourth distance, i.e., the shortest distance between the terminal device and the network device within the service area, and D02 is the third distance, i.e., the farthest distance N between the terminal device and the network device within the service area. CP RA =T CP / T C =202030k, where T C When the subcarrier spacing is 480 kilohertz (kHz), the sampling interval and k=64 are auxiliary parameters.

[0179] In a possible design solution, the random access preamble carried in the message 1 can be determined according to existing technologies. At this time, the implementation principle of the message 1 can be referred to the relevant introduction in S303 and will not be repeated here.

[0180] The terminal device sends message one to the network device according to at least one first timing advance, that is, the terminal device determines a target timing advance according to at least one first timing advance, and sends message one to the network device according to the target timing advance.

[0181] If the at least one first timing advance includes a first timing advance, the target timing advance is the first timing advance. If the at least one first timing advance includes multiple first timing advances, the target timing advance may be one of the multiple first timing advances, or the target timing advance may be within a range between a minimum value and a maximum value of the multiple first timing advances.

[0182] In one possible design, the network device receiving the first message from the terminal apparatus may include: the network device receiving the first message from the terminal apparatus within a first time period, wherein the length of the first time period is related to the random access preamble carried by the first message.

[0183] In this way, the time length for the network device to receive message one can match the cyclic shift value of the random access preamble code, so that the time length for receiving the message matches the range of the first service area, thereby improving the detection success rate of message one and further improving the random access success rate.

[0184] Optionally, the length of the first time period is related to a cyclic shift value of a preamble sequence of a random access preamble carried by message 1, and the cyclic shift (CS) value of the preamble sequence of the random access preamble carried by message 1 is determined according to the radius of the first service area. For example, the cyclic shift value CS of the preamble sequence of the random access preamble carried by message 1 can be calculated by the following formula:

[0185] CS=(π / 6)*R;

[0186] Wherein, π / 6 represents an angle unit, and R represents the length of the radius of the first service area. It can be understood that the radius of the first service area can be the length of the radius of the cell covering the first service area.

[0187] In this way, when the range of the first service area is larger, the message one can be received in a longer time, thereby improving the detection success rate of the message one and further improving the random access success rate.

[0188] In a possible design solution, the implementation principle of the network device receiving the message 1 from the terminal device can refer to the relevant introduction of S303 and will not be repeated here.

[0189] S503: The network device sends a second message to the terminal apparatus. Correspondingly, the terminal apparatus receives the second message from the network device.

[0190] Among them, message two is used to indicate the time-frequency resources carrying message three.

[0191] For the implementation principle of message two, please refer to the relevant introduction in S304 and will not be repeated here. The difference is that, when the first indication information can also be used to indicate the correspondence between different GNSS capabilities and the time-frequency resource set for random access, the time-frequency resources carrying message three are the time-frequency resources in the time-frequency resource set for random access corresponding to the terminal device. The time-frequency resource set for random access corresponding to the terminal device is the time-frequency resource set for random access corresponding to the GNSS capability of the terminal device corresponding to the terminal device.

[0192] Optionally, when the first indication information is further used to indicate the correspondence between different GNSS capabilities and the time-frequency resource sets used for random access, message 2 includes second indication information, and the second indication information is used to indicate the time-frequency resources carrying message 3. In other words, the time-frequency resources carrying message 3 can be carried in the second indication information in message 2.

[0193] Optionally, the second indication information may indicate that the time domain position of the time-frequency resource set for random access corresponding to the terminal device with GNSS capability is located before the time domain position of the time-frequency resource set for random access corresponding to the terminal device without GNSS capability. In this way, the service efficiency of the entire communication system can be improved.

[0194] The second indication information may indicate the first time advance. For example, the second indication information may carry an index of the first time advance, i.e., a TAC. For example, if the beam radius corresponding to the first service area is 500 km, the elevation angle of the farthest point from the network device in the first service area is 10°, and the transmission delay corresponding to each 1 km is 6.7 microseconds (us), the TAC occupies 14 bits.

[0195] In this way, the first indication information can indicate the correspondence between different GNSS capabilities and the time-frequency resource sets for random access, and the time-frequency resources for carrying message three can be determined from the time-frequency resource sets for random access corresponding to terminal devices without GNSS capabilities.

[0196] In a possible design, S503 may include: the terminal device receives a second message from the network device after the first moment, and the time length between the end moment of sending the first message by the terminal device and the first moment is the first time length.

[0197] The first moment is a moment after the terminal device sends message 1.

[0198] Optionally, the first time length is twice the first time advance.

[0199] In this way, after sending message one, the terminal device can wait for a first time length, such as 2 times the first time advance, and then open the monitoring window to monitor message two. In this way, the time for monitoring message two can be reduced, thereby reducing the power consumption of the terminal device.

[0200] It is understandable that the first time length being twice the first time advance is only used as an example. In actual implementation, the first time length may also be other time lengths, which will not be described in detail here.

[0201] In another possible design solution, the implementation principle of S503 can also refer to the relevant introduction in S304, which will not be repeated here.

[0202] S504: The terminal device sends a third message to the network device according to the time-frequency resource indicated by the second message. Correspondingly, the network device receives the third message from the terminal device on the time-frequency resource. The third message includes the identification information of the terminal device.

[0203] For the implementation principle of message three, please refer to the relevant introduction of S305. For the implementation principle of S504, please refer to the relevant introduction in S305, which will not be repeated here.

[0204] S505: The network device sends a message 4 to the terminal apparatus. Correspondingly, the terminal apparatus receives the message 4 from the network device.

[0205] Message 4 is used to indicate that the terminal device has successfully resolved contention.

[0206] For the implementation principle of message 4, please refer to the relevant introduction in S306, which will not be repeated here.

[0207] In a possible design, S505 may include: the terminal device receives a fourth message from the network device after the second moment, and the time length between the end moment of sending the third message by the terminal device and the second moment is the second time length.

[0208] The second moment is a moment after the end moment of sending the third message by the terminal device.

[0209] Optionally, the second time length is twice the first time advance.

[0210] In this way, after sending message three, the terminal device can wait for a second time length, such as twice the first time advance, and then open the monitoring window to monitor message four. In this way, the time for monitoring message four can be reduced, thereby reducing the power consumption of the terminal device.

[0211] It is understandable that the second time length being twice the first time advance is only used as an example. In actual implementation, the second time length may also be other time lengths, which will not be described in detail here.

[0212] In the embodiment of the present application, the first time length and the second time length can be configured through a broadcast message, such as SIB.

[0213] In another possible design solution, the implementation principle of S505 can also refer to the relevant introduction in S306, which will not be repeated here.

[0214] Based on the random access method provided in Figure 5, the network equipment can configure at least one first time advance corresponding to the first service area where the terminal device is located for the terminal device, so that the terminal device can send message one based on the at least one first time advance to achieve time pre-compensation of message one, so that message one can be aligned with message one of other terminal devices on the network equipment side, thereby improving the success rate of random access.

[0215] For ease of understanding, the random access method provided in FIG. 5 is described below in conjunction with different scenarios.

[0216] In some scenarios, the service area where the terminal device is located, that is, the first service area, is relatively small. For example, when the radius of the first service area is less than 100 km, the TA indicated by the network device can achieve the purpose of aligning the message of the terminal device in the first service area. It is understandable. The radius of the first service area is less than 100 km only for example. In actual implementation, the radius of the first service area can also be other ranges, which will not be repeated here. At this time, the terminal device can send message one for random access according to the TA indicated by the first indication information. For the random access method in this scenario, please refer to Figure 6.

[0217] As shown in FIG6 , the random access method includes:

[0218] S601: The network device sends first indication information to the terminal apparatus. Correspondingly, the terminal apparatus receives the first indication information from the network device.

[0219] The first indication information is used to indicate a first correspondence between a first service area of ​​the network device and at least one first timing advance. The first service area is a service area where the terminal device is located.

[0220] Regarding the implementation principle of the first service area, at least one first timing advance and the first corresponding relationship, reference may be made to the relevant introduction in S501 and will not be repeated here.

[0221] In one possible design, the terminal device is a terminal device without GNSS capability, and the network device is a satellite. It is understood that the network device can also be a drone, etc.

[0222] Optionally, the first indication information may also be used to indicate a correspondence between different GNSS capabilities and a set of time-frequency resources used for random access.

[0223] Regarding the implementation principle that the first indication information can also be used to indicate the correspondence between different GNSS capabilities and the time-frequency resource set for random access, reference can be made to the relevant introduction in S501 and will not be repeated here.

[0224] For the implementation principle of S601, please refer to the relevant introduction of S501, which will not be repeated here.

[0225] S602: The terminal device sends a message 1 to the network device according to at least one first timing advance. Correspondingly, the network device receives the message 1 from the terminal device.

[0226] Message 1 is used for random access and carries a random access preamble.

[0227] The random access preamble carried in Message 1 can be determined based on existing technologies. For the implementation principle of Message 1, please refer to the relevant description in S303. For the implementation principle of the terminal device sending Message 1 to the network device based on at least one first timing advance in S602, please refer to the relevant description in S502. For the implementation principle of the network device receiving Message 1 from the terminal device, please refer to the relevant description in S302. These will not be repeated here.

[0228] S603: The network device sends a second message to the terminal apparatus. Correspondingly, the terminal apparatus receives the second message from the network device.

[0229] Among them, message two is used to indicate the time-frequency resources carrying message three.

[0230] For the implementation principle of the second message, please refer to the relevant introduction in S503. For the implementation principle of S603, please refer to the relevant introduction in S503, which will not be repeated here.

[0231] S604: The terminal device sends a message 3 to the network device according to the time-frequency resources indicated by the message 2. Correspondingly, the network device receives the message 3 from the terminal device on the time-frequency resources.

[0232] Among them, message three includes identification information of the terminal device.

[0233] For the implementation principle of message three, please refer to the relevant introduction in S504. For the implementation principle of S604, please refer to the relevant introduction in S504, which will not be repeated here.

[0234] S605: The network device sends a message 4 to the terminal apparatus. Correspondingly, the terminal apparatus receives the message 4 from the network device.

[0235] For the implementation principle of message 4, please refer to the relevant introduction in S505. For the implementation principle of S605, please refer to the relevant introduction in S505, which will not be repeated here.

[0236] Regarding the technical effects of the method provided in FIG6 , please refer to the relevant introduction in FIG5 , which will not be repeated here.

[0237] In other scenarios, the service area where the terminal device is located, that is, the first service area, is larger. For example, when the radius of the first service area is greater than or equal to 100 km, the TA indicated by the network device and the CP length of the random access preamble can be combined to achieve the purpose of aligning the message of the terminal device in the first service area. It is understandable. The radius of the first service area is greater than or equal to 100 km is only for example. In actual implementation, the radius of the first service area can also be other ranges, which will not be repeated here. At this time, the terminal device can send message one for random access according to the TA indicated by the first indication information and the CP length of the random access preamble corresponding to the GNSS capability. For the random access method in this scenario, please refer to Figure 7.

[0238] As shown in FIG7 , the random access method includes:

[0239] S701: The network device sends first indication information to the terminal apparatus. Correspondingly, the terminal apparatus receives the first indication information from the network device.

[0240] The first indication information is used to indicate a first correspondence between a first service area of ​​the network device and at least one first timing advance. The first service area is a service area where the terminal device is located.

[0241] In addition, the first indication information is also used to indicate the second corresponding relationship. For the implementation principle of the second corresponding relationship, please refer to the relevant introduction in S501.

[0242] For the implementation principle of the first indication information, please refer to the relevant introduction in S501. For the implementation principle of S701, please refer to the relevant introduction in S501, which will not be repeated here.

[0243] S702: The terminal device sends a message 1 to the network device according to at least one first timing advance. Correspondingly, the network device receives the message 1 from the terminal device.

[0244] Message 1 is used for random access and carries a random access preamble.

[0245] The CP length of the random access preamble in the first message is determined according to the GNSS capability of the terminal device and the second corresponding relationship.

[0246] The CP length of the random access preamble in message one is determined based on the GNSS capability of the terminal device and the second corresponding relationship. Please refer to the relevant introduction in S502. The implementation principle of S702 may refer to the relevant introduction in S502, which will not be repeated here.

[0247] S703: The network device sends a second message to the terminal apparatus. Correspondingly, the terminal apparatus receives the second message from the network device.

[0248] Among them, message two is used to indicate the time-frequency resources carrying message three.

[0249] For the implementation principle of the second message, please refer to the relevant introduction in S503. For the implementation principle of S603, please refer to the relevant introduction in S503, which will not be repeated here.

[0250] S704: The terminal device sends a message 3 to the network device according to the time-frequency resources indicated by the message 2. Correspondingly, the network device receives the message 3 from the terminal device on the time-frequency resources.

[0251] Among them, message three includes identification information of the terminal device.

[0252] For the implementation principle of message three, please refer to the relevant introduction in S504. For the implementation principle of S704, please refer to the relevant introduction in S504, which will not be repeated here.

[0253] S705: The network device sends a message 4 to the terminal apparatus. Correspondingly, the terminal apparatus receives the message 4 from the network device.

[0254] For the implementation principle of message 4, please refer to the relevant introduction in S505. For the implementation principle of S705, please refer to the relevant introduction in S505, which will not be repeated here.

[0255] Regarding the technical effects of the method provided in FIG7 , please refer to the relevant introduction in FIG5 , which will not be repeated here.

[0256] In some scenarios, the service area where the terminal device is located, that is, the first service area, is relatively small. For example, when the radius of the first service area is greater than or equal to 100 km, the reception of message 1 by the terminal device in the first service area can be achieved by combining the TA indicated by the network device and the length of the network device's reception time. This is understandable. The fact that the radius of the first service area is greater than or equal to 100 km is only for example. In actual implementation, the radius of the first service area can also be other ranges, which will not be repeated here.

[0257] At this time, the terminal device can send message 1 according to the TA indicated by the first indication information to perform random access. For the random access method in this scenario, please refer to Figure 8.

[0258] As shown in FIG8 , the random access method includes:

[0259] S801: The network device sends first indication information to the terminal apparatus. Correspondingly, the terminal apparatus receives the first indication information from the network device.

[0260] The first indication information is used to indicate a first correspondence between a first service area of ​​the network device and at least one first timing advance. The first service area is a service area where the terminal device is located.

[0261] Regarding the implementation principle of the first service area, at least one first timing advance and the first corresponding relationship, reference may be made to the relevant introduction in S501 and will not be repeated here.

[0262] In one possible design, the terminal device is a terminal device without GNSS capability, and the network device is a satellite. It is understood that the network device can also be a drone, etc.

[0263] Optionally, the first indication information may also be used to indicate a correspondence between different GNSS capabilities and a set of time-frequency resources used for random access.

[0264] Regarding the implementation principle that the first indication information can also be used to indicate the correspondence between different GNSS capabilities and the time-frequency resource set for random access, reference can be made to the relevant introduction in S501 and will not be repeated here.

[0265] For the implementation principle of S801, please refer to the relevant introduction of S501, which will not be repeated here.

[0266] S802: The terminal device sends a message 1 to the network device according to at least one first timing advance. Correspondingly, the network device receives the message 1 from the terminal device.

[0267] Message 1 is used for random access and carries a random access preamble.

[0268] The random access preamble carried in Message 1 can be determined based on existing technologies. For the implementation principle of Message 1, please refer to the relevant description in S303. For the implementation principle of the terminal device sending Message 1 to the network device based on at least one first timing advance in S802, please refer to the relevant description in S502.

[0269] Regarding the network device receiving the message 1 from the terminal device, it may include: the network device receiving the message 1 from the terminal device within a first time period, wherein the length of the first time period is related to the random access preamble carried by the message 1.

[0270] Regarding the implementation principle of the first time length, reference may be made to the relevant introduction in S802 and will not be repeated here.

[0271] S803: The network device sends a second message to the terminal apparatus. Correspondingly, the terminal apparatus receives the second message from the network device.

[0272] Among them, message two is used to indicate the time-frequency resources carrying message three.

[0273] For the implementation principle of message 2, please refer to the relevant introduction in S503. For the implementation principle of S803, please refer to the relevant introduction in S503, which will not be repeated here.

[0274] S804: The terminal device sends message 3 to the network device according to the time-frequency resources indicated by message 2. Correspondingly, the network device receives message 3 from the terminal device on the time-frequency resources.

[0275] Among them, message three includes identification information of the terminal device.

[0276] For the implementation principle of message three, please refer to the relevant introduction in S504. For the implementation principle of S804, please refer to the relevant introduction in S504, which will not be repeated here.

[0277] S805: The network device sends a message 4 to the terminal apparatus. Correspondingly, the terminal apparatus receives the message 4 from the network device.

[0278] For the implementation principle of message 4, please refer to the relevant introduction in S505. For the implementation principle of S805, please refer to the relevant introduction in S505, which will not be repeated here.

[0279] Regarding the technical effects of the method provided in FIG8 , please refer to the relevant introduction in FIG5 , which will not be repeated here.

[0280] The random access method provided in the embodiment of the present application is described in detail above with reference to Figures 5 to 8. The communication device for executing the random access method provided in the embodiment of the present application is described in detail below with reference to Figures 9 and 10.

[0281] For example, Figure 9 is a schematic diagram of the structure of a communication device provided in an embodiment of the present application. As shown in Figure 9, the communication device 900 includes: a processing module 901 and a transceiver module 902. For ease of illustration, Figure 9 only shows the main components of the communication device 900.

[0282] In some embodiments, the communication device 900 may be applicable to the communication system shown in FIG. 4 , and perform the functions of the communication device 900 in the random access method shown in any one of FIG. 5 to FIG. 8 .

[0283] The transceiver module 902 is configured to receive first indication information from a network device.

[0284] The first indication information is used to indicate a first correspondence between a first service area of ​​the network device and at least one first timing advance. The first service area is the service area where the communication device 900 is located.

[0285] The processing module 901 is configured to generate message 1. Message 1 is used for random access.

[0286] The transceiver module 902 is further configured to send message 1 to the network device according to at least one first timing advance.

[0287] In one possible design, at least one first timing advance is associated with at least one distance, where the at least one distance is a distance between at least one first location within the first service area and the network device.

[0288] Optionally, one of the at least one first location may be: a location farthest from the network device in the first service area, or a location closest to the network device in the first service area, or a central location of the first service area.

[0289] In one possible design, the first indication information may further be used to indicate a second correspondence between different GNSS capabilities and CP lengths of the random access preamble. Message one includes the random access preamble, and the CP length of the random access preamble in message one is determined based on the GNSS capabilities of the terminal device and the second correspondence.

[0290] Optionally, in the second corresponding relationship, the CP length of the random access preamble code corresponding to the non-GNSS capability is greater than the CP length of the random access preamble code corresponding to the GNSS capability.

[0291] In one possible design, transceiver module 902 is further configured to receive a second message from the network device. Message 2 indicates the time-frequency resources for carrying message 3. Transceiver module 902 is further configured to send a third message to the network device based on the time-frequency resources indicated by message 2. Message 3 includes identification information of communication device 900. Transceiver module 902 is further configured to receive a fourth message from the network device. Message 4 indicates that contention resolution has been successfully completed for communication device 900.

[0292] Optionally, the first indication information may also be used to indicate a correspondence between different GNSS capabilities and a set of time-frequency resources for random access. Message 2 includes second indication information, which is used to indicate the time-frequency resources carrying message 3. The time-frequency resources carrying message 3 are the time-frequency resources in the set of time-frequency resources for random access corresponding to the GNSS capabilities of the terminal device.

[0293] Optionally, the transceiver module 902 is further configured to receive a second message from the network device after the first moment. The time length between the end moment of sending the first message by the communication device 900 and the first moment is a first time length. The first time length is twice the first timing advance.

[0294] Optionally, the transceiver module 902 is further configured to receive a fourth message from the network device after the second time. The time length between the end time of sending the third message by the communication device 900 and the second time is a second time length, which is twice the first time advance.

[0295] In one possible design, the communication device 900 is a terminal device without GNSS capability, and the network device is a satellite.

[0296] Optionally, the transceiver module 902 may include a receiving module and a sending module (not shown in FIG9 ). The transceiver module 902 is used to implement the sending function and the receiving function of the communication device 900 .

[0297] Optionally, the communication device 900 may further include a storage module (not shown in FIG9 ) storing a program or instruction. When the processing module 901 executes the program or instruction, the communication device 900 may perform the functions of the terminal device in the random access method shown in any one of FIG5 to FIG8 .

[0298] It should be understood that the processing module 901 involved in the communication device 900 can be implemented by a processor or a processor-related circuit component, which can be a processor or a processing unit; the transceiver module 902 can be implemented by a transceiver or a transceiver-related circuit component, which can be a transceiver or a transceiver unit.

[0299] It should be noted that the communication device 900 can be a terminal device, or a chip (system) or other parts or components that can be set in the terminal device, or a device that includes a terminal device, which is not limited in this application.

[0300] In addition, the technical effects of the communication device 900 can refer to the technical effects of the random access method shown in any one of Figures 5 to 8, and will not be repeated here.

[0301] In some other embodiments, the communication device 900 may be applicable to the communication system shown in FIG. 4 , and perform the functions of the network device in the random access method shown in FIG. 5 to FIG. 8 .

[0302] The processing module 901 is configured to generate first indication information, wherein the first indication information is used to indicate a first correspondence between a first service area of ​​the communication device 900 and at least one first timing advance. The first service area is the service area where the terminal device is located.

[0303] The transceiver module 902 is configured to send first indication information to the terminal device.

[0304] The transceiver module 902 is further configured to receive a message 1 from the terminal device.

[0305] Message 1 is sent by the terminal device according to at least one first timing advance, and message 1 is used for random access.

[0306] In one possible design, at least one first timing advance is associated with at least one distance, where the at least one distance is a distance between at least one first location within the first service area and communication device 900 .

[0307] Optionally, one of the at least one first position may be: a position farthest from the communication device 900 in the first service area, or a position closest to the communication device 900 in the first service area, or a central position of the first service area.

[0308] In one possible design, the first indication information may also be used to indicate a second correspondence between different GNSS capabilities and the CP length of the random access preamble. The CP length of the random access preamble in the first message is determined based on the GNSS capability of the terminal device and the second correspondence.

[0309] Optionally, in the second corresponding relationship, the CP length of the random access preamble code corresponding to the non-GNSS capability is greater than the CP length of the random access preamble code corresponding to the GNSS capability.

[0310] In one possible design, the transceiver module 902 is further configured to receive a message 1 from the terminal device within a first time period, wherein the length of the first time period is related to the random access preamble carried by the message 1.

[0311] Optionally, the length of the first time period is positively correlated with the cyclic shift value of the preamble sequence of the random access preamble code carried by message 1.

[0312] In one possible design, transceiver module 902 is further configured to send a second message to the terminal device. Message 2 indicates the time-frequency resources carrying message 3. Transceiver module 902 is further configured to receive a third message from the terminal device on the time-frequency resources. Message 3 includes identification information of the terminal device. Transceiver module 902 is further configured to send a fourth message to the terminal device. Message 4 indicates successful contention resolution for the terminal device.

[0313] Optionally, the first indication information may also be used to indicate a correspondence between different GNSS capabilities and a set of time-frequency resources for random access. Message 2 includes second indication information, which is used to indicate the time-frequency resources carrying message 3. The time-frequency resources carrying message 3 are the time-frequency resources in the set of time-frequency resources for random access corresponding to the GNSS capabilities of the terminal device.

[0314] In one possible design, the terminal device is a terminal device without GNSS capability, and the communication device 900 is a satellite.

[0315] Optionally, the transceiver module 902 may include a receiving module and a sending module (not shown in FIG9 ). The transceiver module 902 is used to implement the sending function and the receiving function of the communication device 900 .

[0316] Optionally, the communication device 900 may further include a storage module (not shown in FIG. 9 ) storing a program or instruction. When the processing module 901 executes the program or instruction, the communication device 900 may perform the functions of the network device in the random access method shown in any one of FIG. 5 to FIG. 8 .

[0317] It should be understood that the processing module 901 involved in the communication device 900 can be implemented by a processor or a processor-related circuit component, which can be a processor or a processing unit; the transceiver module 902 can be implemented by a transceiver or a transceiver-related circuit component, which can be a transceiver or a transceiver unit.

[0318] It should be noted that the communication device 900 can be a network device, a chip (system) or other parts or components that can be set in the network device, or a device that includes a network device. This application does not limit this.

[0319] In addition, the technical effects of the communication device 900 can refer to the technical effects of the random access method shown in any one of Figures 5 to 8, and will not be repeated here.

[0320] For example, FIG10 is a schematic diagram of the structure of another communication device provided in an embodiment of the present application. The communication device may be a terminal device or a network device, or may be a chip (system) or other component or assembly that can be provided in a terminal device or a network device. As shown in FIG10 , the communication device 1000 may include a processor 1001. Optionally, the communication device 1000 may further include a memory 1002 and / or a transceiver 1003. The processor 1001 is coupled to the memory 1002 and the transceiver 1003, such as by a communication bus.

[0321] The following is a detailed introduction to the various components of the communication device 1000 in conjunction with FIG10 :

[0322] The processor 1001 is the control center of the communication device 1000 and can be a single processor or a collective term for multiple processing elements. For example, the processor 1001 can be one or more central processing units (CPUs), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application, such as one or more digital signal processors (DSPs) or one or more field programmable gate arrays (FPGAs).

[0323] Optionally, the processor 1001 may execute various functions of the communication device 1000 by running or executing a software program stored in the memory 1002 and calling data stored in the memory 1002 .

[0324] In a specific implementation, as an embodiment, the processor 1001 may include one or more CPUs, such as CPU0 and CPU1 shown in FIG10 .

[0325] In a specific implementation, as an embodiment, the communication device 1000 may also include multiple processors, such as the processor 1001 and the processor 1004 shown in FIG10 . Each of these processors may be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). The processor herein may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0326] The memory 1002 is used to store the software program for executing the solution of the present application, and the execution is controlled by the processor 1001. The specific implementation method can refer to the above method embodiment and will not be repeated here.

[0327] Alternatively, the memory 1002 may be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, an optical disc storage (including a compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 1002 may be integrated with the processor 1001 or exist independently and be coupled to the processor 1001 via an interface circuit (not shown in FIG. 10 ) of the communication device 1000. This embodiment of the present application does not specifically limit this.

[0328] Transceiver 1003 is used for communication with other communication devices. For example, if communication device 1000 is a terminal device, transceiver 1003 can be used to communicate with a network device or another terminal device. For another example, if communication device 1000 is a network device, transceiver 1003 can be used to communicate with a terminal device or another network device.

[0329] Optionally, the transceiver 1003 may include a receiver and a transmitter (not shown separately in FIG10 ), wherein the receiver is used to implement a receiving function, and the transmitter is used to implement a sending function.

[0330] Optionally, the transceiver 1003 may be integrated with the processor 1001 or exist independently and be coupled to the processor 1001 through an interface circuit (not shown in FIG. 10 ) of the communication device 1000 . This embodiment of the present application does not specifically limit this.

[0331] It should be noted that the structure of the communication device 1000 shown in FIG10 does not constitute a limitation on the communication device. An actual communication device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0332] In addition, the technical effects of the communication device 1000 can refer to the technical effects of the random access method described in the above method embodiment, and will not be repeated here.

[0333] It should be understood that the processor in the embodiments of the present application may be a CPU, but may also be other general-purpose processors, DSPs, ASICs, FPGAs, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0334] It should also be understood that the memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a ROM, a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an EEPROM, or a flash memory. The volatile memory can be a RAM, which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0335] The above embodiments can be implemented in whole or in part by software, hardware (such as circuits), firmware or any other combination. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer program are loaded or executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (such as infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that contains one or more available media sets. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a tape), an optical medium (for example, a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state drive.

[0336] It should be understood that the term "and / or" as used herein simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. A and B can be singular or plural. Furthermore, the character " / " as used herein generally indicates an "or" relationship between the associated objects, but it may also indicate an "and / or" relationship. For specific understanding, please refer to the context.

[0337] In this application, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or plural.

[0338] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0339] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0340] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0341] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0342] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0343] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0344] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

[0345] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A random access method, characterized in that: Applied to a terminal device, the method comprises: Receive first indication information; wherein the first indication information is used to indicate a first corresponding relationship between a first service area of ​​a network device and at least one first timing advance; the first service area is a service area where the terminal device is located; Message one is sent according to the at least one first time advance; wherein the message one is used for random access.

2. The method according to claim 1, characterized in that: The at least one first timing advance is related to at least one distance; the at least one distance is a distance between at least one first location in the first service area and the network device.

3. The method according to claim 2, characterized in that One of the at least one first position is: a position in the first service area that is farthest from the network device, or a position in the first service area that is closest to the network device, or a central position in the first service area.

4. The method according to any one of claims 1 to 3, characterized in that The first indication information is further used to indicate a second correspondence between different global satellite navigation system GNSS capabilities and the cyclic prefix CP length of the random access preamble code; The message one includes a random access preamble code, and the CP length of the random access preamble code in the message one is determined according to the GNSS capability of the terminal device and the second corresponding relationship.

5. The method according to claim 4, characterized in that In the second corresponding relationship, the CP length of the random access preamble code corresponding to the non-GNSS capability is greater than the CP length of the random access preamble code corresponding to the GNSS capability.

6. The method according to any one of claims 1 to 5, characterized in that The method further comprises: Receive message 2; wherein message 2 is used to indicate the time-frequency resources carrying message 3; Sending the message three according to the time-frequency resources indicated by the message two; wherein the message three includes identification information of the terminal device; Received message four; wherein, the message four is used to indicate that the terminal device contention resolution is successful.

7. The method according to claim 6, characterized in that The first indication information is also used to indicate the correspondence between different GNSS capabilities and a set of time-frequency resources used for random access; the message two includes second indication information, and the second indication information is used to indicate the time-frequency resources carrying the message three; the time-frequency resources carrying the message three are the time-frequency resources in the set of time-frequency resources used for random access corresponding to the GNSS capability of the terminal device.

8. The method according to claim 6, characterized in that Receive message 2, including: Message 2 is received after a first moment; the time length between the end moment of sending the message 1 and the first moment is a first time length; the first time length is twice the first time advance.

9. The method according to claim 6, characterized in that Receive message 4, including: Message four is received after the second moment; the time length between the end moment of sending the message three and the second moment is the second time length; the second time length is twice the first time advance.

10. The method according to any one of claims 1 to 9, characterized in that The terminal device is a terminal device without GNSS capability, and the network device is a satellite.

11. A random access method, characterized in that: Applied to a network device, the method comprises: Sending first indication information; wherein the first indication information is used to indicate a first corresponding relationship between a first service area of ​​the network device and at least one first timing advance; the first service area is a service area where the terminal device is located; Receive message one; wherein, message one is sent by the terminal device according to the at least one first time advance, and message one is used for random access.

12. The method according to claim 11, characterized in that The at least one first timing advance is related to at least one distance; the at least one distance is a distance between at least one first location in the first service area and the network device.

13. The method according to claim 12, characterized in that One of the at least one first position is: a position in the first service area that is farthest from the network device, or a position in the first service area that is closest to the network device, or a central position in the first service area.

14. The method according to any one of claims 11 to 13, characterized in that The first indication information is further used to indicate a second corresponding relationship between the presence or absence of a global satellite navigation system GNSS capability and the cyclic prefix CP length of the random access preamble code; The CP length of the random access preamble code in the message one is determined according to the GNSS capability of the terminal device and the second corresponding relationship.

15. The method according to claim 14, characterized in that In the second corresponding relationship, the CP length of the random access preamble code corresponding to the non-GNSS capability is greater than the CP length of the random access preamble code corresponding to the GNSS capability.

16. The method according to any one of claims 11 to 13, characterized in that: The receiving message 1 comprises: Receive the message one within a first time period; wherein the time length of the first time period is related to the random access preamble code carried by the message one.

17. The method according to claim 16, characterized in that The length of the first time period is positively correlated with the cyclic shift value of the preamble sequence of the random access preamble code carried by the message one.

18. The method according to any one of claims 11 to 17, characterized in that The method further comprises: Send message 2; wherein message 2 is used to indicate the time-frequency resources carrying message 3; Receiving the message three on the time-frequency resource; wherein the message three includes identification information of the terminal device; Send message four, wherein the message four is used to indicate that the terminal device contention resolution is successful.

19. The method according to claim 18, characterized in that The first indication information is also used to indicate the correspondence between different GNSS capabilities and a set of time-frequency resources used for random access; the message two includes second indication information, and the second indication information is used to indicate the time-frequency resources carrying the message three; the time-frequency resources carrying the message three are the time-frequency resources in the set of time-frequency resources used for random access corresponding to the GNSS capability of the terminal device.

20. The method according to any one of claims 11 to 19, characterized in that The terminal device is a terminal device without GNSS capability, and the network device is a satellite.

21. A communication device, characterized in that: The communication device is used to execute the method according to any one of claims 1-10 or any one of claims 11-20.

22. A communication device, characterized in that: The communication device comprises a module for performing the functions as claimed in any one of claims 1-10, or any one of claims 11-20.

23. A communication device, characterized in that: The communication device comprises: a processor; wherein, The processor is used to execute the method according to any one of claims 1-10 or any one of claims 11-20.

24. A communication device, characterized in that: include: processor; The processor is configured to execute a computer program so that the communication device performs the method according to any one of claims 1 to 10 or any one of claims 11 to 20.

25. A communication device, characterized in that: include: processor and interface circuit; wherein, The interface circuit is used to receive code instructions and transmit them to the processor; The processor is configured to execute the code instructions to perform any one of claims 1-10, or the method of any one of claims 11-20.

26. A communication device, characterized in that: The communication device includes a processor and a transceiver, the transceiver is used for information exchange between the communication device and other communication devices, and the processor executes program instructions to perform any one of claims 1-10, or any one of claims 11-20.

27. A computer-readable storage medium, characterized in that: The computer-readable storage medium comprises a computer program or instructions, and when the computer program or instructions are executed on a computer, the computer is caused to perform the method according to any one of claims 1 to 10 or any one of claims 11 to 20.

28. A computer program product, characterized in that The computer program product comprises: a computer program or instructions, and when the computer program or instructions are run on a computer, the computer is caused to perform the method according to any one of claims 1 to 10 or any one of claims 11 to 20.

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