Method and apparatus for updating timing offsets - Patents.com

Abstract

To provide a method and an apparatus for updating a timing offset, which is particularly applicable to NTN networks such as satellite communication.SOLUTION: A method includes the steps of sending a third message including index information used to indicate a second timing offset that is an updated first timing offset to a network device by a terminal device on the basis of a first timing offset that is used to indicate a degree of delay in sending the third message by the terminal device, sending a fifth message to the network device by the terminal device on the basis of a second timing offset. In this method, the timing offset can be effectively updated in time on the basis of ensuring an enough time for the terminal device to make a timing advance adjustment, thereby avoiding waste of time-frequency resources.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This application claims priority to Chinese Patent Application No. 202010100465.X, entitled "METHOD AND APPARATUS FOR UPDATING TIMING OFFSET," filed with the State Intellectual Property Office of China on February 18, 2020, which is incorporated herein by reference in its entirety. This application claims priority to Chinese Patent Application No. 202010299099.5, entitled "METHOD AND APPARATUS FOR UPDATING TIMING OFFSET," filed with the State Intellectual Property Office of China on April 7, 2020, which is incorporated herein by reference in its entirety. This application claims priority to Chinese Patent Application No. 202011105437.3, entitled "METHOD AND APPARATUS FOR UPDATING TIMING OFFSET," filed with the State Intellectual Property Office of China on October 15, 2020, which is incorporated herein by reference in its entirety.

[0002] The present application relates to the field of communication technology, and in particular to a method and apparatus for updating a timing offset. [Background technology]

[0003] Currently, New Radio (NR) technology is moving from the standardization stage to the commercial deployment stage. The NR standard is researched and designed for terrestrial communications. Compared with terrestrial communications, non-terrestrial networks (NTN) communications are characterized by a wide coverage area and flexible networks.

[0004] In terrestrial communication networks, the altitude difference between a base station and a terminal is not large. However, as shown in Figure 1, in non-terrestrial networks, the altitude difference between a base station / satellite and a terminal is relatively large (generally greater than 500 km). Therefore, the round-trip delay and round-trip delay difference of a terminal within the same beam / cell in NTN are much larger than those of a terminal within the same cell in NR. For example, when the diameter of a cell in a terrestrial cellular network is 350 km, the maximum round-trip delay within the cell is 1.17 ms. However, when the orbital altitude of an NTN satellite is 600 km and the beam diameter is 350 km, the maximum round-trip delay can reach approximately 13 ms (when the UE's communication angle is 10 degrees), as shown in Figure 2.

[0005] Generally, to ensure that the base station receives the uplink signal transmitted by the terminal at the designated time, the terminal needs to adjust the timing advance before transmitting the uplink signal. However, based on the uplink-downlink timing relationship, the amount of timing advance adjustment that the terminal can make is much less than 13 milliseconds (ms).

[0006] Therefore, how to ensure that the terminal device has enough time to perform timing advance adjustment is a problem that needs to be solved. Summary of the Invention

[0007] The embodiments of the present application provide a method and apparatus for updating the timing offset, ensuring that the terminal device has enough time to perform timing advance adjustment, and updating the timing offset in a timely and effective manner, thereby avoiding the waste of time-frequency resources.

[0008] According to a first aspect, the present application provides a method for updating a timing offset, the method comprising: a step of the terminal device transmitting a third message to the network device based on a first timing offset, the first timing offset being used to indicate a delay degree of the transmission of the third message by the terminal device, the third message including index information, the index information being used to indicate a second timing offset, the second timing offset being the updated first timing offset; The terminal device transmits a fifth message to the network device based on the second timing offset.

[0009] According to the technical solution provided in the present application, in one aspect, by setting a timing offset, the terminal device has enough time to perform timing advance adjustment. In another aspect, by updating the timing offset, the terminal device can use an appropriate timing offset in a timely manner. Compared with a method in which the timing offset is not updated, this embodiment of the present application can reduce end-to-end delay and avoid wasting resources by ensuring that the terminal device has enough time to perform timing advance adjustment.

[0010] In a possible embodiment, before the terminal device transmits a third message to the network device based on the first timing offset, the method further includes the steps of: the terminal device transmitting a first message to the network device, the first message including a random access preamble; and the terminal device receiving a second message transmitted by the network device, the second message including a random access response message; and after the terminal device transmits the third message to the network device based on the first timing offset, the method further includes the step of the terminal device receiving a fourth message transmitted by the network device, the fourth message including a random access contention resolution message.

[0011] In this embodiment of the present application, the first message may be understood as Msg1 in a four-step random access process, the second message may be understood as Msg2 in a four-step random access process, the third message may be understood as Msg3 in a four-step random access process, and the fourth message may be understood as Msg4 in a four-step random access process.

[0012] In a possible implementation, indicating the second timing offset using the index information includes including the second timing offset in the index information.

[0013] In a possible implementation, indicating the second timing offset using the index information includes including a first adjustment parameter set in the index information and determining the second timing offset using the first adjustment parameter set.

[0014] In this embodiment of the present application, the number of bits used by the terminal device when transmitting the first adjustment parameter set is much smaller than the number of bits used by the terminal device when directly transmitting the second timing offset, thereby reducing signaling overhead.

[0015] In a possible embodiment, the first set of adjustment parameters includes any one or more of the following: parameters determined based on the start-up delay period of the random access response RAR receiving window and the period of the RAR receiving window; or parameters determined based on the start-up delay period of the random access contention resolution timer and the period of the random access contention resolution timer; or parameters determined based on a common timing advance; or parameters determined based on the orbital altitude of the network device; or parameters determined based on a round-trip delay between the terminal device and the network device.

[0016] In a possible implementation, indicating the second timing offset using the index information includes including in the index information a variation between the second timing offset and the reference timing offset.

[0017] In this application, the reference timing offset is the timing offset currently used by the terminal device or a preset timing offset.

[0018] In a possible embodiment, the fourth message includes a second timing offset; or the fourth message includes a variation between the second timing offset and a reference timing offset, the reference timing offset being the timing offset currently used by the terminal device or a preset timing offset.

[0019] In possible embodiments, the method further includes the steps of: the terminal device receiving validity information transmitted by the network device, the validity information being used to indicate the validity time of the second timing offset; or the terminal device transmitting validity information to the network device, the validity information being used to indicate the validity time of the second timing offset; or the second timing offset becoming valid m slots after the terminal device transmits the third message, where m is a predetermined integer; or the second timing offset becoming valid n slots after the terminal device receives the fourth message, where n is a predetermined integer.

[0020] In a possible embodiment, before the terminal device transmits the third message to the network device based on the timing offset, the method further includes a step in which the terminal device receives a broadcast message transmitted by the network device, the broadcast message including one or more of: a start-up delay period of the RAR reception window and a period of the RAR reception window; or a start-up delay period of the random access contention resolution timer and a period of the random access contention resolution timer; or a common timing advance; or an orbital altitude of the network device.

[0021] In a possible embodiment, when the broadcast message includes the RAR receiving window start-up delay period and the RAR receiving window period, the first timing offset satisfies the following condition:

number

[0022] In a possible implementation, when the broadcast message includes the random access contention resolution timer start delay period and the random access contention resolution timer period, the first timing offset satisfies the following condition:

number

[0023] RCR_timer is the period of the random access contention resolution timer, which indicates the maximum time interval allowed between the moment the terminal device starts the random access contention resolution timer after sending the third message and the moment the terminal device receives the fourth message; RCR_offset is the start delay period of the random access contention resolution timer, which is used to indicate the delay period for delaying the start of the random access contention resolution timer after the terminal device sends the third message; slot_duration is the unit of period; and ΔK offset is the timing offset difference, which is an integer.

[0024] In a possible embodiment, the fifth message includes any one of data information, a feedback message, or a sounding reference signal (SRS).

[0025] Optionally, the feedback message includes a fourth message feedback message.

[0026] In a possible embodiment, the method further includes the steps of: the terminal device receiving a timing advance adjustment command sent by the network device, the timing advance adjustment command being used to instruct updating the second timing offset; and the terminal device sending an updated second timing offset or a second adjustment parameter set to the network device based on the second timing offset, the second adjustment parameter set being used to determine the updated second timing offset.

[0027] In a possible embodiment, the method further includes a step in which the terminal device receives an updated second timing offset or a variation between the updated second timing offset and the reference timing offset from the network device when one or more of the following conditions are met: the terminal device switches cells; or the terminal device switches beams; or the terminal device switches bandwidth parts (BWPs).

[0028] According to a second aspect, the present application provides a method for updating a timing offset, the method including the steps of: receiving, by a network device, a third message transmitted by a terminal device based on a first timing offset, wherein the first timing offset is used to indicate a delay degree by which reception of the third message by the network device is delayed, the third message includes index information, the index information is used to indicate a second timing offset, and the second timing offset is the updated first timing offset; and receiving, by the network device, the fifth message sent by the terminal device.

[0029] In a possible embodiment, before the network device receives a third message transmitted by the terminal device based on the first timing offset, the method further includes the steps of: the network device receiving a first message transmitted by the terminal device, the first message including a random access preamble; and the network device transmitting a second message to the terminal device, the second message including a random access response message; and after the network device receives the third message transmitted by the terminal device based on the first timing offset, the method further includes the step of the network device transmitting a fourth message to the terminal device, the fourth message including a random access contention resolution message.

[0030] In a possible implementation, indicating the second timing offset using the index information includes including the second timing offset in the index information.

[0031] In a possible implementation, indicating the second timing offset using the index information includes including a first adjustment parameter set in the index information and determining the second timing offset using the first adjustment parameter set.

[0032] In a possible embodiment, the first set of adjustment parameters includes any one or more of the following: parameters determined based on the start-up delay period of the random access response RAR receiving window and the period of the RAR receiving window; or parameters determined based on the start-up delay period of the random access contention resolution timer and the period of the random access contention resolution timer; or parameters determined based on a common timing advance; or parameters determined based on the orbital altitude of the network device; or parameters determined based on a round-trip delay between the terminal device and the network device.

[0033] In a possible implementation, indicating the second timing offset using the index information includes including in the index information a variation between the second timing offset and the reference timing offset.

[0034] In this application, the reference timing offset is the timing offset currently used by the terminal device or a preset timing offset.

[0035] In a possible embodiment, the fourth message includes a second timing offset, or the fourth message includes a variation between the second timing offset and a reference timing offset, where the reference timing offset is the timing offset currently used by the terminal device or a preset timing offset.

[0036] In possible embodiments, the method further includes the steps of: the network device transmitting validity information to the terminal device, the validity information being used to indicate the validity time of the second timing offset; or the network device receiving validity information transmitted by the terminal device, the validity information being used to indicate the validity time of the second timing offset; or the second timing offset becoming valid m slots after the network device receives the third message, where m is a predetermined integer; or the second timing offset becoming valid n slots after the network device transmits the fourth message, where n is a predetermined integer.

[0037] In a possible embodiment, before the network device receives the third message transmitted by the terminal device based on the first timing offset, the method further includes a step in which the network device transmits a broadcast message, the broadcast message including one or more of: a start-up delay period of the RAR reception window and a period of the RAR reception window; or a start-up delay period of the random access contention resolution timer and a period of the random access contention resolution timer; or a common timing advance; or an orbital altitude of the network device.

[0038] In a possible embodiment, when the broadcast message includes the start-up delay period of the RAR receiving window and the period of the RAR receiving window, the first timing offset satisfies the following condition:

number

[0039] where K offset1is the value of the first timing offset, RAR_window is the duration of the RAR receiving window, which is used to indicate the period during which the terminal device receives the RAR, RAR_offset is the start-up delay period of the RAR receiving window, which is used to indicate the delay period for delaying the start-up of the RAR receiving window after the terminal device transmits the first message, slot_duration is the unit of duration, and ΔK offset is the timing offset difference, which is an integer.

[0040] In a possible implementation, when the broadcast message includes the random access contention resolution timer start delay period and the random access contention resolution timer period, the first timing offset satisfies the following condition:

number

[0041] where K offset1 is the value of the first timing offset, RCR_timer is the period of the random access contention resolution timer, which indicates the maximum time interval allowed between the moment the terminal device starts the random access contention resolution timer after sending the third message and the moment the terminal device receives the fourth message, RCR_offset is the start delay period of the random access contention resolution timer, which is used to indicate the delay period for delaying the start of the random access contention resolution timer after the terminal device sends the third message, slot_duration is the unit of period, and ΔK offset is the timing offset difference, which is an integer.

[0042] In a possible embodiment, the fifth message includes any one of data information, a feedback message, or a sounding reference signal SRS.

[0043] In a possible embodiment, the method further includes the steps of: the network device sending a timing advance adjustment command to the terminal device, where the timing advance adjustment command is used to instruct the terminal device to update the second timing offset; and the network device receiving the updated second timing offset or the second adjustment parameter set sent by the terminal device, where the second adjustment parameter set is used to determine the updated second timing offset.

[0044] In a possible embodiment, the method further includes a step in which the network device transmits the updated second timing offset or the variation between the updated second timing offset and the reference timing offset to the terminal device when one or more of the following conditions are met: the terminal device switches cells; or the terminal device switches beams; or the terminal device switches band portions BWP.

[0045] For the advantageous effects of the second aspect, please refer to the advantageous effects of the first aspect, and the details will not be described again here.

[0046] According to a third aspect, the present application provides a communications device, the device including: a processing unit and a transmitting unit, the processing unit configured to generate a third message including indicator information, the indicator information being used to indicate a second timing offset, the second timing offset being an updated first timing offset, the first timing offset being used to indicate a delay degree of transmission of the third message by the communications device, the transmitting unit configured to transmit the third message to a network device based on the first timing offset, and the transmitting unit further configured to transmit a fifth message to the network device based on the second timing offset.

[0047] In a possible embodiment, the sending unit is further configured to send a first message including a random access preamble to the network device, the receiving unit is further configured to receive a second message sent by the network device including a random access response message, and the receiving unit is further configured to receive a fourth message sent by the network device including a random access contention resolution message.

[0048] In a possible implementation, indicating the second timing offset using the index information includes including the second timing offset in the index information.

[0049] In a possible implementation, indicating the second timing offset using the index information includes including a first adjustment parameter set in the index information and determining the second timing offset using the first adjustment parameter set.

[0050] In a possible embodiment, the first set of adjustment parameters includes any one or more of the following: parameters determined based on the start-up delay period of the random access response RAR receiving window and the period of the RAR receiving window; or parameters determined based on the start-up delay period of the random access contention resolution timer and the period of the random access contention resolution timer; or parameters determined based on a common timing advance; or parameters determined based on the orbital altitude of the network device; or parameters determined based on a round-trip delay between the communication equipment and the network device.

[0051] In a possible implementation, indicating the second timing offset using the index information includes including in the index information a variation between the second timing offset and the reference timing offset.

[0052] In this application, the reference timing offset is the timing offset currently used by the terminal device or a preset timing offset.

[0053] In possible embodiments, the fourth message includes a second timing offset; or the fourth message includes a variation between the second timing offset and a reference timing offset, the reference timing offset being the timing offset currently used by the communication device or a preset timing offset.

[0054] In possible embodiments, the receiving unit is further configured to receive validity information sent by the network device, where the validity information is used to indicate the validity time of the second timing offset; or the transmitting unit is further configured to send validity information to the network device, where the validity information is used to indicate the validity time of the second timing offset; or the second timing offset becomes valid m slots after the communication device sends the third message, where m is a predetermined integer; or the second timing offset becomes valid n slots after the communication device receives the fourth message, where n is a predetermined integer.

[0055] In a possible embodiment, the receiving unit is further configured to receive a broadcast message sent by the network device, the broadcast message including one or more of: a start-up delay period of the RAR receiving window and a duration of the RAR receiving window; or a start-up delay period of the random access contention resolution timer and a duration of the random access contention resolution timer; or a common timing advance; or an orbital altitude of the network device.

[0056] In a possible embodiment, when the broadcast message includes the RAR receiving window start-up delay period and the RAR receiving window period, the first timing offset satisfies the following condition:

number

[0057] In a possible implementation, when the broadcast message includes the random access contention resolution timer start delay period and the random access contention resolution timer period, the first timing offset satisfies the following condition:

number

[0058] where K offset1 is the value of the first timing offset, RCR_timer is the period of the random access contention resolution timer, which indicates the maximum time interval allowed between the moment the communication device starts the random access contention resolution timer after sending the third message and the moment the communication device receives the fourth message, RCR_offset is the start delay period of the random access contention resolution timer, which is used to indicate the delay period for delaying the start of the random access contention resolution timer after the communication device sends the third message, slot_duration is the unit of time period, and ΔK offset is the timing offset difference, which is an integer.

[0059] In a possible embodiment, the fifth message includes any one of data information, a feedback message, or a sounding reference signal SRS.

[0060] In a possible embodiment, the receiving unit is further configured to receive a timing advance adjustment command sent by the network device, where the timing advance adjustment command is used to instruct updating the second timing offset. The sending unit is further configured to send an updated second timing offset or a second adjustment parameter set to the network device based on the second timing offset, where the second adjustment parameter set is used to determine the updated second timing offset.

[0061] In a possible embodiment, the receiving unit is further configured to receive an updated second timing offset or a variation between the updated second timing offset and the reference timing offset from the network device when one or more of the following conditions are met: the communication device switches cells; or the communication device switches beams; or the communication device switches band portions BWP.

[0062] According to a fourth aspect, the present application provides a communications device, the device including: a receiving unit configured to receive a third message transmitted by a terminal device based on a first timing offset, the first timing offset being used to indicate a delay degree of a delay for the network device to receive the third message, the third message including indicator information being used to indicate a second timing offset, the second timing offset being an updated first timing offset; and the receiving unit is further configured to receive a fifth message transmitted by the terminal device.

[0063] In a possible embodiment, the device further includes a transmitting unit. The receiving unit is configured to receive a first message transmitted by the terminal device, the first message including a random access preamble. The transmitting unit is configured to transmit a second message to the terminal device, the second message including a random access response message. The transmitting unit is further configured to transmit a fourth message to the terminal device, the fourth message including a random access contention resolution message.

[0064] In a possible implementation, indicating the second timing offset using the index information includes including the second timing offset in the index information.

[0065] In a possible implementation, indicating the second timing offset using the index information includes including a first adjustment parameter set in the index information and determining the second timing offset using the first adjustment parameter set.

[0066] In a possible embodiment, the first set of adjustment parameters includes one or more of the following: parameters determined based on the start-up delay period of the random access response RAR receiving window and the period of the RAR receiving window; or parameters determined based on the start-up delay period of the random access contention resolution timer and the period of the random access contention resolution timer; or parameters determined based on a common timing advance; or parameters determined based on the orbital altitude of the communication device; or parameters determined based on the round-trip delay between the terminal device and the communication device.

[0067] In a possible implementation, indicating the second timing offset using the index information includes including in the index information a variation between the second timing offset and the reference timing offset.

[0068] In this application, the reference timing offset is the timing offset currently used by the terminal device or a preset timing offset.

[0069] In a possible embodiment, the fourth message includes a second timing offset; or the fourth message includes a variation between the second timing offset and a reference timing offset, the reference timing offset being the timing offset currently used by the terminal device or a preset timing offset.

[0070] In possible embodiments, the transmitting unit is further configured to transmit validity information to the terminal device, the validity information being used to indicate the validity time of the second timing offset; or the receiving unit is further configured to receive validity information transmitted by the terminal device, the validity information being used to indicate the validity time of the second timing offset; or the second timing offset becomes valid m slots after the communication device receives the third message, m being a predetermined integer; or the second timing offset becomes valid n slots after the communication device transmits the fourth message, n being a predetermined integer.

[0071] In a possible embodiment, the transmitting unit is further configured to transmit a broadcast message, the broadcast message including one or more of: a start-up delay period of the RAR receiving window and a duration of the RAR receiving window; or a start-up delay period of the random access contention resolution timer and a duration of the random access contention resolution timer; or a common timing advance; or an orbital altitude of the communication device.

[0072] In a possible embodiment, when the broadcast message includes the RAR receiving window start-up delay period and the RAR receiving window period, the first timing offset satisfies the following condition:

number

[0073] In a possible embodiment, when the broadcast message includes a random access contention resolution timer start delay period and a random access contention resolution timer period, the first timing offset satisfies the following condition:

number

[0074] In a possible embodiment, the fifth message includes any one of data information, a feedback message, or a sounding reference signal SRS.

[0075] In a possible embodiment, the transmitting unit is further configured to transmit a timing advance adjustment command to the terminal device, where the timing advance adjustment command is used to instruct updating of the second timing offset. The receiving unit is further configured to receive the updated second timing offset or a second adjustment parameter set transmitted by the terminal device, where the second adjustment parameter set is used to determine the updated second timing offset.

[0076] In a possible embodiment, the transmitting unit is further configured to transmit the updated second timing offset or the variation between the updated second timing offset and the reference timing offset to the terminal device when one or more of the following conditions are met: the terminal device switches cells; or the terminal device switches beams; or the terminal device switches band portions BWP.

[0077] According to a fifth aspect, the present application provides a communications device including a processor, the processor executing a computer program or instructions in a memory to perform a method according to the first aspect.

[0078] According to a sixth aspect, the present application provides a communications device including a processor, the processor invoking a computer program or instructions in a memory to perform a method according to the second aspect.

[0079] According to a seventh aspect, the present application provides a communications device including a processor and a memory, the memory configured to store computer-executable instructions, and the processor configured to execute the computer-executable instructions stored in the memory, enabling the communications device to perform a method according to the first aspect.

[0080] According to an eighth aspect, the present application provides a communications device including a processor and a memory, the memory configured to store computer-executable instructions, and the processor configured to execute the computer-executable instructions stored in the memory, enabling the communications device to perform a method according to the second aspect.

[0081] According to a ninth aspect, the present application provides a communications device including a processor, a memory, and a transceiver, the transceiver configured to receive or transmit signals, the memory configured to store program code, and the processor configured to execute the program code, enabling the communications device to perform a method according to the first aspect.

[0082] According to a tenth aspect, the present application provides a communications device including a processor, a memory, and a transceiver, the transceiver configured to receive or transmit signals, the memory configured to store program code, and the processor configured to execute the program code, enabling the communications device to perform a method according to the second aspect.

[0083] According to an eleventh aspect, the present application provides a communications device including a processor and an interface circuit configured to receive code instructions and transmit the code instructions to the processor, the code instructions being executed by the processor to perform the method set forth in the first aspect.

[0084] According to a twelfth aspect, the present application provides a communications device including a processor and an interface circuit configured to receive code instructions and transmit the code instructions to the processor, the code instructions being executed by the processor to perform the method set forth in the second aspect.

[0085] According to a thirteenth aspect, the present application provides a computer-readable storage medium configured to store instructions or a computer program, the instructions or the computer program being executed to perform a method according to the first aspect.

[0086] According to a fourteenth aspect, the present application provides a computer-readable storage medium configured to store instructions or a computer program, the instructions or the computer program being executed to perform a method according to the second aspect.

[0087] According to a fifteenth aspect, the present application provides a computer program product, the computer program product comprising instructions or a computer program which, when executed, performs the method of the first aspect.

[0088] According to a sixteenth aspect, the present application provides a computer program product, the computer program product comprising instructions or a computer program, which when executed perform the method according to the second aspect.

[0089] According to a seventeenth aspect, the present application provides a computer program configured to perform the method according to the first aspect.

[0090] According to an eighteenth aspect, the present application provides a computer program configured to perform the method according to the second aspect.

[0091] According to a 19th aspect, the present application provides a communication system including a terminal device and a network device, wherein the terminal device is configured to perform a method according to the first aspect and the network device is configured to perform a method according to the second aspect. [Brief explanation of the drawings]

[0092] [Figure 1] 1 is a schematic diagram of the architecture of an NTN communication system according to an embodiment of the present application; FIG. [Figure 2] FIG. 1 is a schematic diagram of the relationship between round trip delay and minimum elevation angle according to an embodiment of the present application; [Figure 3] 1 is a schematic diagram of the architecture of an NTN communication system according to an embodiment of the present application; FIG. [Figure 4] 1 is a schematic flowchart of a four-step random access method according to an embodiment of the present application; [Figure 5a] FIG. 1 is a schematic diagram of the relationship between timing advance and signals according to an embodiment of the present application; [Figure 5b] FIG. 1 is a schematic diagram of the relationship between timing advance and signals according to an embodiment of the present application; [Figure 5c] FIG. 1 is a schematic diagram of the relationship between timing advance and signals according to an embodiment of the present application; [Figure 6] 3 is a schematic flowchart of a method for updating a timing offset according to an embodiment of the present application; [Figure 7a] FIG. 1 is a schematic diagram of the relationship between timing advance and signals according to an embodiment of the present application; [Figure 7b] FIG. 1 is a schematic diagram of the relationship between timing advance and signals according to an embodiment of the present application; [Figure 8a] FIG. 2 is a schematic diagram of reference angles of a service link and a feeder link according to an embodiment of the present application; [Figure 8b] FIG. 10 is a schematic diagram of the relationship between maximum round trip differential delay and minimum elevation angle according to an embodiment of the present application; [Figure 9] FIG. 1 is a schematic diagram of the relationship between m and effective time according to an embodiment of the present application; [Figure 10a] 3 is a schematic flowchart of a method for updating a timing offset according to an embodiment of the present application; [Figure 10b] 3 is a schematic flowchart of a method for updating a timing offset according to an embodiment of the present application; [Figure 11]1 is a schematic flowchart of a two-step random access method according to an embodiment of the present application; [Figure 12] 3 is a schematic flowchart of a method for updating a timing offset according to an embodiment of the present application; [Figure 13] 1 is a schematic diagram of the structure of a communication device according to an embodiment of the present application; [Figure 14] 1 is a schematic diagram of the structure of a communication device according to an embodiment of the present application; [Figure 15] 1 is a schematic diagram of a reference point-based NTN communication system according to an embodiment of the present application; FIG. [Figure 16] FIG. 1 is an architecture diagram of an NTN system that replaces Koffset values ​​based on reference point coordinates according to one embodiment of the present application. [Figure 17] 1A is a schematic diagram of a Koffset value / Koffset reference point coordinate indicator according to an embodiment of the present application; FIG. [Figure 18] 1B is a schematic diagram of a Koffset value / Koffset reference point coordinate indicator according to an embodiment of the present application; [Figure 19] FIG. 10 is a schematic diagram of a Koffset angle according to an embodiment of the present application. [Figure 20] FIG. 2 is a schematic diagram of the relationship between signaling and slots according to an embodiment of the present application; [Figure 21] FIG. 2 is a schematic diagram of the relationship between signaling and slots according to an embodiment of the present application; DETAILED DESCRIPTION OF THE INVENTION

[0093] In the specification, claims, and accompanying drawings of this application, the terms "first," "second," "third," "fourth," etc. are intended to distinguish between different objects, but do not indicate a particular order. Furthermore, the terms "including," "having," and any other variations thereof are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include additional steps or units that are not listed, or may optionally include additional steps or units that are specific to the process, method, product, or apparatus.

[0094] The term "one embodiment" as used herein means that a particular feature, structure, or characteristic described with reference to an embodiment may be included in at least one embodiment of the present application. Phrases appearing in various places in the present specification do not necessarily refer to the same embodiment, nor are they an embodiment that is separate or optional and exclusive from another embodiment. It is explicitly and implicitly understood by those skilled in the art that an embodiment described herein can be combined with another embodiment.

[0095] In this application, "at least one (item)" means one or more, "multiple" means two or more, and "at least two (items)" means two, three, or more than three. The term "and / or" is used to describe an association relationship for describing associated objects and indicates that three relationships may exist. For example, "A and / or B" may represent three cases: only A is present, only B is present, and both A and B are present, where A and B may be singular or plural. The character " / " typically indicates an "or" relationship between associated objects. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of a single item or multiple items. For example, "at least one item of a, b, or c" may represent a, b, c, "a and b," "a and c," "b and c," or "a, b, and c," where a, b, and c may be singular or plural.

[0096] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings.

[0097] The method provided herein can be applied to an NTN communication system. As shown in Figure 3, the communication system may include a terminal device, a satellite (also called a satellite base station), and a ground station (also called a gateway station or gateway).

[0098] The terminal device may also be referred to as user equipment (UE), terminal, or the like. The terminal device is a device having wireless transmission and reception capabilities. The terminal device may be indoors, outdoors, handheld, wearable, or vehicle-mounted, and may be deployed on land, such as on a vessel on the water, or in the air, such as on an airplane, balloon, or satellite. The terminal device may be a mobile phone, a tablet computer (Pad), a computer with wireless transmission and reception capabilities, a virtual reality (VR) terminal device, an augmented reality (AVR) terminal, or the like. The terminal device may be a wireless terminal for augmented reality (AR) terminal device, a wireless terminal for industrial control, a wireless terminal for self-driving, a wireless terminal for remote medical, a wireless terminal for smart grid, a wireless terminal for transportation safety, a wireless terminal for smart city, or a wireless terminal for smart home, etc. It should be understood that the terminal device may alternatively be a terminal device for a future 5G network, or a terminal device for a future evolved public land mobile network (PLMN), etc. For ease of explanation, the following will use an example in which the terminal device is a UE to describe the method in the embodiment of the present application.

[0099] Optionally, in the communication system shown in Figure 3, device-to-device (D2D), vehicle-to-everything (V2D), Communication technologies such as V2X (Vehicle to Everyday Life), machine to machine (M2M), etc. may be used for communication between terminals. The communication method of the terminal devices is not limited in the embodiments of the present application.

[0100] The satellite can provide wireless access services to the terminal device, schedule wireless resources for the accessed terminal device, and provide a reliable wireless transmission protocol and a data encryption protocol. Artificial Earth satellites, aircraft, and the like can be used as wireless communication base stations, for example, evolved NodeBs (eNBs) and 5G base stations (gNBs). Alternatively, the satellite can be used as a relay for these base stations to transparently transmit wireless signals from these base stations to the terminal device. In this case, the ground station can be considered as a wireless communication base station. Therefore, in some embodiments of the present application, for example, in a satellite playback scenario, the network device can be the satellite base station shown in FIG. 3. In other embodiments, for example, in a satellite transparency scenario, the network device can be the ground station shown in FIG. 3. Therefore, for ease of explanation, the method of the present application will be described below using an example in which the network device is a base station.

[0101] In the embodiment of the present application, the network device may include, but is not limited to, the aforementioned base station. For example, the base station may be a base station in a future communication system such as a sixth-generation communication system. Optionally, the network device may alternatively be an access node, a wireless relay node, a wireless backhaul node, or the like in a wireless local area network (wireless fidelity, Wi-Fi) system. Optionally, the network device may alternatively be a radio controller in a cloud radio access network (CRAN) scenario. Optionally, the network device may alternatively be a wearable device, an in-vehicle device, or the like. Optionally, the network device may alternatively be a small cell, a transmission receive point (TRP), or the like. It will be understood that the network device may alternatively be a base station in a future evolved PLMN, or the like.

[0102] Optionally, the satellite may be a geostationary earth orbit (GEO) satellite, a non-geostationary earth orbit (NGEO) satellite, or a a medium Earth orbit (MEO) or low Earth orbit (LEO) satellite in a medium Earth orbit (NGEO) or low Earth orbit (LEO), or a high altitude platform station (HPA) It may also be an Altitude Platform Station (HAPS).

[0103] The ground station may be configured to connect the satellite to the core network. For example, when the satellite acts as a wireless communication base station, the ground station can transparently transmit signaling between the satellite and the core network. Alternatively, the ground station may be used as a wireless communication base station, and the satellite may transparently transmit signaling between the terminal device and the ground station. For example, during communication, the ground station can transmit signaling from the core network to the satellite via a feedback link (also called a feeder link). The satellite transmits signaling to the terminal device via a service link between the satellite and the terminal device. Correspondingly, the terminal device can transmit signaling to the satellite via the service link, and the satellite transmits signaling to the core network via the ground station.

[0104] It will be understood that Figure 3 shows only one satellite and one ground station. In actual operation, an architecture including multiple satellites and / or multiple ground stations may be used as needed. Each satellite may serve one or more terminal devices, each satellite may correspond to one or more ground stations, and each ground station may correspond to one or more satellites. This is not a particular limitation of the present application.

[0105] To fully understand the method presented herein, the following provides a detailed description of the four-step random access method associated with the embodiment of the present application shown in FIG.

[0106] 401: The UE receives a random access preamble, which may also be referred to as a first message (Msg1). The random access preamble is used to notify the base station of a random access request, and to allow the base station to calibrate uplink timing and timing advance so that the base station can estimate the transmission delay between the base station and the UE. The timing advance (TA) command is used to communicate calibration information to the UE.

[0107] 402: After detecting the random access preamble, the base station sends a random access response, which may also be referred to as a second message (Msg2). The random access response (RAR) may include the sequence number of the random access preamble received in 401, a timing advance command, uplink resource allocation information, a temporary cell-radio network temporary identifier (TC-RNTI), etc.

[0108] 403: The UE receives a random access response. If the random access preamble indicated by the sequence number of the random access preamble in the random access response is the same as the random access preamble sent by the UE to the base station in step 401, the UE considers the random access response to be the random access response for this UE. That is, the UE receives the random access response for this UE. After receiving the random access response, the UE transmits an uplink message on the uplink resource indicated by the random access response, for example, transmits uplink data on a physical uplink shared channel (PUSCH), where the uplink message is also referred to as a third message (Msg3). Msg3 may carry a unique user identifier.

[0109] 404: The base station receives the UE's uplink message and returns a contention resolution message to the UE that performs successful access, where the contention resolution message is also referred to as a fourth message (Msg4). The base station includes a unique user identifier in Msg3 of the contention resolution message to indicate the UE that performs successful access. Other UEs that fail to access initiate random access again.

[0110] From the above description, it can be seen that in order to enable timing alignment between the uplink signal and the downlink signal when the uplink signal arrives at the satellite base station, the UE needs to perform a timing advance adjustment when transmitting the uplink signal, as shown in Figure 5a. The relatively large round-trip delay in the NTN causes a relatively large difference between the timing of the uplink signal received at the satellite base station and the timing of the downlink signal. Therefore, in the NTN system, the amount of timing advance adjustment for the uplink signal is relatively large.

[0111] To derive the problem to be solved in this application, for example, after a UE receives physical downlink shared channel (PDSCH) data transmitted by a base station, the UE performs a hybrid automatic repeat request (HARQ)-acknowledgement (ACK). A HARQ-ACK message must be sent to the base station to feedback that the PDSCH has been received correctly.

[0112] For example, if a UE receives PDSCH data in slot n, it needs to feed back a HARQ-ACK message in slot n+K1. That is, the maximum timing advance adjustment that a UE can perform is K1 slots. Generally, the maximum value of K1 is 15. When the subcarrier spacing (SCS) is 30 kHz and one slot is 0.5 ms, the maximum timing advance adjustment that a UE can perform is 7.5 ms. From FIG. 2, it can be seen that the round-trip delay between a UE and a base station in an NTN is much larger than 7.5 ms. Therefore, K1 slots cannot provide enough time for a UE to perform a timing advance adjustment, i.e., it cannot meet the timing advance requirement for compensating for the round-trip delay of a beam or cell in an NTN. Specifically, as shown in FIG. 5b, if the timing advance adjustment amount of uplink data transmitted by a UE is larger than K1 slots, the UE cannot transmit a HARQ-ACK message on time.

[0113] The solution to this problem is to add a timing offset K so that there is enough time between the moment the UE receives the PDSCH data and the moment the UE sends the HARQ-ACK message to allow for a timing advance adjustment. offset That is, on the satellite base station side, the HARQ-ACK message is sent in slot n+K1+Koffset As shown in Figure 5c, offset A value is introduced and the UE uses K offset The value can be used to adjust the slot in which the UE transmits the HARQ-ACK message so that the UE has enough time to make the timing advance adjustment.

[0114] Therefore, the method provided in the present application will be described below from the following aspects: First, a method for updating a timing offset in the present application will be described; Second, a method for transmitting a first timing offset, a method for transmitting a second timing offset, an effective time, an updating method, etc. included in the method will be described; Next, a switching scenario according to the present application will be described; Finally, another method for updating a timing offset in the present application will be described.

[0115] 6 is a schematic flowchart of a method for updating a timing offset according to the present application. Optionally, this method can be applied to a four-step random access scenario. As shown in FIG. 6, this method specifically includes the following steps:

[0116] 603: The UE receives a first timing offset K offset1 and sending a third message (Msg3) to the base station based on the first timing offset, where the first timing offset is used to indicate a delay in the transmission of the third message by the UE, and the third message includes index information, where the index information is used to indicate a second timing offset, and the second timing offset is the updated first timing offset.

[0117] In response, the base station receives the third message transmitted by the UE based on the first timing offset, which is used to indicate the delay of the base station's reception of the third message.

[0118] The UE transmitting the third message to the base station based on the first timing offset can be understood as follows: For example, if the UE receives the RAR message in slot n when the base station transmits a signal, the UE transmits the third message to the base station based on the first timing offset in slot n+K2+Δ+K. offset1 Similarly, the base station transmits a third message to the base station in slot n+K2+Δ+K offset1 and receiving a third message at K2. K2 is a parameter that the base station instructs the UE through broadcast or downlink control information (DCI), and Δ is a value pre-agreed upon by the system. The specific values ​​or sources of K2 and Δ are not limited by this application.

[0119] The first timing offset may also be referred to as an initial timing offset. Optionally, the UE may obtain the first timing offset from a broadcast message. Alternatively, the UE may determine the first timing offset based on associated adjustment parameters broadcast in the broadcast message. It should be understood that the following should be referred to for how the UE obtains the first timing offset based on associated adjustment parameters. Details will not be described here. For how the UE indicates the second timing offset to the base station, please refer to the following description.

[0120] Optionally, before the aforementioned step 603, the method shown in FIG. 6 further includes the following steps:

[0121] 601: A UE sends a first message (Msg1) to a base station, where the first message includes a random access preamble.

[0122] In response, the satellite base station receives the first message sent by the UE.

[0123] In the present embodiment, in a satellite transparent scenario, the base station corresponds to the ground station shown in Figure 3. In a satellite regenerative scenario, the base station corresponds to the satellite base station shown in Figure 3.

[0124] 602: The base station sends a second message (Msg2) to the UE, and the second message includes a random access response (random RAR) message.

[0125] In response, the UE receives the second message sent by the base station.

[0126] Optionally, before step 605, the method shown in FIG. 6 further includes the following steps:

[0127] 604: The base station sends a fourth message to the UE, where the fourth message includes a random access contention resolution message.

[0128] In response, the UE receives a fourth message.

[0129] Specifically, after the UE receives the second message sent by the base station, the UE can derive a timing advance (i.e., a TA value or TA_New) based on the timing advance command included in the second message and the common timing advance (or the timing advance previously used by the UE). Furthermore, the UE performs a timing advance adjustment on the transmitted signal based on the timing advance. Furthermore, the UE can determine a second timing offset based on the timing advance. Optionally, the timing advance TA_New and the second timing offset can satisfy the following equation (1):

number

[0130] TA_New is the timing advance used when the UE transmits the third message, slot_duration is the unit of duration, and is represented by the symbol

number

[0131] Optionally, taking into account the effect of processing delays and the altitude at which the UE is located, a fixed value such as Δt may be added to or subtracted from TA_New when calculating the second timing offset, i.e.,

number

number

[0132] It will be appreciated that in equation (1), rounding up is used as an example to describe the relationship between the timing advance and the second timing offset, and in certain implementations, the second timing offset may alternatively be determined in a rounding down manner.

[0133] It will be appreciated that the above discussion of rounding up and rounding down is also applicable to the following:

[0134] After the UE obtains the second timing offset according to Equation (1), in some embodiments, the UE may determine whether to update the first timing offset using the second timing offset based on an update threshold. For example, the update threshold is 1. If the difference between the timing offset obtained according to Equation (1) and the first timing offset is less than 1, the UE may determine not to update the first timing offset. Conversely, if the difference between the timing offset obtained according to Equation (1) and the first timing offset is 1 or more, the UE may determine to update the first timing offset, and the timing offset obtained according to Equation (1) is the second timing offset. It should be understood that the description regarding whether the UE updates the first timing offset when the update threshold is 1 is not limited in this application. As another example, the update threshold may be 2, etc. If the value of the update threshold is relatively large, the frequency of updating the first timing offset decreases. Therefore, signaling overhead can be reduced, and frequent conveyance of indicator information using a third message and another message in the RRC connection phase can be avoided.

[0135] Furthermore, after the UE determines to update the first timing offset, the UE transmits indicator information to the base station, and the base station receives the indicator information transmitted by the UE.

[0136] It will be appreciated that the update threshold may be preset by the base station or preset according to a protocol. Alternatively, the UE may obtain the update threshold using a broadcast message. The broadcast message may include a system information block (SIB) 1, a master information block (MIB), ... MIB, or other system information Alternatively, the UE may receive any one or more of a radio resource control (RRC) message, a downlink control information (DCI), a group DCI, a media access control (MAC), or a timing advance command. The UE may obtain the update threshold using any one or more of the following: a Time Admission Control (TAC) command, a Time Admission Control (TAC ...

[0137] The above is just an example, and the manner in which the UE obtains the update threshold and the specific value of the update threshold are not limited in this application.

[0138] After the UE obtains the second timing offset according to Equation (1), in another embodiment, after the UE transmits the indicator information to the base station, the base station can further determine whether to update the first timing offset using the second timing offset based on an update threshold. For how the base station performs the update, please refer to the description of the UE. The details will not be described again here.

[0139] Optionally, after the base station determines to update the first timing offset, the base station can further use an Msg4 message to transmit to the UE the second timing offset, the variation between the second timing offset and the reference timing offset, or an adjustment parameter used to indicate the second timing offset. The reference timing offset is the timing offset used by the UE, or the timing offset set by the base station (e.g., the timing offset set using a broadcast message), or a preset fixed timing offset. The timing offset currently used by the UE is, for example, the above-mentioned first timing offset. The preset timing offset can be understood as follows: The reference timing offset is preset by the base station or preset according to a protocol, etc. It will be understood that the description of the reference timing offset is also applicable to the reference timing offset appearing hereinafter in this application.

[0140] For example, if the reference timing offset is 20 and the second timing offset is 21, the variation may be +1. As another example, if the reference timing offset is 20 and the second timing offset is 19, the variation may be -1. Alternatively, the variation may be 0. The above example is shown using the reference timing offset minus the second timing offset as an example. However, in embodiments of the present application, the variation may alternatively be obtained using the reference timing offset minus the second timing offset.

[0141] Note that the adjustment parameter included in message 4 and indicating the second timing offset may be different from the adjustment parameter included in the third message and used to indicate the second timing offset. For example, the first adjustment parameter included in the third message and used to indicate the second timing offset may be a timing advance used by the UE to transmit the third message, and the adjustment parameter included in Msg4 and indicating the second timing offset may be some adjustment parameter related to the difference between the second timing offset and the first timing offset. Furthermore, after receiving the second timing offset, the adjustment parameter indicating the second timing offset, or the variation between the second timing offset and the reference timing offset included in Msg4, the UE may update the first timing offset. After the second timing offset becomes effective, the UE may transmit the fifth message based on the second timing offset.

[0142] For a clearer explanation of how the UE or base station determines whether to update the first timing offset using the second timing offset based on the update threshold, the following uses an example for illustration.

[0143] For example, the second timing offset acquired by the UE according to Equation (1) is 15, the first timing offset is 14, and the update threshold is 2. When the UE determines whether to update the first timing offset using the second timing offset, the UE may determine not to update the first timing offset because the difference between the first timing offset and the second timing offset is less than 2. Therefore, to reduce signaling overhead, the UE may not transmit indicator information to the base station. When the base station determines whether to update the first timing offset using the second timing offset, the terminal may use the indicator information to indicate that the second timing offset is 15. Therefore, after the base station receives the indicator information, the base station may determine not to update the first timing offset based on the fact that the difference between the first timing offset and the second timing offset is less than 2 and the update threshold is 2. Furthermore, Msg4 may not include the second timing offset.

[0144] For example, the second timing offset obtained by the UE according to Equation (1) is 17, the first timing offset is 14, and the update threshold is 2. When the UE determines whether to update the first timing offset using the second timing offset, the difference between the first timing offset and the second timing offset is greater than 2, so the UE can determine to update the first timing offset. Further, the UE transmits indicator information to the base station. When the base station determines whether to update the first timing offset using the second timing offset, the UE can use the indicator information to indicate that the second timing offset is 17. Therefore, after the base station receives the indicator information, the base station can determine to update the first timing offset based on the fact that the difference between the first timing offset and the second timing offset is greater than 2 and the update threshold is 2. Further, message 4 may include the second timing offset.

[0145] It will be understood that the above are merely examples and that the above numbers should not be understood as limitations of the present application.

[0146] 605: The UE sends a fifth message to the base station based on the second timing offset.

[0147] In response, the base station receives a fifth message.

[0148] The fifth message may include a HARQ-ACK message, which may be the HARQ-ACK message of the fourth message. Alternatively, the fifth message may further include an uplink data message, an uplink reference signal (e.g., a sounding reference signal), etc.

[0149] It should be understood that the description of the UE transmitting the fifth message to the base station based on the second timing offset should refer to the description of the UE transmitting the third message to the base station based on the first timing offset. Details will not be described again here. For the description of the effective time of the second timing offset, please refer to the following.

[0150] According to the technical solution provided in the present application, in one aspect, a timing offset is set so that the UE has enough time to perform a timing advance adjustment. In another aspect, the timing offset is updated, for example, the first timing offset or the second timing offset is updated, so that the UE can use an appropriate timing offset. Compared with a method in which the timing offset is not updated, the embodiment of the present application can reduce end-to-end delay and avoid resource waste by ensuring that the UE has enough time to perform a timing advance adjustment.

[0151] For example, in an NTN system, the relative distance between the LEO satellite and the UE is constantly changing, which means that the round trip delay is also constantly changing. offset If K is not updated, the UE will set a relatively large K to ensure normal communication. offset Therefore, we need to use the value K offset is not updated, the delay length (K1+K shown in Fig. 7a) that the UE delays sending the feedback message. offset ) can be much larger than the timing advance. As shown in Figure 7a, after transmitting Data 1, the base station continues to transmit Data 2 to 10 before receiving the HARQ-ACK (in the figure, A / N represents ACK or NACK) for Data 1, filling the entire time domain resource. Therefore, the base station needs to use 10 processes to avoid wasting time domain resources.

[0152] K offset When the UE can update the timing advance, the delay by which the UE delays the transmission of the HARQ-ACK is not much larger than the timing advance used by the UE. As shown in Figure 7b, the UE can update the timing advance by a relatively appropriate K offset In this case, the number of downlink processes on the base station side can be reduced to 7. offset After updating, the base station can receive HARQ-ACK feedback by waiting for 6 data lengths after transmitting data 1. Compared with waiting for 9 data lengths before updating, the end-to-end delay is reduced. Therefore, the solution of the present application can reduce the number of processes for the base station to transmit downlink data and reduce the end-to-end delay.

[0153] The timing offset K shown in this application offset If not otherwise specified, the timing offset is the first timing offset K offset1 , the second timing offset K offset2, or an updated second timing offset, etc. offset is a general term and has no special meaning.

[0154] The following describes in detail another method that may be involved in the method shown in FIG.

[0155] It is understood that the following methods can be cross-referenced or the methods can be further combined, and the solutions are within the protection scope of the present application.

[0156] The method by which the UE obtains the first timing offset from the broadcast message is as follows.

[0157] For example, the base station may determine the maximum round trip delay, e.g.

number

[0158] Here, max_RTD represents the round trip delay of the point farthest from the base station in the beam or cell area covered by the base station, i.e., the maximum round trip delay. In this case, the number of bits for transmitting the timing offset in different scenarios is expressed as follows:

[0159] In the following example, it will be understood that the subcarrier spacing is 120 KHz. The duration unit is 0.125 ms, where slot_duration is the slot length.

[0160] In a transparent scenario in GEO, the cell diameter D = 200 km, the maximum round trip delay is 541.1 ms, and the required K offset The maximum value is 541.1 / 0.125=4329=13 bits.

[0161] In the GEO regenerative scenario, the cell diameter D = 200 km, the maximum round trip delay is 270.5 ms, and the required K offset The maximum value is 270.5 / 0.125=2164=12 bits.

[0162] In the transparent scenario of LEO-1200, the cell diameter D = 100 km, the maximum round trip delay is 25.8 ms, and the required K offset The maximum value is 41.7 / 0.125=334=9 bits.

[0163] In the LEO-1200 regeneration scenario, the cell diameter D = 100 km, the maximum round trip delay is 12.9 ms, and the required K offset The maximum value is 20.9 / 0.125=168=8 bits.

[0164] In the transparent scenario of LEO-600, the cell diameter D = 100 km, the maximum round trip delay is 25.8 ms, and the required K offset The maximum value is 25.8 / 0.125=207=8 bits.

[0165] In the LEO-600 regeneration scenario, the cell diameter D = 100 km, the maximum round trip delay is 12.9 ms, and the required K offset The maximum value is 12.9 / 0.125=104=7 bits.

[0166] It will be appreciated that the maximum round trip delay in the transparent scenario shown above may represent the maximum round trip delay between the reference point, the satellite, and the earth station. The maximum round trip delay in the regenerative scenario shown above may represent the maximum round trip delay between the reference point and the satellite. The reference point may be a reference point within the coverage area of ​​a beam or a cell.

[0167] Optionally, the base station may broadcast the value of the first timing offset to the UE. For example, the base station may transmit the value of the first timing offset to the UE by using the formula

number

number

number

[0168] From the previous example, in different scenarios, the base station offset1 It may be seen that directly broadcasting a specific value of requires a relatively large amount of bits. Therefore, in order to reduce signaling overhead, the UE may obtain the associated adjustment parameter from the broadcast message, and thereby obtain the first timing offset based on the associated adjustment parameter.

[0169] The method for determining the first timing offset based on the related adjustment parameters broadcast in the broadcast message is as follows.

[0170] In the present method, to obtain the first timing offset, the UE k , ΔK offset , ΔK offset_timeIt should be understood that one or several parameters such as α, α, and β need to be obtained, and the base station can send the parameters to the UE in the following signaling manner.

[0171] The base station transmits the aforementioned parameters to the UE using a broadcast message, which includes a system information block (SIB), a master information block (MBI), and a base station information block (BSB). MIB, or other system information Alternatively, any one or more of the following may be included: Radio Resource Control (RSC) information (OSI) In the RRC connection phase, when the base station needs to inform the UE of the first timing offset of another cell or beam, the base station may inform the UE of the first timing offset by sending an RRC message, a downlink control information (DCI), a group DCI, a media access control (MAC) message, or a timing advance command. The base station may further transmit the aforementioned parameters to the UE using one or more of a Time Admission Control (TAC) command (Time Admission Control Advance Command). Optionally, the base station may alternatively transmit the aforementioned parameters on a PDSCH allocated together with or separately from the data transmission. Optionally, in addition to transmitting the aforementioned parameters using a broadcast message or a unicast message, the base station may further transmit the aforementioned parameters in a multicast manner. It will be understood that the above description of each parameter is also applicable to other embodiments of the present application.

[0172] Method 1:

[0173] Typically, a UE receives RAR-related information delivered by a base station using a preset reception window. However, the round-trip delay of satellite communication is relatively large. Therefore, after transmitting the random access preamble, the UE activates the reception window for detecting RAR-related information after a certain time delay. Theoretically, the activation delay period of the RAR reception window is related to the round-trip delay of the point closest to the base station within the beam / cell covered by the base station, i.e., the minimum round-trip delay. The timing offset is related to the maximum round-trip delay of the beam / cell covered by the base station. The activation delay period of the RAR reception window can be notified to the UE by the base station. Therefore, to reduce signaling overhead, a first timing offset can be determined based on the activation delay period of the RAR reception window.

[0174] Optionally, the first timing offset and the start-up delay period of the RAR receiving window may satisfy the following equation (2):

number

[0175] K offset1 is the first timing offset, and S k is a scale factor, which must be a non-negative number. RAR_delay is the startup delay period for the RAR receiving window. slot_duration is the unit of duration.

[0176] Optionally, the first timing offset and the start-up delay period of the RAR receiving window may satisfy the following equation (3):

number

[0177] ΔK offset is the timing offset difference, and the timing offset difference is an integer.

[0178] For example, the base station may calculate the beam / cell coverage area based on, for example, the aforementioned formula

number

[0179] Optionally, the first timing offset and the start-up delay period of the RAR receiving window may satisfy the following equation (4):

number

[0180] ΔK offset_time is the duration difference, which may be a positive number, a negative number, or 0. Furthermore, the dimension of the duration difference may be different from RAR_delay, which can reduce signaling overhead.

[0181] It will be appreciated that the duration difference value may be any value, such as a positive number, a negative number, or zero.

[0182] Optionally, the first timing offset and the start-up delay period of the RAR receiving window may satisfy the following equation (5):

number

[0183] It will be appreciated that for an explanation of the parameters in equation (5), reference should be made to equations (2), (3), and (4).

[0184] It is understood that the relationship between the first timing offset and the start-up delay period of the RAR receiving window can be in different forms based on the aforementioned parameters, but this is not limited in the present application. For example, according to Equation (2) and Equation (3), the first timing offset and the start-up delay period of the RAR receiving window can be, for example,

number

[0185] Method 2:

[0186] The UE receives RAR-related information delivered by the base station using a preset reception window. Therefore, the base station needs to notify the UE of the duration of the RAR reception window (RAR_window). After transmitting the preamble, the UE detects the RAR-related information during the RAR reception window. Theoretically, the duration of the RAR reception window is related to the round-trip delay difference of the beam / cell covered by the base station. Therefore, to reduce signaling overhead, the first timing offset can be determined based on the duration of the RAR reception window.

[0187] Optionally, the first timing offset and the duration of the RAR receiving window may satisfy the following equation (6):

number

[0188] Optionally, the first timing offset and the duration of the RAR receiving window may satisfy the following equation (7):

number

[0189] Optionally, the first timing offset and the duration of the RAR receiving window may satisfy the following equation (8):

number

[0190] Optionally, the first timing offset and the duration of the RAR receiving window may satisfy the following equation (9):

number

[0191] It is understood that the relationship between the first timing offset and the duration of the RAR receiving window may be in different forms based on the aforementioned parameters, but this is not limited in this application. For example, another derivation formula may be obtained, and the first timing offset and the duration of the RAR receiving window may be, for example,

number

[0192] It will be understood that for the explanation of the parameters in the formulas of Method 2, reference should be made to the parameters shown in Method 1.

[0193] Method 3:

[0194] For methods 1 and 2, since the base station not only needs to notify the UE of the duration of the RAR receiving window, but also needs to notify the UE of the startup delay period of the RAR receiving window, the first timing offset can alternatively be determined based on the duration of the RAR receiving window and the startup delay period of the RAR receiving window.

[0195] Optionally, the first timing offset, the duration of the RAR receiving window, and the startup delay duration of the RAR receiving window may satisfy the following equation (10):

number

[0196] Optionally, the first timing offset, the duration of the RAR receiving window, and the startup delay duration of the RAR receiving window may satisfy the following equation (11):

number

[0197] Another method for deriving the first timing offset may be obtained by modifying equations (10) and (11) based on the parameters shown in Method 1 and Method 2, for example:

number

number

[0198] It will be understood that for the explanation of the parameters in the formulas of Method 3, reference should be made to the parameters shown in Methods 1 and 2.

[0199] Method 4:

[0200] In the four-step random access process, after sending Message 3, the UE starts the random access contention resolution timer (ra-ContentionResolutionTimer) and begins detecting Message 4. If Msg4 is successfully received before the random access contention resolution timer expires, the access is considered successful. For example, the value range of the random access contention resolution timer includes {8 ms, 16 ms, 24 ms, 32 ms, 40 ms, 48 ​​ms, 56 ms, 64 ms}. The round-trip delay in NTN is relatively large. For example, the round-trip delay in GEO scenarios is approximately 250 ms. In this case, to ensure that Msg4 is received before the timer expires, a start delay time must be introduced into the random access contention resolution timer. Theoretically, the start delay time of the random access contention resolution timer is related to the round-trip delay of the point closest to the base station within the beam / cell covered by the base station, i.e., the minimum round-trip delay. Generally, the base station can use SIB 1 to send the start delay time RCR_offset of the random access contention resolution timer to the UE. To reduce signaling overhead, the first timing offset may be determined based on a start delay period of a random access contention resolution timer.

[0201] Optionally, the first timing offset and the start delay period of the random access contention resolution timer may satisfy the following equation (12):

number

[0202] Optionally, the first timing offset and the start delay period of the random access contention resolution timer may satisfy the following equation (13):

number

[0203] Optionally, the first timing offset and the start delay period of the random access contention resolution timer may satisfy the following equation (14):

number

[0204] Optionally, the first timing offset and the start delay period of the random access contention resolution timer may satisfy the following equation (15):

number

[0205] For the derivation relationship between the first timing offset and the start delay period of the random access contention resolution timer, another derivation formula can be obtained using the aforementioned parameters, e.g.,

number

[0206] It will be understood that for the explanation of the parameters in the formulas of Method 4, reference should be made to the parameters given in the previous methods.

[0207] Method 5:

[0208] Similarly, the base station notifies the UE of the period of the random access contention resolution timer (RCR_timer). Theoretically, the period of the random access contention resolution timer is related to the round-trip delay difference of the beam / cell covered by the base station. Therefore, to reduce overhead, the first timing offset can be determined based on the period of the random access contention resolution timer.

[0209] Optionally, the first timing offset and the period of the random access contention resolution timer may satisfy the following equation (16):

number

[0210] Optionally, the first timing offset and the period of the random access contention resolution timer may satisfy the following equation (17):

number

[0211] Optionally, the first timing offset and the period of the random access contention resolution timer may satisfy the following equation (18):

number

[0212] Optionally, the first timing offset and the period of the random access contention resolution timer may satisfy the following equation (19):

number

[0213] For the derivation relationship between the first timing offset and the period of the random access contention resolution timer, another derivation formula can be derived using the aforementioned parameters, e.g.,

number

[0214] It will be understood that for the explanation of the parameters in the formulas of Method 5, reference should be made to the parameters given in the previous methods.

[0215] Method 6:

[0216] For Methods 4 and 5, the base station not only needs to notify the UE of the period of the random access contention resolution timer, but also needs to notify the UE of the start delay period of the random access contention resolution timer, so the first timing offset can alternatively be determined based on the period of the random access contention resolution timer and the start delay period of the random access contention resolution timer.

[0217] Optionally, the first timing offset, the period of the random access contention resolution timer, and the start delay period of the random access contention resolution timer may satisfy the following equation (20):

number

[0218] Optionally, the first timing offset, the period of the random access contention resolution timer, and the start delay period of the random access contention resolution timer may satisfy the following equation (21):

number

[0219] Another method of deriving the first timing offset may be obtained by modifying equations (20) and (21) based on the parameters shown in Method 1 and Method 2, for example:

number

number

[0220] It will be understood that for the explanation of the parameters in the formulas of Method 6, reference should be made to the parameters given in the previous methods.

[0221] Method 7:

[0222] During the initial access phase, to provide UEs without positioning capabilities with a timing advance used to transmit random access preambles, the base station broadcasts a common timing advance (common TA) to the beam or cell, and the UE uses the common timing advance to determine the timing advance used to transmit the random access preamble. The common timing advance can be calculated in the following manner: select a reference point within the coverage area of ​​the beam or cell (the point closest to the base station can be selected), calculate the round-trip delay between the reference point and the satellite (satellite regenerative scenario), or calculate the round-trip delay between the reference point, the satellite, and the earth station (satellite transparent scenario), and set the common timing advance equal to the round-trip delay or equal to the round-trip delay plus / minus a fixed value. The reference point can be a point on the service link or a point on the feeder link, but this is not limited herein. Similarly, the base station can transmit the coordinates of the reference point location to the UE, and the UE obtains the common timing advance by calculation based on the round-trip delay between the satellite location and the reference point location. The common timing advance can be a positive or negative value.

[0223] In the case of a UE with positioning capability, the UE can obtain a timing advance that can be used for transmitting the random access preamble by calculation based on the UE's location information and satellite location information (which can be obtained from ephemeris information). However, a UE with positioning capability can still obtain a common timing advance that the base station broadcasts to the beams or cells.

[0224] Therefore, the first timing offset may be obtained based on the common timing advance TA_common.

[0225] Optionally, the first timing offset and the common timing advance TA_common may satisfy the following equation (22):

number

[0226] Optionally, the first timing offset and the common timing advance may satisfy the following equation (23):

number

[0227] Optionally, the first timing offset and the common timing advance may satisfy the following equation (24):

number

[0228] Optionally, the first timing offset and the common timing advance may satisfy the following equation (25):

number

[0229] For the derivation relationship between the first timing offset and the common timing advance, the aforementioned parameters can be used to derive another derivation formula, e.g.,

number

[0230] It will be appreciated that for an explanation of the parameters in the formula of Method 7, reference should be made to the previous methods.

[0231] Method 8

[0232] Alternatively, the first timing offset may be determined based on the satellite's orbital altitude H. The satellite's orbital altitude is related to the minimum round-trip delay of the base station's coverage area. The orbital altitude may be the round-trip delay of the sub-satellite point in FIG. 8a. The satellite's orbital altitude may be obtained from ephemeris information.

[0233] Optionally, the first timing offset and the orbit height H may satisfy the following equation (26):

number

[0234] H is the orbital altitude and c is the speed of light.

[0235] Optionally, the first timing offset and the orbit height H may satisfy the following equation (27):

number

[0236] Optionally, the first timing offset and the orbit height H may satisfy the following equation (28):

number

[0237] Optionally, the first timing offset and the orbit height H may satisfy the following equation (29):

number

[0238] For the derivation relationship between the first timing offset and the orbit height, the aforementioned parameters can be used to derive another derivation formula, e.g.,

number

[0239] It can be seen that in the transparent mode, there can be two delays: one in the feeder link and one in the service link. Therefore, equations (26) to (29) and variants can be further optimized, i.e., 2×H / c can be replaced by 4×H / c.

[0240] It will be appreciated that for explanations of the parameters in the formulas of Method 8, reference should be made to the previous methods.

[0241] Method 9:

[0242] The base station transmits the service link reference angle and / or feeder link reference angle corresponding to the coverage beam / cell to the UE. As shown in FIG. 8a, the service link reference angle can be determined based on the angle formed by the service link reference angle reference point, the satellite, and the sub-satellite point, and the service link reference angle reference point can be the point farthest from the satellite and within the coverage beam / cell range (or the location of the reference point can be determined based on the specific network deployment). The sub-satellite point is the point where the line connecting the satellite and the center of the Earth intersects with the Earth's surface. Therefore, the UE can calculate the round-trip delay on the service link: 2×H / cos(α) / c based on the service link reference angle α.

[0243] Similarly, as shown in FIG. 8a, the base station can transmit a feeder link reference angle to the UE to calculate the round trip delay of the feeder link. The feeder link reference angle can be determined based on the angle formed by the feeder link reference angle reference point, the satellite, and the sub-satellite point. The feeder link reference angle reference point can be the location of the earth station. Therefore, the UE can calculate the round trip delay on the feeder link: 2×H / cos(β) / c based on the feeder link reference angle β.

[0244] Finally, the UE calculates K based on the service link reference angle α and / or the feeder link reference angle β transmitted by the base station. offset1 can be calculated.

[0245] Optionally, the first timing offset and the reference angle α of the service link may satisfy the following equation (30):

number

[0246] Optionally, the first timing offset and the reference angle β of the feeder link may satisfy the following equation (31):

number

[0247] Optionally, the first timing offset, the reference angle α of the service link, and the reference angle β of the feeder link may satisfy the following equation (32):

number

[0248] For the derivation relationship between the first timing offset and the reference angle, other parameters in the aforementioned method can be used to derive another derivation formula, e.g.,

number

number

[0249] It will be appreciated that reference should be made to the methods described above for an explanation of the parameters of the above formulas.

[0250] In the method shown in FIG. 6, the indicator information may be used to indicate the second timing offset, and the method by which the UE indicates the second timing offset to the base station includes the following method.

[0251] Method 1:

[0252] The indicator information includes a second timing offset. For example, as shown in the above example, the second timing offset can occupy the same number of bits as the first timing offset, and the number of bits can be 13 bits, 12 bits, 9 bits, 8 bits, or 7 bits.

[0253] Method 2:

[0254] The index information includes a first adjustment parameter set, and the first adjustment parameter set is used to determine the second timing offset, i.e., the index information includes the first adjustment parameter set, and the base station determines the second timing offset based on the first adjustment parameter set.

[0255] The first set of tuning parameters includes: Second Timing Offset K offset2 and a parameter determined based on the RAR reception window startup delay period RAR_delay, or Second Timing Offset K offset2 and a parameter determined based on the duration of the RAR receiving window RAR_window, or Second Timing Offset K offset2 , a parameter determined based on the RAR reception window startup delay period RAR_delay and the RAR reception window period RAR_window, or Second Timing Offset K offset2 and a parameter determined based on the start delay period RCR_offset of the random access contention resolution timer, or Second Timing Offset K offset2and a parameter determined based on the period of the random access contention resolution timer RCR_timer, or Second Timing Offset K offset2 , a parameter determined based on the random access contention resolution timer start delay period RCR_offset and the random access contention resolution timer period RCR_timer, or Second Timing Offset K offset2 and a parameter determined based on the common timing advance TA_common, or Second Timing Offset K offset2 and a parameter determined based on the orbital altitude H of the network device; or Second Timing Offset K offset2 and a parameter determined based on the round trip delay between the terminal device and the network device; or Second Timing Offset K offset2 and a parameter determined based on the reference angle α of the service link, or Second Timing Offset K offset2 and a parameter determined based on the reference angle β of the feeder link, or Second Timing Offset K offset2 , a parameter determined based on the service link reference angle α and the feeder link reference angle β, or the timing advance that the UE uses to transmit the third message (which in different scenarios may also be understood as the timing advance that the UE has most recently used), or the difference between timing offsets, which may be the difference between a second timing offset and a reference timing offset. The reference timing offset may be the timing offset currently used by the UE or a preset timing offset. The timing offset currently used by the UE may be the first timing offset.

[0256] For example, the first adjustment parameter set includes a timing advance TA_New used by the UE to transmit the third message. After receiving TA_New, the base station:

number

[0257] The method by which the UE transmits TA_New to the base station is as follows: For example, the UE transmits the quantized value N TA is transmitted to the base station. N TA After receiving the quantization coefficient S, the base station sets the agreed quantization coefficient S to N TA to obtain the TA value (unit: seconds or milliseconds) that the UE actually uses. In this way, the signaling length representing the TA can be reduced, and the signaling overhead can be reduced. For example, assume that the quantization coefficient S is 100 / (15000*2048)≒3.25us. TA_New=4ms. The quantization value N TA = 4ms / 3.25us ≈ 1231. 11 bits are required. If Ts = 32.5ns used in LTE is used to quantize the TA value, then 4ms / 32.5ns ≈ 123077, and 17 bits are required. It can be seen that 6 bits are saved.

[0258] In another example, to reduce signaling overhead, the UE may transmit a parameter value based on the round-trip delay of the satellite's orbital altitude to the base station, so that the base station can use the parameter value to calculate the TA value that the UE will actually use. For example, the UE may transmit a parameter value based on the round-trip delay of the satellite's orbital altitude to the base station, so that the base station can use the parameter value to calculate the TA value that the UE will actually use. TA (V TA can be a positive or negative value) to the base station, which then calculates the round trip delay of the sub-satellite point as a time amount V TA or the amount of time V from the round trip delay of the sub-satellite point TA Subtract this to obtain the TA value used by the UE. If the satellite orbital altitude is H (unit: m), the round trip delay of the sub-satellite point is 2 × H / c, where c is the speed of light 3 × 10 8m / s. The base station calculates TA_New=2*H / c+V TA According to the formula, the TA value used by the UE can be obtained by calculation.

[0259] In another example, the UE may use a multiple value or scale factor M associated with the satellite's orbital altitude. TA (e.g., the round trip delay of the sub-satellite point of the satellite) to the base station. The base station multiplies the round trip delay of the sub-satellite point by the multiplier value to obtain the TA value to be used by the UE. That is, the base station calculates TA_New=2*H / c*M TA The TA value used by the UE can be calculated according to the formula. For example, if the satellite orbital altitude is 600 km, the round trip delay of the satellite orbital altitude is 600e3*2 / 3e8=4 ms. If the TA value used by the UE is 4.2 ms, V TA The base station then calculates the TA value that the UE will actually use based on 4+0.2=4.2 ms. If this method is not used, the UE will need to transmit 4.2 ms to the base station, which will occupy more bits. Alternatively, the UE may use a multi-value M based on the round trip delay of the sub-satellite points. TA is transmitted to the base station, where M TA = 4.2 / 4 = 1.05. This reduces the signaling overhead because 4.2 (ms) does not need to be transmitted to the base station.

[0260] In another example, the UE receives RAR-related information delivered by the base station using a preset receiving window. Because the round-trip delay in satellite communication is relatively large, after transmitting the preamble, the UE activates the receiving window and starts detecting the RAR-related information only after a certain RAR_delay. The RAR receiving window delay RAR_delay is notified to the UE by the base station. Therefore, to reduce signaling overhead, the UE transmits a parameter value based on the RAR receiving window delay RAR_delay to the base station, so that the base station can calculate the TA value actually used by the UE.

[0261] In another example, in order to reduce signaling overhead, the UE transmits a parameter value based on a common TA to the base station, so that the base station can calculate the TA value that the UE actually uses. It should be understood that the above methods may be used together. It should be understood that in this application, the method by which the UE transmits the timing advance to the base station that the UE uses can be applied to the same method below. For example, in a subsequent communication process, when the UE needs to update the second timing offset, the method can be used to transmit the timing advance to the base station that the UE uses.

[0262] For example, the indicator information transmitted from the UE to the base station is ΔK=K offset2 -K offset1 That is, ΔK represents the difference between the timing offsets. Correspondingly, after receiving ΔK, the base station offset2 =K offset1 +ΔK according to the formula K offset2 Get the value of .

[0263] Optionally, the UE may transmit the first adjustment parameter set to the base station using the method for the UE to obtain the first timing offset from the broadcast message in the present application. offset1 The updated K offset1 (i.e., the second timing offset K offset2 ) and this method includes equations (2) to (32) and other equations listed. k , ΔK offset , ΔK offset_time , α, β, etc. to the base station. Correspondingly, the base station obtains the second timing offset by calculation using the method of Equations (2) to (32) in the method in which the UE obtains the first timing offset from the broadcast message.

[0264] For example, K in Eq. (11) offset1 K offset2 , the UE

number

number

[0265] For example, K in equation (27) offset1 K offset2 , the UE

number

number

[0266] ΔK offset The symbols are the same as those in (3) above, but it will be understood that they have different meanings. offset The value of ΔK may be broadcast by the base station. offset is obtained by transformation according to the above equations (11) and (27), and UE is offsetThe value of is transmitted to the base station.

[0267] Optionally, the UE may k , ΔK offset , ΔK offset_time , α, and β to the base station, and the base station obtains the second timing offset by calculation using the variation value.

[0268] For example, the parameter S k The variation value of is 0.2, and the last S sent by the UE to the base station k is 1.3, or the last S sent by the base station to the UE k 1.3 or agreed reference S k In this case, the base station k The updated value of 1.3 + 0.2 = 1.5 can be obtained.

number

[0269] Optionally, the index information can include a ΔK, e.g., 001. offset The index number of the different ΔK offset may correspond to different index numbers. See, for example, the table query method in Method 3 below.

[0270] Optionally, the indicator information may further include the latest location information of the UE, and the latest location information may include the latest three-dimensional location coordinates. In this way, the base station side uses the satellite position and the UE position to calculate the round trip delay between the satellite and the UE, obtains the TA value TA_New used by the UE, and obtains the latest timing offset, i.e.,

number

[0271] Method 3:

[0272] In the above method, K offset or K offset and the reference timing offset, e.g., K offset ∈{1,3,5,7} or K offset ∈{1.5, 3.5, 5.5, 7.5}. offset The signaling overhead can be reduced by configuring discrete timing offsets, where it will be appreciated that the timing offsets may include a first timing offset, a second timing offset, an updated second timing offset, etc.

[0273] As shown in Figure 8b, the maximum round-trip delay difference of the beam covered by the base station is 2.28 ms. Using slots as the unit of time, K offset When expressing the subcarrier width as 120KHz and the minimum slot length as 0.125ms, K offset =2.28 / 0.125=18.24. In this case, the UE or the base station offset It takes 5 bits to transmit K offset is quantized, e.g., K offset ∈{0, 3, 6, 9, 12, 15, 18, 21}, and the UE or base station is K offset For example, the UE or the base station may need 3 bits to transmit K based on the mapping relationship as shown in Table 1. offset , i.e., 100 can be sent. [Table 1]

[0274] It will be appreciated that the above mapping relationships are merely examples and should not be construed as limitations on this embodiment of the present application. offsetThe difference between the reference timing offset and the reference timing offset can also be expressed using discrete values.

[0275] A method for a base station to indicate an updated first timing offset to a UE includes:

[0276] As mentioned above, "after the base station determines to update the first timing offset, the base station may further use an Msg4 message to transmit the second timing offset, the variation between the second timing offset and the reference timing offset, or an adjustment parameter used to indicate the second timing offset to the UE."

[0277] After determining to update the first timing offset, the base station transmits an adjustment parameter to the UE, which is used to indicate the second timing offset. For the transmission of the adjustment parameter, refer to the above-mentioned method in which the UE obtains the first timing offset from a broadcast message and the method in which the UE indicates the second timing offset to the base station. offset1 The updated K offset1 (i.e., the second timing offset K offset2 ) and this method includes equations (2) to (32) and other equations listed. k , ΔK offset , ΔK offset_time , α, β, etc. to the UE. Correspondingly, the UE obtains the second timing offset by calculation using the method of Equations (2) to (32) in "Method for the UE to obtain the first timing offset from the broadcast message."

[0278] For example, the adjustment parameter that the base station sends to the UE and that is used to indicate the second timing offset is S k , ΔK offset , ΔKoffset_time , α, and β. Correspondingly, the UE receives the variation value and calculates the second timing offset using the variation value. See Method 2 for a specific example in which the UE indicates the second timing offset to the base station.

[0279] The method for determining the effective time of the second timing offset includes the following method.

[0280] Method 1:

[0281] The base station transmits validity information to the UE, which is used to indicate the validity time of the second timing offset, i.e., the time when the UE and the base station start to use the second timing offset. In response, the UE receives the validity information.

[0282] Optionally, after receiving the third message (including the indicator information), the base station transmits valid information to the UE. For example, the valid information may be ACK or NACK information. After receiving the ACK information, the UE updates the timing offset at a specified time. For example, it may be agreed that the timing offset is updated immediately after the UE receives the ACK information. Alternatively, it may be agreed that the UE updates the timing offset q slots after receiving the ACK information, where q is a non-negative integer.

[0283] Optionally, the validity information may alternatively include second timing offset update completion information (K offset2 For an example of this method, see the previous method where the valid information is an ACK.

[0284] Alternatively, the UE transmits the updated timing offset to the base station. After receiving the updated timing offset transmitted by the UE, the base station can transmit useful information to the UE. The updated timing offset includes the updated first timing offset, i.e., the second timing offset, or the updated second timing offset.

[0285] Optionally, validation information can be included in the fourth message.

[0286] Optionally, before receiving the third message, the base station may further initially indicate the validity time to the UE, which may be applied to determine the validity time of the second timing offset, or may be applied to the updated second timing offset, etc.

[0287] Optionally, the base station can transmit useful information to the UE using a broadcast message, which includes a system information block (SIB) 1, a master information block (MIB), and a base station information block (BSB). MIB, or other system information Alternatively, any one or more of the following may be included: Radio Resource Control (RSC) information (OSI) In the RRC connection phase, the base station sends RRC messages, downlink control information (DCI), group DCI, media access control (MAC), or timing advance commands. The base station may further transmit the utility information to the UE using any one or more of the Transmission Advance Command (TAC). Optionally, the base station may alternatively transmit the utility information together with the data transmission or on a separately allocated PDSCH. Optionally, in addition to transmitting the utility information using broadcast or unicast messages, the base station may further transmit the utility information in a multicast manner.

[0288] It will be appreciated that this embodiment of the present application does not place any restrictions on when the base station transmits the useful information to the UE, and the particular format of the useful information is also not limited to this embodiment of the present application.

[0289] Method 2:

[0290] The UE transmits validity information to the base station, where the validity information is used to indicate the validity time of the second timing offset, and the base station receives the validity information in response.

[0291] Optionally, the UE may transmit the useful information to the base station after (or before) transmitting the third message to the base station, or alternatively, the UE may transmit the useful information to the base station after (or before) receiving the fourth message transmitted by the base station.

[0292] Optionally, validation information can be included in a third message.

[0293] Optionally, the useful information can be included in Physical Uplink Control Channel (PUCCH) information, etc.

[0294] For the specific method of Method 2, please refer to the description of Method 1. The details will not be described again here.

[0295] Method 3:

[0296] For the UE, the second timing offset takes effect m slots after the UE transmits the third message, where m is a preset integer. Alternatively, the second timing offset takes effect n slots after the UE receives the fourth message, where n is a preset integer.

[0297] In the case of a base station, the second timing offset may take effect m slots after receiving the third message. Alternatively, the second timing offset may take effect n slots after the base station transmits the fourth message.

[0298] It will be understood that the unit of slot is used as an example for the purposes of explanation herein, and is not limiting. For example, it may be agreed that the second timing offset will take effect after a time length of m subframes or frames. Alternatively, it may be agreed that the unit of m is milliseconds, microseconds, etc.

[0299] Using Figure 9 as an example, the second timing offset or the updated second timing offset begins to take effect at the mth slot after the UE transmits the third message. That is, the UE begins to transmit signals to the base station using the second timing offset or the updated second timing offset at the mth slot after transmitting the third message. Correspondingly, the second timing offset or the updated second timing offset begins to take effect at the mth slot after the base station receives the third message. That is, at the mth slot after receiving the third message, the base station begins to receive signals transmitted by the UE using the second timing offset or the updated second timing offset.

[0300] It should be understood that the above m or n may be preset by the base station or may be preset in a protocol or the like. This is not limited to this embodiment of the present application. When m or n is preset by the base station, the base station may transmit the value of m or n to the UE using a broadcast message, a multicast message, or a unicast message. For example, the value of m or n may be notified to the UE or the base station using the method of transmitting significance information in the above-mentioned method 1, i.e., the method of including the value of m or n in the significance information.

[0301] It should be understood that the validity time is related to the channel delay and may be a value related to one-way or round-trip delay. Therefore, in addition to notifying the validity time to the UE or the base station using the validity information transmission methods described in Methods 2 and 3, the validity time can also be agreed upon using known parameters related to one-way or round-trip delay. For example, according to a protocol agreement calculation method, the UE and the base station obtain the validity time using the same method. The calculation method for the validity time is as follows:

number

[0302] Based on the above calculation method, for example, a correction value ΔT is added (the correction value may be agreed upon using a protocol or may be transmitted by the base station to the UE, where ΔT is an integer). For example:

number

[0303] For example, the base station and the UE

number

[0304] It will be understood that for the aforementioned values ​​of m or n, the effective time is specified based on the time for transmitting and receiving a signal. Absolute time may be used to specify the effective time. For example, the base station transmits validity information to the UE, where the validity information includes a validity time, and the validity time instructs the UE to start using the updated timing offset in the first slot of the 98th frame to transmit a signal. Correspondingly, the base station starts receiving signals in the first slot of the 98th frame using the updated timing offset to receive the signal transmitted by the UE. The absolute effective time may be transmitted to the UE in the aforementioned manner of transmitting the value of m or n. Details will not be described again here.

[0305] After the UE acquires the latest timing offset, i.e., the second timing offset, the UE can use the second timing offset after the second timing offset becomes effective to transmit data information scheduled by the base station, control channel information, etc. The following will specifically describe the types included in the fifth message.

[0306] Method 1:

[0307] The fifth message includes a message transmitted over the physical downlink shared channel (PDS), such as the HARQ-ACK message of the fourth message (Msg4). The HARQ-ACK feedback message for the PDSCH data is included. As shown in FIG. 6, step 605 may be as follows: the UE transmits a HARQ-ACK message to the base station based on the second timing offset, and the HARQ-ACK message is used to confirm that the contention access message is correctly received. In response, the base station receives a HARQ-ACK message. For example, if the UE's reception of the PDSCH signal ends in slot x, the UE may receive a HARQ-ACK message for the PDSCH data in slot x+K1+K2. offset and sends the corresponding HARQ-ACK feedback.

[0308] Method 2:

[0309] The fifth message includes uplink data. As shown in Figure 6, step 605 may be as follows: The UE transmits uplink data scheduled by the base station to the base station based on the second timing offset (the base station uses an RAR grant and DCI to indicate the scheduled uplink data). Correspondingly, the base station receives the uplink data. For example, the base station uses a DCI command to schedule the UE to transmit physical uplink shared channel (PUSCH) data, where the DCI signaling is in slot x, and the UE transmits the PUSCH data in slot x.

number

[0310] Method 3:

[0311] The fifth message includes a sounding reference signal (SRS), and the base station sends DCI signaling in slot x to trigger the aperiodic SRS signal. After the UE receives the trigger signaling, the aperiodic SRS signal is sent in slot x.

number

[0312] It should be understood that the above communication steps using the updated timing offset are merely illustrative examples, and the updated timing offset or communication steps using the timing offset are not limited. For example, the base station uses the updated timing offset or timing offset when deciding to transmit reference resource timing information of the channel state information.

[0313] The following describes how the UE updates the timing offset for subsequent communications after accessing the system.

[0314] In the subsequent communication process between the UE and the base station (i.e., after the UE accesses the base station), relative motion occurs between the UE and the satellite (which also changes the round-trip delay between the UE and the base station). Therefore, it is necessary to adjust the timing advance used by the UE. Therefore, in one method, the UE can obtain the timing advance based on the timing advance adjustment command (TA adjustment) sent by the base station. In another method, the UE can obtain the timing advance based on the location information of the UE and the location information of the base station.

[0315] There are two ways to update the timing offset in subsequent communications:

[0316] The difference between the two methods is whether the decision to update the timing offset in use is made on the UE side or on the base station side (the timing offset to be used includes the second timing offset).

[0317] Method 1: The UE side decides whether to update the timing offset, which includes the following steps:

[0318] Upon receiving the timing advance adjustment command (e.g., a timing advance change rate or a timing advance adjustment value) sent by the base station, the UE can use the timing advance adjustment command to adjust the timing advance used by the UE to transmit signals and determine whether to update the second timing offset based on the adjusted timing advance. Alternatively, the UE can adjust the timing advance used based on the UE's location information, ephemeris information, etc., and determine whether to update the second timing offset based on the timing advance.

[0319] Here, the second timing offset is a general term for the timing offset used by the UE after accessing the system, and can be understood as the timing offset used by the UE and the base station. This feature is also applicable to other embodiments of the present application.

[0320] The UE can determine whether to update the second timing offset based on the adjusted timing advance (i.e., the latest timing advance adjustment value used by the UE). The UE can determine whether to update the timing offset by referring to the difference between the timing offset obtained according to Equation (1) and the timing offset currently being used (in this case, TA_New is replaced with the latest timing advance adjustment value). For specific operations, please refer to the description of FIG. 6, in which the UE determines whether to update the first timing offset using the second timing offset based on an update threshold. Details will not be described here. If the UE decides to update the timing offset, the UE transmits the updated second timing offset, the variation between the updated second timing offset and the reference timing offset, or the second adjustment parameter set to the base station. For specific transmission methods and specific parameters, please refer to the above-mentioned "Method for the UE to Indicate the Second Timing Offset to the Base Station." It should be noted that the second timing offset in this method needs to be replaced with the updated second timing offset, and another related corresponding substitution is performed.

[0321] For example, K in Eq. (11) offset1 is the updated K offset2 Replaced by, UE updated

number

number

[0322] For example, the UE k , ΔK offset , ΔK offset_time , α, and β to the base station, and the base station calculates the corresponding updated second timing offset using the method described above in equations (2) to (32). k , ΔK offset , ΔK offset_time , α, and β to the base station, and the base station obtains an updated timing offset (i.e., an updated second timing offset) by calculation using the changed value. For a specific example, see "Method in which the UE indicates the second timing offset to the base station" in Method 2 above.

[0323] Furthermore, after the UE transmits the updated second timing offset or the second adjustment parameter to the base station, the base station receives the updated second timing offset or the second adjustment parameter transmitted by the UE. After the updated second timing offset takes effect, the UE transmits uplink data scheduled by the base station to the base station based on the updated second timing offset.

[0324] It should be understood that for the method related to the effective time of the updated second timing offset, reference should be made to the description of the method for determining the effective time of the second timing offset, and the details will not be described again here.

[0325] Method 2: The base station side decides whether to update the timing offset, including:

[0326] When the UE receives a timing advance adjustment command (e.g., a timing advance change rate or a timing advance adjustment value) sent by the base station, the timing advance adjustment command is used to instruct the UE to update the timing advance, and the UE can adjust the timing advance used by the UE to transmit signals according to the timing advance adjustment command to obtain the adjusted timing advance.

[0327] The UE transmits the second timing offset, the variation between the updated second timing offset and the reference timing offset, or the second adjustment parameter set to the base station based on the adjusted timing advance (see the above-mentioned method 1). Correspondingly, the base station receives the corresponding information transmitted by the UE, obtains the second timing offset, and further determines whether to update the timing offset, i.e., whether to update the second timing offset. For specific operations, please refer to the description of FIG. 6, in which the base station determines whether to update the first timing offset using the second timing offset based on the update threshold. Details will not be described here.

[0328] When the base station determines that the timing offset needs to be updated, the base station sends the UE the updated second timing offset, the variation between the updated second timing offset and the reference timing offset, or an adjustment parameter used to indicate the updated second timing offset. For related designs of the parameters sent by the base station to the UE, refer to the aforementioned method for the UE to obtain the first timing offset from a broadcast message, the method for the UE to indicate the second timing offset to the base station, and the method for the base station to indicate the updated first timing offset to the UE. Details will not be described again here.

[0329] For example, K in the method in which the UE obtains the first timing offset from the broadcast message offset1is the updated K offset2 (i.e., updated second timing offset), and the method includes equations (2) to (32) and other equations listed. k , ΔK offset , ΔK offset_time , α, β, etc. to the UE. In response to this, the UE obtains an updated second timing offset by calculation using the method of equations (2) to (32) in the "Method for the UE to obtain the first timing offset from the broadcast message."

[0330] Furthermore, the UE obtains an updated second timing offset based on the received variation between the updated second timing offset and the reference timing offset or the adjustment parameter used to indicate the updated second timing offset. After the updated second timing offset takes effect, the UE transmits uplink data scheduled by the base station to the base station based on the updated second timing offset.

[0331] It should be understood that for the method regarding the effective time of the updated second timing offset, reference should be made to the description of the method for determining the effective time of the second timing offset, and the details will not be described again here.

[0332] It will be understood that the uplink data in the above two methods is merely a generic term and may be any information transmitted by the UE.

[0333] The UE also needs to update the second timing offset in the following scenarios: for example, when the UE is handed over to a cell, when the UE switches beams, or when the UE switches bandwidth parts BWP.

[0334] Bandwidth part (BWP), transmission configuration indicator configuration indicator (TCI), or synchronization signal block (synchronization It should be understood that different beams can be distinguished using a protocol based on a signal block (SSB). In other words, a beam can be instructed based on a beam width prediction (BWP), a transmission control signal (TCI), or an SSB. Therefore, a beam switch can be instructed to a UE and a base station through a switch of a BWP, a TCI, or an SSB. Therefore, for a UE and / or a base station, the actual switch can be a switch of a BWP, a TCI, or an SSB. Therefore, a beam described herein can be replaced with a BWP, a TCI, or an SSB.

[0335] In a beam switching scenario, in this embodiment of the present application, the beam before switching is called a serving beam, and the beam after switching is called a target beam. Also, the base station transmitting the serving beam may be called a serving base station (or the serving base station is the base station to which the serving beam belongs), and the base station transmitting the target beam may be called a target base station (or the target base station is the base station to which the target beam belongs). Using FIG. 3 as an example, the current terminal device is within the coverage of beam #2. Beam #2 is the serving beam of the terminal device. Beam #3 (or beam #1) used by the UE after switching is the target beam. It should be understood that the serving beam can be replaced by a serving BWP, a serving TCI, or a serving SSB. Therefore, the target beam can be replaced by a target BWP, a target TCI, or a target SSB. For ease of explanation, the following describes the embodiment of the present application using beams as an example.

[0336] In a handover scenario, the timing offset used by the serving beam or the target beam may be different. Therefore, the UE needs to update the second timing offset. It should be understood that the updated second timing offset in this specification may be understood as the timing offset used by the target beam. In the following, this application will be described using the timing offset used by the target beam as an example.

[0337] Before handover, the base station notifies the UE in advance of the timing offset to be used in the target beam using the following two methods.

[0338] (1) Transmit to the UE the difference between the timing offset used by the UE in the target beam or cell and the timing offset used by the UE in the serving beam or cell.

[0339] (2) The UE calculates the timing offset using the timing advance that the base station notifies it to use in the target beam or cell.

number

[0340] In some scenarios, the UE needs to notify the base station of the timing offset to be used in the target beam or cell. For example, when the UE performs an inter-satellite handover, the UE can use the UE's location information and the target satellite's location information (which can be obtained from the ephemeris information) to calculate the timing advance to be used after the handover. In this case, the UE needs to report the timing offset to be used in the target beam or cell. The following two methods are included:

[0341] (1) The UE notifies the base station of the timing offset value that the base station will use in the target beam or cell.

[0342] (2) The UE transmits the timing advance to be used in the target beam or cell to the base station. The base station receives the timing advance transmitted by the UE and calculates the timing advance by the formula

number

[0343] The UE can obtain the timing offset used in the target beam or cell, or the difference between the timing offsets, using a broadcast message, where the broadcast message may include any one or more of SIB1, MIB, or OSI. Alternatively, the UE can obtain the timing offset used by the target beam using any one or more of an RRC message, DCI, group DCI, MAC, or TAC. Optionally, in addition to obtaining the timing offset used by the target beam using a broadcast or unicast message, the UE can further obtain the timing offset used by the target beam in a multicast manner. Optionally, the timing offset used by the target beam may alternatively be transmitted together with the data or in a separately assigned PDSCH. It will be appreciated that the UE can alternatively obtain the variation between the timing offset used by the target beam and the reference timing offset using the aforementioned methods.

[0344] Furthermore, when the UE performs beam switching, the timing offset that the UE uses in the target beam can be transmitted in the initial BWP signaling, the BWP downlink common signaling (BWP-DownlinkCommon), the BWP uplink common signaling (BWP-UplinkCommon), the BWP downlink dedicated signaling (BWP-DownlinkDedicated), the BWP uplink dedicated signaling (BWP-UplinkDedicated), or the measurement signaling (MeasObjectNR).

[0345] For example, when the UE performs beam switching, if the UE switches to the initial BWP, K offset is delivered in the RRC signaling corresponding to BWP. When the UE switches to non-initial BWP, K offsetis distributed by BWP-DownlinkCommon or BWP-UplinkCommon. Here, K offset Alternatively, the timing offset may be obtained by using information about the timing offset, e.g., the timing offset value, S k , ΔK offset , ΔK offset_time , α, β, etc., or parameter differences.

[0346] For example, when a UE performs a beam switch, the base station uses BWP-DownlinkDedicated and BWP-UplinkDedicated signaling to determine the K offset can be transmitted to the UE; or K used in the target beam offset and K used in the serving beam offset The difference between the two is sent to the UE. An example is as follows:

[0347] For example, the signaling format delivered by the base station is as follows: BWP-DownlinkDedicated::= SEQUENCE { pdcch-Config SetupRelease { PDCCH-Config} pdsch-Config SetupRelease { PDSCH-Config} sps-Config SetupRelease { SPS-Config} radioLinkMonitoringConfig SetupRelease { RadioLinkMonitoringConfig} Koffset INTEGER (0...m) ... } Alternatively, BWP-UplinkDedicated ::= SEQUENCE { pucch-Config SetupRelease { PUCCH-Config} pusch-Config SetupRelease { PUSCH-Config} configuredGrantConfig SetupRelease { ConfiguredGrantConfig} srs-Config SetupRelease { SRS-Config} beamFailureRecoveryConfig SetupRelease { BeamFailureRecoveryConfig} Koffset INTEGER (0...m) … }

[0348] Parameter K offset is the K used by the UE in the target beam. offset or K used in the target beam offset and K used in the serving beam offset In the above signaling, m represents a positive integer, for example, m=16. For example, the UE receives the BWP-DownlinkDedicated signaling sent by the base station, and then reads the Koffset of the signaling, where the value of Koffset is a value determined by the base station from an integer between 0 and 16.

[0349] Before initiating a BWP or beam or cell handover, a measurement procedure needs to be triggered. Therefore, the base station uses the measurement configuration and the corresponding RRC signaling in the handover to determine the K offset, or K used in the target beam offset and K used in the serving beam offset The difference between the two can then be transmitted to the UE.

[0350] For example, the signaling format delivered by the base station is as follows: MeasObjectNR ::= SEQUENCE { carrierFreq ARFCN-ValueNR, Koffset INTEGER (0...m) … }

[0351] According to the inter-cell handover signaling procedure, the K used in the target beam offset is transmitted to the UE in the beam of the serving cell using an RRC Reconfiguration message, and K used in the target beam offset and K used in the serving beam offset The difference is transmitted to the UE.

[0352] It will be appreciated that the above classification methods can be combined with each other. For example, one embodiment of the present application provides a method for updating timing offsets, as shown in Figures 10a and 10b.

[0353] As shown in FIG. 10a, the method for updating the timing offset includes the following steps.

[0354] 1001. The base station determines a common timing advance (common TA) and a first timing offset (K offset1 ) to broadcast.

[0355] 1002. The UE transmits a random access preamble to the base station, and in response, the base station receives the random access preamble.

[0356] Optionally, UEs without positioning capability can transmit random access preambles using a common timing advance. UEs with positioning capability can transmit random access preambles using a timing advance derived based on the UE's location information and satellite information. Alternatively, UEs with positioning capability can transmit random access preambles using a common timing advance.

[0357] 1003. The base station sends a random access response including a timing advance command to the UE. In response, the UE receives the random access response.

[0358] 1004. The UE determines a second timing offset based on the timing advance to use (ie, the latest timing advance), eg, according to equation (1).

[0359] Optionally, the UE may obtain a second timing offset according to equation (1) and determine to update the first timing offset with the second timing offset using the aforementioned update threshold.

[0360] 1005. The UE transmits an Msg3 message to the base station based on the broadcasted first timing offset. In response, the base station receives an Msg3 message based on the first timing offset. The Msg3 message includes a second timing offset.

[0361] 1006. The base station sends a contention resolution message or a conflict resolution message to the UE. In response, the UE receives the contention resolution message or the conflict resolution message.

[0362] 1007. The base station sends a timing advance adjustment command to the UE. In response, the UE receives the timing advance adjustment command.

[0363] 1008. The UE determines an updated timing advance based on the timing advance adjustment command or the UE's location information and the satellite's location information. After determining the updated timing advance, the UE can calculate an updated second timing offset based on the updated timing advance. The UE transmits the updated second timing offset to the base station.

[0364] 1009. The UE transmits uplink data scheduled by the base station to the base station based on the second timing offset, and in response, the base station receives the uplink data based on the second timing offset.

[0365] Optionally, after the updated second timing offset takes effect, the UE may further transmit uplink data to the base station that is scheduled by the base station based on the updated second timing offset.

[0366] The method described in this application will be explained using an example. Assume that the uplink subcarrier spacing is 15 kHz. In the random access process, the base station calculates the maximum round trip delay based on the beam coverage range to be 20.87 ms. offset1 is 21. The base station side is K offset1 =21 to the UE via broadcast or Msg2, and the UE offset1 = 21. Furthermore, the UE calculates K offset1 Assume that the TA value used when the UE sends Msg3 is 19.9 ms, i.e., TA_New=19.9 ms. In this case,

number

[0367] After the UE has successfully accessed the system, in the subsequent communication process between the UE and the base station, the distance between the UE and the satellite will change, and the timing advance of the UE will change accordingly. After the UE calculates and obtains the latest timing advance based on the TA adjustment command or TA rate command delivered by the base station side, or based on the UE's location information and ephemeris information, the timing advance for the UE to transmit uplink data will change. At this time, the TA value used by the UE is 18.9 ms, and the UE:

number

[0368] To avoid repetition, in the following we will only show the differences between the method shown in Figure 10b and the method shown in Figure 10a.

[0369] For steps 1101 to 1103, please refer to the corresponding steps 1001 to 1003.

[0370] 1104. The UE transmits Msg3 to the base station based on the broadcasted first timing offset. In response, the base station receives Message 3 based on the first timing offset. Msg3 includes the timing advance used by the UE.

[0371] 1105. The base station determines a second timing offset based on the timing advance used by the UE.

[0372] Optionally, after the base station obtains the second timing offset based on the timing advance used by the UE, the base station may further determine to update the first timing offset with the second timing offset using the aforementioned update threshold.

[0373] 1106. The base station sends a contention resolution message or a collision resolution message to the UE. In response, the UE receives the contention resolution message or the collision resolution message. The contention resolution message or the collision resolution message includes a second timing offset.

[0374] 1107. The base station sends a timing advance adjustment command to the UE. In response, the UE receives the timing advance adjustment command.

[0375] Furthermore, the UE determines the latest timing advance based on the timing advance adjustment command or the location information of the UE and the location information of the base station.

[0376] 1108. The UE transmits the latest timing advance to the base station, and in response, the base station receives the latest timing advance.

[0377] Furthermore, the base station determines an updated second timing offset based on the latest timing advance, and the base station transmits the updated second timing offset to the UE.

[0378] 1109. The UE transmits uplink data to the base station based on the second timing offset, and in response, the base station receives the uplink data based on the second timing offset.

[0379] Optionally, after the updated second timing offset takes effect, the UE may further transmit uplink data to the base station based on the updated second timing offset.

[0380] It should be understood that Figures 10a and 10b are just two examples, and the classification methods presented in this application can be further combined based on internal logic, and the solutions fall within the protection scope of this application.

[0381] The above method can be applied to a scenario: the area covered by the base station (beam / cell or BWP) may include UEs with positioning capabilities, or may include UEs without positioning capabilities, or may include UEs that do not use positioning capabilities. Alternatively, the above method can be applied to a scenario where UEs in the area covered by the base station do not have positioning capabilities or do not use positioning capabilities. For example, because the UEs do not have positioning capabilities or do not use positioning capabilities, the UEs need to determine the first timing offset based on the common timing advance broadcasted by the base station. Furthermore, the above equation (1) is replaced by the following equation (33):

number

[0382] TA_common is the common timing advance, and TA_command is the timing advance adjustment amount included in the random access response.

[0383] Furthermore, the above method can be further applied to a scenario in which the UE precisely adjusts its timing advance according to the timing advance command sent by the base station, and the UE precisely adjusts its timing advance according to the timing advance adjustment command sent by the base station. Therefore, both the UE and the base station know the timing advance adjustment value used by the UE in real time. In this case, since the UE precisely adjusts the timing advance according to the method instructed by the base station, Msg3 sent by the UE after receiving Msg2 sent by the base station may not include indicator information. After the base station sends a timing advance adjustment command to the UE, the UE does not send an updated second timing offset or a second adjustment parameter set to the base station. That is, in this scenario, the UE precisely adjusts its timing advance according to the timing advance command (included in Msg2) and timing advance adjustment command sent by the base station. Therefore, both the base station and the UE know the change in the timing offset. The base station and the UE may agree on a formula for updating the timing offset, and the base station and the UE may update the timing offset according to the formula and an update threshold.

[0384] Therefore, when the UE does not have or does not use the positioning function, this method proposes a method for updating the timing offset without signaling interaction, which can reduce signaling overhead.

[0385] The UE adjusts the timing advance to be used according to the timing advance adjustment command of the base station. When the timing advance adjustment amount used by the UE changes, the UE determines whether to update the timing offset by referring to the difference between the timing offset obtained according to Equation (1) and the timing offset currently being used (in this case, the latest timing advance adjustment amount is replaced with TA_New). For specific operations, please refer to the description of FIG. 6, in which the UE determines whether to update the first timing offset using the second timing offset based on the update threshold. Details will not be described here. If the UE decides to update the timing offset, the new timing offset will be used based on the effective time. For related designs of the effective time of the updated timing offset, please refer to the description of the method for determining the effective time of the second timing offset. Details will not be described again here.

[0386] While sending the timing advance adjustment command to the UE, the base station can calculate the timing advance currently used by the UE. Therefore, the difference between the timing offset obtained according to Equation (1) and the currently used timing offset can be used to determine whether to update the timing offset. For specific operations, please refer to the description of FIG. 6, in which the base station determines whether to update the first timing offset using the second timing offset based on the update threshold. Details will not be described here. If the base station decides to update the timing offset, the new timing offset is used based on the effective time. For related designs of the effective time of the updated timing offset, please refer to the description of the method for determining the effective time of the second timing offset. Details will not be described again here.

[0387] This method reduces signaling by allowing the UE and the base station to calculate and update the timing offset using the same equation. It will be understood that the method has been described using equation (1) as an example, and the specific form of the equation is not limited.

[0388] That is, the UE and the base station can separately determine the timing offset to be updated according to the same formula or method, so that the updated timing offset can take effect immediately at a specified time, a preset time, or a protocol-specified time. In this manner, signaling interactions between the UE and the base station are avoided, thereby reducing signaling overhead.

[0389] The following describes another method for updating the timing offset in accordance with the present application.

[0390] To reduce access delay and signaling overhead, a two-step random access process is currently proposed. As shown in FIG. 11, in the first step, the terminal device simultaneously transmits a random access preamble and data to the base station. In the second step, the base station transmits a random access response to the terminal device. In one aspect of the two-step random access process, the terminal device transmits the random access preamble and data in the first step, thereby reducing the delay of uplink data transmission. In another aspect, the base station does not need to transmit scheduling information corresponding to Msg3 to the terminal device, thereby reducing signaling overhead. Generally, MsgA can be used to represent the first interaction message of the two-step random access. MsgA is transmitted by the terminal device to the base station. MsgA includes an MsgA preamble portion and an MsgA data portion. The preamble is carried on the physical random access channel (PRACH) of MsgA, and the data part is carried on the PUSCH physical channel of MsgA.

[0391] 12 is a schematic flowchart of a method for updating a timing offset according to an embodiment of the present application. Optionally, this method can be applied to two-step random access. As shown in FIG. 12, this method includes the following steps:

[0392] 1201. The base station receives a first timing offset K offset1 Alternatively, the base station broadcasts one or more of a common timing advance (common TA), an orbital altitude at which the base station is located, a duration of the MsgB receiving window, and a startup delay duration of the MsgB receiving window. For this method, refer to the above-mentioned method for the UE to obtain the first timing offset from the broadcast message. Details will not be described again here.

[0393] 1202. To request access to the system, the UE sends MsgA to the base station using the broadcasted common TA or a TA value calculated by the UE. In response, the base station receives MsgA.

[0394] 1203. The base station transmits MsgB to the UE. In response, the UE receives MsgB.

[0395] MsgB includes a timing advance command, a preamble ID, and the like.

[0396] 1204. The UE determines a first timing offset K offset1 , and sends a HARQ-ACK message of MsgB to the base station based on the received HARQ-ACK message. In response, the base station receives a HARQ-ACK message.

[0397] Optionally, the UE may use a second timing offset K based on the timing advance used. offset2 can be further determined. offset2 and K. offset1For the relationship between the update threshold and the timing advance command included in the MsgB, see the update threshold in Figure 6 above. In this case, the timing advance used by the UE can be understood as the timing advance determined according to the timing advance command included in the MsgB.

[0398] 1205. The UE transmits the indicator information to the base station, and in response, the base station receives the indicator information.

[0399] The indicator information is used to indicate the second timing offset, and it should be understood that for how to indicate the second timing offset, reference should be made to the aforementioned method in which the UE indicates the second timing offset to the base station.

[0400] After the UE transmits the indicator information to the base station, the base station receives the indicator information transmitted by the UE and obtains a second timing offset. After the second timing offset is valid, the UE transmits uplink data scheduled by the base station to the base station based on the updated second timing offset.

[0401] It should be understood that for the method regarding the effective time of the second timing offset, reference should be made to the description of the method for determining the effective time of the second timing offset, and the details will not be described again here.

[0402] Optionally, in the aforementioned step 1201, the base station can broadcast only a common timing advance (common TA). In this case, a terminal without positioning capability can transmit a preamble using the common TA to request access. A UE with positioning capability obtains a relatively accurate TA value based on its own location information and satellite location information (which can be obtained from ephemeris information), and then performs timing advance adjustment before transmitting a preamble. Therefore, when transmitting MsgA, a UE with positioning capability can use PUSCH data to convey the TA value used by the UE. For a method of transmitting the TA value, refer to the method of reporting the latest TA value used by the UE in Msg3 in four-step random access. After receiving the TA value, the base station can determine whether to update the timing offset based on the UE's latest TA value. For a related design for determining whether to update, refer to the update threshold in the aforementioned Figure 6.

[0403] Optionally, if the base station can distinguish whether the UE uses the positioning function, in some embodiments, a UE without the positioning function may not carry the TA value used by the UE in MsgA. A way to distinguish whether the UE uses the positioning function is, for example, to distinguish whether the UE has / uses the positioning function based on different preamble groups, based on an identifier in the uplink signal, or based on whether the TA value used by the UE is carried in MsgA.

[0404] Optionally, if the base station cannot distinguish whether the UE has positioning capability, the UE without positioning capability also carries the TA value used by the UE in the PUSCH data when sending MsgA. For the method of sending the TA value, refer to the method of reporting the latest TA value used by the UE in Msg3 in 4-step random access.

[0405] In some embodiments, after the base station receives MsgA, if MsgA carries a TA value for the UE to use, the base station may calculate the TA value by using the formula

number

number

[0406] In another embodiment, if MsgA does not convey the TA value used by the UE, it indicates that the UE will transmit the preamble using the broadcasted common TA value. Thus, both the UE and the base station can use the formula

number

number

[0407] It should be understood that for a specific description of the indication method and the effective time of the second timing offset, reference should be made to the aforementioned method.

[0408] Optionally, the method shown in FIG. 12 may further include: The base station transmits a timing advance adjustment command to the UE, and the UE receives the timing advance adjustment command. The UE transmits data information to the base station according to the timing advance adjustment command, where the data information includes an updated second timing offset, or the data information includes a second adjustment parameter set, and the second adjustment parameter set is used to determine the updated second timing offset.

[0409] It should be understood that the above method for updating the timing offset in the two-step random access method can be applied to a UE that does not have or does not use positioning function within the coverage area of ​​a base station, and can also be applied to the UE to precisely adjust the timing advance according to the timing advance command sent by the base station, so that both the UE and the base station know the timing advance adjustment value used by the UE in real time.

[0410] In the above method, the timing advance adjustment is performed by the UE. However, there may be a scenario where the base station compensates for part of the delay and the UE performs the timing advance adjustment for the remaining delay.

[0411] In this case, when the UE determines the timing offset, the value for delay compensation for the uplink signal at the base station side can be subtracted from the aforementioned parameter related to the timing advance.

[0412] For example, the above formula

number

number

[0413] Here, max_RTDD represents the maximum round trip delay difference of the beam or cell covered by the satellite. Delay_compensated represents the value of delay compensation performed on the uplink signal at the base station. The maximum round trip delay difference can be understood as the difference between the maximum round trip delay between the UE and the base station within the beam or cell and the delay compensation value at the base station.

[0414] For example, the above equation (11) can be replaced with the following equation (36):

number

[0415] For example, the above equation (33) can be replaced with the following equation (37):

number

[0416] The above describes the embodiments of the present application in detail, and the following describes the communication device in the present application.

[0417] 13 is a schematic diagram of the structure of a communication device according to an embodiment of the present application. As shown in FIG. 13, the communication device includes: a processing unit 1301, a sending unit 1302, and a receiving unit 1303.

[0418] In one embodiment, the processing unit 1301 is configured to generate a third message, wherein the third message includes index information, the index information is used to indicate a second timing offset, the second timing offset is an updated first timing offset, and the first timing offset is used to indicate a delay degree for the communication device to transmit the third message.

[0419] The transmitting unit 1302 is configured to transmit a third message to the network device based on the first timing offset. The transmitting unit 1302 is further configured to transmit a fifth message to the network device based on the second timing offset.

[0420] In a possible embodiment, the sending unit 1302 is further configured to send a first message including a random access preamble to the network device, the receiving unit 1303 is further configured to receive a second message sent by the network device including a random access response message, and the receiving unit 1303 is further configured to receive a fourth message sent by the network device including a random access contention resolution message.

[0421] In a possible implementation, indicating the second timing offset using the index information includes including the second timing offset in the index information.

[0422] In a possible implementation, indicating the second timing offset using the index information includes including a first set of adjustment parameters in the index information and determining the second timing offset using the first set of adjustment parameters.

[0423] In a possible embodiment, the first set of adjustment parameters includes any one or more of the following: parameters determined based on the start-up delay period of the random access response RAR receiving window and the period of the RAR receiving window; or parameters determined based on the start-up delay period of the random access contention resolution timer and the period of the random access contention resolution timer; or parameters determined based on a common timing advance; or parameters determined based on the orbital altitude of the network device; or parameters determined based on a round-trip delay between the communication equipment and the network device.

[0424] In a possible embodiment, the fourth message includes a second timing offset; or the fourth message includes a variation between the second timing offset and a reference timing offset, the reference timing offset being the timing offset currently used by the communication device or a preset timing offset.

[0425] In a possible embodiment, the receiving unit 1303 is further configured to receive validity information transmitted by the network device, the validity information being used to indicate an effective time of the second timing offset. Alternatively, the transmitting unit 1302 is further configured to transmit validity information to the network device, the validity information being used to indicate an effective time of the second timing offset. Alternatively, the second timing offset becomes effective m slots after the communication device transmits the third message, where m is a predetermined integer. Alternatively, the second timing offset becomes effective n slots after the communication device receives the fourth message, where n is a predetermined integer.

[0426] In a possible embodiment, the receiving unit 1303 is further configured to receive a broadcast message sent by the network device, the broadcast message including one or more of: a start-up delay period of the RAR receiving window and a duration of the RAR receiving window; or a start-up delay period of the random access contention resolution timer and a duration of the random access contention resolution timer; or a common timing advance; or an orbital altitude of the network device.

[0427] In a possible embodiment, when the broadcast message includes the start-up delay period of the RAR receiving window and the period of the RAR receiving window, the first timing offset satisfies the following condition:

number

[0428] Koffset1 is the value of the first timing offset. RAR_window is the duration of the RAR receiving window, which is used to indicate the period during which the communication device receives the RAR. RAR_offset is the start-up delay period of the RAR receiving window, which is used to indicate the delay period for delaying the start-up of the RAR receiving window after the communication device transmits the first message. slot_duration is the unit of period. ΔK offset is the timing offset difference, which is an integer.

[0429] In a possible implementation, when the broadcast message includes the random access contention resolution timer start delay period and the random access contention resolution timer period, the first timing offset satisfies the following condition:

number

[0430] RCR_timer is the random access contention resolution timer period, which indicates the maximum time interval allowed between the moment the communication device starts the random access contention resolution timer after sending the third message and the moment the communication device receives the fourth message. RCR_offset is the random access contention resolution timer start delay period, which is used to indicate the delay period for delaying the start of the random access contention resolution timer after the communication device sends the third message. slot_duration is the unit of time. ΔK offset is the timing offset difference, which is an integer.

[0431] In a possible embodiment, the fifth message includes any one of data information, a feedback message, or a sounding reference signal SRS.

[0432] In a possible embodiment, the receiving unit 1303 is further configured to receive a timing advance adjustment command sent by the network device, where the timing advance adjustment command is used to instruct updating the second timing offset. The sending unit 1302 is further configured to send an updated second timing offset or a second adjustment parameter set to the network device based on the second timing offset, where the second adjustment parameter set is used to determine the updated second timing offset.

[0433] In a possible embodiment, the transmitting unit 1302 is further configured to receive an updated second timing offset or a variation between the updated second timing offset and the reference timing offset from the network device when one or more of the following conditions are met: the communication device switches cells; or the communication device switches beams; or the communication device switches band portions BWP.

[0434] When the communication device is a terminal device or a component in a terminal device that implements the above-mentioned functions, the processing unit 1301 may be one or more processors, the sending unit 1302 may be a transmitter, and the receiving unit 130 3 may be a receiver, or the transmitting unit 1302 and the receiving unit 1303 may be integrated into one component such as a transceiver.

[0435] When the aforementioned communication device is a chip, the processing unit 1301 may be one or more processors, or logic circuits, etc., the transmitting unit 1302 may be an output interface, and the receiving unit 1303 may be an input interface, or the transmitting unit 1302 and the receiving unit 1303 are integrated into one unit, for example, an input / output interface or a communication interface.

[0436] The communication device in this embodiment of the present application has all the functions of the terminal device in the above-mentioned method, and the details will not be described again here.

[0437] Referring again to Figure 13, in another embodiment, the receiving unit 1303 is configured to receive a third message transmitted by the terminal device based on a first timing offset. The first timing offset is used to indicate a delay in the network device receiving the third message. The third message includes index information, which is used to indicate a second timing offset, and the second timing offset is the updated first timing offset. The receiving unit 1303 is further configured to receive a fifth message transmitted by the terminal device.

[0438] In a possible embodiment, the receiving unit 1303 is configured to receive a first message sent by the terminal device, the first message including a random access preamble. The sending unit 1302 is configured to send a second message to the terminal device, the second message including a random access response message. The sending unit 1302 is further configured to send a fourth message to the terminal device, the fourth message including a random access contention resolution message.

[0439] In a possible implementation, indicating the second timing offset using the index information includes including the second timing offset in the index information.

[0440] In a possible implementation, indicating the second timing offset using the index information includes including a first set of adjustment parameters in the index information and determining the second timing offset using the first set of adjustment parameters.

[0441] In a possible embodiment, the first set of adjustment parameters includes one or more of the following: parameters determined based on the start-up delay period of the random access response RAR receiving window and the period of the RAR receiving window; or parameters determined based on the start-up delay period of the random access contention resolution timer and the period of the random access contention resolution timer; or parameters determined based on a common timing advance; or parameters determined based on the orbital altitude of the communication device; or parameters determined based on the round-trip delay between the terminal device and the communication device.

[0442] In a possible embodiment, the fourth message includes a second timing offset; or the fourth message includes a variation between the second timing offset and a reference timing offset, the reference timing offset being the timing offset currently used by the terminal device or a preset timing offset.

[0443] In a possible embodiment, the transmitting unit 1302 is further configured to transmit validity information to the terminal device, where the validity information is used to indicate the validity time of the second timing offset. Alternatively, the receiving unit 1303 is further configured to receive validity information transmitted by the terminal device, where the validity information is used to indicate the validity time of the second timing offset. Alternatively, the second timing offset becomes valid m slots after the communication device receives the third message, where m is a preset integer; or the second timing offset becomes valid n slots after the communication device transmits the fourth message, where n is a preset integer.

[0444] In a possible embodiment, the transmitting unit 1302 is further configured to transmit a broadcast message, which includes one or more of: a start-up delay period of the RAR receiving window and a duration of the RAR receiving window; or a start-up delay period of the random access contention resolution timer and a duration of the random access contention resolution timer; or a common timing advance; or an orbital altitude of the communication device.

[0445] In a possible embodiment, when the broadcast message includes the start-up delay period of the RAR receiving window and the period of the RAR receiving window, the first timing offset satisfies the following condition:

number

[0446] K offset1 is the value of the first timing offset. RAR_window is the duration of the RAR receiving window, which is used to indicate the period during which the terminal device receives the RAR. RAR_offset is the start-up delay period of the RAR receiving window, which is used to indicate the delay period for delaying the start-up of the RAR receiving window after the terminal device transmits the first message. slot_duration is the unit of period. ΔK offset is the timing offset difference, which is an integer.

[0447] In a possible implementation, when the broadcast message includes the random access contention resolution timer start delay period and the random access contention resolution timer period, the first timing offset satisfies the following condition:

number

[0448] RCR_timer is the period of the random access contention resolution timer, which indicates the maximum time interval allowed between the moment the terminal device starts the random access contention resolution timer after sending the third message and the moment it receives the fourth message. RCR_offset is the start delay period of the random access contention resolution timer, which is used to indicate the delay period for delaying the start of the random access contention resolution timer after the terminal device sends the third message. slot_duration is the unit of time. ΔK offset is the timing offset difference, which is an integer.

[0449] In a possible embodiment, the fifth message includes any one of data information, a feedback message, or a sounding reference signal SRS.

[0450] In a possible embodiment, the transmitting unit 1302 is further configured to transmit a timing advance adjustment command to the terminal device, where the timing advance adjustment command is used to instruct the terminal device to update the second timing offset. The receiving unit 1303 is further configured to receive the updated second timing offset or a second adjustment parameter set transmitted by the terminal device, where the second adjustment parameter set is used to determine the updated second timing offset.

[0451] In a possible embodiment, the transmitting unit 1302 is further configured to transmit the updated second timing offset or the variation between the updated second timing offset and the reference timing offset to the terminal device when one or more of the following conditions are met: the terminal device switches cells; or the terminal device switches beams; or the terminal device switches band portions BWP.

[0452] When the communication device is a network device or a component within a network device that realizes the above-mentioned functions, the processing unit 1301 may be one or more processors, the transmitting unit 1302 may be a transmitter, and the receiving unit 1303 may be a receiver, or the transmitting unit 1302 and the receiving unit 1303 may be integrated into one component such as a transceiver.

[0453] When the aforementioned communication device is a chip, the processing unit 1301 may be one or more processors, or logic circuits, etc., the transmitting unit 1302 may be an output interface, and the receiving unit 1303 may be an input interface, or the transmitting unit 1302 and the receiving unit 1303 are integrated into one unit, for example, an input / output interface or a communication interface.

[0454] The communication device in this embodiment of the present application has all the functions of the network device in the above-mentioned method, and the details will not be described again here.

[0455] Furthermore, when the aforementioned processing unit is implemented using a processor, the receiving unit and the transmitting unit are integrated into one unit and implemented using a transceiver, as shown in FIG. 14. The communication device 140 includes at least one processor 1420, which is configured to implement the functions of a terminal device in the manner provided in the embodiments of the present application, or the functions of a network device in the manner provided in the embodiments of the present application. The communication device 140 may further include a transceiver 1410. The transceiver is configured to communicate with another device / apparatus using a transmission medium. The processor 1420 is configured to transmit and receive data and / or signaling using the transceiver 1410 and to implement the corresponding method in the aforementioned method embodiments.

[0456] Optionally, the communication device 140 may further include at least one memory 1430 configured to store program instructions and / or data. The memory 1430 is coupled to the processor 1420. A coupling in this embodiment of the present application is an indirect coupling or communication connection between devices, units, or modules for information exchange between the devices, units, or modules, and may be electrical, mechanical, or in other forms. The processor 1420 may operate in cooperation with the memory 1430. The processor 1420 may execute program instructions stored in the memory 1430. At least one of the at least one memory may be included in the processor.

[0457] The particular connection medium between the transceiver 1410, the processor 1420, and the memory 1430 is not limited in this embodiment of the present application. In this embodiment of the present application, the memory 1430, the processor 1420, and the transceiver 1410 are connected using the bus 1440 of FIG. 14. The bus is represented by a thick line in FIG. 14. The manner of connection between the other components is an example for illustrative purposes and is not intended to be limiting. Buses are categorized as address buses, data buses, control buses, etc. For ease of representation, only one thick line is used to represent a bus in FIG. 14, but this does not imply that there is only one bus or only one type of bus.

[0458] In the embodiments of the present application, the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a separate hardware component, capable of implementing or executing the methods, steps, and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor, or any conventional processor, etc. The steps of the methods disclosed with reference to the embodiments of the present application may be performed and completed directly by a hardware processor, or may be performed and completed using a combination of hardware and software modules in a processor.

[0459] It will be understood that for the specific implementation of the communication device shown in Fig. 14, reference should be made to the functions of the terminal device shown in Fig. 13. Alternatively, for the specific implementation of the communication device shown in Fig. 14, reference should be made to the functions of the network device shown in Fig. 13.

[0460] In some embodiments provided herein, it should be understood that the disclosed systems, devices, and methods may be implemented in other ways. For example, the above-described device embodiments are merely examples. For example, the division of units is merely a logical division of functions, and actual implementations may result in other divisions. For example, multiple units or components may be combined or integrated into another system, or some functions may be ignored or not performed. Furthermore, the shown or discussed mutual couplings or direct couplings or communication connections may be implemented via some interfaces. Indirect couplings or communication connections between devices or units may be realized in electrical, mechanical, or other forms.

[0461] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one location or distributed across multiple network units. Some or some of the units may be selected based on the actual requirements for achieving the objectives of the solutions in the embodiments of the present application.

[0462] Furthermore, the functional units in the embodiments of the present application may be integrated into one processing unit, and each unit may exist physically independently, or two or more units may be integrated into one unit. The integrated unit may be implemented in the form of hardware or a software functional unit.

[0463] When the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, the integrated unit may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application may essentially, or a part that contributes to the prior art, or all or a part of the technical solution may be realized in the form of a software product. The computer software product is stored in a storage medium and includes some instructions for instructing a computer device (which may be a personal computer, a server, a network device, etc.) to execute all or a part of the steps of the method of the embodiments of the present application. The aforementioned storage medium may include a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RRAM), etc. This includes any medium capable of storing program code, such as a hard disk, a magnetic disk, or an optical disk.

[0464] Furthermore, according to the method for updating a timing offset provided in an embodiment of the present application, the present application further provides a computer program, which is configured to perform the operations and / or processes performed by a terminal device in the method provided in the present application.

[0465] The present application further provides a computer program, which is used to perform the operations and / or processes performed by the network device in the methods provided herein.

[0466] The present application further provides a computer-readable storage medium that stores computer instructions that, when executed on a computer, enable the computer to perform the actions and / or processes performed by the terminal device in the methods provided herein.

[0467] The present application further provides a computer-readable storage medium that stores computer instructions that, when executed on a computer, enable the computer to perform the actions and / or processes performed by the network device in the methods provided herein.

[0468] The present application further provides a computer program product, which includes computer code or instructions, which, when executed on a computer, perform the methods of the method embodiments of the present application.

[0469] The present application further provides a computer program product, which includes computer code or instructions, which, when executed on a computer, perform the methods of the method embodiments of the present application.

[0470] The present application further provides a wireless communication system including the terminal device and the network device in the embodiment of the present application.

[0471] The above description is merely a specific embodiment of the present application, and the protection scope of the present application is not limited to this embodiment. Any modifications or replacements that can be easily conceived by those skilled in the art within the technical scope disclosed in the present application shall fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

[0472] Based on the above description of FIG. 6 and related methods, Msg2 can carry an adjustment parameter ΔK, where ΔK is determined using the coverage area of ​​the beam in which the UE is located. Similarly, the adjustment parameter ΔK value of Koffset can also be determined based on the coverage area of ​​the cell in which the UE is located. Correspondingly, it can be expressed as Koffset determination formula (K offset =f{Max_RTD_cell / time_duration}), e.g.

number

[0473] When the base station performs delay compensation when receiving the signal transmitted by the UE, the formula for determining Koffset is rewritten based on the above method and formula. For example, optionally, Koffset is determined using the coverage area of ​​the beam,

number

number

[0474] ΔK can be changed from being carried in Msg2 to being transmitted in RRC setup signaling, i.e., Msg4. Preferably, when ΔK-related information is carried by RRC setup signaling (Msg4), the Koffset used when the UE transmits Msg3 can function (i.e., the initial Koffset obtained by the UE based on the broadcast message is greater than the maximum round trip delay).

[0475] Optionally, in the related method described above, Koffset may be carried only in Msg2, i.e., the UE directly transmits Msg3 using Koffset transmitted by Msg2, in which case Koffset may be the beam-level or cell-level Koffset.

[0476] In the above-mentioned FIG. 6 and related methods, Koffset is transmitted based on a four-step random access process. In a two-step random access process, MsgB can be used to transmit ΔK or Koffset. The above formula is used for design. The UE obtains Koffset according to the agreed formula using the broadcast parameters and ΔK.

[0477] It will be understood that the above formulas are merely illustrative examples, and the specific formula formats for obtaining Koffset and ΔK are not limited. For example, the broadcast parameters may further include the duration of the RAR receive window, the start-up delay period of the RAR receive window, the duration of the random access contention resolution timer, and the start-up delay period of the random access contention resolution timer.

[0478] For example, optionally, Koffset and ΔK are obtained using the following equations:

number

[0479] where RAR_window is the duration of the RAR receiving window and RAR_delay is the startup delay period of the RAR receiving window.

number

[0480] Or,

number

[0481] where RCR_timer is the period of the random access contention resolution timer, and RCR_offset is the start delay period of the random access contention resolution timer.

[0482] Or,

number

[0483] Or,

number

[0484] where TA_common is the broadcast common timing advance.

[0485] Compared to sending the K value directly to the UE, signaling overhead can be reduced by using the parameters and ΔK broadcast together. Furthermore, as shown in Table 2, the cell-level K, beam-level K, and UE-level K are compared in terms of signaling overhead and end-to-end delay. It can be seen that the beam-level K has a smaller end-to-end delay than the cell-level K, and the beam-level K has less signaling overhead than the UE-level K. [Table 2]

[0486] 15 is a schematic diagram of a reference point-based NTN communication system according to the present application. The timing offset can be updated in the reference point-based NTN communication system. Optionally, the timing offset updating method can be applied to a four-step random access scenario, and the method specifically includes the following steps:

[0487] 1501. The satellite (gNB) broadcasts multiple Koffset value information to the cell coverage area.

[0488] 1502. After receiving the broadcast message, the UE determines a corresponding Koffset value based on the received SSB index number.

[0489] Optionally, the multiple Koffset value information in step 1501 may be Koffset numbers or IDs, for example, Koffset1, Koffset2, or Koffset3. In step 1502, for example, if the SSB index number received by the UE is 1, Koffset1 is used. If the SSB index number received by the UE is 3, Koffset3 is used. By establishing a relationship (e.g., a mapping relationship) between the Koffset value and the SSB index number, the method enables the UE to use beam-level Koffset values, thereby reducing end-to-end delay.

[0490] Alternatively, the satellite may broadcast information such as Koffset1, ΔKoffset2, ΔKoffset3, ΔKoffset4, etc. The UE may obtain the corresponding Koffset value using the following formula: Koffset1=Koffset1 Koffset2=Koffset1+△Koffset2 Koffset3=Koffset1+△Koffset3 Koffset4=Koffset1+△Koffset4 … (basic value+specific variable) Or, Koffset1=Koffset1 Koffset2=Koffset1+△Koffset2 Koffset3=Koffset1+△Koffset2+△Koffset3 Koffset4=Koffset1+△Koffset2+△Koffset3+△Koffset4 … (basic value+accumulated variables)

[0491] From Table 3 - the relationship between the number of synchronization broadcast blocks, subcarrier spacing, and carrier frequency, it can be seen that up to 64 synchronization broadcast blocks (SSB) can be broadcast when the carrier frequency is greater than 6 GHz. The SSB indexes are the 64 synchronization broadcast block indexes, and these indexes are jointly indicated by 3 bits of the PBCH and 3 bits implicitly indicated in the PBCH scrambling mode. [Table 3]

[0492] Optionally, the multiple Koffset value information in step 1501 may be multiple Koffset reference point coordinates, for example, Koffset reference point coordinate 1, Koffset reference point coordinate 2, and Koffset reference point coordinate 3. In step 1502, after receiving the broadcast message, the UE calculates a Koffset value to be used based on the received SSB index number (SSB index) and using the corresponding Koffset reference point coordinate.

[0493] For example, in the NTN system architecture diagram shown in Figure 16, which replaces the Koffset value based on the reference point coordinate, if the SSB index number received by the UE is 3, the Koffset reference point coordinate 3 is used to obtain the Koffset value to be used. The UE calculates the round trip delay RTD_reference between the Koffset reference point 3 and the satellite based on the Koffset reference point coordinate 3 and the satellite position coordinate (which can be obtained using ephemeris information), and then calculates the Koffset value to be used based on the round trip delay. Optionally, the following formula can be used:

number

[0494] Optionally, if the effect of service link delay and feeder link delay on the calculation of Koffset is taken into account, for example, when the satellite operates in transparent mode, each UE uses two reference points to calculate the Koffset value to be used.

[0495] In step 1501, the multiple Koffset value information may be multiple Koffset reference point coordinates and one Koffset feeder link reference point coordinate (see the design and method described in Figure 8a), for example, Koffset feeder link reference point coordinate, Koffset reference point coordinate 1, Koffset reference point coordinate 2, Koffset reference point coordinate 3, etc.

[0496] In step 1502, after the UE receives the broadcast message, determining a corresponding Koffset value based on the received SSB index number includes calculating a Koffset value to be used using the Koffset feeder link reference point coordinate and the corresponding Koffset reference point coordinate based on the received SSB index number. For example, if the SSB index number received by the UE is 1, the Koffset feeder link reference point coordinate and the corresponding Koffset reference point coordinate 1 are used to obtain a Koffset value to be used. The UE calculates a round trip delay RTD_reference between the Koffset reference point and the satellite based on the Koffset feeder link reference point coordinate 1 and the satellite position coordinate (which can be obtained from the ephemeris information). The UE calculates a round trip delay RTD_reference_feeder between the Koffset feeder link reference point and the satellite based on the Koffset feeder link reference point coordinate and the satellite position coordinate. Then, the UE calculates a Koffset value to be used based on RTD_reference and RTD_reference_feeder. Optionally, the following formula can be used:

number

[0497] Optionally, an indicator is added to indicate whether to transmit multiple Koffset values ​​or multiple Koffset reference point coordinates in order to flexibly configure the broadcast Koffset value or Koffset reference point on the network side. As shown in the schematic diagram of the Koffset value / Koffset reference point coordinate indicator in FIG. 17 , a Koffset value / Koffset reference point coordinate indicator is introduced to indicate whether to transmit at least one Koffset value or at least one Koffset reference point coordinate later. For example, an indicator of 0 indicates that at least one Koffset value will be transmitted later, and an indicator of 1 indicates that at least one Koffset reference point coordinate will be transmitted later. When the indicator is 0, the Koffset values ​​to be transmitted later may be Koffset1, Koffset2, Koffset3, etc. When the indicator is 1, the Koffset reference point coordinates to be transmitted later may be Koffset reference point coordinate 1, Koffset reference point coordinate 2, Koffset reference point coordinate 3, etc. For specific usage methods of the Koffset values ​​and reference points, please refer to the above-mentioned embodiments. If the effect of feeder link delay on the determination of the Koffset value is taken into account, the Koffset feeder link reference point coordinate may be transmitted along with the Koffset reference point coordinate, as shown in the schematic diagram of the Koffset value / Koffset reference point coordinate indicator in FIG. 18.

[0498] Flexible configuration of the broadcasted Koffset value and / or Koffset reference point benefits the system in various modes.

[0499] 1. Gaze mode (steerable): When the system operates in gaze mode, the coverage area of ​​the satellite beam remains unchanged for a certain period of time, and the broadcasted Koffset reference point does not change. The system can configure the broadcasted Koffset reference point using an indicator. Therefore, the system does not need to update the value, reducing the complexity of system broadcast updates.

[0500] 2. Non-stare mode: When the system operates in non-stare mode, the coverage area of ​​the satellite beam moves with the movement of the satellite. In this case, the Koffset value of the beam remains unchanged. Therefore, the system can use the indicator to configure the broadcast Koffset value.

[0501] Optionally, based on the same idea as above, the K value or the K reference point can be further replaced with a corresponding K angle value. The UE calculates the round trip delay value using the K angle value, and then obtains the K value using the above method.

[0502] As shown in the schematic diagram of the Koffset angle (Koffset feeder link angle) in Figure 19, when the speed of the satellite in the moving direction is V, the satellite (gNB) broadcasts at least one Koffset angle (corresponding to a beam) and a Koffset feeder link angle to the UE. The Koffset angle can replace the above Koffset value or Koffset reference point, and the Koffset feeder link angle can replace the above Koffset value or Koffset feeder link reference point.

[0503] The UE determines the corresponding Koffset angle based on the SSB index. α and Koffset feeder link angle

number

number

[0504] The UE determines the corresponding Koffset angle based on the SSB index. α If only Koffset is obtained, the UE may optionally calculate Koffset to use according to the following formula:

number

[0505] In gaze mode, Koffset is expressed using the Koffset angle method, which can avoid frequent updates and reduce the complexity of the system broadcast procedure compared to the Koffset value method.

[0506] The above has described the method for determining the cell-level initial timing offset and the beam-level initial timing offset, the method for updating the timing offsets, etc. Below, the method for determining the beam-level initial timing offset and the method for determining the cell-level initial timing offset will be further described.

[0507] The method for determining the beam-level (eg, beam-specific or beam-specific) initial timing offset is as follows.

[0508] For example, as described above in FIG. 15, the base station may use multiple Koffset (K offsetThe base station broadcasts timing offset Koffset value information to the cell coverage area, and the UE then determines the corresponding Koffset value based on the SSB index number, TCI number, beam number, or the like. Broadcasting multiple Koffset value information to the cell coverage area by the base station includes the base station broadcasting multiple timing offset Koffset values ​​using an SIB 1 message, or the base station broadcasting Koffset values ​​corresponding to multiple beams using a broadcast message such as an SIB 1 message. The beam-level timing offset means that the UE uses the same timing offset value in the beam corresponding to the offset, i.e., uses a beam-level timing offset. For example, the beam-level timing offset may be determined using the maximum round-trip delay between the gNB and the UE in the beam. The beam-level timing offset includes a beam-level initial timing offset. The "initial" in the initial timing offset refers to the parameter used to initially access the beam (or the first n times, e.g., the first or second time) or the basic parameter used in the beam.

[0509] In a possible embodiment, the base station can broadcast multiple Koffset values ​​using random access configuration generic (RACH-ConfigGeneric) signaling in the SIB 1 message or signaling having a similar function. The RACH-ConfigGeneric signaling is included in a parameter set used in the process of the terminal randomly accessing the system. Alternatively, it may be understood that multiple Koffset values ​​are added to the RACH-ConfigGeneric parameter (or signaling, etc.) in the SIB 1 signal. For example, the RACH-ConfigGeneric signaling can include one or more variable fields, and the one or more variable fields are used to indicate the multiple Koffset values.

[0510] For example, the RACH-ConfigGeneric parameter may include a variable field Koffset-list, which may represent multiple Koffset values, i.e., may indicate values ​​of timing offset amounts corresponding to multiple beams. As another example, the variable field Koffset-list may include two variable fields Koffset1 and Koffset-diff, where Koffset1 represents the timing offset value of beam 1 and Koffset-diff represents the difference between the timing offset of another beam and the timing offset of beam 1. In another example, there may be up to 63 timing offset differences. That is, the variable field Koffset-list may represent Koffsets of 64 beams, which means that 63 timing offset differences are used to determine timing offsets corresponding to 63 beams. Then, Koffset1 may be used to determine the timing offset corresponding to one beam.

[0511] In other words, the variable field Koffset-diff in this embodiment of the present application can be understood as ΔKoffset2, ΔKoffset3, ΔKoffset4, etc. in the previous embodiment.

[0512] For example, the RACH-ConfigGeneric signaling format in the SIB 1 message is shown as follows:

number

[0513] In this embodiment of the present application, the value ranges of the variable fields Koffset1 and Koffset-diff may relate to the calculation of the maximum round trip delay between cells or beams (e.g., related to orbital altitude and minimum intersection angle), the maximum round trip delay difference between cells or beams, and the timing offset period unit slot_duration in communication scenarios supported by the standard protocol.

[0514] For example, in a GEO transparent scenario, when the minimum communication angle is 10 degrees, the maximum round-trip delay is 541.46 ms, and the duration unit slot_duration uses the minimum slot length, i.e., 0.125e-3 seconds, as an example. In the signaling examples below, the minimum slot length is also used as an example duration unit, and details will not be described again. Since 541.46e-3 / 0.125e-3=4331.68, the variable field Koffset1 requires 13 bits to represent a range of 0 to 4332. The 13 bits of the variable field Koffset1 can represent a range of 0 to 8191. In the signaling example above, only the range of 0 to 4332 is used, and the unused range of 4333 to 8191 can be reserved or reserved for other indication purposes.

[0515] The range of values ​​for the variable field Koffset-diff depends on the maximum round-trip delay difference between beams, the satellite orbital altitude, the cell size, or the minimum communication elevation angle It can be determined based on:

[0516] For example, in a GEO transparent scenario, the cell diameter is 450 km, the minimum intersection angle is 10 degrees, and the maximum round trip delay difference within the cell is 2.933e-3 seconds. Since 2.933e-3 / 0.125e-3=23.464, 6 bits are required to indicate a range of values ​​from -24 to +24, and the 6 bits of the timing offset difference in the variable field Koffset-diff can indicate -31 to +31. In the signaling example above, only the range from -24 to +24 is used, and the range from -31 to +31 is used. ~- The unused range of 25 and +25 to +31 may be reserved or reserved for another indication use.

[0517] For example, after obtaining the Koffset-list signaling, the UE can separately obtain the Koffset value of beam 1 corresponding to Koffset1 based on the variable field Koffset1 and the variable field Koffset-diff. If Koffset-diff has 63 timing offset differences, the UE can further obtain that the Koffset value of beam 2 is Koffset1 + the first Koffset-diff value (i.e., Koffset1 + the first timing offset difference), the Koffset value of beam 3 is Koffset1 + the second Koffset-diff value (i.e., Koffset1 + the second timing offset difference), etc. As described above, the beam numbers such as beam 1, beam 2, etc. may be related to the SSB index number or TCI number, e.g., the SSB index number or TCI number is the beam number. Such a signaling transmission method provides flexibility and can reduce the signaling bit rate in a multi-beam scenario.

[0518] Optionally, it may be agreed that after receiving the Koffset-diff value, the UE subtracts a fixed value to obtain the difference between the timing offsets corresponding to the beams that the UE can use. Compared with the aforementioned solution of directly transmitting the usable timing offset difference to the UE, in this method, the UE obtains the difference between the timing offsets corresponding to the usable beams by calculation, leaving the calculation amount to the UE, thereby reducing the calculation complexity on the base station side. For example, the Koffset-diff variable field uses 6 bits to represent 0 to 48, which is subtracted by a fixed value (assuming a fixed value of 24) after the UE receives the Koffset-diff value, thereby allowing the UE to use an offset difference representation range of -24 to +24. As a specific example, the value of the Koffset-diff variable field is 8. After receiving the value, the UE subtracts the fixed value 24 from the value 8 to obtain -16. The UE uses -16 as the timing offset difference of the beam corresponding to this value.

[0519] The method for determining the cell-level (cell-specific or cell-specific) initial timing offset is as follows.

[0520] The base station broadcasts the initial Koffset value of the cell using a broadcast message (such as SIB 1) or transmits the initial Koffset value to the UE using RRC signaling (such as RRC setup signaling, RRC reconfiguration signaling, or RRC restart signaling). In other words, the base station may enable the UE in the cell to obtain the initial Koffset value using the above-mentioned method, so that the UE in the cell uses the initial Koffset value. The cell-level timing offset means that the UE in the cell uses the same timing offset value corresponding to the timing offset, i.e., uses the cell-level timing offset. For example, the cell-level timing offset may be determined using the maximum round-trip delay between the gNB and the UE in the cell. The cell-level timing offset includes a cell-level initial timing offset. The "initial" in the initial timing offset refers to the parameters used to initially access the cell or the basic parameters used in the cell.

[0521] In a possible implementation, the base station may use RACH-ConfigGeneric signaling in the SIB 1 message to broadcast a Koffset value corresponding to a cell. For example, the RACH-ConfigGeneric signaling may include one or more variable fields, and the one or more variable fields may be used to indicate the Koffset value. For example, the one or more variable fields may be variable fields Koffset_initial, Koffset-LEO, Koffset-complement, Koffset-LEO-600, Koffset-LEO-1200, and Koffset-GEO in the following embodiments.

[0522] A specific description of the RACH-ConfigGeneric signaling may be as follows:

[0523] Method 1

[0524] A new variable field Koffset_initial is added to the RACH-ConfigGeneric parameter to indicate the initial timing offset that the UE uses in the cell. For example, the value range of the variable field Koffset_initial may be determined based on the maximum round trip delay (e.g., related to the orbital altitude and the minimum intersection angle) in the communication scenario supported by the standard protocol. It will be appreciated that for a description of the value range of the variable field Koffset_initial, reference should be made to the above description of the variable field Koffset1. This signaling transmission method reduces more signaling overhead than beam-level Koffset signaling transmission.

[0525] For example, the RACH-ConfigGeneric signaling format in the SIB 1 message is shown as follows:

number

[0526] Method 2

[0527] Two new variable fields, Koffset-LEO and Koffset-complement, are added to the RACH-ConfigGeneric parameter and can be used to determine the initial timing offset. For example, the value ranges of Koffset-LEO and Koffset-complement (including the representation range and / or the number of bits represented) can be determined based on the satellite's orbital altitude range and minimum intersection angle. Therefore, to further reduce signaling bits, a combined indication can be performed on the initial timing offset based on the orbital altitude range.

[0528] For example, the RACH-ConfigGeneric signaling format in the SIB 1 message is shown as follows:

number

[0529] The newly added variable field Koffset-complement is optional, and indicates whether or not the variable field Koffset-complement may be sent. For whether or not to send the variable field Koffset-complement, or the conditions for sending the variable field Koffset-complement, see the examples below.

[0530] For example, in a scenario where the orbital altitude is 1200 km or less, when the minimum azimuth angle is 10 degrees, the maximum round trip delay is 41.745895 ms, the initial timing offset is 41.745895e-3 / 0.125e-3=333.9672, and the corresponding number of bits is 9. Therefore, the network side can only send Koffset-LEO signaling (9 bits), that is, Koffset-complement is not sent. In this case, only 9 bits of signaling need to be sent to indicate the timing offset parameter. The value range is 0 to +334. The range that can be indicated by 9 bits is 0 to +511. In the above signaling example, only the range 0 to +334 is used, and the unused range of +335 to +511 can be reserved or reserved for other indication purposes.

[0531] In another example, in a scenario where the orbital altitude is greater than 1200 km, the network side can transmit Koffset-LEO and Koffset-complement signaling (4 bits) to the UE, where Koffset-complement represents the most significant bits and Koffset-LEO represents the least significant bits. Koffset-LEO and Koffset-complement constitute 13-bit signaling, which indicates a range of 0 to 4332. The range that can be represented by 13 bits is 0 to 8191. In the above signaling example, only the range of 0 to 4332 is used, and the unused range of 4333 to 8191 can be reserved or reserved for another indication purpose. For the indication range of the combination of Koffset-LEO and Koffset-complement, please refer to the description of the variable field Koffset1 above.

[0532] Therefore, after obtaining the Koffset-LEO or Koffset-LEO and Koffset-complement signaling, the UE can obtain the timing offset to be used based on the signaling. This signaling transmission method provides flexibility and can reduce some signaling bits in scenarios where the orbital altitude is not high.

[0533] It should be understood that the Koffset range in the signaling of the above example is merely an example. In this application, the value range of Koffset is not limited, and the value range of Koffset can be agreed upon based on actual deployment conditions.

[0534] Method 3

[0535] Three new variable fields, Koffset-LEO-600, Koffset-LEO-1200, and Koffset-GEO, are added to the RACH-ConfigGeneric parameter to indicate the timing offset that the UE uses in the cell. The value range of Koffset-LEO-600, Koffset-LEO-1200, or Koffset-GEO (including the representation range and / or the number of represented bits) may be determined based on the range of satellite orbital altitudes and the minimum intersection angle. Koffset-LEO-600 represents a timing offset-related parameter corresponding to an orbital altitude of 600 km or less, Koffset-LEO-1200 represents a timing offset-related parameter corresponding to an orbital altitude of more than 600 km but less than or equal to 1200 km, and Koffset-GEO represents a timing offset-related parameter corresponding to an orbital altitude of 36000 km or less. The Koffset-LEO-600, Koffset-LEO-1200, or Koffset-GEO parameters can be set to optional. See the example below for how to send the signaling.

[0536] For example, in a scenario where the orbit altitude is below 600 km, the network side can only send Koffset-LEO-600 signaling, i.e., it does not send Koffset-LEO-1200 or Koffset-GEO. When the minimum elevation angle is 10 degrees, the maximum round trip delay in the LEO-600 scenario is 25.755 ms, the maximum timing offset is 25.755e-3 / 0.125e-3=206.04, and the corresponding number of bits is 8 bits (corresponding to the description in the LEO-600 transparent scenario in the above embodiment). In this case, the UE only needs to send 8 bits of signaling to determine the timing offset, and the range used to indicate the timing offset is 0...+207. The range that can be indicated by 8 bits is 0 to +255. In the signaling example above, only the range 0 to +207 is used, and the unused range of 208 to 255 is reserved or may be reserved for another indication use.

[0537] In another example, in a scenario where the orbital altitude is greater than 600 km but not greater than 1200 km, the network side can send Koffset-LEO-1200 signaling to the UE, i.e., does not send Koffset-LEO-600 or Koffset-GEO. In this case, it is necessary to send 9-bit signaling (corresponding to the description of the LEO-1200 transparent scenario in the previous embodiment) so that the UE is configured to determine the timing offset. It should be understood that for the description of the value range of Koffset-LEO-1200 signaling, reference should be made to the previous description of Koffset-LEO. The details will not be described again here.

[0538] As another example, in a scenario where the orbital altitude is greater than 1200 km, the network side can only transmit the Koffset-GEO signal, i.e., it does not transmit Koffset-LEO-600 and Koffset-LEO-1200. In this case, it is necessary to transmit 13-bit signaling (corresponding to the description of the GEO-transparent scenario in the above embodiment) so that the UE is configured to determine the timing offset, and the range used to represent the timing offset is 0 to +4332. It should be understood that for the description of the value range of the Koffset-GEO signaling, reference should be made to the above descriptions of Koffset-LEO, Koffset-complement, and Koffset-LEO-600. The details will not be described again here.

[0539] For example, the RACH-ConfigGeneric signaling format in the SIB 1 message is shown as follows:

number

[0540] It will be appreciated that the signaling format values ​​mentioned above are merely examples and should not be understood as limitations of this embodiment of the present application.

[0541] In this embodiment of the present application, the base station can further add a new variable field corresponding to the timing offset to the PUSCH-ConfigCommon physical layer uplink shared channel common configuration signaling in SIB 1 or the PUSCH-Config physical layer uplink shared channel configuration signaling in RRC signaling. For a specific description of adding a new variable field corresponding to the timing offset to the PUSCH-ConfigCommon physical layer uplink shared channel common configuration signaling in SIB 1 or the PUSCH-Config physical layer uplink shared channel configuration signaling in RRC signaling, please refer to the above Methods 1 to 3. The details will not be described again here.

[0542] It will be understood that the signaling values ​​shown in this embodiment of the present application are merely examples and should not be construed as limitations on this embodiment of the present application.

[0543] The above methods and embodiments can be combined with each other, and methods and procedures for updating timing offsets in different scenarios can be combined, for example, the following will refer to different scenarios for updating a combination of cell-level timing offsets, beam-level timing offsets, or UE-level timing offsets.

[0544] In other words, the cell-level Koffset, beam-level Koffset, or UE-level Koffset shown above can be used together.

[0545] It will be appreciated that UE level (UE specific or UE specific) timing offset indicates that different timing offset values ​​can be used between UEs within a cell / beam.

[0546] For example, the UE obtains a cell-level Koffset value using a broadcast message during initial access. After the UE initiates random access, the base station updates the Koffset value used by the UE to the beam level based on the beam in which the UE is located. As shown in Table 2, updating Koffset from the cell level to the beam level can reduce the end-to-end delay. Furthermore, when the UE requires a higher delay, such as in a scenario requiring low delay, the base station and UE can update the Koffset used to the UE-level Koffset value. As shown in Table 2, the end-to-end delay (including scheduling delay) after updating Koffset to the UE level is smaller than the cell-level and beam-level Koffset, which is suitable for scenarios with low delay requirements.

[0547] For example, the UE obtains a cell-level Koffset value using a broadcast message during initial access. After the UE initiates random access, the gNB determines whether the Koffset value used by the UE needs to be updated based on the UE's service type and / or different delay requirements.

[0548] (1) If a UE does not require high delay performance and is insensitive to delay, the base station may allow this type of UE to continue using the cell-level Koffset or update to the beam-level Koffset.

[0549] (2) When the UE requires high delay performance and low delay, the base station can update the timing offset value used by the UE to Koffset at the UE level. In the solution process, the gNB needs to send signaling to the UE to instruct whether to update Koffset at the beam level or to update Koffset at the UE level, or the UE needs to request the gNB to update Koffset at the beam level or to update Koffset at the UE level.

[0550] For example, when a UE requires low latency, the UE can autonomously determine to update the cell-level Koffset value to the UE-level Koffset value and report it to the base station. Alternatively, the UE can autonomously determine to update the beam-level Koffset value to the UE-level Koffset value and report it to the base station.

[0551] In another example, when a UE requests delay performance, the UE can transmit indicator information to the base station, where the indicator information can be used to indicate the delay requirement of the UE or the level of timing offset that the UE needs to use (e.g., cell level, beam level, or UE level). Thus, the base station receives the indicator information and determines whether to update the timing offset value used by the UE based on the indicator information. When Koffset should be updated, the base station transmits information used to instruct the UE to update the Koffset value. For example, the base station can instruct the UE to update Koffset to a beam-level Koffset value or a UE-level Koffset value.

[0552] Optionally, the base station can instruct the UE whether to enable the Koffset update mechanism or which Koffset update mechanism is being used. If not enabled, the cell-level Koffset is not updated to the beam-level Koffset or the UE-level Koffset, and the UE does not need to report the TA or delay requirement or Koffset level to be used. For example, the base station can send the following signaling to the UE, or the UE can send the following signaling to the base station to instruct whether to enable the Koffset update mechanism:

[0553] The signaling indicates whether to enable a UE-specific Koffset update mechanism. If enabled, it indicates that the base station and the UE can update Koffset from cell-level or beam-level to UE-level Koffset. If not enabled, it indicates that the UE continues to use the Koffset level it is currently using. The advantage is that different Koffset update mechanisms can be selected based on the service requirements and scheduling delay requirements of the UE, and the extra overhead of Koffset signaling can be avoided.

[0554] The signaling indicates whether to enable a beam-specific Koffset update mechanism. If enabled, it indicates that the base station and UE can update Koffset from cell level or UE level to beam level Koffset. If not enabled, it indicates that the UE continues to use the Koffset level it is using. The advantage is that different Koffset update mechanisms can be selected based on the service requirements and scheduling delay requirements of the UE, and the extra overhead of Koffset signaling can be avoided.

[0555] The signaling indicates whether to use a beam-specific Koffset or a UE-specific Koffset update mechanism, or whether to not support updating Koffset to another level. In this scenario, the signaling indication method is to indicate whether the base station and / or UE supports updating the Koffset level to the beam level or the UE level, or to change / not change the Koffset usage level. The signaling indication can avoid ambiguity of the Koffset update mechanism between the base station and the UE. Further benefits include selecting different Koffset update mechanisms based on the service requirements and scheduling delay requirements of the UE, thereby avoiding additional overhead related to updating Koffset signaling.

[0556] The following uses the combination of the above methods and embodiments as an example in a specific scenario for illustration.

[0557] Scenario 1: Update the cell-level Koffset value to the beam-level Koffset value.

[0558] In this scenario, it is assumed that the cell-level Koffset value is obtained when the UE is first accessed.

[0559] For example, after a UE requests access to the system, a base station such as a gNB transmits a timing offset difference ΔKoffset in Msg2, Msg4, or RRCsetup signaling. After receiving ΔKoffset, the UE can update Koffset, i.e., Koffset_new = Koffset_old + ΔKoffset. Koffset_old represents the Koffset value, reference timing offset value, or initial Koffset used by the gNB and the UE. Koffset_new represents the updated Koffset value used by the gNB and the UE, i.e., the timing offset value obtained based on Koffset_old. The gNB can determine the ΔKoffset value here based on the beam level Koffset. That is, the gNB determines that the UE needs to use an updated Koffset value, Koffset_new, based on the beam in which the UE is located (e.g., the gNB determines the Koffset_new value based on the maximum round-trip delay between the UE and the gNB in ​​the beam coverage area in which the UE is located), and then obtains the ΔKoffset value based on ΔKoffset = Koffset_old - Koffset_new. The gNB can send ΔKoffset using signaling such as Msg2, Msg4, or RRCsetup, and the signaling is set to optional (indicating that ΔKoffset may or may not be sent). If the network side decides not to update Koffset, the gNB does not send ΔKoffset to the UE, i.e., it is considered that the gNB and the UE do not update the Koffset in use.

[0560] In a possible embodiment, the base station can configure ServingCellConfig signaling to transmit ΔKoffset using the serving cell in RRCsetup signaling, and RRCReconfiguration and RRCResume signaling can also include ServingCellConfig signaling, or can use RRCReconfiguration and RRCResume signaling to transmit the ΔKoffset value. For example, the serving cell configuration ServingCellConfig signaling includes one or more variable fields, and the one or more variable fields can be used to indicate ΔKoffset.

[0561] Method 1

[0562] A new variable field, Koffset-difference, is added to the serving cell configuration, ServingCellConfig, parameter to indicate the timing offset difference ΔKoffset. The UE can update Koffset using the timing offset difference, Koffset-difference. The value range of Koffset-difference (e.g., representation range or corresponding number of bits) depends on the maximum round trip delay difference between beams, the satellite orbital altitude, the cell size, and the minimum communication delay. elevation angle It can be determined based on:

[0563] For example, the maximum round trip delay difference between cells in a GEO transparent / regenerative scenario is 10.3 ms, which is 10.3e-3 / 0.125e-3=82.4, so the variable field Koffset-difference requires 8 bits to indicate -83 to 83. The 8 bits of Koffset-difference can indicate -127 to +127. In the signaling example above, only the range of -83 to 83 is used, and the unused ranges of -127 to -84 and +84 to +127 can be reserved or reserved for other indication purposes. The transmit timing offset differential scheme can reduce signaling overhead compared to directly transmitting the full Koffset value.

[0564] For example, the signaling format described above may be as follows:

number

[0565] Method 2

[0566] To indicate the difference between the Koffset values ​​that a UE uses in multiple beams in a cell and the cell-level Koffset, a new variable field, Koffset-difference-list, is added to the ServingCellConfig parameter or a parameter with a similar function. That is, Koffset-difference-list represents multiple Koffset differences, for example, the difference between the Koffset values ​​corresponding to up to 64 beams and the cell-level Koffset corresponding to the cell in which the beams are located.

[0567] For example, the signaling format described above may be as follows:

number

[0568] In this embodiment of the present application, the value range of the variable field Koffset-difference-list may relate to the maximum round trip delay of a cell or beam (e.g., related to orbital altitude and minimum intersection angle) in a communication scenario supported by the standard protocol, the maximum round trip delay difference between a cell and a beam, and the calculation timing offset period in units of slot_duration.

[0569] For example, in a GEO transparent scenario, the cell diameter is 450 km, the minimum intersection angle is 10 degrees, and the maximum round trip delay difference within the cell is 2.933e-3 seconds. Since 2.933e-3 / 0.125e-3=23.464, 6 bits are needed to indicate a range of values ​​from -24 to +24, and the 6 bits of the timing offset difference in the variable field Koffset-difference-list can indicate -31 to +31. In the signaling example above, only the range from -24 to +24 is used, and only the range from -31 to +31 is used. ~- The unused range of 25 and +25 to +31 may be reserved or reserved for another indication use.

[0570] For example, after receiving the Koffset-difference-list signaling, the UE can determine a beam-level Koffset value corresponding to the beam where the UE is located based on the difference between the Koffset value currently in use (or the previously received Koffset value or the cell-level Koffset value currently in use) and the Koffset value indicated by the variable field Koffset-difference-list. For example, if the Koffset-difference-list indicates 64 Koffset differences, the UE selects a corresponding Koffset difference in the Koffset-difference-list based on the beam number where the UE is located (e.g., determined based on the correspondence between the beam number and the SSB number or the TCI number). For example, if the beam number is 5, the fifth Koffset difference indicated by the Koffset-difference-list (assuming the beam number starts from 1) or the fourth Koffset difference indicated by the Koffset-difference-list (assuming the beam number starts from 0) is selected. The UE can obtain the beam level Koffset value corresponding to the beam in which the UE is located based on the Koffset value used by the UE + the selected Koffset-difference-list value (i.e., the Koffset value used by the UE + the timing offset difference selected based on the beam number). Both the UE and the gNB use this method to calculate and update the beam level Koffset value. This signaling transmission method provides flexibility and can reduce the signaling bit rate in a multi-beam scenario.

[0571] Method 3

[0572] To indicate the timing offset difference ΔKoffset used for different track ranges, two new variable fields, Koffset-difference-GEO and Koffset-difference-LEO, are added to the ServingCellConfig parameter, and the UE can update Koffset using the timing offset difference. The gNB selects to transmit Koffset-difference-GEO or Koffset-difference-LEO based on the communication scenario (orbital altitude range). Therefore, after obtaining Koffset-difference-GEO or Koffset-difference-LEO, the UE can obtain the ΔKoffset value and then update the Koffset value based on Koffset_new = Koffset_old + ΔKoffset.

[0573] Koffset-difference-GEO represents the timing offset difference used when the orbital altitude in a communication scenario is greater than 1200 km and less than 36000 km. The expression range of Koffset-difference-GEO is determined based on the maximum round-trip delay difference between beams, which is related to the satellite orbital height, cell size, and minimum intersection angle. For a specific explanation, see the description of Koffset-difference above. When the orbital altitude in a communication scenario is greater than 1200 km and less than 36000 km, the network side only needs to send Koffset-difference-GEO signaling, that is, it does not send Koffset-difference-LEO signaling. In this case, the terminal needs to send 8-bit signaling to determine the timing offset.

[0574] Koffset-difference-LEO indicates the timing offset difference parameter for orbital altitudes of 1200 km or less. The representation range is determined based on the maximum round-trip delay difference between beams. For example, in a LEO-1200 scenario, the maximum round-trip delay difference within a cell is 3.18 ms, which is 3.18e-3 / 0.125e-3=25.44. Therefore, the variable field Koffset-difference-LEO requires 6 bits to indicate a range of -26 to 26. The 6 bits of Koffset-difference-LEO can indicate a range of -31 to +31. In the signaling example above, only the range of -26 to 26 is used; the unused ranges of -31 to -27 and +27 to +31 can be reserved or used for other indications. The transmit timing offset difference solution provides flexibility and can reduce some signaling bits in scenarios where the orbital altitude is not high.

[0575] For example, the signaling format mentioned above may be as follows:

number

[0576] Optionally, the gNB can further transmit the timing offset difference ΔKoffset value, i.e., Koffset difference, to the UE using MAC CE signaling. Thus, after receiving the Koffset difference, the UE updates Koffset based on Koffset_new = Koffset_old + ΔKoffset. For example, the MAC CE signaling can be used to transmit the aforementioned 8-bit Koffset-difference signaling or 6-bit Koffset-difference-LEO signaling to the UE to represent the ΔKoffset value. For a specific description of MAC CE signaling, please refer to the above description. The details will not be described again here.

[0577] Scenario 2: Update the Koffset value at the beam level.

[0578] In stare mode, as the satellite changes relative to the UE, the beam level (beam specific) Koffset of the beam on which the UE is located changes.

[0579] When the system uses a beam-level initial Koffset, the gNB can update the beam-specific Koffset through the following signaling manner. That is, the gNB and UE still use the beam-specific Koffset, but the specific Koffset value is changed and updated. That is, in a possible embodiment, the network device can indicate the updated Koffset (i.e., the beam-specific Koffset) using RRC signaling, RRC reconfiguration signaling, or MAC CE signaling. Illustratively, the RRC reconfiguration signaling includes one or more variable fields (such as Koffset-list), and the one or more variable fields are used to indicate the updated Koffset. For example, the RRC signaling ServingCellConfig includes ΔKoffset. For example, the MAC CE signaling includes ΔKoffset. This will be described in detail below.

[0580] Method 1: RRC Reconfiguration Signaling: For example, RRC Reconfiguration signaling is used to update Koffset. Accordingly, the base station sends RRC reconfiguration signaling to the UE. After receiving the RRC reconfiguration signaling, the UE selects a corresponding Koffset value based on the beam in which the UE is located and updates the Koffset value in use. For example, the RRC reconfiguration signaling includes the aforementioned updated value of the Koffset-list variable field. For the design of a specific signaling length, please refer to the aforementioned description of the Koffset-list variable field parameter.

[0581] Method 2: RRC signaling: For example, a Koffset difference such as ΔKoffset is added to ServingCellConfig in RRC signaling. ΔKoffset may be determined based on the Koffset value Koffset_new to be updated. For example, the gNB determines the updated Koffset value Koffset_new to be used by the UE based on the latest positional relationship between the beam, satellite, and gateway in which the UE is located (for example, the gNB determines the Koffset_new value based on the maximum round-trip delay between the gNB and the UE within the beam coverage area in which the UE is located), and then obtains the ΔKoffset value based on ΔKoffset = Koffset_old - Koffset_new. Therefore, the base station sends RRC signaling to the UE. After receiving the RRC signaling, the UE updates Koffset based on Koffset_new = Koffset_old + ΔKoffset. For the signaling design of Koffset-difference, see the description of the Koffset-difference variable field parameter above.

[0582] Method 3: MAC CE signaling: For example, the gNB can use MAC CE signaling to transmit the timing offset difference ΔKoffset value, i.e., Koffset difference, to the UE. For the signaling design of the Koffset difference, please refer to the description of the Koffset-difference parameter.

[0583] In the above Scenario 1, when the gNB and UE use the cell-level initial Koffset solution, after the UE requests access to the system, the gNB and UE update Koffset from the cell level to the beam level. When the relative positions between the satellite, the UE, and the gateway change, the beam-level Koffset of the beam in which the UE is located also changes. In other words, the beam-level Koffset value changes and needs to be updated. The gNB can update the beam-specific Koffset value using the following two signaling modes:

[0584] ΔKoffset is carried in RRC signaling, for example, in ServingCellConfig signaling in RRC signaling.

number

[0585] For a description of the Koffset-difference variable field, see the description of adding a new variable field, Koffset-difference, to the ServingCellConfig parameters.

[0586] The gNB transmits the ΔKoffset value, i.e., the differential value Koffset, to the UE using MAC CE signaling.

[0587] Scenario 3: Update the Koffset value at the UE level.

[0588] If the UE can report TA, it indicates that the UE has established a connection with the gNB at this point, and a usable Koffset value is obtained. Therefore, the gNB only needs to update Koffset based on this value.

[0589] For example, in the embodiment shown in FIG. 6, the UE can use Msg3 to report the TA value and indicate the second timing offset. That is, the UE can transmit to the gNB the TA information or location information that the UE uses in the RACH process in Msg3 (or in another message, such as a message transmitted when the timing offset needs to be updated later). When a TA value is transmitted, the TA value can be the TA value or a quantized TA value, or an updated Koffset value or Koffset difference. After accessing the system, the UE can also report a value related to the TA value that the UE uses in another uplink message and use the gNB to determine the updated Koffset value.

[0590] For example, in the above-mentioned method in which the UE transmits indicator information to indicate the second timing offset, the UE may transmit a TA correlation value to the gNB, and subtract the common TA (where the common TA value may be a positive value, a negative value, or a zero value) from the TA value the UE is using, or may subtract the absolute value of the common TA from the TA value the UE is using (i.e., determine the difference between the absolute value of the TA used and the common TA), i.e., TA_applied (e.g., TA_applied=TA_use-TA_common) is transmitted to the gNB, or half of the TA_applied value is transmitted to the gNB (after the gNB receives the TA_applied value, it multiplies it by 2 to obtain the TA_applied value). TA_use represents the TA value the UE is using or will use, TA_common represents the common TA value, and TA_applied represents the difference between TA_use and TA_common. After receiving the TA correlation value sent by the UE, the gNB obtains the TA value that the UE is using or intends to use based on TA_use=TA_applied+TA_common.

[0591] For example, to transmit the TA value, use 16Ts / 2. u is used as the time dimension, and TA_use-TA_common is 16Ts / 2 u If the UE or gNB determines by calculation that

number

number

[0592] In a possible implementation, the UE may indicate the TA or a TA-related value using the third message, the fifth message, or another uplink message (e.g., a granted PUSCH resource, or an uplink physical layer control channel message, etc.). Exemplarily, the third message, the fifth message, or another uplink message may include one or more variable fields (such as TA-applied, TA-applied-LEO-600, TA-applied-LEO-1200, TA-applied-GEO, Koffset_difference_UE, and the like), and the one or more variable fields may be used to indicate the TA or a TA correlation value.

[0593] Method 1

[0594] A variable field TA-applied (timing advance to be used) is added to indicate the TA correlation value reported by the UE. After receiving TA-applied, the gNB determines the TA value that the UE uses or will use. The representation range and number of bits of the TA-applied signaling are determined by the orbit altitude, minimum intersection angle, and time dimension in the communication scenario.

[0595] For example, if the satellite's orbital altitude is below the GEO orbit and the minimum elevation angle is 10 degrees, the time dimension unit is 16Ts / 2 uis used, and the representation range of TA-applied must be 0 to 4155513, which requires 22 bits to be represented. 22 bits can represent a range of 0 to 4194303. In the above signaling example, only the range of 0 to 4155513 is used, and the unused range of 4155514 to 4194303 may be reserved or reserved for another indication. For example, after receiving the TA-applied parameter, the gNB can add the TA-applied parameter to the common TA (quantized common TA value) and multiply the common TA parameter by the time dimension unit to obtain the TA value used by the UE, or TA-applied represents the TA value used by the UE, i.e., the time length of the TA used by the UE after multiplying the TA-applied parameter by the time dimension unit. It should be understood that protocols support different satellite orbital altitudes, minimum communication altitudes, and time dimension units, and the indication range that TA-applied needs to support may differ. The range of indications and the amount of bits for TA-applied can be defined based on a particular communication scenario.

[0596] For example, the signaling format of the aforementioned TA-applied is shown as follows:

number

[0597] Method 2

[0598] Three new variable fields, TA-applied-LEO-600, TA-applied-LEO-1200, and TA-applied-GEO, have been added and are used by the gNB to determine the timing advance value currently used by the UE. The representation range and number of bits for TA-applied-LEO-600, TA-applied-LEO-1200, and TA-applied-GEO can be determined based on the satellite's orbital altitude range, the minimum possible intersection angle, and the time dimension unit. TA-applied-LEO-600 represents a parameter related to the timing advance value used by the UE in communication scenarios where the orbital altitude is 600 km or less. TA-applied-LEO-1200 represents a parameter related to the timing advance value used by the UE in communication scenarios where the orbital altitude is 1200 km or less. TA-applied-GEO represents a parameter related to the timing advance value used by the UE in communication scenarios where the orbital altitude is 36,000 km or less. Referring to the design principles of the representation range and bit number of the aforementioned parameter TA-applied, the representation range and bit number of TA-applied-LEO-600, TA-applied-LEO-1200, TA-applied-LEO-1200 and TA-applied-GEO can be obtained.

[0599] For example, the UE adds related signaling, TA-applied-LEO-600 / TA-applied-LEO-1200 / TA-applied-GEO, to the RRCsetupRequest signaling in Msg3 for reporting the TA. The UE obtains the satellite's orbital altitude based on the ephemeris information or satellite orbital information, and selects one of the corresponding TA-applied-LEO-600 / TA-applied-LEO-1200 / TA-applied-GEO signaling to transmit the TA value. In a scenario where the orbital altitude is below 600 km, the UE can use the TA-applied-LEO-600 signaling instead of transmitting the TA-applied-LEO-1200 and TA-applied-GEO. The advantage of this is that the UE can transmit the TA correlation value using a shorter signaling length in a low-earth-orbit satellite communication system.

[0600] For example, the signaling formats for TA-applied-LEO-600, TA-applied-LEO-1200, and TA-applied-GEO are as follows:

number

[0601] Method 3

[0602] For example, in the above-described method in which the UE transmits indicator information to indicate a second timing offset, the UE can report the Koffset value or Koffset difference to be updated instead of reporting the TA correlation value. For example, using the Koffset difference as an example, a new variable field Koffset_difference_UE is added to indicate the timing offset difference that the UE reports to the gNB and the difference between the Koffset value that the UE updates and the Koffset in use. It will be understood that the UE can also report the Koffset difference in a separate uplink message.

[0603] The Koffset_difference_UE indication range is related to the number of occupied bits and the frequency and threshold of the updated Koffset reported by the UE. Here, using an example where the Koffset difference is less than or equal to 7, Koffset_difference_UE needs to occupy 3 bits. After receiving Koffset_difference_UE, the gNB can obtain the Koffset value updated by the gNB and the UE according to Koffset_new=Koffset_old+Koffset_difference_UE.

[0604] For example, the signaling format of the aforementioned Koffset_difference_UE is shown as follows:

number

[0605] For example, in the above-described method in which the UE transmits indicator information to indicate the second timing offset, the UE can report its location information to the gNB. For example, a geocentric coordinate system (Earth-centered, Earth-fixed, ECEF) can be used. Assume that the range to be represented is a maximum of 20 km from the Earth's surface and the Earth's radius is 6371 km. In this case, each dimension of the three-dimensional coordinate position needs to represent -6391 to 6391 km. If the representation resolution of each dimension of the three-dimensional coordinate is 0.125 m, 27 bits are required, and then 27*3 = 81 bits are required for three dimensions. If the representation resolution of each dimension of the three-dimensional coordinate is 0.25 m, 26 bits are required, and then 26*3 = 78 bits are required for three dimensions. For example, adding a variable field UE-Position represents the UE's location coordinate. The variable field UE-Position includes three variable values ​​representing the UE's three-dimensional coordinate correlation value. The range and number of occupied bits of the UE-Position signaling are related to the radius of the Earth, the maximum distance the UE can be located in the horizontal plane, and the resolution expressed by the position coordinates. For example, the location information signaling sent by the UE can be expressed as follows:

number

[0606] For example, the RRCsetupRequest message may carry the aforementioned TA-applied-LEO-600, TA-applied-LEO-1200, TA-applied-GEO, UE-Position, or Koffset_difference_UE signaling.

[0607] After receiving the UE-Position signaling, the gNB multiplies the received three-dimensional coordinate correlation value by the coordinate resolution. For example, it is assumed that the coordinate resolution is 0.125 m, the UE-Position signaling value received by the gNB is (50976000, 1688000, 1592000), and the actual ECEF three-dimensional coordinate of the UE can be obtained by the gNB as (50976000*0.125=6372 km, 1688000*0.125=211 km, 1592000*0.125=199 km).

[0608] Optionally, to reduce signaling overhead, it may be agreed that the UE may transmit coordinate differences by subtracting a fixed value from the location coordinates transmitted by the UE. For example, the UE may transmit coordinate differences after subtracting 6,371 km from each latitude of the three-dimensional coordinates transmitted by the UE. After receiving the coordinate differences, the gNB may add 6,371 km to each latitude to obtain the UE's coordinate values. The above-described signaling design can reduce signaling overhead.

[0609] Method 4

[0610] The gNB and the UE may agree that the UE will report TA-related parameters to the gNB using an uplink physical layer control channel (PUCCH) message. For example, the UE may use the uplink physical layer control channel message to transmit TA-related signaling parameters or indicator information (used to indicate the second timing offset) transmitted by the UE in the methods and embodiments of the present application. In this manner, the UE may avoid requesting uplink resources to report the TA-related parameters, thereby saving scheduling time for requesting uplink resources.

[0611] In this embodiment of the present application, after the UE accesses the system, the UE can send the TA value to the gNB using an uplink MAC CE message or PUSCH. For details, please refer to the above-mentioned method for designing the TA-related signaling length.

[0612] The above method and embodiment describes how to update Koffset in cell handover. The following uses an example of a signaling process in a specific communication scenario.

[0613] (1) In the handover process, RRCReconfiguration signaling is first measured and then sent by the source gNB to the UE. It can be known from the signaling that cell-level or beam-level Koffset exists in RRCReconfiguration. Therefore, the UE can obtain the Koffset value of the target cell / beam using RRCReconfiguration. In the case of RACHless handover, the source cell also sends RRCReconfiguration signaling to the UE. The UE can receive SIB 1 of the target cell and also obtain the Koffset of the target cell / beam.

[0614] (2) After the handover is completed, the UE can update Koffset from the cell level to the beam level. Alternatively, Koffset is updated to the UE level, which is the same as the signaling process after the UE randomly accesses the cell.

[0615] A satellite switch may be equivalent to a cell handover, see the handover signaling process above.

[0616] The above method and embodiment describes how to update Koffset in a beam switch. The following uses an example of a signaling process in a specific communication scenario.

[0617] When the source beam and the target beam belong to the same cell, the satellite does not switch beams, and then the UE can continue to use the cell-level or UE-level Koffset that it is currently using.

[0618] When the Koffset used by the UE is related to the beam level, there are two types of discussion.

[0619] 1. If the system uses a beam-level initial Koffset solution, the gNB can update the beam-specific Koffset through the following two signaling methods:

[0620] (1) Update the Koffset-list using RRC signaling, for example, using RRCReconfiguration signaling. The UE selects a corresponding Koffset value based on the beam in which the UE is located, i.e., updates the Koffset value in use.

[0621] Alternatively, the UE needs to select the Koffset value to be used for the corresponding target beam based on the Koffset group sent in the broadcast signal (e.g., Koffset-list message).

[0622] (2) The gNB can use MAC CE signaling to transmit the ΔKoffset value, i.e., the Koffset difference, to the UE. After receiving the message, the UE updates Koffset based on Koffset_new = Koffset_old + ΔKoffset. For example, the aforementioned 8-bit or 6-bit signaling can be transmitted to the UE using MAC CE signaling to indicate the ΔKoffset value.

[0623] 2. If the system uses a cell-level initial Koffset solution and the UE accesses the system using a beam-level Koffset, the gNB can update the beam-specific Koffset using the following two signaling methods:

[0624] (1) ΔKoffset is conveyed in RRC signaling, for example, ServingCellConfig signaling in RRC signaling (for example, Koffset-difference signaling is used).

[0625] (2) The gNB transmits the ΔKoffset value, i.e., the Koffset difference, to the UE using MAC CE signaling.

[0626] Gateway switch:

[0627] When a soft gateway switch occurs, the UE may receive two gateway signals simultaneously, which may be equivalent to a cell handover process.

[0628] When a hard gateway switch occurs, the UE can only receive one gateway signal at a time and temporarily switches from the source gateway to the target gateway. In this case, the fractional delay of the feeder link changes. The gNB can send the Koffset to the UE, or the difference between the Koffset to be used in the target gateway and the current Koffset, i.e., ΔKoffset.

[0629] Since UEs across beams or across cells need to update their Koffset values, RRCReconfiguration signaling can be used to convey ΔKoffset and update Koffset.

[0630] Alternatively, the gNB uses MAC CE signaling to transmit the Koffset or ΔKoffset of the target gateway to the UE.

[0631] When ΔKoffset is transmitted, the same number of bits as the complete Koffset may also be required. For example, in some special scenarios, when the network side performs timing compensation on the uplink signal before switching and the network side does not perform timing compensation on the uplink signal after switching, ΔKoffset needs to include the complete round-trip delay. In this case, the number of bits required for ΔKoffset is the same as the number of bits required to indicate the complete Koffset. If the protocol does not support this special scenario, the number of bits required to indicate ΔKoffset is less than the number of bits for the complete Koffset, and thus the signaling bits can be reduced.

[0632] In the above-mentioned method in which the UE transmits indicator information to indicate the second timing offset, the UE transmits the TA correlation value to the gNB. The following uses an example to describe how the UE reports the TA or TA correlation value it is using.

[0633] The UE reports the TA or TA correlation value that the UE is using, and the gNB determines the TA value of the UE, and therefore determines the Koffset value that the UE needs to update. For details, see the above description:

number

[0634] Method 1: The UE reports the TA rate.

[0635] In order to reduce the signaling overhead for the UE to report the TA value, the UE can report the TA change rate (TA rate) TA_R used by the UE and the TA value TA_Va used by the UE to the gNB. The UE can obtain the TA change rate by calculation based on information such as the UE position, satellite position, velocity direction, and velocity size. Both the UE and the gNB can calculate the TA value that the UE will subsequently use based on TA_R and TA_Va, and then calculate the Koffset value. For example,

number

number

[0636] Method 2: Report the TA difference.

[0637] To reduce the signaling overhead for the UE to report the TA, each time the UE reports the TA value it is using, the UE can report to the UE the difference between the TA value it is using and the previously reported TA value, or the difference between the TA value it is using and the TA value previously indicated by the gNB, thereby reducing the indication range and signaling bits required to report the TA. For example, the TA value reported by the UE to the gNB is TA1, and in this case, the TA value used by the UE is TA2. In this case, the TA value reported by the UE to the gNB is TA2-TA1. Upon receiving the UE-reported (TA2-TA1) value, the gNB can add it to the TA value TA1 previously reported by the UE to obtain the TA value TA2 used by the UE.

[0638] Method 3: Reporting TA values

[0639] The UE periodically reports the TA value, and the gNB configures resources for periodically reporting the TA to the UE. Therefore, the UE can report the TA used by the UE based on the resources for reporting the TA configured by the base station (see the above embodiment for the reporting method). For example, the gNB configures a TA reporting period of 8 seconds and time domain resources and frequency domain resources with a period of 8 seconds for the UE through RRC signaling. The UE periodically reports the TA value of the resources.

[0640] The UE reports the TA value in a semi-static manner. In addition to configuring resources for TA periodic reporting to the UE, the gNB also needs to send activation or deactivation (disablement) signaling to the UE to instruct the UE whether to start the TA periodic reporting function. For example, the gNB can activate or deactivate the TA periodic reporting function using MAC CE. After receiving the activation or deactivation (disablement) signaling, the UE starts or stops periodic reporting of the TA value.

[0641] The UE reports the TA value non-periodically. The gNB configures uplink resources for reporting the TA value to the UE and sends a trigger report TA value command to the UE. After receiving the command (or signaling), the UE reports the TA value in use to the gNB. For example, the gNB can use a DCI command to trigger the UE to report the TA value. After receiving the trigger command, the UE reports the TA value immediately or after a specified period of time. Specifically, for example, the UE receives a DCI trigger command in downlink slot n, and the UE can report the TA value it is using in uplink slot n+M. M is a non-zero integer, and M is the TA value used by the UE, for example,

number

number

[0642] The above methods for reporting TA and TA correlation values ​​can be used together and will not be described again in detail here.

[0643] In this embodiment of the present application, Koffset can solve the problem that the timing of receiving uplink data on the network side is later than the timing of transmitting the corresponding downlink data. For example, as shown in Figure 20, the gNB receives an uplink HARQ-ACK corresponding to a PDSCH carrying a MAC-CE command (or MAC CE signaling) in uplink slot n. The MAC-CE command is a downlink signal configuration command, and the UE receives the uplink HARQ-ACK corresponding to a PDSCH carrying a MAC-CE command (or MAC CE signaling) in downlink slot n.

number

number

number

[0644] For example, the MAC CE configuration instruction of the downlink signal carried on the PDSCH may be a resource configuration for the downlink ZP CSI-RS or a resource configuration for an already deactivated downlink ZP CSI-RS. As another example, the instruction carried on the PDSCH may be a mapping relationship between the TCI status and the codepoint (transmission configuration instruction) in the DCI domain. As another example, the instruction carried on the PDSCH may be a semi-static CSI reporting configuration for activation / deactivation. As another example, the instruction carried on the PDSCH may be a CSI-RS / CSI-IM configuration for activation / deactivation.

[0645] From Figure 20, it can be seen that the timing compensation of uplink data performed by the network side or gNB is

number

number

[0646] To improve the above problem, Koffset, which is related to the uplink data timing compensation value on the network side, can be introduced.

number

[0647] For example, Koffset in this embodiment can be obtained using the following formula:

number

[0648] Here, time_compensated is a timing compensation value used by the network side to receive uplink data transmitted by the UE, and its unit may be seconds, milliseconds, microseconds, slot length, symbol length, or another time unit. time_compensate is equivalent to delay_compensated. The gNB can transmit the Koffset value to the UE. In this way, both the gNB and the UE can obtain the Koffset value and determine the effective time of the downlink signal configuration command based on the Koffset value.

[0649] Alternatively, the gNB may further calculate Koffset according to the following formula:

number

[0650] Here, ΔK represents an integer agreed upon in the protocol to adjust the Koffset value (to account for calculation errors and / or processing delays).

[0651] Alternatively, gNBs can:

number

[0652] After the UE receives Koffset and ΔK, both the gNB and the UE obtain the valid time of the downlink signal configuration command based on Koffset_new. That is, the UE determines whether the downlink configuration is valid in the slot

number

[0653] Alternatively, the gNB can transmit the time_compensated value to the UE, and the UE and NB can obtain the Koffset value to use by calculation according to the following formula:

number

[0654] Optionally, when calculating Koffset, a fixed value can be added / subtracted based on the formula given in this application. For example,

number

number

[0655] Alternatively, the gNB can transmit the time_compensated value and the ΔK value to the UE, and the UE and gNB can obtain the Koffset value to use by calculation according to the following formula:

number

[0656] Here, time_compensated may be a time amount or a quantized time amount, that is, the time unit of time_compensated may be determined based on actual usage and is not limited in this specification.

[0657] Alternatively, the gNB can transmit the time_compensated value and the Δtiming_offset value to the UE, and the UE and gNB can obtain the Koffset value to use by calculation according to the following formula:

number

[0658] Here, Δtiming_offset is an adjustment value of time_compensated obtained by taking into account processing delays by the gNB, calculation errors, etc. The adjustment value may be a time amount or a quantized time amount. That is, the time unit of Δtiming_offset may be determined based on actual usage conditions.

[0659] In order to reduce signaling overhead and the number of information bits for transmitting Koffset-related information, the gNB can transmit a timing offset ΔKoffset based on a time-related quantity value at another time (both the UE and the gNB know the time_related quantity value, for example, the time_related quantity value agreed upon by the gNB and the UE, or the time_related quantity value sent by the gNB to the UE, or the time_related quantity value sent by the UE to the gNB). The UE and the gNB calculate the Koffset to be used according to the agreed formula.

number

[0660] Alternatively, Koffset can be obtained directly by calculation using time_related parameters, that is, by the following formula:

number

[0661] Alternatively, the gNB can transmit a time difference component Δtiming (Δtiming is a time length value) based on another time-related quantity value, and the UE and gNB can obtain the Koffset to be used by calculation according to an agreed formula, i.e., the following formula:

number

[0662] Alternatively, the gNB can transmit a scale factor S (S is a non-negative number) based on another time-related quantity value, and the UE and gNB derive the Koffset to use according to an agreed-upon formula, i.e.,

number

[0663] Alternatively, the gNB may jointly transmit ΔKoffset and / or Δtiming and / or S. The UE and the gNB obtain the Koffset to use according to an agreed upon formula, for example, the following formula:

number

[0664] For example, the time_related parameter can be 2H / c or 4H / c, where H represents the satellite orbital altitude (which the UE can obtain from the ephemeris information sent by the network side) and c represents the speed of light.

[0665] Alternatively, the time_related parameter may be a common timing advance (common TA) amount. The common timing advance can be obtained by selecting a reference point within the coverage area of ​​a beam or cell (e.g., the point closest to the base station can be selected) and calculating the satellite reference point. Alternatively, the common timing of the round-trip delay between the reference point, the satellite, and the earth station is equal to or becomes equal to the round-trip delay plus / minus a fixed value (the fixed value takes into account the inaccuracy of satellite position information or processing delay, the effect of the UE's position height when using TA, and the fixed value can be fixed or changeable for a period of time). The reference point may be a point on the service link or a point on the feeder link. Based on different reference point positions, the transmitted common TA value may be a positive value, a negative value, or zero, but this is not limited herein. Similarly, the base station may transmit the coordinates of the reference point position to the UE, and the UE obtains the common timing advance by calculation based on the round-trip delay between the satellite position and the reference point position.

[0666] Alternatively, the time_related parameters may be the existing timer or receive window parameters in the above-described methods and embodiments, and combinations thereof, since the timer length and receive window length parameters are related to the round trip delay, processing delay, etc. of the UE and the gNB. Furthermore, the gNB transmits these parameters to the UE by broadcast, unicast, or other methods. In this way, both the UE and the gNB know the timer length and receive window length. For example, several timer lengths related to round trip delays agreed upon or transmitted between the UE and the gNB can be used or formed as time_related parameters as follows: Start delay time (timer offset) of the discontinuous reception downlink retransmission round trip timer (drx-HARQ-RTT-TimerDL) offset_of_drx-HARQ-RTT-TimerDL; Start delay time (timer offset) of discontinuous reception uplink retransmission round trip timer (drx-HARQ-RTT-TimerUL) offset_of_drx-HARQ-RTT-TimerUL; Random access contention resolution timer (ra-ContentionResolutionTimer) startup delay period (timer offset) offset_of_ra-ContentionResolutionTimer or RCR_offset; Scheduling request prohibition timer (sr-ProhibitTimer) timer_sr-ProhibitTimer; Reassembly timer (t-Reassembly) timer_t-Reassembly; Discard Timer (discardTimer) timer_discardTimer; Received RAR (Random Access Response) signal reception window length (ra-ResponseWindow) timer_ra-ResponseWindow.

[0667] The time_related parameter may include one or more of the aforementioned parameters. For example, the time_related parameter may be a time length represented by offset_of_drx-HARQ-RTT-TimerDL. After the UE receives ΔKoffset sent by the gNB, both the gNB and the UE can obtain the Koffset to use by calculation according to the following formula:

number

[0668] Similarly, after the UE receives S transmitted by the gNB, both the gNB and the UE can obtain the Koffset to be used by calculation according to the following formula:

number

[0669] In another example, the time_related parameter may be the sum of the lengths of time represented by offset_of_drx-HARQ-RTT-TimerDL and timer_t-Reassembly. After the UE receives ΔKoffset sent by the gNB, both the gNB and the UE can obtain Koffset to use by calculation according to the following formula:

number

[0670] According to the introduction above, it can be understood that "the base station not only needs to notify the UE of the duration of the RAR receiving window, but also needs to notify the UE of the startup delay period of the RAR receiving window, so the first timing offset can alternatively be determined based on the duration of the RAR receiving window and the startup delay period of the RAR receiving window." Therefore, Koffset is calculated based on the sum of the duration of the RAR receiving window and the period indicated by the startup delay time of the RAR receiving window, that is,

number

[0671] According to the above introduction, it can be understood that "because the base station not only needs to notify the UE of the period of the random access contention resolution timer, but also needs to notify the UE of the start delay period of the random access contention resolution timer, the first timing offset can alternatively be determined based on the period of the random access contention resolution timer and the start delay period of the random access contention resolution timer." Therefore, Koffset is calculated based on the sum of the period of the random access contention resolution timer and the start delay period of the random access contention resolution timer, that is,

number

[0672] Different solutions for obtaining Koffset can be obtained using the above-mentioned methods and the formulas, parameters, and methods in the embodiments, and the details will not be described again here.

[0673] In order to reduce signaling overhead and the number of information bits for transmitting information related to Koffset, Koffset can be obtained using information transmitted to the UE, and the gNB and the UE agree on a formula for calculating Koffset. The relationship between the uplink compensation value on the network side, the TA value used on the UE side, and the round trip delay between the UE and the gNB can be described using the following formula: time_compensated=RTD(UE, gNB)-TA_related

[0674] The TA_related parameter represents a parameter related to the TA value used by the UE. For example, TA_related may be equal to the TA value used by the UE. RTD(UE, gNB) is the round trip delay between the UE and the gNB, or the round trip delay between the UE and the satellite. For example, the aforementioned parameter RCR_offset is related to the minimum round trip delay between the gNB and the beam / cell where the UE is located. The time length represented by RCR_offset can be substituted into the aforementioned formula instead of RTD(UE, gNB) to obtain the time_compensated value, and Koffset is substituted into the aforementioned formula, for example, the formula

number

number

[0675] Each parameter in the embodiment of the present application (including Koffset, Δ, time_compensated, Δtiming_offset, Δtiming, and S) is stored in a system information block (SIB) 1, other system information (SIB) 2, and other system information (SIB) 3. system information (OSI), or master system information block (master It will be appreciated that the parameters may be transmitted by the network device to the terminal in a broadcast manner using at least one broadcast information parameter including a Radio Resource Control (RRC) information block (MIB), etc. Alternatively, the parameters may be transmitted to the terminal via unicast or multicast. If the parameters are transmitted in a radio resource control (RRC) connection phase, the network device may transmit the RRC information, an RRCReconfiguration message, downlink control information, etc. control information (DCI), group DCI, media access control The information may be conveyed or indicated in at least one of a MAC control element (CE), a timing advance command (TAC), or a data transmission or a separately assigned PDSCH to the UE.

[0676] As described in the above embodiments, after the UE acquires the latest timing offset, i.e., the second timing offset, the UE can transmit data information scheduled by the base station, control channel information, etc. to the base station using the second timing offset after the second timing offset becomes effective. In the above three methods, for example, in Method 1, K1 is a value obtained using the PDSCH-to-HARQ-timing-indicator command index table in the DCI (a table transmitted using dl-DataToUL-ACK signaling). In Method 2, K2=0,...,32, and the DCI command indicates the value of K2. PUSCH subcarrier spacing =

number

number

number

[0677] In addition to the three methods mentioned above, the embodiments of the present application further provide some methods as shown below.

[0678] (1) PUSCH transmission timing scheduled by DCI

[0679] If the UE receives uplink grant / schedule information in downlink slot n, the UE's PUSCH data is

number

number

number

[0680] In addition to DCI, PUSCH can also be scheduled by another method, configured grant, which requires the use of Koffset, and the solution of the present invention for automatically updating Koffset can be used.

[0681] (2) PUSCH transmission timing scheduled by RAR grant

[0682] The UE receives PDSCH data carrying the RAR message in downlink slot n. The UE must transmit random access message 3 (Msg3) in uplink PUSCH slot n+K2+Δ+Koffset, where Δ is a value specified by the protocol.

[0683] (3) PUSCH transmission timing carrying CSI

[0684] When a UE receives the requested DCI in downlink slot n by channel state information (CSI), the UE needs to transmit the CSI in slot n+K+Koffset of the uplink PUSCH, where the value of K is indicated by the DCI command.

[0685] (4) Timing of CSI reference resources

[0686] If the UE needs to send a CSI report in uplink slot n', then CSI_ref - The CSI reference resource must be transmitted to the UE at Koffset, where:

number

number

number

[0687] (5) MAC CE valid timing

[0688] The gNB receives an uplink HARQ-ACK corresponding to a PDSCH carrying a MAC-CE command in uplink slot n, where the MAC-CE command is a configuration for a downlink signal, and the UE determines whether the MAC-CE command for the downlink configuration is valid in downlink slot n.

number

number

[0689] The gNB receives an uplink HARQ-ACK corresponding to the PDSCH carrying an instruction in uplink slot n, where the instruction is for configuring an uplink signal, and the UE determines that the instruction for uplink configuration is received in uplink slot n.

number

number

[0690] In the above embodiment, the representation of the initial timing offset also includes the first timing offset, Koffset1, K offset1 It will be understood that Koffset and K offsetmay be understood as the same parameter, time_duration and slot_duration may be understood as the same parameter, and ΔKoffset and ΔK may be understood as the same parameter. Furthermore, in the above-mentioned embodiments, Koffset or timing offset may be understood as an initial timing offset, an updated timing offset, etc. Specifically, the initial timing offset or the updated timing offset may be determined based on the specific case of a specific embodiment. The above-mentioned Max_RTD_beam may be understood as the maximum round-trip delay between the base station and the beam coverage area in which the UE is located.

[0691] It should be understood that the above-described execution sequence of updating the timing offset and using the timing offset is not limited to this embodiment of the present application. For example, when sending a message used to update the timing offset, the UE or network device may not send a message used to update the timing offset based on the timing offset. In another example, when the UE or network device sends a message based on the timing offset, the message may not include information used to indicate the updated timing offset. Using FIG. 10a as an example, for example, when the UE sends an uplink message to the base station based on a second timing offset, the uplink message may not include the updated second timing offset.

[0692] It should be understood that the above methods and embodiments are described using four-step random access and two-step random access as examples. The above methods, such as methods for obtaining and updating timing offsets, are not limited to being used in the random access step, but may be used in any phase of communication. For example, the second and third messages described herein can be replaced with downlink and uplink messages.

[0693] It will be understood that implementations not described in one embodiment may be referred to in another embodiment, etc., and will not be described again in detail here.

Claims

1. A communication method applied to a terminal, the method comprising: determining a second timing offset based on a timing advance value used for the timing advance adjustment; transmitting indicator information indicating the second timing offset in response to a difference between the second timing offset and a timing offset previously reported by the terminal being equal to or greater than an update threshold, or in response to receiving a trigger command transmitted by a network device; method.

2. The method of claim 1 , wherein the indicator information includes the second timing offset.

3. The second timing offset satisfies the following formula: [Number 164] where K offset２ 3. The method of claim 1, wherein TA_New is the second timing offset, TA_New is the timing advance currently used by the terminal, and slot_duration is a unit of time period.

4. The method of claim 3 , wherein the unit of the period is 1 ms or a slot length.

5. The update threshold is obtained by a broadcast message sent by the network device; or The update threshold is obtained by a unicast message sent by the network device; or The method of claim 1 , wherein the update threshold is preset according to a protocol.

6. The broadcast message includes a system information block (SIB) 1, a master information block (MIB) 2, and a master information block (MIB). MIB), or other system information OSI (Operations for Standardization and Interoperability Information), or The unicast message may include a radio resource control (RRC) message, a downlink control information (DCI), a group DCI, a media access control (MAC), or a timing advance command.

6. The method of claim 5, wherein the method further comprises one of:

7. The method of claim 1 , wherein the indicator information is carried in one of a MAC CE message, Msg3, or MsgA.

8. 1. A communication method applied to a network device, the method comprising: receiving indicator information indicating a second timing offset from a terminal; the second timing offset is obtained based on a timing advance value, the timing advance value being usable for timing advance adjustment; the indicator information is transmitted by the terminal in response to a difference between the second timing offset and a timing offset previously reported by the terminal being equal to or greater than an update threshold, or in response to receiving a trigger command transmitted by the network device. method.

9. The method of claim 8 , further comprising the step of transmitting the trigger command to the terminal.

10. The method according to claim 8 or 9, wherein the indicator information includes the second timing offset.

11. The second timing offset satisfies the following formula: [Number 165] where K offset２ 11. The method according to claim 8, wherein TA_New is the second timing offset, TA_New is the timing advance currently used by the terminal, and slot_duration is a unit of time period.

12. The method of claim 11 , wherein the unit of the period is 1 ms or a slot length.

13. The method according to any one of claims 8 to 12, further comprising transmitting the updated threshold value in a broadcast or unicast message.

14. The broadcast message includes a system information block (SIB) 1, a master information block (MIB) 2, and a master information block (MIB). MIB), or other system information OSI (Operations for Standardization and Interoperability Information), or The unicast message may include a radio resource control (RRC) message, a downlink control information (DCI), a group DCI, a media access control (MAC), or a timing advance command.

14. The method of claim 13, wherein the command includes one of:

15. The method of any one of claims 8 to 14, wherein the indicator information is carried in one of a MAC CE message, Msg3, or MsgA.

16. A terminal device, the device comprising: a processing unit configured to determine a second timing offset based on a timing advance value used for the timing advance adjustment; a transmitting unit configured to transmit indicator information indicating the second timing offset in response to a difference between the second timing offset and a timing offset previously reported by a terminal being equal to or greater than an update threshold, or in response to receiving the trigger command transmitted by a network device. device.

17. The device of claim 16 , wherein the indicator information includes the second timing offset.

18. The second timing offset satisfies the following formula: [Number 166] where K offset２ 18. The device of claim 16 or 17, wherein TA_New is the second timing offset, TA_New is the timing advance currently used by the terminal, and slot_duration is a unit of time period.

19. The device of claim 18, wherein the unit of the period is 1 ms or a slot length.

20. The update threshold is obtained by a broadcast message sent by the network device; or The update threshold is obtained by a unicast message sent by the network device; or 20. The device of claim 16, wherein the update threshold is preset according to a protocol.

21. The broadcast message includes a system information block (SIB) 1, a master information block (MIB) 2, and a master information block (MIB). MIB), or other system information OSI (Operations for Standardization and Interoperability Information), or The unicast message may include a radio resource control (RRC) message, a downlink control information (DCI), a group DCI, a media access control (MAC), or a timing advance command.

21. The device of claim 20, further comprising one of: a time advance command (TAC);

22. 22. The device of claim 16, wherein the indicator information is carried in one of a MAC CE message, Msg3, or MsgA.

23. A communications device, the device comprising: a receiving unit configured to receive indicator information indicative of a second timing offset from a terminal; the second timing offset is obtained based on a timing advance value, the timing advance value being usable for timing advance adjustment; the indicator information is transmitted by the terminal in response to a difference between the second timing offset and a timing offset previously reported by the terminal being equal to or greater than an update threshold, or in response to receiving a trigger command transmitted by a network device. device.

24. The device of claim 23 , further comprising a transmitting unit configured to transmit the trigger command to the terminal.

25. 25. The device of claim 23 or 24, wherein the indicator information includes the second timing offset.

26. The second timing offset satisfies the following formula: [Number 167] where K offset２ 26. The device of claim 23, wherein TA_New is the second timing offset, TA_New is the timing advance currently used by the terminal, and slot_duration is a unit of time period.

27. 27. The device of claim 26, wherein the unit of the period is 1 ms or a slot length.

28. 28. The device of any one of claims 23 to 27, wherein the sending unit is configured to send the update threshold in a broadcast message or a unicast message.

29. The broadcast message includes a system information block (SIB) 1, a master information block (MIB) 2, and a master information block (MIB). MIB), or other system information OSI (Operations for Standardization and Interoperability Information), or The unicast message may include a radio resource control (RRC) message, a downlink control information (DCI), a group DCI, a media access control (MAC), or a timing advance command.

29. The device of claim 28, further comprising one of: a time advance command (TAC);

30. 30. The device of claim 23, wherein the indicator information is carried in one of a MAC CE message, Msg3, or MsgA.

31. 1. A terminal device including a processor coupled to a memory, the memory is configured to store computer-executable instructions; The processor is configured to execute the computer-executable instructions stored in the memory to enable the terminal device to perform the method of any one of claims 1 to 7. Terminal equipment.

32. A communications device including a processor coupled to a memory, the memory is configured to store computer-executable instructions; The processor is configured to execute the computer-executable instructions stored in the memory to enable the communications device to perform the method of any one of claims 8 to 15. Communication equipment.

33. A terminal device including a processor and an interface circuit, The interface circuit is configured to receive code instructions and transmit the code instructions to the processor, which executes the code instructions to perform the method of any one of claims 1 to 7. Terminal equipment.

34. A communications device including a processor and an interface circuit, The interface circuit is configured to receive code instructions and transmit the code instructions to the processor, which executes the code instructions to perform the method of any one of claims 8 to 15. Communication equipment.

35. A computer-readable storage medium configured to store instructions that, when executed, perform the method of any one of claims 1 to 7. A computer-readable storage medium.

36. A computer-readable storage medium configured to store instructions that, when executed, perform a method according to any one of claims 8 to 15. A computer-readable storage medium.

37. A communication system comprising a terminal device according to any one of claims 16 to 22 and a communication device according to any one of claims 23 to 30.

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